JPH0446706A - Drill work device - Google Patents

Abstract

PURPOSE:To enable boring with extremely high accuracy by providing a torque sensor for detecting load of a drill, a drill advancing and retreating means and a control means, and carrying out advancing and retreating by means of the control means according to the load. CONSTITUTION:When friction between a drill and a workpiece 1 due to shortage of cutting oil to a surface to be cut and uneveness in the quality of the workpiece 1, torque load increases to generate uneveness in the diameter of hole to be bored, which leads to brakage of the drill 2. If the torque is in over load conditions or conditions just before the over load, the advance of drill 2 is stopped and retreated rapidly, and then, for example, after cutting oil is applied thereto, the drill 2 is advanced fast to the position just before the original point. Since, in the case the retreat is carried out after stopping cutting on its way, deformation of a workpiece remains at the deepest face and the tip of drill 2 strikes thereon so that the drill 2 itself deformed slightly, cutting at a slow speed is started from the position before the drill 2 touches the deepest part. Then the drill 2 is advanced further while the deformation of the workpiece at its deepest part is cut, and operation is returned to the cutting mode to continue the cutting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The invention relates to a drilling device capable of performing extremely precise drilling operations.

[Prior Art] In recent years, with the advancement of technology, there has been a demand for fine perforations. Particularly when drilling extremely small diameters (unlike when drilling larger diameters), the following problems arise.

In other words, as the drill becomes thinner, the torsional strength of the drill decreases geometrically, making it more likely to break or deform.Furthermore, as the drilling depth increases compared to the drill diameter, the tip of the drill deviates from the drilling direction. Decrease, the so-called "flow"
occurs. When such a phenomenon occurs, the perpendicularity of the through hole,
The roundness or surface roughness of the inner surface of the hole will decrease significantly.

In particular, these problems become noticeable in the case of deep holes that are 10 times or more the diameter of the drill. Moreover, the higher the hardness and toughness of the workpiece, the more noticeable it becomes.

Conventionally, various methods have been proposed as processing methods for komei to solve these problems.

For example, there is a known method of drilling a pilot hole using drilling, various types of electric discharge machining, or laser machining, and then expanding the pilot hole with a wire cut or reamer to correct the roundness and perpendicularity of the pilot hole. ing.

However, such a two-step construction method has low workability and increases manufacturing costs. Furthermore, there are problems such as rust generation in the wire cutting method, automatic connection uncertainty in the case of extremely small diameters, and high processing costs in the case of temporary electric discharge machining and laser machining, where the pilot hole correction is incomplete when using a reamer. Ta.

In addition, in the case of laser machining, the finishing process can be completed in just one step using an electric discharge machine, which may cause material deterioration due to heat on the machined surface, but it requires a long time and also increases manufacturing costs. Reduction is not possible.

On the other hand, there are techniques that attempt to solve the above problems by devising the drilling method itself. For example, there is a device that does not simply move a drill forward toward a workpiece, but drills a hole by repeatedly moving the drill forward and backward in steps. In addition, as another technology, it has a built-in torque side ratio mechanism,
There is a device for retracting the drill if the torque increases during cutting (Japanese Utility Model Publication No. 10060/1983).

In the former type of equipment that operates in repetitive steps, the drill is more likely to deform, wear, or break if it continues cutting under excessive torque. After it has been repaired, it will be cut again. The latter device stops cutting to protect the drill.

[Problems to be Solved by the Invention] However, these devices do not take into account the forward and backward speed of the drill. to)
The flow and deformation of the drill caused problems with the inner surface roughness, perpendicularity, roundness, etc. of the formed through-hole.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems and provides a drilling device that enables drilling with extremely high accuracy.

[Means for Solving the Problem] In order to achieve this object, the drilling device of the first invention (
As illustrated in FIG. 1(A), a rotation mechanism of a drill, a torque sensor that detects the torque load applied to the drill, a movement mechanism that allows the drill to move forward and backward in the direction of the rotation axis of the drill, and a workpiece. The drilling machine is a drilling machine comprising: a control means for driving and controlling the moving mechanism during machining; The drill is separated from the workpiece by retreating, and then when the drill is returned to its original position, it is rapidly traversed to just before its original position, and then it is cut to a predetermined depth at a very slow advance, and then it is cut at a cutting feed rate. .

As illustrated in FIG. 1(B), the drill processing device 1 of the second invention includes a rotation mechanism for the drill, a movement mechanism that allows the drill to move forward and backward in the direction of the rotational axis of the drill, and a drilling mechanism for drilling the workpiece. a control means for driving and controlling the moving mechanism when drilling the center hole, the control means fast-forwarding the drill until just before the drill contacts the workpiece, and then fast-forwarding the drill from just before the contact. It is characterized in that cutting is performed at a very slow advance to a first predetermined depth, and cutting is performed at a cutting feed from the first predetermined depth to a second predetermined depth.

