JPS62188651A - Surface copying device - Google Patents

Abstract

PURPOSE:To enable two axis direction copying and improve copying accuracy by providing a spindle inclination detecting part and a reversing means for reversing a spindle 180 deg. at the moving limit of a work table, on a spindle on which a stylus is installed. CONSTITUTION:When copying in the X-axis direction, if there is even a least amount of light received by photoelectric elements 52a, 52b on the Y-axis, a command board 50a is rotated to make the light receiving amount zero and an element 52c wholly receives light, and a stylus center 01 precede a spindle center 02 and is moved in the -X direction. When a stylus S comes to the ascending face of a model M, a spindle 10 is slightly inclined and is moved backward by a preceding amount corresponding to the amount of eccentricity at which the spindle 10 is eccentrically installed to a rotation center, making the contact point between the stylus S and the model M agree with the contact point between a knife and a workpiece to carry out copying with high accuracy. Since the spindle is not inclined on the descending face, copying can be carried out equally with high accuracy. When a table arrives at the right limit, a photoelectric element 52d wholly receives light, to carry out feeding in the +X direction.

Description

[Detailed Description of the Invention] Is the present invention a work 1fl? It relates to a surface (or scan line) tracing device of the first order.

As a conventional surface profiling device, the one disclosed in Japanese Patent Publication No. 5G-4378, which was previously published by the present inventor, holds a stylus spindle so that it can be slightly tilted and displaced in the axial direction, and is The stylus is held so that it can be rotated in the forward and reverse directions within a range of 180 degrees, and the stylus is slightly tilted and fixed at the tip of the stylus spindle. This person then points the tip of the stylus forward in the tracing direction and moves the table in one direction to cut.When this process is complete, the stylus spindle is rotated 180 degrees to reverse the direction of the stylus, and the person moves the table in the other direction. It was sent to the factory for cutting.

However, as mentioned above, the stylus is tilted relative to the spindle, which makes the part difficult to fabricate.Moreover, when the model moves from a steeply descending surface to a horizontal surface, the stylus straddles both sides like the hypotenuse of a right triangle. state, and it becomes impossible to trace the model surface in this range.

In addition, in the prior art, as a means for maintaining the orientation of the stylus tip in a constant direction, two conductive wires are connected from positions diametrically opposite to each other across the center of the lower end surface of an insulating ring fixed to the outer periphery of the tracer outer cylinder. Stoppers are suspended from the spindle, and conductive contact rods projecting from the spindle cross-abut the stops. Then, the spindle rotation motor is controlled so that the contact rod contacts and separates from the stopper with a very small amplitude. With such means, one direction on the horizontal plane (X
The orientation of the stylus could only be maintained (or in the Y-axis force direction).

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a surface profiling device that has a stylus that does not tilt and can maintain the orientation of the stylus in two directions: the X-axis and the Y-axis.

In order to achieve this object, the configuration of the present invention is as follows. That is, a spindle with a stylus attached to its lower end is held in a tracer case at a slight incline so that it can move up and down as well as rotatably, and the stylus has a circumferential surface and is inserted into the cutter by taking into account the amount of correction of the spindle inclination. The stylus is made thicker and mounted eccentrically with respect to the center of rotation of the spindle, and the inclination of the spindle based on the contact of the stylus with the model is detected analogously by a differential transformer, and the tracer is moved up and down in proportion to the amount of inclination. A spindle inclination detection unit configured to change the speed is provided, a command plate is supported concentrically with the spindle and rotatable at the same speed as the spindle, and the outer periphery of the command plate rotates so as to represent the attitude of the stylus with respect to the model. Four sets of detection means are arranged at equal intervals on the same circumference, which is composed of a smooth curve symmetrical to a straight line orthogonal to the center, and is concentric with the axis of the spindle, corresponding to the outer periphery of the command plate, 2 and tll, which are diametrically opposed to the detection means, are connected so that the motor for rotating the spindle rotates clockwise or counterclockwise, and the center of the stylus is aligned with the spindle during tracing operation by the command plate and the detection means. When the spindle is held so as to be offset in the direction of travel relative to the center, and the workpiece table is at the limit of movement, a signal is generated to invert the spindle by 180 degrees. The reason is that such a reversing means is provided.

, Hereinafter, if one embodiment of the present invention is also used as a contour surface, ν・
The construction will be explained based on the drawings using an example of the device.

