JPS5926406B2 - axis milling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the drive shaft of a shaft milling machine, in particular for crankshaft machining.

The shaft is forged as one piece, and the shaft head and side plates are milled.

For milling, the shaft is rotated and the milling carriage with the milling cutter attached must follow the shaft head.

At this time, control is performed by tracing the model, and the tool carriage is moved accordingly.

At this time, a model sensing device always adjacent to the model is pressed against the model, and its movement is converted into an electrical signal.

The drive for the profiling movement of the tool carriage is thereby controlled in such a way that the carriage moves in the same manner as the model sensing device.

Such a machine is described in German Patent No. 1,513,361.

The main difficulty with this control method is that the model fabrication must be carried out to very high precision (e.g. 10
This must be done within 1/0th of a millimeter).

The required connecting links between the model and the milling head can also be a source of error.

The object of the invention is to create a crankshaft milling machine with numerical control instead of profile control.

Yet another challenge is to eliminate the drawbacks of conventional machines other than profile control.

Conventional crankshaft milling machines are not suitable for conversion from profiling control to numerical control because both the milling feedstock and the workpiece movement (crank pin - space movement) have the same trajectory as the connecting rod. Seem.

In this case, the rotational speed of the workpiece rotation axis is determined independently of the movement of the milling carriage.

Since the calculation procedure for each feed pinch of a sliding milling carriage within tolerances covers a very wide range, the working speed is considerably slowed down if the calculations are carried out sequentially.

However, if this calculation is done outside the machine (in the work plan) and the instructions are given by means of a perforated tape, it is especially important not only for one shaft head of the crankshaft, but also for the new another shaft head and its two. To process twice the number of side panels, this perforated tape would be several hundred meters long.

An axial milling machine in which the workpiece is stationary and the tool rotates around the workpiece via a cam is also described in German Patent Publication No. 2, 2.
09,622 is also well known.

In this case, a mechanical model is installed to guide the internal milling cutter.

However, this machine has some drawbacks.

In other words, first, only the shaft head can be machined and the side plate cannot be machined, second, the shaft head must be brought to a horizontal position before machining (part of the workpiece), and third, the inner ring diameter changes. The blade must be changed every time.

It is even more inappropriate to convert this machine to numerical control.

Another type of T-machine is the so-called numerical trajectory control, which makes it possible to simultaneously set the desired feed rate and circumferential speed.

In this case, the tool carriage moves in two coordinates.

However, in order to transmit this command to a machine in which the workpiece rotates and the tool only moves horizontally, the structure becomes significantly more complex than in a machine using the profile control system.

The solution to the given problem is when the workpiece is stationary and the tool is
The workpiece, which is off-center, is moved at an arbitrary angle via a feed table movable in two coordinate directions, and the calculated motion for machining the shaft head and side plate is decomposed into straight lines and circular arcs. Furthermore, numerically controlled movements can also be carried out along the axis.

With the present invention, the drawbacks of conventional machines as mentioned above are obviated.

Since it is machined without a model, the drive and workpiece are in defined positions, and the tool motion is very simple by decomposing it into straight lines and circular arcs, allowing numerical control of the machine.

According to another embodiment of the invention, the design number ft of the workpiece for all reference points required for numerical control, i.e. the radius of the orthogonal carriage required for interpolation and both coordinate axes (X
, *V-axis) and the axial movement (2 axes) of the feed platform, and is equipped with a dedicated calculator or computer that calculates and issues a signal, and further determines according to the program t. This further simplifies the control.

According to the present invention, a predetermined program is installed in the computer, and control values are calculated from design drawing values and machine positions that change every moment according to the program, and numerical values calculated by the predetermined program.

Regarding this dedicated computer, the inventor took the following considerations into account.In the case of a conventional crankshaft milling machine that rotates two workpieces, it is necessary to bring the workpiece to a certain starting position before starting machining (for example, In the case of a numerical control method that fixes the workpiece by placing the crank pin on the horizontal center line,
A part of the workpiece must be brought to the calculation reference plane.

The control values for controlling the machine are then spatially modified by the angle of the crank pin or crank arm.

This increases program costs considerably.

Generally, for numerical control of machines, a perforated tape is prepared that contains all the data for the straight and curved trajectories, their lengths, their positions in space, as well as the idle and working speeds required for machining the workpieces.

For this purpose, calculations and positioning programs must be created in the preparatory work.

It is also possible to control the machine externally by a central computer without using perforated tape.

However, for the programming of such a central computer, the same preparatory work must be carried out and likewise provided to the central computer via tape or teletype.

6 crank pins and 12 crank arms, a small crankshaft with 7 bearings or less (for example, for automobiles), and 9 crank pins and 18 crank arms, 1
For manufacturing large diesel (eg marine engine) crankshafts with less than 0 bearings, the costs of preparatory work are considerable.

The manufacturer of such a crankshaft is usually not the designer of the crankshaft, and large crankshafts in particular are manufactured on commission.

In order to process one crank pin, 24 operations (addition, subtraction, and multiplication of 4 to 6 digit numbers) are required, and for one crank arm (5 curves), for interpolation 1 Approximately 60 calculations are required to obtain the reference value (X/y value).

If the workpiece is chucked until the entire crankshaft has been machined, this calculation must be performed separately for each shaft head, since each shaft head may occupy a different spatial position.

Furthermore, in order to process a crank pin with a revolution milling machine to which the present invention is applied, it is necessary to turn the crank pin on the revolution circumference rather than on the outer periphery of the shaft head.

This can be easily achieved by calculation.

However, in order to calculate the reference point for interpolation for each pair of crank arms, the spatial position, and therefore the position relative to the machine center, must be plotted on the drawing in order to represent the revolving ellipse consisting of five curves, using different coordinates. must be decided.

Preparation work for providing the perforated tape with all working data for numerically controlled milling machines therefore requires considerable expense.

This operation can only be carried out by experienced personnel, as errors in calculations can result in scrapping of the workpiece.

With the dedicated program computer according to the invention which provides tailored solutions, this drawback is eliminated since the crankshaft milling machine operates as a dedicated machine.

In addition to axial milling machines, the invention can also be applied to grinding machines as well as controlled machines.

According to a special implementation mode of the present invention, design drawing data of the crank pin, crank journal and crank arm;
The angle and distance are given by a block circuit.

However, even this simple data is given to the memory as a signal via the tape.

According to a further embodiment of the invention, for orthogonal feed movements for tool feed in one plane, Z
Simultaneous axial operation allows extra transverse revolution milling.

This movement is numerically controlled in a well-known manner. The dedicated computer used in the invention makes it possible, in the case of external calculations of numerical values or ordinary numerical control, to dispense with step circuit programs which have to be defined externally, which are fed to the machine by means of a tape.

The dedicated computer used in the present invention is programmed with a fixed program for the work order, and the number of constants given to it is relatively small.

By working with this calculator, given the variable values on the drawing of the workpiece, control for axis machining is possible with little electronic equipment expenditure, and on the basis of the preprogram and the response signals of the machine, the crank arm For machining, only the blueprint data is given as a control value, so adjustments can be made very easily.

According to a further embodiment of the invention, when calculating the necessary control values by a computer, it begins by fixing the center of the workpiece axis so that it coincides with the center of the machine axes X, y.

When machining with an internal milling cutter, the center of the milling cutter in its initial position must also coincide with the center of the machine.

Since the crankpin is eccentric, a special implementation of the invention equips the calculator with a quadrant circuit that converts the angles shown on the blueprint into angles in each quadrant.

At the same time, the signs of X and y, ie the direction of motion of the mechanical axes of which they are a part, and the trigonometric functions (sirl or cos) for calculating x/y are determined.

According to yet another implementation of the invention, the quadrant circuit is combined with a program step circuit.

This combination indicates whether the radius for calculating the values of Ru.

Therefore, the quadrant circuit combined with the step program circuit can also be used for sin, cos, 0° to 90°.
This is the determining section of the computer that includes the storage of numerical values and the necessary addition, subtraction, and multiplication units.

In a quadrant circuit, the signs and trigonometric functions are different even in the same quadrant, so considering the working path that moves in a straight line with respect to the four quadrants of the circle, whether the machine moves linearly in the direction of the eccentric shaft head or not ( (notch) or circularly around this shaft head (
Give this instruction according to whether the machine returns to the center of the machine after revolution milling (orbital milling), or after revolution milling.

When rotating around the crank pin or crank arm, all 90 degrees change in each quadrant.

A further implementation of the invention, according to which the quadrant angle calculated in the coordinate system for the quadrant from the actual angles of the crank pin and the crank arm is used in the quadrant circuit in such a way that the respective machining steps are determined from this are configured: rapid and feed of the depth of cut, zero point travel, revolution milling with/without axial motion, sign for distances x, y, sine and cosine of quadrant angle, and quadrant calculator. Memorize these.

In order to solve this problem, it is also necessary to take measures to prevent errors from occurring in the curve drawn by the milling cutter.

This is because this error may impair the accuracy of the target.

Experience has shown that such errors are caused by the forces acting on the workpiece during the milling operation, in particular by machine return errors (play) in the axes.

Due to the influence of such machinery, in the manufacture of crank pins as well as bearings, ellipses are produced instead of ideal circles, and flat or concave surfaces are produced by quadrant changes to the tool.

Since such errors occur even in highly accurate numerical control, they must be taken into consideration in the present invention.

Insofar as such mechanical errors are similar for the working path, workpiece and machine, according to the invention, these errors are eliminated by special measures in the electronic control equipment.