The drill processing device of the third invention, as illustrated in FIG. 1(C), includes a rotation mechanism for a drill, a movement mechanism that allows the drill to move forward and backward in the direction of the rotation axis of the drill, and a drilling machine for drilling a workpiece. a control means for driving and controlling the moving mechanism during drilling, and a drilling apparatus, wherein the control means controls the control means until just before the drill contacts the center hole when drilling the center hole that already exists. Fast forward the drill and cut at a very slow forward speed from just before contact until the center hole angle changes to the drill angle, then cut at a very slow forward speed until the shoulder of the drill completely enters the workpiece.
Next, cutting is performed using a cutting feed.

Drill processing device of the fourth invention (as illustrated in Table 1 (D), a rotation mechanism of a drill, a torque sensor that detects the torque applied to the drill, and a drill that advances the drill in the direction of the rotation axis of the drill) A drilling device comprising: a moving mechanism capable of retracting; and a control means driving and controlling the moving mechanism during drilling of the workpiece, the control means causing the tip of the drill to penetrate the back surface of the workpiece. The present invention is characterized in that cutting is performed by lowering the forward speed of cutting in accordance with the decrease in torque detected by the torque sensor that occurs as a result of this.

A drill processing device according to a fifth aspect of the invention (as illustrated in FIG. 1(E)) includes a rotation mechanism of a drill, a torque sensor for detecting the torque applied to the drill, and a drill that advances the drill in the direction of the rotation axis of the drill. A drilling device comprising: a moving mechanism capable of retracting; and a control means for driving and controlling the moving mechanism during drilling of a workpiece, the control means according to the second invention, the third invention, and the fourth invention. It is characterized by carrying out the control described in the invention.

A drilling device according to a sixth aspect of the invention (as illustrated in FIG. 1(F)) In the fifth aspect, the control means further executes the control described in the first aspect.

[Function] In the first invention (upper control means), each time the Yotorque load becomes overloaded or about to overload, the drill is quickly retreated to separate it from the workpiece, and then when the drill is returned to its original position, it It is rapidly fed to just before the position, then cut at a slow advance to a predetermined depth, and then cut at cutting feed.

When cutting continuously, the supply of cutting oil to the cutting surface may be insufficient, or the material on the workpiece side may be uneven.
Friction between the drill and the workpiece may increase. Increased friction increases the torque load on the drill. As a result, the drill undulates, causing irregularities in the hole inner surface roughness, perpendicularity, hole diameter, etc. In some cases, this may lead to the destruction of the drill.

Therefore, if the load torque becomes overloaded or about to be overloaded, the forward movement of the drill is stopped and the drill is quickly retreated until it separates from the workpiece.

The second retreat opens the hole being cut. Therefore, example 1
i It is possible to infiltrate cutting oil into the hole through the opening, and it is also possible to apply cutting oil to the drill and blow away cutting debris.

Then fast forward the drill to just before the original position.

That is, the cutting operation is started at a very slow advance from a position before the drill tip completely contacts the innermost surface of the hole being cut. This slow forward cutting is carried out to a position slightly deeper than the innermost surface position.

The drill fast-forwards to just before the original position (for Tomoji's reasons).

In other words, if you stop cutting midway and move back, the workpiece will be
The burr remains on its innermost surface. If you simply return the drill to its original cutting stop position in this state, the tip of the drill will collide with the burr and the drill itself will be slightly distorted. This distortion causes waviness of the drill during subsequent cutting. For this reason, start cutting at a slow forward speed from the position before contacting the innermost surface, advance deeper than the original position while cutting the "burr", then return to cutting at cutting feed and continue cutting. .

Drill processing device of the second invention (top) When drilling a center hole, rapid feeding is performed by rapid feeding until just before the drill contacts the workpiece.Then, from the position immediately before contact to a predetermined depth, cutting is performed at ultra-low speed. This ultra-low speed forward movement prevents the tip of the drill from flowing.The drill bits at a precise location, and subsequent cutting with cutting feed forms a center hole at the precise location. .

In the drilling device of the third invention, when drilling a center hole that already exists, first the drill is fast-forwarded until just before the drill contacts the center hole, and the center hole angle changes to the drill angle from just before the contact. Next, cut at a very slow forward speed until the shoulder of the drill completely enters the workpiece.Then, continue cutting at a cutting feed rate.

By gradually increasing the forward speed during cutting in this way, the tip of the drill does not flow and the cutting process can be started without causing center runout with respect to the center hole.

Drill processing device of the fourth invention (the companion control means cuts by reducing the forward speed of cutting in accordance with the decrease in load torque as the tip of the drill penetrates into the back surface of the workpiece. When cutting through a workpiece, if the hole is moved forward at the same speed, a phenomenon will occur where the diameter of the exit part of the hole becomes smaller than the diameter inside the hole.The forward speed of cutting should be reduced depending on the degree of penetration ( A constant diameter at the exit of the drill hole is achieved.Therefore, in the present invention (in view of the fact that the Yotorque decreases with the penetration of the drill, the cutting speed is reduced in proportion to the decrease in torque). .

