JPH05137859A - Stitch data preparing device for sewing machine - Google Patents

Abstract

PURPOSE:To provide a data preparing device which automatically prepares the embroidery stitch data for a desired shape by taking account of the error in the longitudinal feed direction for a worked cloth through the arcuate sewing of the needle of a zigzag sewing machine. CONSTITUTION:The XY position data of the needle set point in an embroidery pattern is memorized in a needle set point memory. The lateral width H of the embroidery pattern, needle swing position reduction calculation coefficient (k) and the X coordinate Zp of the center of the lateral width are calculated (S3-S5 on the basis of the X-position data, and the needle swing data Nn is calculated (S7) on the basis of these data and the X coordinate data of each needle set position. The longitudinal feed data is calculated (S11) on the basis of the Y-position data of the needle set point, and the lateral feed data is calculated (S12) on the basis of the X coordinate data and the needle swing data Nn. When the error in the longitudinal feed direction due to the needle swing becomes one feed step, the longitudinal feed data is rewritten (S13-S15).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vertical feed data for defining a vertical feed amount of a feed dog, horizontal feed data for defining a horizontal feed amount of the feed tooth, and a needle swing position for defining a swing position of a needle. The needle drop point for the work cloth by moving the feed dog in the longitudinal and lateral directions and swinging the needle on an arc locus along the outer circumference of the horizontal hook based on the stitch data that represents one set of data and The present invention relates to a stitch data creating device for a sewing machine in which is moved to form a stitch pattern.

[0002]

2. Description of the Related Art (a) A bed supporting a cloth, (b) a feed dog for moving a work cloth supported by the bed in a vertical direction and a horizontal direction in a plane parallel to the bed, and (c) A needle that reciprocates vertically with respect to the bed and that can take multiple swinging positions on an arc trajectory along the outer periphery of the horizontal hook in the lateral direction with respect to the bed, and (d) a pattern on the work cloth. Vertical feed data that defines the vertical feed amount of the feed dog and horizontal feed data that defines the horizontal feed amount, and needle swing that defines the swing position of the needle at each of the plurality of needle drop points required to embroider A sewing machine including a controller that embroiders a pattern on a work cloth by controlling a feed dog and a needle based on stitch data that represents position data as a set is already known.

When performing embroidery with this type of sewing machine, when the maximum size of the pattern in the lateral direction (hereinafter, simply referred to as the lateral width) exceeds the swing range that the needle can take, the work cloth is laterally moved by the feed dog. In this way, the shortage of the amount of rocking of the needle is compensated for.

In such a sewing machine, in order to sew an embroidery pattern, it is necessary to create stitch data in advance. If the stitch data created in advance is stored in a storage medium such as a ROM and the stitch data of a desired embroidery pattern is read out as necessary, the controller can feed the stitch length data, the horizontal feed data, The needle swing position data is read, the feed dog is moved in the vertical and horizontal directions, and the needle is swung to form an embroidery pattern.

In order to store the stitch data in a storage medium such as a ROM, an operator conventionally determines and inputs longitudinal feed data, lateral feed data, and needle swing position data for each needle drop point. .. Then, since the needle swings on an arc locus along the outer circumference of the horizontal shuttle, the swinging position of the needle changes in the vertical feed direction by the feed dog, and as a result, the vertical movement amount of the needle drop point is changed to the vertical direction. The shape does not match the amount indicated by the feed data, and the shape of the embroidery stitch changes. Therefore, in order to obtain the desired shape of the embroidery stitch, it is necessary to determine the vertical feed data, the horizontal feed data, and the needle swing position data in consideration of the error amount.

[0006]

However, since the number of needle drop points in one embroidery pattern has increased with the recent increase in size and complexity of the embroidery pattern, the pattern data creator has to increase the number of needle drop points vertically. It is a very time-consuming and error-prone task to calculate the feed data, the lateral feed data, and the needle swing data by taking into account the error in the vertical feed direction associated with the needle swing and input them manually. It was.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is vertical feed data and horizontal feed of a feed dog in a state where an error in a vertical feed direction due to needle swing is eliminated. A stitch data creation device for a sewing machine that can automatically create data and needle swing position data.

[0008]

In order to achieve this object, a stitch data creating device for a sewing machine of the present invention provides vertical feed data defining a vertical feed amount of a feed dog and a horizontal feed amount of the feed dog. The feed dog is moved in the vertical and horizontal directions based on the stitch data that represents the set lateral feed data and the needle swing position data that defines the needle swing position, and the needle is moved around the outer circumference of the horizontal hook. A stitch data creating device for a sewing machine, wherein a needle drop point for a work cloth is moved by swinging on an arc locus along a line to form a stitch pattern. Needle position data storing means for storing vertical position data defining the position in the vertical direction and horizontal position data defining the position in the horizontal direction, and vertical position data of the needle drop point. From the above Stitch data calculating means for calculating the vertical feed data of the tooth for each needle drop point, and for calculating the lateral feed data and the needle swing position data from the lateral position data of the needle drop point for each needle drop point. And the stitches created by the stitch data computing means in order to eliminate the variation error amount by calculating the variation error amount from the chord of the arc locus of each of the calculated needle swing positions. And stitch data correction means for correcting and calculating data.