Flat and concave surfaces on the shaft head are particularly troublesome since they can only be corrected by grinding the entire circumference.

In comparison, protrusions in the range of 0.1 to 0.2 rran do not pose a problem.

Planar and concave surfaces occur at fixed locations.

i.e. when cutting in the direction of the crop, when switching out of the cut during the axial return process, and when the drive motor is reversed while the other axis continues to rotate at high speed, the quadrant This is the case when .

According to the control scheme of the invention, during cutting, the setpoint value for the control of the machine axis, which is switched when introduced into the circuit, is reduced by a preset amount.
Electronic control means are then provided such that the calculated value of this axis for interpolation remains unchanged.

This control means prevents flat and concave surfaces when changing the direction of the cut during revolution.

That is, the method for controlling a shaft milling machine for machining a crankshaft according to the present invention includes a tool having a numerical circular trajectory control means and a disc-shaped cutting head having a cutting blade disposed on the inner periphery, The axis of rotation of the cutting head is guided in a circular path and is movable in the longitudinal direction by means of an electrically controlled orthogonal carriage, which is fixedly mounted and carries out the machining strokes required for machining the crankshaft. The drive shaft of the tool for machining the crankshaft, which is stopped during the whole period, can be moved on a linear trajectory to a circular trajectory in any angular position with any center point and radius defined by the measuring means of the device. When machining a crankshaft using an axis milling machine, the target value at the time of cut for the above drive axis control, which can be switched immediately if the quadrant changes, is preset for each axis (X and y). The calculated value of the above-mentioned axis for circular interpolation will not change, while reducing it by an amount that almost matches the amount of play of the machine, independent of the shaft head diameter and cutting speed, until the revolution starts. By implementing this control method, it is possible to prevent the occurrence of flat surfaces and concave surfaces when the quadrant changes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

The crankshaft milling machine shown schematically in FIG. 1 has orthogonal feed tables X, y of portal structure and a bed Z that moves in the axial direction ζ.

1 indicates a circle when the inner diameter of the milling cutter is also assumed to be 1.

Dove is the center of the machine, that is, the center position of the machine feed tables X and y, where X moves horizontally and y moves vertically.

Z designates the feed direction of the portal column with the two orthogonal carriages X, y, ie the direction of movement of the crankshaft to the next head or arm and the direction of movement of the axial milling of the head or arm.

m 2m is the generator Tay A drive motor with axes X, y.

The drive motor is a DC servo motor equipped with a tachometer to determine the number of rotations of the motor.

Axis X. Digital oscillators D and Dg are placed on the y rotation axis.
x gy is attached, and the rotation axis is 20 rrvn/U (however, U means one rotation).

) while the digital oscillator is moving 200001mp
/U, so the position measurement unit is 0.00h++m.

The pulses are therefore used for "actual value" position measurements.

Instead of a DC motor, a step motor can also be used to drive the shaft.

This sharpening pulse oscillator is used to control the above-mentioned feed platform.

According to a special implementation of the invention, the zero point M of the machine.

is the exact center position of both carriages (X and y) and is also the center of the circle.

and center F of the tool.

is also consistent with machine-centeredness. Therefore, the crankshaft (FIG. 2) is mounted on the machine so that its axis center coincides with the machine center of the X and Y axes, aligned with the center of the milling cutter.

The crankshaft shown in FIG. 2 has four crank journals L each having a diameter D.

H is a stroke equal to the distance between the shaft center and the crank pin center.

L1 to L3 are the numerical values of the lengths given to the axis Z for the movement of the milling cutter relative to the crank pin K.

Ma is the cutting margin of the material corresponding to the depth of cut.

The machine center, which coincides with the axial center of the crankshaft and the center of the milling cutter, is very important as the starting point for the entire machining process.

According to a particular implementation of the invention, the machine center is independent of the numerical control and is therefore set with high precision by means of limit switches and pins.

In Figure 3, the machine center is M.

/po - machine center/milling center shown.

In this figure, the position of the crankshaft with its crank pin and crank journal L is shown inside circle 1 of inner milling cutter F, which also corresponds to circle 1.

Furthermore, the deflection angle β for the individual crank pins is shown in circle 1.

Figures 3a-c show a machine-centered setting method that is separate and independent of the numerical control.

According to another implementation of the invention, by configuring the appropriate pins according to this method it is possible to know which position of each carriage is towards the center of the bed at the moment of its movement.

According to yet another implementation of the invention, carriages X and y
The direction detection device with respect to the machine center includes a limit switch be1 for the left end and a limit switch b for the right end.
e3 and a limit switch be2,1 in the center. be2
．． 2. be2.3. Consists of a group of limit switches with be2.4, and four pin groups Nl t N2 along with a feed bar for these left, right, and center limit switches.
．． N3 and N4 are slidably provided in series.

(Figures 3a-30). In this case, the mutual direction of movement of the feed carriage with respect to the machine center is determined by the pin N7. Limit switch be by N3
It is determined from the operating state of 2.1°be2.3.

At the center position, both limit switches be2, 1, b
e2-3 is activated and their contacts are opened, but normally
Since the carriage is offset about 0.2 rran to the right or left of center (due to the hysteresis of the spring switch), only one limit switch will open, thereby indicating direction.

Therefore, since only one pushbutton "center" is required as a switch for starting feeders x and y at the same time, erroneous operation of the switch practically does not occur.

As shown in Figures 3a-30, the limit switch be2
．． ．． is for precise stopping of movement from right to left when pin N1 is on the right, limit switch be2
．． 2 is for switching from fast feed to slow feed when pin N2 moves from right to left, and is a limit switch b.
e2-3 is for precise stopping of movement from left to right when pin N3 is on the left, and limit switch be2.4 is for fast to slow movement when pin N4 is moving from left to right. This is for switching to.

Here, Fig. 3a shows the position of the pin at the center of the bed together with the feeder, Fig. 3b shows the pin at the left end of the bed, and Fig. 3c shows the pin at the right end of the bed.

Therefore, the limit switch arranged as above can accurately stop when adjusting the feed plate to the center of the machine, and at the same time,
To ensure switching from fast feed to slow feed.

To avoid using mechanically operated limit switches such as those mentioned above, which require occasional readjustment to increase the setting accuracy to 0.01 mm, contact and non-contact limit switches (sensors) can be used. It is possible.

At that time, West German Patent No. 1,80 was considered to be reliable.
The monitoring center disclosed in US Pat. No. 9,100 is used.

Since the machine center is always the starting point when machining a crank pin or crank arm, the system according to the invention described above for finding and confirming the machine center - without any numerical values - is of great importance.

In addition, this includes the crank pin according to Fig. 4a, Fig. 4b
It is also of interest to the computer as a starting point for the calculation of the tool trajectory of the crank journal according to the diagram or of the crank arm according to FIG.

Figure 4a shows data for crank pin machining.

Here, RF is the inner radius of the milling cutter, H is the stroke, that is, the distance from the center of the crankshaft to the center of the crankpin, and Mo/
Fo is the machine center and the center of the orthogonal coordinate axis x/y, Rg is the crank pin radius, Ma is the cutting margin of the material, and is the sum of feed amounts S and S with different feed speeds.

β is the angle of deviation of the crankpin in the quadrant circle 1, which is given for the number Z of crankpins to be machined.

Figure 4b gives data for machining the crank journal, in which case the angle β is always 0 and the stroke H
is also 0.

Figure 5 shows the machining of the crank arm.

Here, a is a half radius of the major axis.

Arm center W. The distances from the center points A1 and A2 of the circle are indicated by al and B2, and the arm center W.

From center B of the circle. and the distance to B2 is bl and b
2.

C is arm center W. From machine center M. (axis center line).

The angle β with respect to the position of the arm W inside the milling circle 1 corresponds to the angle β with respect to the position of the crank pin.

Angle α indicates the opening angle of the small circle.

The opening angle of the great circle is 1800-α.

The radius of the crank arm small circle is indicated by r, and the radius of the large circle is indicated by R.

Figures 5a, b show the method of quadrant selection for the crank pin and crank arm deflection angles for infeed and revolution milling.

The quadrant is shown below A in FIG. 6aI.

Here, the initial angle β is the rotation angle in FIG.

The four quadrants of circle 1 are indicated by I to ■.

In FIG. 6a1, the quadrant of angle β is determined under A,
The quadrant angle β is determined under B.

In FIG. 6al1, the sign of x/y and the trigonometric functions for β are determined.

Setting the radius and introducing the value is C1 for the cutting operation.
(Fig. 6al1), under C2 for zero point movement (Fig. 6al1, and under C3 for rotational movement).
FIG. 6b) is carried out.

Furthermore, the initial values of the crank pin and arm in circle 1 are determined by its argument β.

Furthermore, for machining, it is necessary to know the angle of one quadrant O of the circle 1 so that the motion of the axes x and y can be calculated.

According to the embodiment of FIGS. 5a and 5b of the invention, the design angle β given to one crank pin or arm is
is determined by a quadrant circuit (Fig. 6aI) with a comparator.
In the following part, through the comparison element K, the quadrant angle 90°, 18
1. Compared to 0°, 240°, and 360°. (
Ru.

Here, 00 is the right side of the coordinate circle on the horizontal X axis, and the quadrant is determined in the counterclockwise direction.

Therefore, by the first calculation step, the quadrant counter Z
It is determined via an evaluation circuit comprising an evaluation circuit (evaluation element A,) that the blueprint angle, for example β-288°, lies in the fourth quadrant.

