JPH0714561B2 - Numerical control device for basic shoe type for lathes - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical control device using shape data in place of a basic shoe shape for a lathe which follows a shoe shape.

[0002]

2. Description of the Related Art Conventionally, the production of basic shoe molds has been done manually by professional craftsmen, but in recent years, it has been more detailed due to the tradition of the technique and custom shoes or size development based on consumer's health and comfort. Due to the increasing demands for various shoe shape adjustments, the application of general-purpose three-dimensional numerical control milling machines to computer-aided design and basic shoe shape production is being tried.

As a numerical control of a tracing rod in a tracing lathe of this type, there is a conventional one described in Japanese Patent Publication No. 1-20032, for example.

This conventional technique is a one-dimensional profile that moves vertically as well as in the horizontal direction. One-dimensional profile is obtained by controlling the movement of the stylus so that the displacement amount ε becomes the reference displacement amount ε o. In the profile control device, a storage means for storing the feed velocity characteristic of each axis with respect to the displacement amount ε of the stylus, and a deviation Δε (= ε-εo) between the displacement amount ε and the reference displacement amount εo are integrated and integrated. The output εi is generated, and the error Δεc (= ε
-.Epsilon.o-.epsilon.i) and a speed generation unit for generating the feed rate of each axis by using the error .DELTA..epsilon.c according to the feed rate characteristic.

[0005]

Among the above-mentioned conventional techniques, the former three-dimensional numerically controlled milling cutter has the following problems in cutting the shoe mold. (A) For cutting a shoe mold having a complicated three-dimensional continuous curved surface, it is necessary to reduce the diameter and the amount of movement of the blade, which makes it difficult to perform the cutting within a practical cutting time.

(B) The equipment including the computer is expensive, and it has been difficult to introduce it into the shoe and shoe mold industry, which is often used by small and medium-sized enterprises.

The latter one-dimensional tracing control device can perform highly accurate machining regardless of the shape of the model, but
Since it requires a model, it was difficult to cut the shoe mold from the work at low cost in a short time.

In order to solve these problems, the present invention is based on actual shoe shape data which is numerically three-dimensionally designed by a computer or three-dimensional shape measurement data of a model shoe shape made of a material which is easy to process. The purpose of the present invention is to cut out a three-dimensional shape such as a shoe tree in a short time at low cost by using a material that can withstand shoe manufacturing.

[0009]

SUMMARY OF THE INVENTION The above-mentioned object of the present invention is to model a workpiece by moving a cutting tool corresponding to model data.
To configure a machining control device that performs machining of the same shape as
In order to hold the shoe last, it is necessary to cut the shoe shape data, which is obtained by digitizing the shoe surface shape with a set of three-dimensional coordinate points of a number of cross-sectional contour lines orthogonal to the shoe axis, with a shoe-matching lathe. the part geometry in the shoe shape data and the same coordinate system of the shoe
Means for expressing the grip portion shape data as a set of three-dimensional coordinate points having appropriate positions and dimensions as a shoe shape, and converting into cutting shoe shape data obtained by subdividing by a predetermined number , and shoe surface
Means for calculating the swing angle of the arm copying by the Save have disc impinges obliquely approximating an arc in a section of the cutting shoe shape to calculate the contact touch point of the shoe contour point, the profiling arm the arm displacement increment so that the position error of the against the swinging angle to the rotation angle of the tracing arm drive motor corresponding to the rotation angle of the arm position and the base shoe attachment portion rotation shaft of the shoe-type copying lathe arm is minimized Means for calculating the rotation angle of the corresponding motor in advance, an arm drive mechanism section for converting the rotation angle of the drive motor into a linear motion via a feed screw mechanism, and driving the arm, and this arm drive mechanism.
This is achieved by including a shoe-shaped axial direction moving mechanism section that fits a part on a rail on the arm swinging mechanism section placed on the axial rail and passively moves the arm swinging mechanism section in the axial direction. It could be.

[0010]

The basic shoe-shaped alternative numerical control device for a shoe-type lathe according to the present invention digitizes the surface shape of the cutting shoe by a set of three-dimensional coordinate points of a large number of equally-spaced cross-sectional contour lines orthogonal to the shoe axis. The geometrical shape of the grip of the shoe shape required when cutting the shoe shape data with a shoe-type lathe is the same coordinate system as the shoe shape data, and each data has an appropriate position and size as a shoe shape. Change to cutting shoe shape data represented by a set of dimensional coordinate points.