A fifth invention is one in which the control means executes the control described in the second invention, third invention, and fourth invention to produce a combined effect of the operations thereof; By adding the effects of the invention, a more sophisticated combined effect of the above-mentioned effects is produced.

In addition, in each invention, the expressions ``ultra-fine advance'', ``fine-speed advance'', and ``cutting feed J'' do not simply refer to the forward and backward speed of the drill, but rather to the forward and backward speed relative to the rotation of the drill. (For example, 1'L is the moving distance of the drill per one rotation of the drill.) Also, for each invention, the absolute value of the speed is in the relationship of "ultra-fine forward movement", "fine-speed forward movement", <"cutting feed". be.

Therefore, if the invention is different, the same expression does not necessarily indicate the same speed. "Fast forward" again.

"Quickly retreat" (up) The maximum allowable speed on the melon mechanism is used, which may or may not be related to rotational speed.

[Example] An example of the present invention will be described in detail below based on the drawings.

FIG. 2 shows a schematic perspective view of a drilling device as an embodiment of the present invention. A groove 3 is formed in the base 1 of the drilling machine, and this groove 3 allows the top of the base to
It is divided into two areas 5 and 7.

In one area 5, a (rolling guide way 9°) is placed in the groove 3. On the wayway 9°]
Work base] 3 is placed on a tongue track base 9 via the main body of a rolling guide (not shown). ]], it is possible to move only in the Y direction shown by the arrow in the figure. In addition, a vertical wall section 5 is provided on the side edge of the groove 3 of the work base 3, and a rolling guide track 17 and 19 is provided on the vertical surface of the work base 3. ,
It is installed vertically on the track base 9,1 on the workpiece circumferential base]3. A workpiece fixing table 2] is placed on this track 17.19 via the body of a rolling guide (not shown).By being guided by the tongue track 17.19, it moves only in the x direction shown by the arrow in the figure. It is considered possible. The workpiece W is placed at a predetermined position on the workpiece fixing table 2 by the positioning member 21a and fixed onto the workpiece fixing table 2 by a chuck device (not shown).

The workpiece base] 3 is provided with a female threaded portion 25a of a pole screw at its lower part. The male threaded portion 25b screwed into the female threaded portion 25a is connected to the servo motor 23 fixed to the base 1.
Rotated by Therefore, by driving the servo motor 23 and rotating the male threaded portion 25b, the position of the workpiece base 3 in the Y direction can be arbitrarily set.

Similarly, the workpiece fixing table 2] is provided with a female threaded portion 27a of a pole screw at the lower part thereof.
lx! It is rotated by a servo motor 29 fixed to the male threaded part 27b (front wall part) 5 that fits together with the workpiece fixing table 2. Therefore, by driving the servo motor 29 and rotating the male threaded part 27b, The position in the x direction can be set arbitrarily.

By controlling the rotation of both servo motors 23 and 29, the workpiece W can be placed at any position on the XY plane.

In another area 7 on the base] a track 31.33 of the rolling guide is arranged perpendicular to the groove 3.On the track 31.33 there is a main body 34 of the rolling guide The drill machining unit 35 is guided by the mounting tongue tracks 31 and 33 via the grooves shown in the figure, so that it is movable only in the Z direction shown by the arrow in the figure.The drill machining unit 35 is A base 37 is provided, and a female threaded portion 37a of a pole screw is provided at the bottom of the base 37.
The male screw portion 37b11 screwed into the base 7a is rotated by a servo motor 38 fixed to the edge of the base. Therefore,
By driving the servo motor 38 and rotating the male threaded portion 37b, the position of the drilling unit 35 in seven directions can be set arbitrarily.

The configuration of the drilling unit 35 is shown in FIG.

In addition, in FIG. 2, the drill processing unit 35 has a cover 35.
Although there is a cover 35a, FIG. 3 shows it with the cover 35a removed.

The drill base 37 of the drill processing unit 35 is provided with a standing wall 39 at the edge on the groove 3 side.The drill mechanism 4 is disposed therein.

The configuration of this drill mechanism section 41 is shown in FIG.

There is no storage space provided inside the strong casing 43 of the drill mechanism section 4. Two spindle outer cylinders 45 are provided inside the strong casing 43.
, 47 are stored.

A pair of bearings 49, 51, 53, and 55 are fitted inside both spindle outer cylinders 45 and 47, and these bearings 49. 51. Each spindle 57.59 is rotatably supported within a spindle barrel 45.47 via an angle 53.55.

At the front end of one spindle 57 (the drill grip part 5
7a is formed. Insert the drill 61 (61a) into the drill fitting hole 57c drilled in the drill grip part 57a, and screw the tightening nut 57b onto the drill 61 (
61a) can be fixed coaxially. In this embodiment, the cutting drill 61 has a cutting part diameter of 0. 1~0.
A drill with a diameter of 5 mm and a total length of 60 mm is used.

A slit plate 63 and a mirror plate 65 shown in FIG. 5(A) are coaxially fixed to the rear end of the spindle 57.