FIG. 1 shows an overall view of a profile milling machine, where 1 is a table, 2 is a spindle head, 3 is a tracer arm, 4 is a Z-axis motor, T is a tracer, S is a stylus, and C is a cutter. 2 to 4, the tracer spindle 10 extends between the upper box part A1 and the lower box part A2 to the tracer case.
is accommodated.

The tracer spindle 10 has a main body 11 and a stylus mounting f.
f1112, a ball holding recess 13 whose upper end face is shaped like an upper wide cone to detect the inclination of the spindle 10, and a lower support spherical fulcrum part 14 which allows the spindle 10 to be slightly inclined.

The stylus S has a cylindrical part on the upper side of the hemispherical part, and is made thicker than the blade C by adding an amount of spindle inclination correction.As shown in Fig. 12, the stylus S has a cylindrical part on the upper side of the hemisphere. , mounted.

In the spindle upper holding part 20, a displacement rod 22 is vertically penetrated through the center of the support block 21 and held in a stepped manner so as to be rotatable and vertically movable via a bearing 21a. Four holding portions 22n having a shape are formed.

A spherical intermediate displacement member 23 is held between the four holding parts 22a and the ball holding recess 13. Further, a spring retainer 24 is removably provided on the upper box portion A1 (it may be adjustable with a screw), and a push-down spring 25 is interposed between the spring retainer 24 and the displacement rod 22.

Next, the spindle lower support part 30 is attached to the Lusus spindle 1.
0 is held approximately vertically so as to be rotatable and slightly tiltable, and supported so as to be slightly movable up and down. The spindle 10 is fitted onto the outer periphery of the case A2 so as to be slightly slidable up and down.
A support cylinder 31 is provided which is substantially concentric with the support cylinder 31 . The support cylinder 31 consists of a cylindrical main body 311 and a circumferential raised part 312 provided on the inner surface of the cylinder via a step at a midway point in the axial direction.
Pressure oil inlets 313 and 314 for pushing down and lifting the spindle are provided on the upper and lower sides of the upper and lower surfaces of the spindle 2, respectively.

The circumferential protuberance gl on the lower outer periphery of case A2! A stepped portion A21 is formed on the upper side of the support tube 312, and serves as an upper stopper for regulating the upper limit position of the support tube 31.

On the other hand, in order to regulate the lower limit position of the support cylinder 31, a support cylinder lower stopper 32, which is substantially concentric with the spindle 10, is attached to the lower inner surface of the lower cylinder part A2 and is attached to the outer thread 321a of the cylinder 321.
Fixed via. The outer circle 7 runno 322 provided at the lower end of the mounting cylinder 321 is in close contact with the lower end surface of the lower cylinder part A2, and the upper part of its circumferential edge is connected to the circumferential raised part 312.
It becomes a stopper.

A lifting member 33 for temporarily slightly lifting the spindle 10 is attached to the lower part of the support cylinder 31 approximately concentrically with the spindle 10. The member 33 supports the support 1i
A mounting 7 flange 331 is attached to the inner surface of the '1I31 via an external screw 331a, and a cylindrical body 332 is integrally formed in the center of the flange 331 and lifts the spindle 10 with its upper end surface.
Consists of.

Further, in order to support the spindle 10 via a tactile force adjustment spring 352, which will be described later, a spring receiver 34 is provided approximately concentrically with the spindle 10. The spring receiver 34 consists of a bottomed cylindrical spring receiver body 341 with a hole attached to the inner surface of the cylindrical body 332 via an external screw 342, and a tactile pressure adjustment handle 343 provided at the lower end thereof.

In order to receive the spherical portion 14 of the spindle 10, a spindle receiver 35 is provided which is substantially concentric therewith. The spindle receiver 3
5 is the contact pressure of the stylus S against the spindle tray 351 and the mole M, which is 119! spring 352 and spring id n
Contains 353.

The spindle drive unit 40 for rotating the tracer spindle 10 is as shown in the fJS3 diagram as follows. That is, a motor 41, a first drive pongee 42, a pinion 43, and a gear 44 are provided, and an engaging tooth-shaped drive piece 45 is attached to the lower surface of the gear 44.

A second drive shaft 4G, which is a hollow shaft, is loosely fitted on the outer periphery of the tracer spindle main body 11, and has a bearing 461 on the side and a lower end so that it can rotate approximately concentrically with the spindle 10 and can slightly slide up and down. The shaft is supported by the spindle spherical part 14.