Next, based on the cutting shoe shape data and the tracing disk data equal to the outer contour of the tool lathe lathe, the shoe surface and the tracing disk surface at the axial position of the tracing arm and the rotation angle around the axis are obtained. The contact position with is searched, and the horizontal movement amount of the tip of the following arm is obtained from this.

In addition, the profile arm swing control program interpolates the horizontal movement amount of the profile arm tip in order to correspond to the angle of the profile shoe rotation axis increasing at a constant rate and the position of the profile arm in the profile axis direction. Then, it is re-arranged in a spiral shape, and this is converted into the rotation angle of the drive motor of the basic shoe-shaped alternative moving mechanism section. Further, this value is instructed to the drive motor according to the measured actual rotation angle and arm position.

Further, the basic shoe-shaped substitute moving mechanism section converts the rotation angle of the drive motor into a linear movement by means of a feed screw,
Push the follower arm through the drive plate. Further, the movement of the arm swing transmission mechanism portion in the axial direction of the shoe form is performed by the power of the shoe form following lathe through the profile arm moving force transmission groove.

[0014]

EXAMPLES Examples will be described with reference to the drawings. First of all, the basic idea of the present invention is to use a tool corresponding to model data.
Follow machining control that moves and performs machining of the same shape as the model on the work
Per To configure the control device, when cutting the shoe shape data obtained by digitizing a set of 3-dimensional coordinate point of a number of cross-sectional contour orthogonal to shoe surface shape shoe axis shoe copying lathe The required shoe shape grip portion geometrical shape is represented by a set of three-dimensional coordinate points having the same coordinate system as the shoe shape shape data and the shoe shape grip portion shape data having an appropriate position and size as a shoe shape , and
A means for converting into cutting shoe shape data that has been subdivided by a predetermined number , and a contact disk that obliquely hits the shoe surface is approximated to an arc in the cross section of the cutting shoe shape and the contact point with the shoe shape contour point. Means for calculating the swing angle of the profile arm by calculating the touch points, and the swing angle of the profile arm corresponds to the arm position of the shoe model profile lathe and the rotation angle of the basic shoe model attachment part rotation axis. and means for positional error of the arm for the rotation angle of the tracing arm drive motor is calculated in advance the rotation angle of the motor corresponding to the arm displacement increments so as to minimize the, feed screw rotation angle of the drive motor A linear motion through a mechanism to drive the arm, and an arm drive mechanism part that fits the arm drive mechanism part on a rail on an arm swing mechanism part placed on the rail in the axial direction to move the arm swing mechanism. Receiving the dynamic mechanism It is obtained by and a shoe-axis direction moving mechanism portion for moving axially manner.

Next, the structure of the basic shoe-type alternative numerical control device for a shoe-type lathe according to the present invention will be described concretely and in detail with reference to the illustrated example. FIG. 1 is a basic shoe-shaped substitute mechanism M according to the present invention.
The overall principle structure related to EM is shown. An arm drive mechanism unit AD and a shoe-shaped axial direction moving mechanism unit MM are attached to an existing profile lathe CL to form a basic shoe-shaped substitute mechanism MEM.

In FIGS. 1, 2 and 3, the arm drive mechanism unit AD is composed of a pair of guide shaft mounts 2, 1 on the drive mechanism unit substrate 1.
2 and the guide shaft 4 with the slide bearing block 3 for the guide shaft inserted between the two mounting bases 2 and 2
Similarly, attach a pair of feed screw bearings 5 and 5 to the above, and with these bearings 5 and 5, the arm arm drive plate feed screw screw 7 which is screwed into the screw hole opened in the female screw block 6 for feed screw.
The screw screw 7 rotatably supports both ends of the screw.

Then, a follower arm drive plate 8 is attached between the blocks 3 and 6 to connect both blocks, and the guide shaft
4 and the screw screw 7, a pair of plates 10 and 10 for forming the moving force transmission groove 9 are mounted on the substrate 1 at a predetermined interval and in parallel with the guide shaft 4 and the screw screw 7, and further. The output shaft of a tracing arm drive motor 13 is attached to one end of the screw screw 7 via a shaft coupling 11 to the end face of the substrate 1 via a mounting plate 12.