Then, the evaluation element has a subtractor that works in block B below, and quadrant 1. n, l[, 0° in IV, 9
0°.

180° and 270° are set, and these values are subtracted from the angle β of that quadrant.

Therefore, the quadrant angle β is, for example, 28 in quadrant ■.
8-270=18° is the angle to β.

The following calculations proceed using only this angle β.

According to the implementation of the invention, the X and y pulses are now calculated from the interpolation element or directly by the current value detectors on the x, y axes, as a supplement to the calculator for the displacement x, y in the case of a straight cut. Counters Z and Z are provided.

The values of counters Z and Z are the machine center M.

xt/yt for the rapid traverse stroke and the value of the feed stroke X2/y2 to correspond to the distance from
is added.

Furthermore, according to the implementation method of the present invention, it is possible to know from the control panel in which quadrant the work route is currently progressing.
A special counter Z is provided for the quadrant adjustment and advance circuits in parallel with the step circuit.

In Figure 6am, quadrant 1 for crank pin machining.
The sequential working paths in II, I, and IV are shown in principle diagrams.

Here, block C1 shows the determination of the sign and trigonometric functions.

This determination is made by linear interpolation in the coordinate circle 1 for the cutting operation.

The rapid feed radius S is given in a), and the feed radius Svo is given in b).

In C2, the principle of zero point movement is shown by radius H.

Values given below this figure (cos β and S stone β)
The radius H is multiplied by the reference point X3 for zero point movement.
r Y3 is obtained.

The principle diagram at C3 (Figure 6b) shows the method for determining the trajectory when performing circular interpolation on the coordinate circle 2.

The values given below this figure (cosβ and sinβ
) plus the radius R gives the reference point X4. for the start and end of the circular interpolation. y4 is obtained.

Below that are shown the limit values of the axes x and y corresponding to quadrants I to ■.

The calculation is performed based on the determination of the initial quadrant angle β of the machining path and the data provided by the quadrant circuit for the selected quadrant.

Since the final value is first determined by the fourth quadrant change, the beginning and end of the interpolation can also be determined by the quadrant number Zq (X4/yJ whereas the values of steps 33/34 are determined in the subsequent calculations by steps 9/10). ).

The initial value and final value are determined by a step circuit having Z quadrants.

In the method of implementation of the invention, the electronic step circuit of the calculator collects the blueprint values required for each step given by the block circuit or perforated tape in order to advance the working path correctly, and performs preliminary calculations by addition and subtraction to calculate the radius. determine,
The data defined in the quadrant circuit is input to one or several multipliers, and from these data Xl for tool rapid feed is calculated.
/ Y 2 / Y 2 for t cutting feed of I,
Calculations are performed to provide linear and circular interpolation elements t using the values of X4/y4νX5/V5 for the orbit and xR, /y□ for fast reversal as calculation reference points.

When calculating or determining the calculated values for the crank pin, first the numerical values, namely: the radius R of the inner milling cutter, the crank pin radius RZ, the stroke H11, the feed amount S, S and the deflection angle β, ~6 are
1v02 is provided by a recircuit or perforated tape.

The position of the crank pin is then calculated by the quadrant circuit described above under A and B based on FIG. 6a1 as follows: 01 angle β one angle β.

02 Angle β-quadrant 1 to IV-Z (quadrant counter) 03
Sign of x/y - ± 04 Trigonometric function for angle β - 5in/cos05
Counter indication 2 on axis X = 0 06 Counter indication 2 on axis y = 0 Addition and subtraction are then performed.

Input 011 H-R2=Z1 012R+Z2S ・・・・・・・・・・・・Sa
F l a 013 ■o1+■o22Z3 0145a-Z3-8e ・・・・・・・・・・・・
5e015 R-R=R・・・・・・・・・R
With uZu, the preliminary calculation ends.

The actual calculation of the reference points is then performed by multiplication.

1) Linear interpolation: Figure 73 Center M.

Rapid feed of cut 2) Zero point movement 3) Circular interpolation: Figure 9a Center Z.

12 ±y4→±ys(yo)131
．． Quadrant change X.

-0 (center) -Zx14 ±y, -R
*After passing through the comparison element - Z setting *When one of the values of Z /Z is 0, the other value of y becomes the calculated value R, 15 counter Z, switching to the next quadrant, for example 1 →■ 16 Interpolation direction X.

→±X517 ±y5″y.

182, Quadrant change shi x5 = R = Z u 19 yO=0=Z.

Setting after control 20 counter Z9 ■→■ 2.1 Interpolation direction Upper X5→X.

2.2 Yo→±y5233, quadrant change X.

=0 −ZX24 ±V5=R2Z u y setting 25 Counter Z, I→■ 26 interpolation direction Xo→±X5 27 ±y5″y.

284, Quadrant change shi x = R = Z 5uX 29 yo-0-Zy tiering Constant 0 counter Zq ■→1 31 Interpolation direction ±X, →±x4 32 ±yo → ±y4 4) Linear correction Center M.

Return (standard) 37 directions 10XR20 =ZX38
=Z.

±y□−〇This calculation is performed by an adder and a multiplier immediately after input to the control panel, and the calculated value is stored in memory.

Calculations can also continue while the work path is in progress.

The calculated values are shown in Figures 7a, 7b, 8 and 9a.

FIG. 7a shows the cutting path of the crank pin.

Here the pigeon is the machine center and the origin of the Cartesian coordinates, and S
is the center F of the milling cutter.

The entire process is shown.

In Figure 7a the following is shown: S - (s
+s) - Rapid forwarding stroke Sea vQ
I Vo 2vot '”' VO2
- Feed strokes with different feed speeds (M - Material cutting margin) X1ty1 == Linear interpolation reference point: Rapid feed of center pigeon X2. y2 - Reference point for the feed. Possibly subdivided into X2-11 V2-I P X2-2 + y2-2.

Au End point of linear interpolation = Reference point 1 of revolution circle (2) for revolution milling = Trigonometric function gus for earth symbol and crank pin quadrant angle β corresponding to x/y in this arc, Quadrant 7b with cos shows the cutting path of the crank journal.

However, :S is the center F of the milling cutter. whole process, 58-5
vo1 is the fast forwarding stroke X1. s vot is sending M-x2
(Ma-Material cutting allowance).

The direction of movement of the milling cutter is, in principle, in the +X direction from left to right.

FIG. 8 shows the cutting path for machining the crank arm.

However, :S is the entire stroke, S - VOI is the fast forward stroke s
e, 5vo1 is the feed amount (material cutting margin Ma, X 1
/Y 1 is the reference point for the straight line and end point N of linear interpolation.

Figure 9a shows the working path for revolution milling of the crank pin and journal.

Namely: Center M.

1 for the quadrant of and from the coordinates XMo/yMo, the center Z equal to the crankpin center.

2 for the quadrant with and the coordinates XZo/y2 which give the earth sign for X, y in this arc and the trigonometric function of the angle β for the revolution milling! , indicating movement to o.

R is milling center F.

X3/y3 is the movement distance M of the zero point.

-+ZO. X4/V4 is centered at Z.

represents the reference point N within the revolution for circular interpolation.

Here, the direction of movement of the milling cutter is counterclockwise.

xs/y5 is the maximum value corresponding to H, and Xo/Yo
is the zero point for circular interpolation 90°/180°/270°10°.

The "start" command causes the computer described above to combine the variable data and calculate the length of the first "cut" working path shown in FIG. 7a.

At that time, S is RF10 (H-R2).

Here R2 is the milling radius and H is the stroke (-M.

-Zo=distance from machine center to pin center), RZ is pin radius.

The axial distances x, y are calculated according to the sign and trigonometric function, for example, β, −30° in quadrant I.

This cutting path consists of the cutting stroke x1+y1, where the milling cutter advances until it approaches the workpiece and the feed rate is changed, and the feed stroke X2+y2, and depending on the speed, X2-1/V2-1 and x2.2/y2. It is divided into .2.

The final feed stroke is then switched to slow feed near the pin, thereby machining the pin diameter within tolerance.

The end point that the center of the milling cutter reaches after finishing the cut is A
We are now on circle 2 for the next revolution milling as shown by .

The cutting path for machining the crank arm is also determined in the same manner according to FIG.

In this case, due to the rough machining of the workpiece, no feed stroke is necessary, but for precise adjustment a precircuit for slow feed is provided.

The cutting path (Fig. 7b) for the crank journal is as follows:
As a rule, it is always on the X axis only, so the depth of cut is +
This is done in the direction of movement of X. The distance corresponds to RF-R2.

In this case as well, the process is divided into rapid forwarding and forwarding.

The feed stroke is oriented in the direction of the material cutting mark applied to the shaft head.

The linear distance x/y is provided as a reference point in the interpolation element, which generates the pulses and voltages to the drive motor of the machine axis.

A detector on the machine axis converts the pulses into a counter Z built into the computer.

Tell me with Z.

This number is set to 0 before cutting, so during cutting it shows the instantaneous distance from the machine center dove to the axis.

After starting, the interpolation element provides a signal for each partial path, in which case instead of the step circuit of the perforated tape, the registers of the computer are switched step by step, and the reference point for the next working step is determined by the quadrant circuit and the computer. be called.

Steady position control is also performed by interpolation.

According to the method of implementation of the present invention, the total stroke sa-cutting amount calculated in order to increase reliability is always added to the counter Z for the y-axis and the Z for the y-axis by means of a comparison element. / Yl +X2-1 /
It is compared with y2-2.