A passive piece 462 that is engaged with and driven by the driving piece 45 is provided at the upper end of the pongee 4G. Further, an engagement notch 463 is provided at the lower end of the shaft 46, and a rotating arm 47 that engages with the notch 463 and transmits the rotation of the shaft 46 to the spindle 10 is provided on the spindle 10.

The table movement command unit 50 is housed in the case A1 and is located in the third.
As shown in FIG. 8.9, the table movement detecting section SO1+ consists of a table movement guide blocking plate 50m, an insulating disk 51, a photoelectric element 52, and a light source 53.

That is, the charging element mounting insulating disk 5 is concentrically attached to the post 441 of the gear 44 and fixed within the case Al.
1 has four grooves 5 arranged radially at equal intervals on the circumference on its surface.
1a, and a mounting piece 51b is attached to the groove by a tightener 51c so as to be movable forward and backward in the radial direction of the disc. The photoelectric conversion element 52 includes four rectangular thin plate pieces 52a and 52b, as shown in Figure 8-9.

52c and 52d respectively to the four mounting pieces 51! ] and arranged at equal intervals on the same circumference concentric with the axis 02 of the spindle 11;
521+ faces the table's longitudinal movement direction (Y-axis),
Elements 52c and 52d indicate the left-right movement direction of the table (X pongee)
It was made to face. The voltage generated by these four elements is increased 111 to operate the upper X and Y drive DC motors (not shown), or to the servo valve to drive the hydraulic motor or hydraulic cylinder. The light source 53 faces the photoelectric element 52. The light source 53 faces the photoelectric element 52.

The table movement command light blocking plate 50a is fixed concentrically to the spindle 10 between the photoelectric element 52 and the light source 53 via the gear post 441 and nut 442. Then, as shown in FIG. 10, the distance f%tL from the rotation center 02 to the outer circumference of the command plate 50a is determined by plus or minus 90 degrees from the periapsis R at zero degree.
symmetrical with respect to the straight line n passing through the periapsis R1 and the center of rotation 02, respectively, up to ! 1 (1-cc+5B) (however, the maximum increase in the distance from the rotation center 02 of the command plate 50a to the outer circumference, B: the angle formed by the radius with respect to the line of symmetry 11 of the command plate 50a) gradually increases according to the curve, When the angle range other than the above is constant, that is, the outer periphery is set as a circular arc, and when the near point R corresponds to any one of the charging elements 52, for example 52c, according to the rotation of the command plate 50a, the element 7 -52
The light-receiving area of c is set to be the maximum, and the light-receiving area is set to zero when the distance corresponds to the constant angular range. *Then, connect the straight line 1 with the stylus center 01 and the spindle center 02.
is located. (FIG. 13) The spindle inclination detection unit 60 detects that when the stylus S contacts the model as shown in FIG. 3, the spindle 10 slightly inclines with respect to the vertical.
emits a signal that changes the rotation speed of the In the detection unit 60, a differential transformer 62 consisting of a core 622 whose moving force direction is parallel to the moving direction of the displacement rod 22 is inserted into the cylindrical recess 6.1 of the block 21 via a coil 621 and a support spring 63. be accommodated. The core holding rod 64 faces vertically and is attached by an arm 65 with an external screw so that its height can be adjusted. The core holding arm 65 extends vertically and horizontally from the top of the displacement rod 22, and a height adjusting member 66 of the coil 621 is removable with a screw at the upper end of the tracer case upper box part A1 directly above the differential transformer. established in

Here, the signal from the differential transformer 62 is determined as follows. That is, when the stylus S is not in contact with the model M and the table, the stylus S is pushed against the case AI by its own weight.
: On the other hand, it is at the lowest position, and the differential transformer 62 generates a negative voltage. When the stylus S contacts the model M, the voltage becomes zero depending on the amount of inclination, and then becomes positive.

Next, the operating state will be explained.

For contour tracing (X-Y axis tracing), spindle 1
0 is at the lowest position for case 8, and the differential transformer's flap 7622 is on the upper and lower sides of the zero voltage position, and the differential transformer 6
2 is at a position where the voltage shows a slightly negative value. The motor 41 therefore rotates at a low speed and imparts rotation to the tracer spindle 10 and stylus S via the reduction gears 43, 44 and the Pt52 drive pongee 46.

As shown in FIG. 13a, when the model M and the styler XS are separated and are not in contact, the spindle 10 is rotated by the motor 41 in the direction of the arrow.