The shoe-shaped axial movement mechanism MM comprises a pair of parallel rails 22 mounted on the movement mechanism installation board 21 and a slide guide seat with a dovetail groove for horizontal movement on the lower surface of the drive mechanism board 1 respectively. 14, 14 is fitted, and an encoder 24 for arm position detection is mounted between a pair of encoder mounting brackets 23, 23 mounted on the lower surface of the end of the one substrate 1, and the gear 25 mounted on the input shaft and the other side It engages with the rack 26 attached to the lower edge of the end of the substrate 21. On the other hand, the rotation angle θ of the arm 41 can be detected by the rotation angle detecting encoder 29 by the gear 28 that meshes with the gear 27 attached to the existing shoe-shaped rotating shaft 44.

Further, as shown in FIG. 4, the follower portion FM at the tip of the follower arm has a pair of moving force with the drive plate contact bearing 32 at the tip of the existing follower arm 41 via the L-shaped mounting fitting 31. A transmission groove contact bearing 33 and a block 34 to which the bearing 33 is attached.

In the present invention, the basic shoe type table replacement mechanism M described above is used.
The EM is installed on the existing profile lathe CL shown in FIG. 12, and the outline of each part in FIG. 12 will be described first.

In FIG. 12, reference numeral 41 indicates a tracing arm, 42 is a cutting arm, 43 is a tracing arm swing transmission lever, 44 is a shoe-shaped rotary shaft, 44a is a drive pulley, and 45 is a workpiece rotary shaft. 45a is a drive pulley, 46 is a rotation synchronizing belt hung between the above-mentioned pulleys, 47 is an arm mechanism feed screw screw that rotates on the pulley 47a, and this screw 47 is of a separate motor via the pulleys and belt 46. The rotating force causes the rotating shafts 44 and 45 to rotate synchronously.

Reference numeral 48 is a profiled disc, 49 is a shoe-shaped profile lathe blade, MSM is a basic shoe model, and CSM is a shoe model to be cut.

As shown in each of FIGS. 1 to 3, the basic shoe-shaped substitute mechanism MEM of the present invention is mounted on the existing profile lathe CL on the base a between the shoe-shaped rotating shafts 44, 44 of the opposed projections. The follower part FM as shown in FIG. 4 is attached to the end of the follower arm 41, and the follower arm drive plate 8 between the blocks 3 and 6 has a bearing for contacting the drive plate of the follower part FM.
The bearing 32 for contacting the moving force transmitting groove 9 is disposed in the moving force transmitting groove 9 between the plates 10 and 10.

As shown in FIGS. 1 and 2, the following arm 41 of the follower arm 41 is always in elastic contact with the drive plate 8 by the spring 50, and as the drive plate 8 reciprocates, the bearing 32 swings to the left and right, Plate 1 by forward / reverse rotation of arm mechanism feed screw 47
When the bearing 33 pushes 0, 10, the arm drive mechanism A
D moves back and forth along rails 22,22. This movement amount is detected by the encoder 24, and the swing (rotation) amount is detected by the other encoder 29.

FIG. 5 shows the above-described basic shoe-shaped substitute moving mechanism portion M.
In the system diagram of the control unit of the EM, the shoe shape data MD is stored in a data storage device of a personal computer via a magnetic recording medium, and cutting conditions are set from a keyboard according to instructions displayed on a monitor.

A control command based on the above data is sent to the arm drive motor via the drive motor control board and the control box.
Drive to be sent to 13.

Further, the rotation angle θ of the tracing arm 41 and the position of the arm are detected by a rotation angle detecting encoder 29 and an arm position detecting encoder 24, and are input to a personal computer via a counter board and calculated here. The control amount of the arm driving motor 13 is corrected.

1 and 12, reference numeral 47a
The member indicated by is a well-known arm pivoting lateral moving plate that is screwed into the screw screw 47 and moves in the axial direction of the screw 47, and its movement is strictly regulated by well-known guide means such as an additional guide member. I am trying not to move sloppyly.

Further, the shoe shape numerical data is displayed in the orthogonal coordinate system shown in FIG. 6, and the cross section position perpendicular to the shoe shape axis and the points on the contour line in the cross section are displayed in polar coordinates (cylindrical coordinate system). However, since both can be converted to each other, an embodiment of the present invention will be described below in the case of the cylindrical coordinate system display.

(B) The cutting shoe shape data generation program converts the shoe shape data MD into the contour lathe coordinate system, adds the attachment portion necessary for gripping the work material to the shoe shape data, and the surface of the shoe shape. The cross-sectional pitch is subdivided in order to calculate the contact position with the flat disc with high accuracy.