The slit plate 63 forms a pair with a photointerrupter 67 attached to the rear end of the spindle outer cylinder 45, and serves as a rotation sensor in which a number of pulses corresponding to the rotation of the slit plate 63 are output from the photointerrupter 67. . Lead wires 67a and 67b for a light emitting power source and for outputting a rotation pulse signal are led out from the photointerrupter 67. The mirror plate 65 serves as a torque transmission mechanism using friction, as will be described later.

Incidentally, the spindle outer cylindrical body 45 (has a circumferential groove 45a extending over the entire circumference on the outer periphery. One upper introduction hose 6 is inserted into this circumferential groove 45a.
From 8, the cutting oil introduction hole 1a drilled in the casing 43
Cutting oil is introduced through the spindle outer cylinder body 45 to cool the spindle outer cylinder body 45. Drills 61, 61 due to thermal expansion due to this cooling
Since fluctuations in the position of the tip of a can be prevented, it can contribute to stable position control.

Furthermore, cutting oil (passes through a plurality of injection passages 45b drilled forward from the circumferential groove 45a, and is injected all around the drill 61 (61a) from a plurality of injection ports 45c as shown in FIG. 6. By doing so, the cutting oil is uniformly attached to the drill 61 (61a), and the cutting waste (dust powder) wrapped around the drill 61 (61a) can be removed.In addition, the inner surface of the hole that is being formed in the work W Cutting oil is applied to the entire surface.

The spindle outer cylindrical body 45 has a truncated conical outer shape, and a threaded portion 45d is formed on the outer peripheral surface of its tip. Therefore, as shown in FIG. 4, tightening requires screwing a nut 45e onto the male threaded portion 45d protruding from the casing 43 (
i The spindle outer cylindrical body 45 can be pressed and fixed to the inner surface of the storage space of the casing 43.

A slit plate 69 and an elastic body 71 shown in Table 5(B) are coaxially fixed to the front end of the other spindle 59. Forms a pair with photo interrupter 73,
It plays the role of a rotation sensor similar to the one described above. Lead wires 73a and 73b for a light emitting power source and for outputting a rotation pulse signal are led out from the photointerrupter 73.

The elastic body 71 has four protrusions 71a in the direction of the rotation axis.

71b, 71c, and 71d are provided.

These protrusions 71a to 71d (,t, are shaped like a truncated cone.

The elastic body 7] is integrally molded from rubber, for example. This elastic body 7] (Yo, the other spindle 57
Together with a mirror plate 65 provided at the rear end of the mirror plate 65, a torque transmission mechanism is configured.

Furthermore, the two rotation sensors and this torque transmission mechanism serve as a torque sensor.

A single pulley 75 is provided at the rear end of the spindle 59. Torque is transmitted to this pulley 75 from a drill rotation motor 77 shown in FIG. 3 via a V-belt 79.

Incidentally, a male threaded portion 47a is formed on the rear outer circumferential surface of the spindle outer cylinder body 47. Further, the tip of the bolt 43a screwed into the casing 43 is inserted into an axial guide groove 47b of the spindle outer cylinder 47. Furthermore, the tip of a bolt 43e that is screwed from the casing 43 side is inserted into a circumferential groove 47d that is formed all around the circumferential direction of the tightening nut 47c that is screwed into the male threaded portion 47a. . Therefore, as shown in FIG. 4, by adjusting the amount of rotation of the tightening nut 47c relative to the male threaded portion 47a, the position of the spindle outer cylinder 47 within the storage space of the casing 43 can be arbitrarily adjusted within a predetermined range. can.

By adjusting the position of the spindle outer cylinder 47, the mirror plate 65 of the spindle 57 and the elastic body 7 of the spindle 59 can be brought into contact with each other with an arbitrary pressure. This contact causes the rotation of the drill rotation motor 77 to
Pulley 75, spindle 59, elastic body 71, mirror plate 65
, the spindle 57 and the drill 61 (61a).

When the friction between the workpiece W and the drill 61 (61a) increases rapidly and there is a risk that the drill 6] may be twisted, the mirror plate 65 and the elastic body 7 may be damaged by a torque that is less than the torsional strength of the drill 61. Set the contact pressure between the mirror plate 65 and the elastic body 7 so that the mirror plate 65 and the elastic body 7 begin to slip (L) Before the drill 6 is screwed off, the mirror plate 65 and the elastic body 7 will slip and the torque will increase. Since the drill 6 is prevented from rising, the drill 6] is not destroyed.

As shown in FIG. 3, a control box 8] is further provided on the drill base 37.

The control box 81 is provided with an input panel 81a equipped with various switches as a table input device, a display panel 81b as an output device, etc. Inside the control box 81, as shown in FIG. An electronic control circuit 83 mainly composed of a computer is provided.The electronic control circuit 83 (I CPLI 83a, ROM 8
3b, RAM83c, input interface circuit 83d
and an interface circuit 83e. These are interconnected by a bus (not shown).