When the table is manually moved to bring the model M close to the stylus S and make contact with it, the stylus S is pressed against the model M by the eccentricity of the stylus S and the rotation of the motor 41. As the displacement of the ball 23 increases with the inclination of the spindle 10, the motor 41 decelerates proportionally, and tj%13
The state shown in FIG. 6 is reached, and a table signal in the direction of arrow F is generated by elements 52a and 52e. Therefore, when the model M approaches further and the spindle inclination increases, the voltage of the transformer 62 becomes zero and the motor 41 stops. At this time it was the 13th
As shown in figure e, the straight line JII,n is parallel to the tangential direction at the contact point of the model M. As the model M approaches, the voltage of the transformer 62 finally becomes positive and the motor 41 reverses, resulting in the state shown in Figure 13d, where the model is sent in the direction F and the model M moves away, ending up in the state shown in Figure 13c. Return to

In other words, the back type conversion element 52 is
The table servo Iso (No. 13 at 1η) is used to move 11, 11 along the model M in a predetermined direction while keeping it parallel to the horizontal tangent to the model M passing through the contact point between the stylus S and the model M. send.

Here, the tracing speed must be constant tl:,L, that is, f:tr111 In the diagram, Fj, 5Ouf for the diameter on the charging elements 52u, 52d.
) The rotation angle of the W line 11 is B, the photoelectric element S2a at that time,
The light receiving length of 52d is l+1. If l+2, the maximum light receiving height of the photoelectric element is equal to ■4, so 1+1 = TI-tl ・(1-cos[3)=H・C
09Bb2 = H-H・If-cos(90-B)
l=H・5inBHere, since the tracing speed in each axial direction is proportional to b1・b2, the combined speed in each axial direction is J
It is proportional to I+ 12+ b2', therefore. In other words, the tracing speed is always constant.

If the signal generation direction of the photoelectric element is reversed to that described above, that is, if the elements on the right, left, upper and lower sides are arranged so that the table is sent in the positive X, negative The near point R of the command plate 50m may be located at .

Next, when this device is used as a surface (X-Z pongee or Y-Z pongee) tracing device, an electric signal from the differential transformer 62 is applied to the motor (Z-axis motor) 4 for feeding the spindle head. In this case, the stylus S does not need to be eccentric with respect to the spindle 10.

This operating state will be explained based on FIG. 14.

When the tracer 'r is not in contact with the model M, the stylus S° is at the lowest position relative to case 8 due to gravity, the differential transformer 62 generates a negative signal, and the motor 4 lowers the tracer T. When the tracer T contacts the model M sent in the direction of the arrow F and follows the horizontal plane, the stylus S rises relative to case 8, and the tracer height is held constant with the differential transformer 62 at zero potential. First, when the stylus S reaches the right upward slope, the stylus S slightly falls in the direction of tracing movement relative to the model M. At this time, the core 622 rises, the differential transformer 62 generates a positive signal proportional to the amount of rise, and the motor 4 causes the tracer T to rise at a speed proportional to the amount of rise.

Next, when tracing a downward slope to the right from a horizontal plane, the model M is always moving away from the stylus S, so
The stylus S is located at a low position relative to the case 8 with almost no inclination. Therefore, the differential transformer 62 generates a negative signal, causing the motor 4 to lower the tracer T.

Now, when the stylus S hits a vertical surface or a steep slope, the same thing as described above occurs, but since the amount of tilt of the stylus S increases, the tracing accuracy is impaired. To solve this problem, move the stylus S to case A in response to the tilt.
1. : , t'j L Just lift it up. That is, when the tilt of the stylus S increases and the positive or negative signal of the differential transformer becomes larger than a preset value, the signal is sent to, for example, a refueling solenoid valve (not shown) to open it, and the tracer support tube is opened. The structure is such that pressure oil is sent to the oil hole 314 of 31 to lift the front cylinder 31 relative to the case A. The lifting amount is from zero to a slightly lower negative signal generation position as shown by the chain line U in the f:1S14 diagram. In this way, the stylus S is always in contact with the model M, and the amount of inclination thereof is prevented from increasing, thereby maintaining a slight inclination.

As mentioned above, surface tracing 1': Since the stylus S is inclined when it reaches the ascending surface of the model M, the knife C is relatively in front of the stylus S, and the biting of the knife C is large. becomes. On the other hand, when it reaches the downward surface, the blade C
The bite becomes smaller.

To solve this problem, when the stylus S traces the ascending surface of the model M, a correction amount that compensates for the stylus inclination is added to the contact point of the stylus S with the model M, and when the stylus S traces the upward direction of the model M, The stylus S may be rotated 180 degrees.