As shown in FIG. 7, the coordinate system of the cutting shoe shape traces a line passing through the center 51 of the outer contour line of the heel part and the point 52 below 1/25 of the foot length from the toe point in the vertical plane including the shoe shape axis. Lathe rotary shaft 53
The origin of the axis of rotation is set at a point 54 15mm behind the midpoint of the heel contour line, and the rotation angle is 55 when the shoe last is placed on a horizontal plane.
To 0 °.

As for the mounting part, the heel part height is 56 in front of the toe point.
A cylinder 57 having a diameter of 1/4 and a length of 50 mm is formed, and a cone 58 having a height of 30 mm is formed behind the cylinder 57. The rear part of the heel is an elliptic cylinder 59 having a minor diameter of 1/4 of the heel height 56 and a major diameter of 3/4.

For the overlapping portion of the attachment portion shape data and the shoe shape data, the shoe shape data is used with priority.

The sectional pitch is subdivided by interpolating the front and rear cross sections of the shoe shape data so as to obtain a cross section every 1.75 mm orthogonal to the rotation axis for the entire length including the front and rear mounting portions. Each cross-sectional contour shape A is stored as radius data 60 at every 1 ° at an angle 55 around the rotation axis.

It should be noted that the size of the mounting portion and the degree of subdivision can be set arbitrarily, but here, it was determined with reference to the current cutting conditions.

(B) As shown in FIG. 8, the profile disk contact point search program searches for contact points between the cutting shoe shape data 61 at a certain rotation angle and the profile disk shape data 63 at the profile arm position 62. .

The difficulty in this calculation is that the blade is mounted so as to be inclined with respect to the rotary shaft of the work material in order to improve the cutting efficiency. Therefore, the profile disc is also attached to the shoe mold as shown in FIG. This is because the contact point between the shoe-shaped surface having a complicated three-dimensional curved surface and the ring-shaped blade tip rotation surface may move discontinuously.

[0038] Here, in order to satisfy both of shortening of preventing deterioration and computation time of the computation accuracy, conventional sufficient approximation accuracy in the cutting area 63 shown in FIG. 9 for the copying disk strikes the obliquely assuming an axis orthogonal arc 65 with, for contact point lines Tsu name in two stages correction calculation and its search by calculation procedure shown in FIG. 10.

That is, the cross section from the -5 cross section position to the +16 cross section position where the profile disc may come into contact with the surface of the shoe pattern around the pattern cross section 66 at the profile arm position 62 in the rotation axis direction shown in FIG. Take out the contact point of each cross section with the approximate disk approximate circle corresponding to this cross sectional position, and find the contact point of the cross section where the center of the following circular disk is the farthest from the shoe-shaped axis of rotation and the contact point candidate at that rotation angle and arm position. Choose to.

Further, an arc passing through three points in the front and rear direction of the cross section centering on this point is calculated, and the contact position between this arc and the disk approximate circle is recalculated to correct the shape approximation error.

In order to further speed up the search, it is assumed that the contact point at the next time is next to the searched contact point, and the distance between the tracing disc surface and the shoe surface is non-negative minimum at this arm position. If so, the contact point search is omitted. If this search is performed both in the rotation direction and the rotation axis direction, it is possible to obtain a tracing disk contact point for the entire surface of the shoe shape, and to know the horizontal movement amount of the tracing arm tip by simple geometrical calculation. it can.

(C) The profile arm swing control program matches the actual cutting situation in which the shoe mold is rotated and the blade is moved in the axial direction at the same time, and the profile arm tip for each cross-sectional position is adjusted according to the procedure shown in FIG. The horizontal movement amount is interpolated and rearranged in a spiral shape.

Next, in consideration of the minimum resolution and the dynamic characteristics of the drive motor 13, the arm displacement increment control amount is corrected so that the accumulated error with respect to the arm displacement increment at each control time point is minimized.

By carrying out these calculations in advance and having a controlled variable in the form of a table in which the rotation angle and arm position are used as parameters, high-speed processing is not required, and the basic shoe-type mounting of the profile lathe shown in FIG. 13 can be performed. According to the signals from the rotation axis angle detector 29 and the axial arm position detector 24, it is possible to output the control amount of the drive motor 13 for moving the arm tip, that is, the blade position to the same position as when the actual shoe last is actually present. it can.

In the usual shoe mold production, in order to improve the smoothness of the cut surface and the dimensional accuracy, the cutting is performed in two stages of rough cutting and finish cutting.