Signals from the two photointerrupters 67 and 73 and the input panel 81a are input to the input interface circuit 83d, and processing such as A/D conversion is performed as necessary. 73
As described above, each of the photointerrupters 67 and 73 is used as a part of the rotation sensor, and the photointerrupters 67 and 73 and the torque transmission mechanism described above are also used as a set as the torque sensor 85. Signals from sensors and switches necessary for control such as this (tL limit switch) are input as necessary.

Output interface circuit 83e1 table XYZ (7) Subo motors in each direction 29. 23. 38, drill rotation motor 77 and display panel 81b (control signal 1
．． ＋I am working hard.

The CPU 83all reads the program stored in the ROM 83b, executes various calculations according to the contents while referring to the input signals from the input interface circuit 83d and the data stored in the RAM 83c, and
3c or store the result in 8 power interface circuit 8.
3e outputs necessary control signals.

Next 1. The processing executed by the electronic control circuit 83 will be explained.

FIGS. 8 to 14 show flowcharts of the processing.

In addition, regarding the moving speed of drill 6] and 61a in the following process, "ultra-low speed" is 0.5 μm per rotation of the drill,
``Fine speed J is 1 μm per rotation of the drill, and ``Cutting feed'' is 93 μm per rotation of the drill.4 rapid feed corresponds to the maximum allowable speed.

When the process is started by turning on the power, initial settings are first performed (step 1] 0). In the initial settings (work base) 3. Work fixing base 21. Drill base 37 are moved from initial position 1 to initial position 1 by driving each motor 23, 29° 38. In the initial setting, processing such as setting the RAM 83c and input interface circuit 83d to an initial state is performed as necessary, and furthermore, settings for interrupt processing, which will be described later, are also performed.

Next, the system waits for a mode input (step 115).

At this time, a mode input instruction is given to the operator via the display panel 81b. 1 in mode. t.

There are a manual setting mode and an automatic processing mode, and either one is selected by the operator inputting from the input panel 81a.

First, when the manual setting mode is selected, manual setting processing is started (step 130). Here 1
Data regarding the shape of workpiece W and drill 61 (61
Set the switching position of the forward speed in a). Example l′
L Setting the forward speed switching position of the drill 61 (61a) (upper) When the operator rotates the servo motor 38 using the manual setting dial and switches provided in the control box 81,
This is done by moving the drilling unit 35 forward. For example, as shown in the schematic diagrams in FIGS. 15(A) and 15(B), the tip of the drill 61 (61a) is set by microscopic observation etc. so that it is 10 μm in front of the workpiece W. This value is determined by the detection of , or the number of pulses of the photointerrupter 73, and the value is stored in the RAM 83c and is used as position data for switching the center drill 61a from rapid forward movement to ultra slow forward movement, which will be described later.

When the necessary settings are completed and the operator instructs the end, an affirmative determination is made in the end determination at step 140, and the process waits for mode input again (step 115).

Next, when the operator selects the automatic machining mode, an instruction to install the center drill 61a is displayed on the display panel 81b (step 15o), and then the process waits for an instruction to start the crab (step 160). Here the operator is the center drill 6
1a is fixed to the drill grip part 57a of the spindle 57.

When the operator instructs to start from the input panel 81a,
After that, drilling begins.

First, center hole machining (step 170), which will be described later, is performed. When the center hole machining is completed, a drill replacement instruction is issued (step 80). Komei is waiting to start machining (step 190), and when the operator replaces it with the cutting drill 61 and instructs it to start, Komei starts machining (step 190).
Step 200) is started. When the machining process is completed (it is determined whether or not all cuttings have been completed (step 210), if the machining process is not completed (step 210), the process is repeated from step 115, and if all the cutting process has been completed, the process is complete.

The center hole machining process in step 170 is performed as shown in FIG.

First, the servo motor 2 is moved so as to move the initial position for drilling the workpiece W onto the axis of the center drill 61a.
3.29 to adjust the position of the work W on the XY coordinates (Step 3] O).

Next, by rotating the servo motor 38, as shown in FIG.
μm) (step 320)
, This movement to the position immediately before contact (this is carried out based on the data stored in the RAM 83c in the manual setting in step 130 mentioned above.In the following description, unless otherwise specified, the position of the workpiece W is is naturally adjusted by a servo motor 23.29,
The following explanation assumes that the positions of the drills 61 and 61a are adjusted by the servo motor 38, and that the rotation of the drills 61 and 61a is performed by the drill rotation motor 77.

Next, from the position just before contacting the workpiece W, the center drill 61a
Cuts to a predetermined depth at ultra-low speed while rotating the
step 330). In this example, 10μ above the workpiece W.
Cutting is performed from m to a depth of 011 mm inside the work W.