If the tolerance is exceeded, a correction signal is issued to correct the direction of the machine.

As already mentioned, the center of the milling cutter after cutting, ie point A, is within the revolution (in phase 2
) on top (Figure 9a).

The starting point A for revolution milling is P in the computer data.

B, coincides with calculation reference point X4/y4 corresponding to 9/10.

For the known trajectory control, the milling cutter center does not move directly along the desired contour, but in its own revolution, with a radius that is always larger than the radius of the shaft head to be machined.

At this time, the diameter of the inside 2 of the revolution is the center Z.

= Calculated from input data Ru-RF-R2 with axis center.

Mo and Z. The distance is denoted by xs/ys, which is used to adjust the X, y counters for the axis position.
zero point movement amount.

The revolution of the milling cutter center along the full revolution circle in a counterclockwise direction is carried out in dividing steps by means of circular interpolation elements.

As is customary in this case, one axis and the other axis receive setpoint value pulses alternately.

Furthermore, the generation of the pulses is controlled by a suitable current value detector, and the pulses are then immediately emitted on the other axis.

This provides accurate position control.

When one axis reaches R, it indicates that the end point of the first quadrant in which the work was started - for example, the end point of quadrant I in FIG. 9a - has been reached.

R corresponds to the value of X and y5. In the embodiment shown in the figure, y=Ru-y5, so X520.

This value is passed through the quadrant circuit as a reference point for the interpolation element and has a sign corresponding to the last quadrant, eg ■.

After the fourth quadrant change, the milling center reenters the first quadrant (for angle β-0, unless the end of the I advance is reached) and advances to the reference point.

Control of the interpolation can be done in the same way as for linear extension according to other implementations of the invention.

During the revolution, the new center Z. The X, y distance to is shown in the counters Z , Z .

Z or Z whenever X or y alternates with R
must become u XO.

This is done by the comparison element - and by the tolerance circuit through two levels (eg 15 bits) - if there is a close match, the next quadrant is not advanced.

At this time, counters Z and Zy are set at the beginning of the revolution by the quadrant circuit. settings are made.

Initially the comparison element must also be set to the reference value X4/V4.

Counter ZX. When Zy reaches this value, the revolution is completed in combination with the quadrant counter.

FIG. 9b shows the axial movement required in addition to the orbital movement if the width of the shaft head is wider than the width of the milling cutter.

In known rotary axis control, several pulses are required if they have to be carried out simultaneously.

The present invention makes it possible to perform an additional movement along the axis, so that after the first rotation,
An axial feed movement carried out with a helical movement around the workpiece can also be started at the same time.

At the end of the feed movement between the length L of the crank pin or journal - the width of the milling cutter FB, the revolution movement continues for one more rotation without axial feed, and the second shoulder of the shaft is machined. Ru.

The milling cutter then moves back.

In the figure, S is the cutting stroke, S is the amount of lateral feed per rotation, A is the initial position for the first tool path, E is the final position for the last tool path, and 1 to 6 are revolution display symbols.

sLa is the lateral feed distance Lw-FB of the milling cutter.

This command, ie, adding one revolution without traversal to a complete revolution with simultaneous axial control, can be programmed into the computer according to another implementation of the invention.

In that case, milling width FB1 pin or shaft length L
, it is only necessary to input the transverse feed amount S per revolution, which should be smaller than the milling width FB.

O The lateral feed speed is calculated from the set circumferential speed ■ as follows.

However, R is the radius of the complete rotation circle.

This additional axial milling is used not only for crank pins but also for axial milling of long shafts.

This machining method is particularly advantageous for automatic machining of stepped shafts, where the material is cut very unevenly.

In that case, in addition to inputting "B, LW'S" mentioned above, the length for the next cut O and the angle β that is 0 when the axis is at the center are input for each cut into the block circuit at hand. be done.

Machining allowance around the crank arm In principle, machining can be done in the same way as for the crankshaft.

For this purpose, only the design values necessary for the formation of the arms are used (FIG. 5).

In the case of cutting (FIG. 8), in rapid traverse the milling cutter travels outward from the center of the machine on the central axis of the arm, with the feed rate being switched as it approaches the workpiece.

For the feeding stroke, in a standard case where there is little scraping of the material, one speed change is sufficient.

The total stroke is calculated by the following formula. S aw == Rp (
a c ) However, S−s = s is the fast forward stroke, aW
vol eW S indicates a feeding stroke.

The 0 quadrant and trigonometric functions for machining the arm are shown in Figure 10a along with the calculated revolution curve.

The position of the arm in quadrant 1 corresponds to the position of the crank pin.

Again, this is equal to the angle β, G).

As in the case of the crankpin, angle β is first converted to quadrant angle β.

In the example shown in FIG. 8, the angle β of 30 lies in quadrant I with the following sign and trigonometric function: The value of x t /y t is given to the interpolation element as a reference point for the interpolation.

In the section S, a fast feed takes place, and before the end of the stroke the usual switching circuit for forward or slow feed is placed.

At that time, the reference point X2 "" V for the feed amount S
□, CG! iβ y20t =Vo, s stone β is given, and if necessary, a switching circuit for slow feed is added to start feeding.

Point A in Figures 8 and 10'a is the center F of the milling cutter.

is currently in a revolution position, with the inner edge of the milling cutter opposite the central axis and in the center of the small bore.

The orbit of the center of the milling cutter used to process the outer periphery of the crank arm is a large radius Ru1 with centers A2 and N1 and a small radius R with centers B1 and B2.
It consists of

However, Ru 2
The orbital milling of the crank arm is evident from Figure 10a.

From this, the major axis central axis bisects the angle β of the small circle of the arm, and therefore also the angle of the corresponding revolution curve.

In order to clearly distinguish the order of revolution milling, the first half in the revolution orbit is designated as B, and the corresponding arc of the crank arm is designated as B.

Set to 1. Therefore, the crank arm consists of 4
The result is five curves instead of one.

Milling center F by special counter of quadrant circuit.

It is possible to check which orbital curve is currently on.

Therefore, the five curves of the arm outer circumference ellipse are B.

, ~11305 to the other milling center F.

The orbital ellipse of consists of the revolution curve B-B.

In this case, for example, if u passes over B in the orbit, In this case, the arm is curve B as described above.

Processed in 1.

R is the large radius of revolution 1 orbit B and H with the center at Lunar A2, and R is the middle u3ut+5
U 2 U 4 is the small radius of the orbit B and B whose center is B1 and B2.

Angle α is small diameter aperture B. 3 and B. The angle is 1+BO5.

For calculation of reference points There is something, that is, B
.

A2 at r for 115 and A2 at R for Bu115, but the position of the revolution curve in Cartesian coordinates with respect to the corresponding center depends on the argument angle β of the arm, so that a single revolution curve It should be taken into account that it may fall partially into several quadrants.

If the angle β is 0°, the angle α with respect to the small diameter arc of the arm
and the angle 180°-α with respect to the large diameter is the basis for calculation.

In this case, each revolution curve falls into two quadrants.

In order to obtain a uniform criterion for calculations, the angle β is always taken into account (even if it is 0), so the angle ε containing the angles α and β
is used.

The next angle calculation is done in terms of angle β and α or l.

g The total angle for B is ε1 using α, 1i-2 Ru.

This value can exceed 90°. At that time, use the calculator to calculate 90°.
is drawn and at the same time the new angle is set in the next quadrant.

Therefore, for example, ε11 + βql + α1 - Quadrant I. Therefore, for B, by the angle α2 2 180° - α2 ε2■ - ε11 + α2 - 90° - green ■ For B, by α3 - α 3 ε3 "ε2■ + α3 - 90°-quadrant■ For B, α4-α2=180°-α, 4 ε4[-ε3■10α4-90°2 quadrant■ For Bu5, α5=concubine, ε5I-ε4■+α5-β Calculator stores the angle appropriately using a quadrant circuit and a curve counter ZB.

Figures 10b-f show the necessary radii, angles, and reference points. In the example, β = 30 in quadrant I, so β9 + grass - B1 <90°. Figure 10b shows the reference point for circular interpolation. A revolution orbit curve B is shown.

Here, N is the revolution trajectory 1 The starting point of the path curve B = center is A, declination angle is ut
uQ
XBU A, BU A, but on the other hand, the orbit curve B
End point of u = center is N2. XBUF, whose argument angle is ε.

1 It's also YBUlFi.

Figure 10c shows the revolution curve Bu2 of the center B1 and the angle ε1°B
2; α2−180°−α.

Figure 10d shows the revolution curve B of the center A1 and the angle ε2°3 α3-α indicating B3.

Figure 10e shows the revolution curve Bu4 of the center B2 and the angle ε3°B
4 is shown: α42 1800-α.

m1or diagram Cj, revolution curve B of center N2 and angle ε4
゜5 β, pushing force: α〒 = After starting the milling cutter center A When the milling cutter center A reaches the end of feed position, the milling cutter center is at the starting point of the revolution curve 1 (Fig. 10b).

This reference point is centered at A2, and is calculated by the formula using the sign and trigonometric function obtained in the quadrant 1 circuit l using the angle β and the large radius R. It is input from the calculation calculator to the interpolation element, and at the same time, the appropriate counters Z and Z are input. is set to

y The interpolation element then interpolates in the next direction.

-X→0 10y−+R (large radius), I ZBu=1 Z=1 Interpolation is therefore performed in a counterclockwise direction.

Since the end of the first curve is calculated with R, B1 and is therefore given by 1 +XBUIB +3'BU1E with the same sign, this reference point found is also in the first quadrant.