That is, as described above, the stylus S is eccentrically moved in the advancing direction with respect to the spindle 10, or as shown in FIG. 16, a protrusion S1 is provided on one side of the stylus S.

As an example of a means for maintaining the directionality of the stylus S,
The charging element 52 and the command plate 50a are used. That is,
As shown in FIG. 15, when following the X-wheel direction, the wires are connected so that electric signals from elements S2a and 52b on the Y-axis are sent to the motor 41 via the switch SW and the amplifier AMP. Therefore, the rotation direction of the motor 41 is determined by the element 52a, for example.
43 from 521) are determined to be clockwise and counterclockwise, respectively.

Therefore, if the elements 52a and 52b receive even a small amount of light, the command plate 50a rotates so as to reduce the amount of received light to zero, and as shown in FIG. The table moves in the (-) X direction indicated by the arrow F direction, with the straight line 16.11 along the X axis, ahead of the spindle center 021 in the traveling direction.

When the stylus S follows the ascending surface of the model M, the spindle 10 is slightly tilted, and the leading portion corresponding to the eccentricity of the stylus S is returned to the rear, thereby positioning the contact point between the stylus S and the model M. The position of the contact point of the blade with the workpiece matches the position of the blade and the workpiece, and highly accurate profile cutting is performed.
Next is the descending surface.

Since the spindle 10 hardly tilts when traversing,
Similar to the above, the position of the point of contact between the stylus S and the model M matches the position of the point of contact of the cutter with respect to the workpiece, and highly accurate profile cutting is performed.

When the table reaches the left limit position, a reverse rotation command No. 3 is issued to the motor 41 by a known position detection means consisting of a limit switch and a dog (not shown), and this signal is transmitted to is sent to the reversing means. Then, the motor 41 is rotated in the reverse direction so that the entire element 52d now receives light, and the table is sent in the (+) X-axis direction.

Similarly, when the table reaches its rightmost position, the stylus SL command plate 50a rotates in the opposite direction.
returns to its original position.

By the way, as mentioned above, when tracing the upward plane, the stylus S
is always inclined, and cutting errors due to this cannot be avoided in principle.Therefore, no cutting is done when tracing the rising surface.
This problem can be solved by configuring the cutting to be performed only when tracing the descending surface with little cutting error.

In other words, as shown in the diagram, if the amount of correction of the stylus protrusion S1 is increased so that even if the stylus S contacts the model M, the knife C does not contact the workpiece, the knife C will cut when tracing the ascending surface. Instead, it will be cut only when tracing the descending surface. If the stylus is then reversed using the stylus reversing means described above and the entire model is cut C7.

The servo ability of this device can respond with high precision, so it can easily cope with the vibrations induced by heavy cutting of a 300 ORPM carbide tool, and it can also react in advance in the direction of movement of the stylus S relative to the blade. Since the stylus S has an eccentric point 01, the stylus traces the outline of the model before the knife.

Therefore, even if there is a sudden change in the tracing direction, the displacement of the stylus S can be taken out as the displacement of the stylus S quickly by the amount of eccentricity. During this time, the servo function can sufficiently complete the deceleration and direction change of the table, so that no digging occurs even during high-speed scanning m-cutting.

The analog signal from the photoelectric conversion element 52 can be directly amplified to drive the servo motor. Therefore, compared to a method that uses a pulse motor to drive the table, the analog signal can be amplified as it is and the precision problem that occurs when switching to There are no errors or problems at all.

By providing the means for lifting the input bottle 1ζ, good machining accuracy can be obtained even when cutting along a steeply ascending surface.

Also, by reversing the stylus,
The profile cutting on both sides of the ascending and descending planes is uniform, and the roughness of the cut surface is much finer than that of conventional machines, resulting in a significant reduction in the number of man-hours required for finishing.

As the table movement amount detecting section that outputs an analog electric signal, a wire strain sensor whose electrical resistance value changes depending on strain, a piezoelectric element, a differential transformer, a hydraulic pilot valve, or the like may be used instead of the charging element. In these cases, the leaf spring to which the wire trending element is attached, the core of the differential transformer, or the tip of the spool of the pilot valve is brought into contact with the outer peripheral surface of the command plate 50u, and the table is activated by the signal from C7. and 9 for moving the tracer.Furthermore, these are used in place of the differential transformer of the spindle tilt detection section. 1ull, for example, the tip of a leaf spring that has been biased downward in advance so that a negative signal appears at the upper end of the displacement ball 23 is pressed horizontally and fixed to the case side, and a wire trendeno is attached to the spring. As another example, a piezoelectric element is pressed onto the upper side of the displacement ball 23 via a spring. Alternatively, a light shielding plate is fixed to the spindle 10, and a light source and a charging element are placed on the left side of the spindle 10, and the elements are placed above and below the light shielding plate in the neutral position. 1 will be given.