Then, further to a predetermined depth (0.2 mm in this example)
When the center hole CH is formed on the surface of the workpiece W in this way (step 340),
It is determined whether all the numbers have been completed (step 350). If it has not been completed, a negative determination is made and the center drill 61a
is moved backward in rapid traverse and returned to the original position immediately before contact with the workpiece W (in this embodiment, 10 μm above the workpiece W) (step 36
0). Next, adjust the workpiece Wf so that the position where the second center hole CH should be drilled is on the axis of the center drill 61a.
: Move (step 370). In this way, the process is repeated again from step 330.

When a preset number of center holes CH are formed, an affirmative determination is made in step 350, and the center drill 6
1a is rapidly moved back to the initial position in preparation for the next operation (step 380). In this way, center hole machining is completed.

In step 200, the processing shown in FIG. 10 is executed.

First, the position of the workpiece W is adjusted on the XY coordinates so that the position of the first center hole CH is moved onto the axis of the cutting drill 6 (step 4). Next 1:.

As shown in FIG. 15(B), the cutting drill 6 is rapidly moved forward to a position just before contacting the center hole CH (in this example, 10 μm above the workpiece W) (step 42).
0).

Next, the timer counter Ts is cleared and counting of the bill processing time is started (step 425).

Next, while rotating the cutting drill 6], move forward at ultra-low speed,
Cutting is performed until the center hole angle θC changes to the drill angle θd (step 430). In this embodiment, the drill angle θdc of the center drill 61a is 90°, and the drill angle θd of the cutting drill 61 is 1200°, so the center hole angle θ
Cut until C changes from 90° to completely]20°. A center hole C with a depth of 001 mm is created by the center hole machining described above.
Since H is open, the tip 61 of the cutting drill 6]
When h reaches a position deeper than 0.1 mm, the center hole angle θC becomes completely ]20°.

Next, from that position (depth 0.1 mm in this embodiment), the shoulder 61s of the cutting drill 61 is completely moved forward from the workpiece W.
Cutting is performed to a depth of 0.3 to 0.4 mm in this embodiment (step 440).

Then, cutting is continued with cutting feed (step 450).

Cutting with this cutting feed (by checking the forward distance of the cutting drill 61, the tip 61 of the cutting drill 61
The process continues while determining whether h has penetrated the back surface of the workpiece W (step 460) until an affirmative determination is made. Whether or not the tip 61h has penetrated the back surface of the work W (it can be determined by the depth of good cutting, that is, the feed amount of the servo motor 38).

Once penetrated, cutting is switched to slow forward cutting (step 470). Next, a predetermined location (variable E
While checking the torque value stored in p), control is performed so that cutting is performed by decreasing the drill advance speed in accordance with the decrease in the value (step 480). This control continues until the penetration is completed. When an affirmative determination is made that the penetration has been completed based on the feed amount of the cutting drill 6 (step 490), the value of the timer counter Ts changes to R every time the penetration is completed.
The information is stored in a predetermined array set in the AM 83c (step 495). Next, it is determined whether or not all the pieces have been completed (step 500), and if not all the pieces have been completed, a negative judgment is made, and the cutting drill 6 is moved back in rapid traverse to return to the position just before the contact of the center hole CH [Fig. 15]. (B) Return to ``Illustrated'' (
Step 5] O). Next, the workpiece W is moved so that the second center hole CH position is on the axis of the cutting drill 6 (step 52o). Thus again, step 4
The process is repeated from 25 onwards.

When drilling for all center holes CI-( has been completed, an affirmative determination is made in step 500, and the cutting drill 6) is rapidly moved back to the initial position in preparation for the next operation (step 530). In this way, Komei's processing is completed.

Next, a description will be given of torque determination, step operation processing, and forced termination processing, which are repeatedly interrupted and executed at predetermined intervals while the above-mentioned processing is being executed. Flowcharts of these processes are shown in FIGS. 11 to 13.

When the torque determination process is started at a predetermined period, first, the number of pulses p1 of the photointerrupter 67 is calculated from a pulse counter provided in the input interface circuit 83d that counts the number of pulses of each of the two photointerrupters 67 and 73. and the number of pulses p2 of the photo interrupter 73
(step 610). Next, the pulse number difference Jp
(p2-pl)1&calculate (step 620). This pulse number difference Δp represents a difference in the amount of rotation of the spindle 57, 59 per predetermined time, which corresponds to a torque change per predetermined time.

Next, this pulse number difference/p is expressed as a statistical variable Np as shown in the formula below.
l: Accumulate (step 63o).

Np-Np+Ap Further, the pulse number difference/p is accumulated in the torque variable Ep as shown in the following formula (step 635).

Ep-Ep+Ap Next, it is determined whether or not the pulse number difference Δp is greater than or equal to a reference value pt for determining a step operation (step 640).

If Δp<pt, then 1'L Input interface circuit 8
Each pulse counter provided in 3d is cleared (step 650), and the process is temporarily terminated.

Above the reference value ptl mentioned above, it may be set to the difference in the number of pulses immediately before a slip occurs between the elastic body 71 of the torque transmission mechanism and the mirror plate 65, or it may be set to a difference in the number of pulses greater than that. It may be selected appropriately depending on the performance of the drills 61, 61a and the material of the workpiece W.