. The starting point of the second curve is according to Figure 10c, with the center at B.
+XBU2A □+yBU2A BU-2 and small radius Ru2. Calculated and input by B1.

Similarly, this y is added to the counters Z and Z again. The value is set.

Interpolation is still in the same direction -X → 0 (small radius in this case) +y-+Ru2 It becomes a lever value, +X-)Ru2 y→O Z-■ The target value is switched from quadrant I to quadrant H.

Counter instructions Z that must have the same value
/Z is compared with this calculated value via a comparison element,
If the difference in the axis is too large, a signal is emitted via the tolerance circuit, which is used to correct the control of the machine (emergency retraction).

In the same way, add 2 -XBU E to the set end point of curve B.
・Center B.

10yBU2E Interpolation of quadrant ■ is performed until .

The milling cutter then moves on a third curve centered at A1; the initial and final values of the reference points are given by the perforation tape or by the calculator.

The procedure proceeds over the fourth curve with center B2 and the fifth and final curve with center A until the starting point coincides with the end point of the circular interpolation in the first working quadrant (quadrant I in the example). .

The quadrant counter Z again shows the number I and the curve counter B shows the number 5.

After the revolution is complete, a tool retraction signal is sent to the path controller.

To carry out the extensive calculations described above, a preliminary calculation of supplementary values is first carried out from the given data, as in the case of crankpin milling.

The calculation of the individual steps is then carried out in the same way as for the crankpin.

Fig. 11 shows the direction of the position x to y of the feed stand relative to the machine center (Figs. 3, 3-30), and the milling center F, which goes directly from the "revolution axis" to the machine center.

An explanatory diagram of a retreat route is shown.

Here, RF is the milling cutter, RL-RL is the retreat path from the orbit, and Au is the starting point of the revolving milling cutter.

The straight line Au-Mof, f and the return path from the revolution 2 are M with respect to each axis X, y.

The direction of e X2 ey2 is determined by the limit switches b , b with the aid of a device for directional identification directly relative to the machine center dove.

Control of the return path can also be performed without interpolation.

Then, to ensure accurate stopping, limit switch beX2. ．． 2/2-4 and e Y2.2/2-
4 switches from fast forwarding to slow forwarding before the center.

In the same way as when returning the tool for "shaft head milling",
According to the invention, for the return path of the "side plate milling", instead of controlling the axes by interpolation elements, the machine center M is determined by direction sensing as shown in FIG. 3a.

It is possible to directly control the This direct return path is entered as the standard return path at the end of the revolution, at which time the comparison element that signals the end point of the revolution path switches to the "direction sensing control".

The emergency reversal path button is also coupled to a direct "direction sensing" control from within a straight line or any orbit and its original axis x/y.
moves toward the center of the machine.

Limit switch bex2-2/2-4 and be Y2-2/2-4 6 X2-1/2-3
and M by e Y2-1 /2.3.

In order to stop accurately, the speed is switched to slow feed before the center.

Some adjustments are required to the speed at which the "infeed and revolution milling" strokes are progressed.

The radial rapid traverse stroke should in principle be carried out at the fastest possible speed, for example v = 3000 rran/min.

The radial feed can be adjusted, for example, by means of a potentiometer or a block circuit.

Feed speed V. 30-60 rr for 1° Vo2
Another circuit is provided which is set to an/min.

This circuit forces the partial feed path X2.1/y2
-t up to vol 1 X2-! ■ Until 2/y2.2
.

Give 2. For revolution milling, a manual switch is likewise used to set the speed V in the range 300 to 3000 rIrm/min.

Furthermore, the revolution speed V 2 is automatically changed as described below.

For speed control, a so-called level circuit is also provided in the invention.

This makes it possible to lower the current set values of the feed rate and the speed of the revolving milling cutter, for example, from 100% to a factor of 50.

The switch is conveniently located within easy reach and is useful for audible speed control during milling.

Determination of the indicated speed is done by adjusting the interpolation element and the beat frequency of the calculator, while the axial speed of the radial speed ■
, ■ is performed by interpolation elements in the usual way.

This first gives the shaft drive a basic speed determined from the number of pulses generated per shaft per unit time.

At the same time, via an interpolation element, this basic velocity is corrected by means of a position adjustment using the actual value detector.

Since the axes X and y are both controlled by pulses, the beat speed for the computer is the target value of the stop circuit 'If@/rn
Must be greater than In.

Therefore, for the cutting path in the radial direction, the rapid traverse speed is
, feed rate■.

1/VO2 is just the ratio of the sum of the X and y directions and R. - The magnification is 1 to 1.4 depending on the angle β. - Similarly, in the case of orbital milling, is the magnification for ■? =1.27
Only dogs have to listen.

This is the set point ■, which is determined as a target value in accordance with a special implementation of the invention.

, Vo, vu are multiplied by the above-mentioned multiplier and first sent to a beat generator for frequency determination.

Au - the normal backward path from the start/end point of the revolution trajectory to the pigeon = machine center (Fig. 11a), and from the revolution 2 to the axis center Z.

and the emergency retraction path to the machine center dove is controlled by providing a re-point to the interpolation element, which also specifies the axis speed for radial rapid traverse.

In this case, the axis center Z to reduce the path tolerance.

The backward movement is carried out through a digital front-end circuit, fast forward and slow forward.

When returning to the center of the machine, set the center limit switch according to each direction so that the limit switch reaches the correct stop position.
The slow/speed switching circuit operates as ey2.4 (see Figures 3a to 30).

According to another implementation of the invention, the reversing switch works independently of the numerical-(interpolation element)-control via a direct direction sensing circuit (FIGS. 3a-30), so that each axis is immediately Move towards the center dove.

As with speed, each axis is supplied with a very high DC control voltage from a direction sensing circuit based on Figures 3a-30, so that the axis moves instantaneously towards the center in rapid traverse.

Immediately before the center, for each axis, from the rapid traverse stroke, limit switch b for each direction or 2.3 not ex2.
l Shib or the accuracy required by 2.3, even if ey
In 2.1, the speed is reduced to a slow feed stroke adjusted to stop within a tolerance of ±0.01 mm.

At the center position of feed bars X and y, limit switch b
/2.3 to b /2-3 to e
X2-1 ey2-1 Therefore,
The counters Z and Z attached to this are set at 0 so that they are again at the controlled starting point for starting the work.
be made into

Furthermore, according to another embodiment of the present invention, the incision is made in principle from the longer diameter portion of the crank arm (the seventh
Figure a).

This results in a uniform load on the milling cutter, especially for revolution milling (FIG. 9a).

For this purpose, it is necessary to be able to set two different speeds for the feed.

The revolution speed control is shown in Fig. 13a.

For revolution milling carried out at high speeds, it is possible to automatically perform the necessary speed changes during the revolution, so that during operation, as implemented in the present invention, 360° An equal load is always placed on the crank arm for revolution.

This load level is determined as follows based on another implementation method of the present invention.

Revolution angle O-30° Speed Vu1 30 - 120° ■u2 120 - 210 V, 3 210 - 255° ■u4 255 - 300° Vu5 300 - 360° ■The angle of u is mainly attached to the tool post (milling cutter) according to the number of blades.

0° here corresponds to the starting point, ie point A on quadrant circle 2 for the revolution milling.

For the setting of six types of speeds v ~ V, the individual ul
A potentiometer or block circuit is provided that can be set to a value between 300 and 30,000 Trml/min.

Based on FIG. 13a, in the case of the implementation method, β −0.

In this case, the velocity departure angle γ is equal to the angle β=0, whereas in the m13b diagram it is β −72°.

In this case, 72° corresponds to the revolution starting point of 20°.

In Figure 13a, the revolution begins at point A.

Here, 0°-0° I=V1.

Speeds from ■2 to ■6 are given on the orbital circle.

Like the argument angle β, the velocity angle γ is converted into a quadrant angle γ and its sine value is stored.

The angle β then takes part in determining the value of γ.

This makes it possible to determine the angle γ between the revolution and revolution working paths and thereby carry out a corresponding changeover in the speed circuit.

FIG. 13b shows the quadrant positions of angles γ1 to γ6 when angle β=72°.

FIG. 13c illustrates the identification of the sine values of x and y based on the quadrant positions of γ, 1 to γ96, which is the sum of γ+β, in order to automatically select the speed change from ■ to ■.

In quadrants ■ and ■ <= sin γ, in quadrants I and ■ q ItlTz = sin γ q7. This sine value, which is constant during the revolution, is compared with the stored sine value of the angle γ.

In the case of the same value, no signal is output from the comparison element K shown in FIG. 13c, and the corresponding circuit for v~■ is activated.

(Figure 13c, bottom). In order to set the six speeds V~■, a potentiometer or block circuit is provided which can be set individually to a value of 300 to 3000 tra/min.

Angle γ.

The exponent of ~γ6 is calculated by computer N, which is the 13th
A note was added on page 59 along with figure c.

This table consists of six columns. In column 1 of computer A, the value of angle γ with respect to the revolution speed and the corresponding speed stages V1 to 6 are given.

This angle is given by the angle β (row b) in the upper column of column 2.
are summed in row C shown below.

3 in the next row d only if the snoring angle is greater than 360°.
It is pulled by 60°.

In the next line e, the quadrant angle (β+γ)-γ is determined.

For this angle, the index in column 3 is then summarized in the last row f.

Here, the first index indicates the position of the shaft head on axis Z,
Therefore, the first crank pin shown in column 3 has a first index of 1.