In addition to the hydraulic type, an electric type such as an electromagnetic solenoid or a dielectric electromagnet, or a pneumatic type can be used as a means for lifting the spindle.

Furthermore, the stylus reversing means may be configured to rotate the idiot spindle 180 degrees using hydraulic pressure.

As described above, in the present invention, the stylus has a circumferential surface that is made thicker than the cutter in consideration of the spindle inclination detection part, and is mounted eccentrically with respect to the spindle rotation center, so that the stylus can be easily processed. It became possible to follow the boundary between the steeply descending surface and the horizontal surface of the model in this region.

Further, the inclination of the spindle based on the contact of the stylus with the model is detected analogously by a differential transformer,
Since a spindle inclination detection unit is provided that changes the vertical movement speed of the tracer in proportion to the amount of inclination,
Tracing response speed has become faster. Furthermore, since the eccentric direction of the stylus is held constant by a command plate with a specially curved outer circumference and four sets of detection means, profile cutting in two axes of X and Y is possible. As a result, high-precision, high-speed, heavy-duty cutting is possible as a whole.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a profile milling machine according to the present invention;
Fig. 2 is a plan view of one embodiment of the tracer, Fig. 3 is a top view of the ■-■ cross section of Fig. 2, Fig. 4 is a bottom view of the -1%' cross section of Fig. Pt52, and Fig. ln5 is a cross-sectional bottom view of Fig. 4. V-V sectional view, ff16
The figure is a side view of the spherical support part, and Figure 7 is ■-■ of fjS3 diagram.
8 is a sectional view taken along the line ■-■ of the ttrJ3 diagram, FIG. 9 is a plan view of the arrangement of charging elements, FIGS. 10 and 11 are plan views of the table movement command board, and FIG. 12 is a plan view of the stylus. FIG. 13 is an explanatory diagram of the contour tracing action, FIG. 14 is an explanatory diagram of the surface tracing action, FIG. 15 is a system diagram of one embodiment of the stylus directionality holding and reversing device, and FIG. 16 is another embodiment of the stylus. It is an example effect diagram. T...Tracer, A...Tracer case, S...
Stylus, 10... Tracer spindle, 14...
- Lower support spherical part, 20... Spindle upper holding part, 22
. . . Displacement rod, 23 . Lower stopper, 33... Lifting member, 34... Support spring holder, 3
5...Spindle holder, 352...Spring, 40...
Spindle drive unit, 41... motor, 42... first
Drive shaft, 43... Binion, 44... Gear, 45.
... Drive piece, 4G... Second drive shaft, 47... Rotating arm, 50... Table movement command section, 50a... Table movement command light blocking plate, 50b... Table movement command detection section , 51... Insulating disk, 52... Photoelectric element, 53
... light source, 60 ... spindle inclination detection section, 62.
...Differential transformer, 66...Adjustment member representative

Claims (1)

[Claims] A spindle with a stylus attached to its lower end is held in a tracer case at a slight incline so as to be movable up and down as well as rotatable; Mounted eccentrically with respect to the spindle rotation center, a differential transformer detects the inclination of the spindle based on the contact of the stylus with the model in an analog way, and changes the vertical movement speed of the tracer in proportion to the amount of inclination. A spindle inclination detection unit is provided, a command plate is supported concentrically with the spindle and rotatable at the same speed as the spindle, and the outer periphery of the command plate is
It consists of a smooth curve that is symmetrical to a straight line orthogonal to the rotation center so as to represent the attitude of the stylus with respect to the model, and is on the same circumference concentric with the axis of the spindle, corresponding to the outer periphery of the command plate. Four sets of detection means are arranged at equal intervals, and the two sets facing each other on the diameter of the detection means are connected so that the motor for rotating the spindle rotates clockwise or counterclockwise. During the profiling operation, the spindle is held such that the center of the stylus is displaced in the profiling direction with respect to the center of the spindle, and a signal is generated when the workpiece table reaches a movement limit position, A surface profiling apparatus characterized in that a reversing means for reversing the spindle by 180 degrees is provided.