Depending on the cutting situation, Ap≧pt may be satisfied (Dai).
t is set (step 660), step 650 is processed, and the process ends once.

Next, step operation processing will be explained. When the process is started at a predetermined period, it is determined whether the torque determination flag Ft is set (step 710). If it is not set, the process ends and nothing is done in this process.

As described in the torque determination process above, when Ap≧pt and the torque determination flag Ft is set, an affirmative determination is made in step 710, and then the drill 61.61a
Fast forward and backward movement is performed (step 720). During this backward movement, the drill 61, 61a is moved backward until it is completely removed from the opening of the hole. As a result, as described above, the cutting oil is released from the plurality of injection ports 45c to the drill 61, 61a.
The cutting oil is sprayed around the entire circumference of the drill 61 so that the cutting oil is uniformly attached to the drill 61, and cutting waste (grip powder) wrapped around the drill 61 can be removed. Further, cutting oil is applied to the entire inner surface of the hole that is being formed in the workpiece W. In this way, it is possible to prevent an adverse effect on the drill 61, 61a due to lack of cutting oil.

When the fast forward/reverse operation is completed, the torque variable t=p is cleared (step 725). Of course, when you retreat, use Drill 6.
This is because the torque load to 1 and 61a is "0". In this way, even if an error occurs between the value of the torque variable Ep and the actual torque due to a slip between the elastic body 71 of the torque transmission mechanism and the mirror plate 65, there is a step operation. By doing so, the value of the torque variable Ep can be returned to an accurate torque value.

Next 1: Return the drills 61, 61a into the hole in rapid traverse (
step 730). At this time, it is returned to just before the original position (in this example, 10 μm before the position where cutting was interrupted). This means that cutting is temporarily suspended, so the deepest cut surface has "
There is a burr. Therefore, since the burr was completely returned to its original position, the tips of the drills 61 and 61a collided, causing distortion to the shafts of the drills 61 and 61a, causing vibration and causing deviation in the cutting direction. This is because

Therefore, after rapidly forwarding to the last point, cutting is continued at a very slow speed to a predetermined depth (in this embodiment, 0.1 mm from the position where cutting was interrupted) (step 740). This allows the "burrs" to be removed by cutting.

Next 1: Step operation counter Cs is incremented (step 750). That is, the number of step operations is accumulated in the step operation counter Cs. Next, the torque determination flag Ft is reset (step 760). In this way, processing is transferred to the normal processing side. In other words, Ft = 1 during center hole drilling (L) After step operation processing (steps 720 to 760), center hole processing continues and Ft = 1 during rabbet drilling (step operation processing (step 720)). ~760), the processing of the kongming continues.

However, if the torque increases very rapidly, 1i
There is a risk of damaging the drill 61゜61a even if the rapid forwarding and reversing is not done in time, but when such a rapid torque increase occurs (as described in the table above, the aforementioned mirror plate 65゛ and elastic body 7 with appropriately set contact pressure) Since a slip occurs between the two and the torque load does not increase any further, damage to the drills 61 and 61a can be prevented.

Next, forced termination processing will be explained. When this process is started, it is first determined whether a forced termination condition is satisfied (step 810). As a forced termination condition (above), the following conditions are set here. First, each hole is defined as the required time from the start of cutting at the position to the end of cutting (or the current time) (each time stored in the array in step 495). ), 21st:, the value of the step operation counter Cs accumulated in the step 750, 31st:, the step 630
This is whether any one of the statistical variables NpO values of the pulse number difference Jp accumulated in is greater than or equal to a predetermined value. If either of these conditions is not satisfied, a negative determination is made and the cutting process is continued.

If any of the requirements is satisfied (fS), an affirmative determination is made and the drills 61, 61a are fast-forwarded and retreated (
step 820). Next, the drill rotation is stopped (step 830), and a drill replacement instruction is issued (step 84o). At this time, an alarm may be issued at the same time to prompt the user to replace the drill. Next, the system waits for an instruction to complete the replacement (step 850).

At this time, the operator replaces the drill 61. After replacing it, input the replacement completion instruction (it will be affirmative and return to the original process.

This forced termination process allows the drills 61 and 61a to be checked for damage, and allows Komei to replace the drills 61 and 61a in a timely manner without causing problems or abnormalities to the work.

Note that the forced termination process is not an interrupt process, but is performed in step 20 above.
It may be executed immediately after 0. Alternatively, the process may be executed immediately after an affirmative determination is made in step 210, and checked every time all machining of each workpiece W is completed. In this case, the center drill 6]a and the cutting drill 6] each store data for determination.

Note that the process shown in FIG. 14 is executed at a predetermined period to display the necessary display. That is, various data (Ts, Np, Ep, etc.) stored in the RAM 83c are read out (step 910), predetermined aggregation processing is performed (step 920), and power is displayed on the display panel 81b (step 9).
30).