The second index is taken from line e and indicates in which quadrant the milling center is calculated to be when making speed changes.

For the quadrant angle γ according to line e, for example, the first quadrant is applied, the corresponding sine value is also taken from the memory of the calculated values (with 3 decimal places), and this exponent is written as a number with 3 to 5 digits. It is given.

γ in each horizontal column.

~γ6 has a computability of 0 to f indicating an index corresponding to the column l.

Here, a 3-cylinder axis with an angle β-0° 120.240° is shown in column 3.4.5 as an example, but in the case of a 6-cylinder axis, three more columns 6.7.8 are required in the horizontal direction. It is.

The process of the calculator shown in FIG. 13c1 is constructed so that the index to be used first is entered in the bottom row of each column, so that during operation it is read from bottom to top.

These indices are read downwards into shift register B in the order shown in the table, and from there are collected in comparison element C.

During the revolution, the movements of the axes x, y are continuously recorded numerically in the counter Z/Z.

This value, corresponding to group D in FIG. 13c, is divided in a divider by the radius of the revolution circle, thereby obtaining the sine value of the angle γ at the instantaneous position in the coordinate circle 2 of both axes.

This sine value obtained by the divider is then sent to comparison element C,
That is, it is given to the last three locations of comparison element C.

Similarly, from the block circuit, the position of the crank pin to be processed when moved, for example the first pin-1, is given to the first location of the comparison element.

Next, the value of the quadrant counter Z, which is kept to indicate in which quadrant E the center of the milling cutter is currently located, is
It is placed in the second location of comparison element C.

If the index is 11000, the first crankpin corresponds to the angle β-〇-first quadrant=sin 0.000.

In this case, the comparison element C emits a signal which is routed to the block circuit F through the step counter E shown in FIG. 13C.

Thereby the first potentiometer (1.1) is activated and the frequency of the beat generator T for the calculation speed is determined (block G of the figure).

Counter E simultaneously commands shift register B which provides the next index of column 3 (11500) to the comparison element.

With such an instrumentation according to the invention, it is possible to find the programmed angle γ9 during the "revolution" operation and at the same time to carry out the corresponding changeover of the speed switch.

All six speed stages are thus carried out during the revolution of the milling cutter.

When moving to the next axis head, the index changes from 1 to 2.

At this time, similarly, in block A1, that is, the calculator, the angle β-
The index shown in column 4 of 120 is used.

For milling the crank arm, use a method very similar to that for milling the pin, using the curve easy r 'cl'
The circumferential speed can be changed depending on the wheel R.

In this case as well, it is desirable that the circumferential speeds ■ be equal.
W The following relationship is obtained for the velocity of the center of the milling cutter on the trajectory curve, ■Bu.

For example, if V = 600mm/min, r = 22, and W R = 112, the value of ■ is 3000m++u1
Bul/min.

In the second case, when R-94 and Ro2=40, ■ becomes 255 rrvn/min.

u2 Therefore, the potentiometer has ■ and ■.
2, and this value is compared with the calculated value and selected by the curve counter ZB.

For crank pin and arm machining, it is not recommended to give the milling speed as a constant digital value and to determine the circumferential speed using a computer.

For each curve of the pin and arm, an individual potentiometer allows the operation to be better and more accurately adapted to the milling conditions, material properties.

When the standard working process of the crank journal or crank pin is completed, the portal column equipped with the tool is moved for the next traverse feed, depending on the position of the selector switch W corresponding to the number of shaft heads to be machined. It can be checked whether the tool is being used or not, or whether it has retreated to a starting point where the tool can be replaced.

Selector switches are provided as many as the maximum number of shaft heads that can be machined by the machine.

Working status specified by "type of milling cutter": 1 Crank journal, ■ Crank pin, ■ Further selector switch related to crank arm By the shaft number selector switch ZZ,
The control board identifies whether to move to the second arm of the same shaft head or to the first arm of the next shaft head.

A block circuit is provided for the movement of the shaft head from the first side plate to the second side plate, the value of which is a special counter that counts the number of bends Zk from side plate 1 to side plate 2. The device is set to Zst.

In contrast, the shaft counter ZZ records the absolute value for the next shaft head position up to the side plate 1.

14-17, a method for preventing flat or concave surfaces on a workpiece by means of an electronic device according to the invention will be described.

Flats and concavities are caused by two processes: the response time of the drive when reversing the shaft, and mechanical play in the bore of the shaft and/or the drive.

When cutting in, the axis is always switched to a slow stroke at the end of this movement (approximately o, 1 am/S).

When switching to revolution, the two drives are therefore accelerated to the set circumferential speed V 2 .

Therefore, the response time can be ignored in this case, and only the play is considered when moving from cutting to revolution.

That is, in order to prevent the occurrence of flat and concave surfaces when the quadrant changes, the target value for the machine axis control, which can be switched immediately when the quadrant changes, is set by a preset amount for controlling the axis milling machine. An electronic circuit is provided such that the calculated value of this axis for circular interpolation remains unchanged.

When the shaft (axis X in FIG. 14) is struck on the other side, the rotating shaft and drive stop.

While this axis (axis be.

This causes it to move away from the revolution by a distance δ (proceeding from B to D in Figure 14) until the feces of the play a (from A to C) are removed.

This deviation from within the revolution creates a flat section on the axis with a depth C and a width of about 4δ.

Here, the depth C corresponds to the distance from the dot to F.

In Fig. 14, 0 is the milling center, R is the revolution radius, R
F is the milling radius and R2 is the shaft radius.

The arrow marked F indicates the direction of movement of the milling cutter. Declination angle β
is 30°.

The dotted line U' shows the path within the uncorrected revolution, and the arc U shows the path within the corrected revolution.

The hatched areas indicate flat areas, and points B', D', and Fv on the milling curve are points B', D', and Fv on the revolution circle, respectively.
Corresponds to D and F.

Here, the inventor believes that the size of the flat portion determined by the width and depth is the axis X when changing from cutting to revolution.

It does not depend on the speed of y, but the speed of both ■ and ■ x It was found that it depends on the ratio (see Figure 15).

If ■ is the circumferential speed and β is the quadrant angle, then V = v ・cosβ, V −v ・sinβx
u qyu q ■ The ratio of V is the value shown below y for the angles given below.

According to another implementation of the invention, the axis to be reversed (15th
In the figure, the error in the travel of axis X) is reduced by the play and thus by a.

For example, when cutting at β-18°, a is the distance from XB□8· to Xv□80.

For example, when the path deviates at X O, the axis X is 18 It is stationary, but the other axis y is up to the point y o18 move further.

This causes the reference calculation value y8 to be transferred, and the axis y also issues the command "Arrived at location".

Then the circumferential speeds of both axes are switched and the direction of axis X is changed at the same time.

The carriage of axis X remains stationary until the play is compensated for.

During this time, the feed carriage y further advances by an overtravel amount δ to the point yO, and at this point 18, both feed carriages move on the orbit.

According to the invention, the value of the play a therefore corresponds to the amount of shortening of the play of the machine relative to the axes X and y.

Nevertheless, this value is machine-specific.

This is independent of shaft diameter and working speed. Therefore, there is no need to newly calculate or adjust the value of a for the shaft diameter or various speeds.

If the quadrant changes, then one axis switches, but the other axis also continues to move at high speed.

Therefore, in this case, compared to the case of cutting, the overshoot of the axis to be reversed results in a position error, and as a result, it also deviates from the rotation.

Add to this the risk and idle time when the motor reverses through zero.

The initial speed of the reversing shaft is 1 to 2 trrm within the range of machine data.
/S, so this dead time can be suppressed to about 0.050 seconds or less in total.

Here, the circumferential speed was 600 to 3000 rrm/min, the revolution diameter was 40 to 200 m, and the play was 0.03 to 0.06 mm.

This dead time causes the axis that does not reverse to advance further, and this corresponds to the amount of play, that is, bl.

(See Figure 16) By moving the switching point further back by a distance toward point C (the recess on the rotation axis), b2
According to the triangular relationship with respect to al, when full speed operation of the reversing shaft starts, both feeds come to correspond to the previously calculated revolution.

In Fig. 16, a is play, b is overshoot amount A-B,
bl is the dead time excess amount B-D1 b2 is the total time excess amount CE (position of the shortening target value), G is the starting point of shortening, and al is the shortening amount of A-C corresponding to b2.

As a result of calculating the distance a1 from the machine data given in advance, it is 0.04 to 0.2 inches including play (play is 0).
．． 3 tran).

Coarse adjustment is easily calculated by measuring dead time.

Fine adjustments are made by measuring the shaft after milling.

The set value of the depth of cut must not be changed for linear and circular interpolation elements, so care must be taken to avoid changing the calculated value.

Since the actual value must always correspond to the actual position of the drive, it is undesirable to change this.

FIG. 17 shows a solution to avoid this difficulty.

A value subtracted by a correction value is sent from a position target value counter Z8 for X and y at the output end of the computer R to a comparison element 3 through a subtractor S.

On the other hand, the comparison element 3 is also connected to the current value counter Z, and this! If the two values to be compared match, the signal "arrived at the location" (signal K).

is emitted, and the switch to revolution is executed.

Through logic circuit L1, quadrant 1/I! In the case of the cutting operation H in the quadrant, the value a is the target value of the axis X [subtracted from the slow feed 3 Must be deducted from J.

In the case of revolution, another block circuit is used to determine quadrant I.
The value a1, which is the shortening amount of the value y in /H and the shortening amount of the value - target value - assumes that a counter is used.