Although FIG. 11 described above is basically a control amount generation procedure for finishing, the same control output is used for roughing as well, only by increasing the initial value of the arm displacement increment by an appropriate amount. You can

(D) Based on the above-mentioned control output signal, the basic shoe-shaped substitute moving mechanism section swings the following arm by the following mechanism. In FIG. 1, an arm driving servo motor or stepping motor 13 is a bearing via a shaft coupling 11.
It is connected to a lead screw 7 supported by 5,5. Also,
Guide shaft 4 supported by mounting bases 2 and 2 parallel to this feed screw
Is installed and a follower arm drive plate 8 is mounted between the female screw block 6 and the plain bearing block 3.

Further, in the center of both shafts, there is a groove 9 for transmitting the moving force of the arm in the direction of the shoe-shaped rotating shaft.
It is possible to move on rails 22 and 22 parallel to the shoe-shaped rotating shaft attached to the main body of the lathe by the slide bearings 14 and 14 installed on 1. This amount of movement can be detected by the encoder 24 attached to the substrate 1 by engaging the gear 25 attached to the encoder shaft with the rack 26 (FIG. 2) attached to the lower surface of the substrate 21 on which the moving mechanism portion is installed.

The rotation angle of the basic shoe-type mounting shaft of the profile lathe is detected by the encoder 29 via the rotation shaft gear 27 and the rotation angle detection gear 28.

The encoder 29 is attached to the main body of a lathe having an encoder mounting base by a mounting block, and the width between the blocks can be adjusted by an adjusting bar. Remove the follower disc from the follower arm 41, and use the L-shaped mounting bracket 31 to mount the block 34 having a bearing 32 in contact with the follower arm drive plate 8 and two bearings 33 in contact with both sides of the moving force transmission groove 9 as shown in FIG. Install.

FIG. 4 shows a situation in which the basic shoe-shaped substitute moving mechanism portion is installed in the basic shoe-shaped attachment portion at the rear of the tracing lathe. This device can be installed in the basic shoe-shaped installation space without modifying the profile lathe.

(E) FIG. 5 shows an example of the overall configuration of a device including a computer. Numerical data on the shoe shape by computer-aided design or the like is taken into the computer via a magnetic storage medium or a direct signal line. In the computer, (a) and (b)
Prepare the numerical control by the program described in
Perform actual control with the program described in (c).

Commercially available personal computer (CPU 8
0387, 25 MHz), it takes about 30 minutes to convert the shoe shape data into numerical control data, and the shoe cutting using this data can be performed in about 30 minutes for both rough cutting and finish cutting. .

[0054]

Since the present invention is constructed as described above, it has the following effects. The basic type alternative numerical control device for a shoe-type lathe according to claim 1 uses an existing shoe-lathe-type lathe and a commercially available general-purpose personal computer, so that the initial investment of the equipment is small and the shoe is highly suitable for small and medium enterprises. And, it has the first effect that it is suitable for the shoe last industry.

Further, since a dedicated cutting tool is used, short-time cutting of 1/10 or less is possible as compared with the conventional general-purpose three-dimensional NC milling method, and there is a second effect that it is highly practical.

Furthermore, by improving the efficiency and numerical control of the shoe mold production, it is possible to quickly and inexpensively perform custom shoe mold manufacturing, which is said to be the final measure for improving the suitability of shoes, and by these functions, It also has the third and fourth effects that it can be easily applied to the forming and processing in the medical and welfare aspects in which individual manufacturing is indispensable like a prosthetic foot stump socket.

In the basic shoe-shaped alternative numerical control device for a shoe-type lathe according to claim 2, since the conversion to the cutting shoe shape and the subdivision of the numerical data are carried out at the final stage, a small numerical value is obtained at the shoe-shaped design stage. It is possible to add an effect that the processing speed can be increased by handling the data.

The basic shoe-shaped alternative numerical controller for a shoe-type lathe according to claim 3 shortens the calculation time of the blade position and can improve the accuracy without narrowing the step size of the control. As a result, the use of inexpensive computer could added such an effect is possible.

[Brief description of drawings]

FIG. 1 is a perspective view of the principle of a basic shoe-shaped substitute moving mechanism according to the present invention.

FIG. 2 is a perspective view showing an installation example of a basic shoe-shaped alternative moving mechanism on a shoe-shaped lathe.

FIG. 3 is a perspective view showing a main part of a basic shoe type alternative moving mechanism.

FIG. 4 is a perspective view of a follower arm tip follower portion.

[Fig. 5] System diagram of control unit

6 is a schematic diagram showing an example of Cartesian coordinate representation and polar coordinate representation of shoe shape data. FIG.