The first example is the actual measurement of the inner surface roughness of the through hole formed in this example.
This is shown in Figure 6 (A). Also, for comparison, when using a conventional drilling machine that performs only step operations, Figure 16 (
Shown in B). As can be seen from the comparison, it can be seen that according to this example, a through hole with an extremely smooth inner surface is formed. Of course, this embodiment has much better perpendicularity and roundness.

In the step operation process of the above embodiment, the value of the torque variable Ep is set to rOJ to return the value of the torque variable Ep to an accurate torque value (step 725). If this does not occur, there is a risk that subtle deviations will accumulate until the process of step 480 is performed. In consideration of such a case, Komei may perform the processes of steps 720 to 740 only once immediately after step 470 of the processing process. In this way, the process of step 480 can be executed with an accurate torque value. Of course, step 48
If the process of step 0 simply reduces the forward speed according to the amount of decrease in torque, rather than the absolute value of torque, then the processes of steps 720 to 740 are not necessary immediately after the process of step 470.

It should be noted that the above-mentioned embodiments are merely examples, and it goes without saying that the invention can be implemented in various ways without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, the drilling device of the present invention appropriately switches the forward and backward speed of the drill depending on various factors, so that a highly accurate through hole can be formed.

[Brief explanation of drawings]

1A to 1F are basic illustrations of the present invention, FIG. 2 is a schematic perspective view of a drilling device as an embodiment, and FIG.
Figure 4 is an explanatory diagram of the configuration of the drill processing unit, Figure 4 is an explanatory diagram of the configuration of the drill mechanism, Figure 5 (A) is an illustration of the installation state of the slit plate and mirror plate, and Figure 5 (B) is An explanatory diagram of the installation state of the slit plate and the elastic body, Fig. 6 is an explanatory diagram of the cutting oil injection state, Fig. 7 is a block diagram of the electronic control circuit, and Fig. 8
Figures 14 to 14 are flowcharts of the processing, and Figure 15 (
A) is an explanatory diagram of machining processing using a center drill, Fig. 15 (B) is an explanatory diagram of machining processing using a cutting drill, and Fig. 16 (A
) is a graph showing the inner surface roughness of the through hole formed in the example, and FIG. 16(B) is a graph showing the inner surface roughness of the conventional example. 13... Work base 21... Work fixing base 23. 29, 38... Servo motor 35... Drill processing unit 61... Cutting drill 61a... Center drill 61h... Cutting Tip 61s of the cutting drill...Shoulder of the cutting drill 63.69...Slit plate 65...Mirror plate 6
7.73...Photo interrupter 7]...Elastic body 77...Drill rotation motor 81...-Control box 85...Torque sensor W...Workpiece CH
・・・Center hole

Claims (1)

[Claims] 1. A rotating mechanism for a drill; a torque sensor for detecting a torque load applied to the drill; a moving mechanism for moving the drill forward and backward in the direction of the rotational axis of the drill; a control means for driving and controlling the moving mechanism when the torque load is applied to the workpiece; This drilling device is characterized in that the drill is once separated from the base, and then when the drill is returned to its original position, the drill is rapidly forwarded to just before the original position, and then the drill is cut at a slow advance to a predetermined depth, and then the drill is cut at a cutting feed speed. 2. A drilling device comprising: a rotating mechanism for a drill; a moving mechanism that allows the drill to move forward and backward in the direction of the rotational axis of the drill; and a control means that drives and controls the moving mechanism during drilling of a workpiece. When drilling the center hole, the control means rapidly advances the drill until just before the drill contacts the workpiece, then cuts at a super slow advance from just before the contact to a first predetermined depth, and A drilling device characterized in that cutting is performed with a cutting feed from the bottom to a second predetermined depth. 3. A drill processing device comprising: a rotation mechanism for a drill; a movement mechanism that allows the drill to move forward and backward in the direction of the rotational axis of the drill; and a control means that drives and controls the movement mechanism during drilling of a workpiece. Therefore, when drilling an existing center hole, the control means rapidly advances the drill until just before the drill contacts the center hole, and performs ultra-fine movement from just before contact until the center hole angle changes to the drill angle. Cut at a fast forward speed, then at a slow forward speed until the shoulder of the drill completely enters the workpiece,
Next, the drilling device is characterized by cutting with cutting feed. 4. A rotation mechanism of the drill, a torque sensor that detects the torque applied to the drill, a movement mechanism that allows the drill to move forward and backward in the direction of the rotation axis of the drill, and a movement mechanism that is used when drilling a workpiece. A drill processing device comprising: a control means for controlling the drive of the workpiece; A drilling device characterized by cutting by reducing the forward speed of cutting. 5. A rotating mechanism for a drill, a torque sensor that detects the torque applied to the drill, a moving mechanism that allows the drill to move forward and backward in the direction of the rotational axis of the drill, and a moving mechanism that is used when drilling a workpiece. A drilling device comprising: a control means for controlling the drive of the drilling device, wherein the control means executes the control according to claim 2, claim 3, or claim 4. 6. The drilling device according to claim 5, wherein the control means further executes the control according to claim 1.