Since, in addition to the errors to be checked, the dynamic effects of the milling operation also have to be compensated for, it is possible to find the correct value with the aid of this block circuit.

In the case of cutting work, both axes “arrive at the location (KO)”
J is notified, and the value a becomes 0 at the moment the revolution begins.

In the case of a revolution, in the quadrant angle l, the command ``Arrived at location (KO), J'' is also executed first; however, this acts as a stop command for the reversal axis.

As soon as the moving axis reaches the center of the circle, ie the value becomes 0, the axis to be reversed is switched in the opposite direction.

However, if there is a deviation due to play, the feed bar for that axis will work first.

At this time, the value of a1 becomes 0. Various embodiments of the present invention will be separately described below.

1. When the workpiece is stationary and the tool is moved at an arbitrary angle to the off-centered workpiece via a feed table movable in two coordinate directions, then the calculation for machining the shaft head and side plate is Axial milling machine, in particular for crankshaft machining, characterized in that the determined motion can be resolved into a straight line and a circular arc, and further numerically controlled movements can be carried out along the axis.

2. Provide all the workpiece blueprint values for all reference points required for numerical control, that is, the reference points for both coordinate axes (XtY axes) of the orthogonal feed table, and all data for the axial movement (two axes) of the feed table. Axial milling machine according to claim 1, characterized in that it is equipped with a single-purpose calculator or computer, which calculates and sends the calculations to the interpolation element and/or the distance control element and determines according to a program.

3. A certain program is built into the computer.

The shaft milling machine according to item 2 above, characterized in that the control value is calculated from constantly changing design drawing values and machine positions based on item 2 above, and calculated values based on a fixed program.

4. The shaft milling machine according to item 3 above, wherein the design drawing data of the crank pin, crank journal and crank arm, their angular velocities and distances are given by a block circuit.

5. To the orthogonal feed movement for tool feeding in one plane, for example to infeed revolution milling for particularly long axes, transverse revolution milling is added by a simultaneous movement in the Z-axis direction. The shaft milling machine according to item 1 above, characterized in that:

6. When calculating the necessary control values with a computer, if the workpiece is mounted so that the axis center coincides with the machine axis (X and y) and an internal milling cutter is used,
The shaft milling machine according to item 2 above, characterized in that the center of the milling cutter is also made to coincide with the center of the machine at the initial position.

7. The second aspect of the above, characterized in that the computer is equipped with a quadrant circuit that converts the angle shown in the design drawing into a quadrant angle.
Axial milling machine as described in section.

8. The axial milling machine according to item 7 above, characterized in that the quadrant circuit is combined with a program-step circuit.

9. Position of crank pin and crank arm in Cartesian coordinates from quadrant angle to quadrant circle and various machining processes: depth of cut, revolution milling with/without axial movement, retraction and extreme retraction, calculation for distances x, y Axial milling machine according to claim 7, characterized in that the quadrant circuit is arranged to determine and store the sign of the quadrant angle, the sine and cosine functions of the quadrant angle, and the quadrant position with a quadrant counter.

10. The blueprint angle given to the crank pin or crank arm is passed through the comparison element by the quadrant circuit to the quadrant angles 90° and 180°.

240° and 360°, where O0 is the horizontal
The shaft milling machine according to item 9 above, characterized in that the quadrant is defined on the right side of the shaft and in a counterclockwise direction.

11. The computer's electronic step circuit collects the blueprint data required for each step given by the block circuit or tape, determines the radius through preliminary calculations by addition and subtraction, and calculates the radius in the quadrant circuit in order to proceed correctly on the work path. Input the specified data to 1 or several multipliers, and from this, the values for tool rapid feed (X1/y1), the value for cutting depth (X2/y2), and the value for revolution (x, / '/4 t
The axial milling machine according to item 9 above, characterized in that X5/y5) is given to the linear and circular interpolation elements as a calculation reference point.

12 To supplement the calculator for the travel distances X and y in the case of a straight cut, a counter Z which obtains its pulses directly from the interpolation element or by the "actual value"-detector on the X and y axes.

Z is provided, 1 then: counter (Z and Z)
The value of the rapid feed stroke (X1/y1) and the feed stroke (X2/y2) are added so that the value of the machine matches the distance from the machine center dove to the machine axis (X and y). However, the shaft milling machine described in item 2 above.

13. A separate counter Z is provided for the quadrant adjustment and advance circuit in parallel with the step circuit so that the control panel can tell in which quadrant the working path is located. The shaft milling machine according to item 8 above.

14. The total stroke S - the depth of cut obtained by calculation is determined by the comparison element, the counter Z that corresponds to ImX, and the Z for which axis y.
(sum of partial strokes added to (X1/ yl +
Axial milling machine according to claim 13, characterized in that x2.2/y2-2) is compared and a correction signal is issued for correcting the direction of the machine if the tolerance is exceeded.

15. The axis according to item 6 above, characterized in that the correct center of the two feed tables (X and y) and the zero point Mo: of the machine (5) is also the center of the quadrant circle 1. milling machine.

16. Machine-centered M independent of numerical control.

Axial milling machine according to claim 6, characterized in that the can be set by a limit switch and a pin, which also serve as a direction sensing device.

17. The diameter of the revolution circle (quadrant circle 2) is the center Z.

= Calculated from the data given as the axis center (Ru = Rp - R), then M.

and Z. where the distance is used in the revolution circle to adjust the x and y counters for the axis position,
The axis milling machine according to item 6 above, characterized in that the zero point movement amount is expressed as (X3/y3).

18. When the center of the milling cutter revolves around quadrant circle 2, the reference point (X4/y4) given to the interpolation element simultaneously reaches the counter (
Z and Z) (Claim Whistle 12-17), in which case in the case of counterclockwise forward circular interpolation this counter is set to
The value of X4 of the counter Z in the direction on the radius R of , and at the same time y
.

- The center Z of the shaft head that the counter (Z and Z) should always machine during the revolution, if the value of y4 of the counter Z in the direction O counts and changes the quadrant.

Z from the value of R to 0 and Z from 0 to xu
13. Axial milling machine according to claim 12, characterized in that each corresponding X and y pulse from the circular interpolation element is obtained in such a way as to indicate the value of y Ru.

19. Before moving to the next quadrant by the circular interpolation element, the value of the counter Z is compared with the 0 value or the calculated value R depending on the position of the quadrant, and the value of the counter Z is also compared with the comparison element. 49. Axial milling machine according to item 48, characterized in that a fault signal is emitted if the limit is exceeded.

20. After the milling cutter completes one revolution, the computer starts the axial motion, and an additional axial motion is executed simultaneously with the revolution of the milling cutter, and at the end of the axial motion, after one complete rotation, the As described in item 5 above, for example for machining a shaft head with steps on both sides, the milling cutter is added with an axial movement of the milling cutter in the Z direction, such that the milling cutter is returned in a plane perpendicular to . axis milling machine.

21. In addition to the revolution motion of one complete revolution without axial feed, the complete revolution motion accompanied by the axial motion started at the same time is also programmed into the computer (No. 20 above). Axial milling machine as described in Section.

22. Another counter Z for revolution milling of the crank arm, which keeps track of which revolution curve the milling center is currently on and thus also knows the center of that arc.
9. Axial milling machine according to claim 8, characterized in that the axial milling machine is integrated into a quadrant circuit.

The periphery of the crank arm consists of five arcs, the first
23. The axial milling machine according to item 22, wherein the peripheral arc to be machined has a half angle of the angle of the arc with the smaller radius, and the cutting is always performed in the long diameter direction of the arm.

Sae, in the case of revolution milling of the crank arm, the angle β
Half of angle α and/or angle β of ten small diameter arm arcs
Is half of the ten large diameter arm arc (180°-α) more than 90°? The quadrant circuit examines whether β9+-! (At 90°, angle ε1 β, +■(180°−α) <At 90°, angle ε2 or ε
Item 22 above, characterized in that ε1-90°=ε3 in the case of 1>90°; ε2-90°=ε4 in the case of ε2>90° is used in the calculation for setting the reference point for revolution milling. Axial milling machine described in.

25. At the end of the cutting stroke S, the center of the milling cutter is at the point W A and revolution milling for arm machining is started, but at this time, the starting and ending points of each peripheral curve, which are necessary for circular interpolation, are The required radius, including the reference point X/y,
24. The axial milling machine according to item 23, wherein the angle, sign, and trigonometric function are calculated by a computer.

26. A quadrant counter Z coupled to a quadrant circuit continuously stores the quadrant position of the milling center during the revolution milling, and the machine center M.

X indicating the "retreat" direction to. The shaft milling machine according to item 1 above, characterized in that a code for y is provided.

27. The number of the revolution curve that has progressed is memorized by the counter ZB, and when the value of the final reference point (x/y) is reached on the last curve, a quick return to the machine center pigeon begins. Axial milling machine according to claim 16, characterized in that the direction is defined by a quadrant circuit.

28. For "reverse" and "emergency retract" commands from linear or revolution milling, the counter and calculator are not activated and the direction sensing circuit is used to move the carriage x, y directly to the center M.

27. Axial milling machine according to claim 26, characterized in that the counters Z 1 , Z 2 are set to O at the end of the movement.

29. At the end of the return, the counter Z,
Z is set to 0, which causes the counter value to match the mechanical axis (
Axial milling machine according to claim 28, characterized in that it is adapted to coincide with the positions of x and y).

30, Feed rate (VOI and ■.