FIG. 7 is a detailed explanatory view showing an example of a cutting shoe shape.

FIG. 8 is a schematic top view showing how the conforming disc contacts the cutting shoe mold.

FIG. 9 is a schematic diagram showing the relationship between the oblique cross-sectional shape of the conforming disc and the shoe shape.

FIG. 10 is an explanatory diagram of a procedure for searching for a contact point on a disc that follows the shape of a shoe and correcting it.

FIG. 11 is an explanatory diagram of a control amount calculation procedure of a drive motor.

[Figure 12] Principle diagram of a general shoe-type lathe

[Explanation of symbols]

 1 Drive mechanism substrate 2 Mounting base 3 Slide bearing block for guide shaft 4 Guide shaft 5 Bearing for feed screw 6 Female screw block for feed screw 7 Profile arm drive plate Feed screw screw 8 Profile arm drive plate 9 Profile arm movement force transmission groove 10 Pair of plates 11 Shaft joint 13 Trapping arm drive motor 14 Dovetail slide guide seat 21 Moving mechanism installation board 22 Guide rails 25, 27, 28 Gear 26 Rack 29 Rotation angle detection encoder 41 Trapping arm 42 Cutting arm 43 Trapping Arm swing transmission lever 44,45 Rotation shaft 44a, 45a, 47a Pulley 46 Belt 47 Arm mechanism Feed screw Screw 49 Shoe-shaped lathe blade 50 Spring AD Arm drive mechanism MEM Basic shoe-shaped alternative moving mechanism CSM Work shoe Type FM Follower section MM Shoe type axial movement mechanism section

Claims (3)

[Claims] 1. A contour machining control device for moving a blade in accordance with model data to machine a workpiece into the same shape as a model, wherein a shoe mold surface shape is three-dimensional with a large number of cross-sectional contour lines orthogonal to the shoe mold axis. the shoe in the shoe shape data and the same coordinate system the shoe grips geometry necessary for cutting the shoe shape data obtained by digitizing a set of coordinate points in the shoe copying lathe
Means for expressing the grip portion shape data of 3) by a set of three-dimensional coordinate points having appropriate positions and dimensions as a shoe shape, and converting into cutting shoe shape data obtained by subdividing by a predetermined number , and a shoe shape table.
Means for calculating the swing angle of the calculations to the copying arm contact touch point of the shoe contour points approximates an arc of if have disc hits obliquely in a section of the cutting shoe shape in the plane, the copying arm arm displacement increment so that the position error of the arm against the pivot angle to the rotation angle of the tracing arm drive motor corresponding to the rotation angle of the arm position and the base shoe attachment portion rotation shaft of the shoe-type copying lathe becomes minimum Means for calculating the rotation angle of the motor in advance, an arm drive mechanism section for converting the rotation angle of the drive motor into a linear motion via a feed screw mechanism, and driving the arm, and the arm drive machine.
Fit the構部 in the axial direction of the rail on the arm swinging mechanism section placed on the rails, the shoe type in which and a shoe-axis direction actuator for moving the passive axial said arm swinging mechanism Numerical control device for basic shoe type for model lathe. 2. A means for converting into cutting shoe shape data,
From the shoe shape data, which represents the surface shape of the shoe shape as a set of three-dimensional coordinate points of a number of contour lines in the cross section orthogonal to the shoe axis, the geometric shape of the grip of the shoe shape required when cutting with the shoe lathe Is represented by a set of three-dimensional coordinate points having appropriate positions and dimensions in the same coordinate system as the shoe shape data, the three-dimensional coordinate point data of the contour line in the cross section is interpolated, and the contour point data is obtained at constant angles around the axis 2. A means for obtaining, determining again, using the same angle points in adjacent cross sections, generating contour point data between the cross sections, and converting it to cutting shoe shape data in which the number of cross sections is subdivided. Numerical control device for the basic shoe mold for lathes following the described shoe model. 3. A means for calculating a rotation angle of a motor in advance.
However, the rotation of the shoe mold and the axial movement of the disc must be performed at the same time.
Depending on the actual cutting situation, the calculated axial position
The arm swing angle for each fixed rotation angle in increments of fixed time
Each arm swing angle is converted to the arm drive mechanism motor
Minimum resolution and dynamic characteristics in view of the arm position for each time point
In order to minimize the positioning error, the model corresponding to the arm position increment is
A means for calculating the rotation angle of the data in advance,
Or basic shoe mold alternative numerical control for lathes following the shoe mold described in 2.
apparatus.