2) A circuit for adjusting the speed V of revolution milling, which is separated for the adjustment and forcibly operates in the corresponding feed stroke, automatically changes the circumferential speed V with a special circuit. Axial milling machine according to item 1 above, characterized in that it is provided with other means for causing the rotation.

31. In addition to the speed adjustment mechanism, a circuit that can control the feed speed and revolution milling speed together (level circuit)
The axial milling machine according to item 1 above, characterized in that it comprises:

In the case of 32 depths of cut, the given set speeds for rapid traverse and feed for the radial stroke are input to the interpolation element, by which the calculated speed (beat frequency) of the interpolation element is determined in a known manner. 31. The shaft milling machine according to item 30, wherein the axial milling machine is multiplied by the sum of the spider and house values of the quadrant angle β before the multiplication.

33. The axial milling machine according to item 32 above, characterized in that the circumferential speed of the revolution milling is multiplied by a multiplying factor of 1.27 (4) before being applied to the circular interpolation element.

34. No. 33 above, characterized in that the speed is automatically varied at a constant angle between 0° and 360° so that the milling cutter is uniformly loaded during revolution milling. Axial milling machine as described in Section.

35. While the milling cutter F revolves around the circumference of quadrant 2, n in a certain angular range (from γ to γ)
nl moves at a defined circumferential speed, the starting quadrant angle β of the revolution milling being at the same time 0 angle for the angular range, the switching of the speed range corresponding to the next angle (β + γ ), and The sine value of this angle stored in the comparison element is compared with the quotient of the count values Z, Z and the radius R. If they match in this comparison element, then for the next angle range defined for the new speed. The shaft milling machine according to item 34, characterized in that it emits a signal.

36. In order to give the circumferential speed in the case of milling the side plates, a potentiometer is provided insofar as different radii (r, R..., etc.) are used to determine the desired constant milling speed. Adjustment from speed is by revolution radius (R, R,...
. . . ) and the corresponding u 1 u 2 side plate radius (ry Rt . . . etc.).

37. The load-dependent control voltage of the tool drive motor determined for speed control is controlled by a predetermined value for this armature current or field current and/or for the rotational moment of the milling drive. Any of the above items 30 to 36, characterized in that it is influenced by the measured value and/or the measured value of the cutting pressure on the attachment of the individual blades of the milling cutter for further speed control. Axial milling machine as described.

38. The directional control device (Figs. 3a-3c) simultaneously supplies two axes (X and y) with very high control DC voltages in order to perform a "center" movement in rapid traverse; 30 above, characterized in that, just before the "center" of each movement, the switch from rapid forwarding to forwarding is switched in a well-known manner via pins and limit switches, and independently of each other. Axial milling machine described in.

39. Axial milling machine according to item 38, characterized in that the signs of the X and Y distances of the directional control device (FIGS. 3a-30) simultaneously exhibit positive and negative signs for the control DC voltage.

40. By means of a selector switch Z corresponding to the number of crank pins to be machined, axis Z moves the tool to the next It is decided whether to carry the pulse (crank pin or arm) or to bring the milling carriage column to the starting position, switch axis Z to reverse and stop the machine for tool change. The shaft milling machine according to item 1 above, characterized in that:

41. Another selector switch W with "crank journal", "crank pin" and "crank arm" positions
The above feature, characterized in that Fov determines whether the selector switch Z for each crank pin should be moved to the second arm of the same shaft head or to the first arm of the next shaft head. Axial milling machine according to paragraph 1.

A block circuit is provided for the travel of the 42-axis head from the first crank arm to the second arm, the value of which is determined by a special counter Z that counts the number of bends Zk from arm 1 to arm 2. , whereas the axis counter Z
42. Axial milling machine according to item 41, characterized in that records the absolute value for the next axis head position up to "Arm 1".

43. Electronic control such that during cutting, the target value of the machine axis control, which is switched when introduced into the circuit, is reduced by a preset amount, and at the same time the calculated value of this axis for interpolation remains unchanged. Axial milling machine according to the above claims, characterized in that it is equipped with mechanical control means.

44. The shortening correction amount a during cutting is almost the same as the play of the machine and differs with respect to the axes (X and y), but it is independent of the shaft head diameter and cutting speed, and only until the revolution begins. No. 43 above, characterized in that it is a valid and constant value.
Axial milling machine as described in Section.

45. During revolution machining, the target value for the axis control that is switched when moving to the first quadrant is set by an electronic device to a predetermined value without changing the calculated value of the axis for circular interpolation. Axial milling machine according to the above claims, characterized in that it is shortened.

46, Inugisa al separated with respect to axis (X and y)
can be set by a block circuit that stops the axis that is to move backwards early, and when the axis that continues to move passes through the circle center 0, the reverse axis is switched to the backward direction and the correction value is set. The shaft milling machine according to the above item 45, characterized in that a1 is set to zero.

47. A value subtracted by the correction value a from the position target value-counter Z for the axes (X and y) at the output end of the calculator R is sent to the comparison element 3 through the subtractor S; is connected to the current value counter Zi, and when the comparison values of the two match, the signal ``Arrived at the location JKo'' is issued, the switch to revolution is executed, and the logic circuit L1
Accordingly, in the case of cutting operation E in quadrant I/I, the axis
target value [value a from slow feed X2-3J, and quadrant 11
/IV, the target value of the axis y [delayed feed y2.3 J].
The shaft milling machine according to paragraph 45.

In the case of rotation and revolution, quadrant I is controlled by another block circuit.
/l[ as the shortening amount of the value y, and quadrant 11
Value a1 used as the reduction amount of value X5 in /IV
48. The axial milling machine according to item 47, characterized in that is given during the quadrant change W.

49. The size of al is determined from the triangular relationship in a well-known manner so that after the play a of the reversal shaft has exceeded, the two feed tables move on the orbital circle U again5. The shaft milling machine according to paragraph 45.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the machine, Figure 2 is a front view of the crankshaft (workpiece) after milling, and Figure 3 shows the position of the crank pin inside the inner milling cutter, showing the angle of each shaft head. Figures 3a to 30 are explanatory diagrams showing a limit switch for detecting the direction of both the X and Y feed tables with respect to the machine center, and Figure 4a is an explanatory diagram showing how to calculate numerical values for crank pin machining. The figure is an explanatory diagram for calculating numerical values for crank journal machining, FIG. 5 is an explanatory diagram for calculating numerical values for crank arm machining, and 6aI and II. Figure 6b - Illustration of quadrant selection for crankpin angle for depth of cut and revolution milling, Figure 7a - Illustration of function and quadrant for crankpin depth of cut, Figure 7b
The figure is an explanatory diagram of functions and quadrants for crank journal cutting, Figure 8 is an explanatory diagram of quadrants and trigonometric functions for [re-rank arm notch] machining, and Figure 9a is an explanatory diagram of quadrants and trigonometric functions for crank pin and crank journal, and all Fig. 9b is an explanatory diagram of the orbit of a rolling circle; Fig. 9b is an explanatory diagram showing axial milling; Fig. 10a is an explanatory diagram showing quadrants and trigonometric functions for machining the crank arm, and revolution trajectory curves based on calculation results; Figs. 10b to 10b. Figure 10f is the 10th figure respectively.
Fig. 11 is an explanatory diagram showing the starting and ending points of curves 1 to 5 for the orbit of the pigeon according to the diagram, and Fig. 11 shows the return route from the orbit directly towards the pigeon via the direction detection device according to Figs. 3a and 3b. The illustration shown in FIG. 12 is a direct M via the direction detection device according to FIG. 3b. Fig. 13a is an explanatory diagram showing the angular velocity γ for revolution speed control; Fig. 13b is an explanatory diagram showing the quadrant position of angular velocity γ; Figure 13cl1 is an explanatory diagram showing the sine values of both the X and Y axes based on the quadrant of angular velocity, and Figures 14 and 15 are diagrams showing the configuration of the J grain detection device. "revolution"
Figure 16 is an explanatory diagram showing the same method as above when the quadrant changes, and Figure 11 is an explanatory diagram showing the control method to avoid errors in the workpiece that occur when the quadrant changes. FIG. 2 is an explanatory diagram showing an outline of a correction method for X, y: Body base, MO = machine center, Z: feed direction %T
a: Generator, m, m: Drive motor, D,
D: Digital transmitter, Fo Nikoni GX
center of gy, D: crankshaft diameter, L1 to L3: movement amount of shaft 2, M: machining allowance, L: crank journal, 1:
circle, K-crank pin, b, bel, e
2°be: Limit switch, N1. N2. N 3.
two. N4: Pin, H: Stroke, R: Crank pin radius β: Declination angle, a: Radius, Wo: Middle pin of arm A1゜A2. B1
．． B2: center point of the circle, C: distance, 1-, R: radius.

Claims (1)

[Claims] 1. A tool consisting of a disc-shaped cutting head having a cutting blade arranged on the inner periphery is provided, and the rotation axis of the cutting head is guided along a circular trajectory by a numerically controlled orthogonal feed table and is movable in the longitudinal direction. , and the drive shaft of the tool for machining the crankshaft, which is fixedly mounted and is stopped during the entire period of the required machining stroke, moves on a straight trajectory to a circular trajectory with an arbitrary center point and a defined radius. When machining a crankshaft using an axis milling machine that moves on the circular trajectory, the target value for the tool movement changes from a linear trajectory to a circular trajectory, and each axis (X or y ) for each axis (X or y ) is reduced by a preset constant amount for each axis milling machine.