[0009]

According to the present invention having the above-mentioned structure, the vertical position data for defining the position of each of the plurality of needle drop points in the needle drop point data storage means and the horizontal direction for defining the position in the horizontal direction. Position data and are stored. The stitch data calculation means calculates the vertical feed data of the feed dog for each needle drop point from the vertical position data of the needle drop point, and the lateral feed data and the needle swing from the horizontal position data of the needle drop point. The position data is calculated for each needle drop point. The stitch data correction means calculates the variation error amount from the chord of the arc locus of each of the plurality of needle swing positions calculated by the stitch data calculation means, and stitches are corrected to eliminate the variation error amount. Compensate the data.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 3, the sewing machine according to the present embodiment has a needle which is vertically moved across a needle hole 10 formed through a needle plate T which constitutes a sewing machine bed on which a work cloth is placed. 11 and a horizontal full rotary hook 13 which is arranged below the needle plate T and cooperates with the needle 11 to form a stitch on the work cloth,
It is arranged in the opening of the needle plate T and appears on the upper surface of the needle plate to sandwich the work cloth with a presser foot (not shown) and feed it vertically (Y in the figure).
Direction) and a lateral feed direction (X direction in the drawing) at a predetermined feed pitch. The needle hole 10 is formed in an arc shape along the outer periphery of the horizontal shuttle 13, and the needle 11 is swung along the arc hole around the rotation axis of the horizontal shuttle along the needle hole 10. It
This is because the 13 blade points 131 of the horizontal hook are rotating, so that the contact between the needle and the blade points is always kept constant.

As shown in FIG. 2, the control device of the sewing machine is as follows.
CPU30, ROM31 and R, which are the core of the logical operation circuit
AM 32 and stitch data memory 33 as EEPROM
And an input / output circuit 35 are connected to each other via a common bus 34. A sewing machine motor 41, a needle swing step motor 42, a vertical feed step motor 43, a horizontal feed step motor 44, and a needle bar release solenoid 45 are connected to the input / output circuit 35 via drivers 36 to 40, respectively.

The needle bar releasing solenoid 45 controls a known needle bar releasing device, and the needle bar releasing device releases the drive connection between the needle bar crank mechanism and the needle bar by exciting the solenoid 45. Stopping the rod (needle 11) above the work cloth to perform only relative feeding between the needle and the work cloth, and connecting the needle bar crank mechanism and the needle bar by demagnetization to reciprocate the needle bar up and down. Is.

The ROM 31 has a stitch data memory 3
The stitch data stored in No. 3 is read out for one stitch in response to the detection of a specific rotation phase of the spindle rotated by the sewing machine motor 41, and the needle swing step motor 42, the vertical feed step motor 43, and the horizontal feed. A program for driving and controlling the step motor 44 and the needle bar release solenoid 45 is stored. As will be described later, this stitch data is created for each feed control unit of one set of needle swing position data, vertical feed data, horizontal feed data, and needle bar release data, and is stored in the stitch data memory 33. It is stored. The feed control unit indicates the drive amount of the needle swing and the vertical and horizontal feed of the feed dog performed during one rotation of the main shaft of the sewing machine regardless of whether the needle is vertically moved. The creation of this stitch data will be described later.

As the mechanical characteristics of this sewing machine, as shown in FIG. 4, the number of steps of the needle swinging step motor 42 is set to 14, and the needle swinging position data is from -7 to 7. Is given as an integer value up to (a value indicating the needle swing position). That is, when the value of the needle swing position data is -7, the needle 11 is swung to the leftmost position in FIG. 3, and when the value of the needle swing position data is 7, the needle 11 is the rightmost position. Is swung to the position. Further, when the value of the needle swing position data is 0, the needle swing position is swung to the center position of the horizontal swing with the maximum amplitude Wm. The magnitude of one step of this swing is set to 0.5 mm. The radius of the needle swing trajectory is set to 18 mm.

On the other hand, the feed amount of one step of the vertical feed step motor 43 for moving the feed dog 20 in the Y direction in FIG. 3 is set to 0.34 mm, and the feed dog 20 is moved in the X direction in FIG. The feed amount of one step of the lateral feed step motor 44 to be moved is set to 0.7 mm. The vertical feed data of the vertical feed step motor 43 is given in a format in which plus and minus signs are added to the number of steps. A positive value indicates forward feed, and a negative value indicates reverse feed. .. Similarly to the vertical feed data, the horizontal feed data of the horizontal feed step motor 44 is given in a format in which the number of steps is added with a plus or minus sign. In the case of a plus value, the work cloth is viewed from the work feed side. Is sent to the left, and a negative value indicates that the work cloth is sent to the right when viewed from the work cloth feeding side.

Prior to forming embroidery stitches using the sewing machine constructed as described above, the stitch data memory 3 is formed.
It is necessary to store the stitch data in 3. The configuration of the data creation device 50 for creating this stitch data will be described.

As shown in FIG. 1, the data creating apparatus 50 includes a CPU 51 which is the center of a logical operation circuit, a ROM 52 which stores the programs shown in FIG. 9, and an RA.
The M53 and the M53 are connected to each other via a common bus 54. Further, a digitizer (not shown) for inputting the needle entry point as position data in the XY directions is connected to the common bus 54, and a needle entry point memory for storing the needle entry point data input by the digitizer. (Needle drop point data storage means) 60 is connected, and a PROM writer 61 for writing stitch data in the stitch data memory 33 is connected via an output port.

In the sewing machine, the needle has a radius of 18
The rocking motion is 14 steps along an arc locus of mm, and not only the position in the horizontal direction changes but also the position in the vertical direction also changes with each step. That is, the swinging position of the needle changes from the chord of the arc locus at each step, and when the both ends of the arc locus are used as a reference, the amount of change at each step becomes a value as shown in FIG. In the present embodiment, it is stored in advance in the ROM 52 in the form of a table of error amounts with respect to the needle swing position (referred to as a needle position error table).

A stitch data area is set in the RAM 53, and the stitch data area is set in FIG.
As shown in FIG. 12, needle swing data, needle bar release data, and feed dog 20 are provided corresponding to each of the needle drop points P1 to P37.
Vertical feed data (described later), horizontal feed data of the feed dog 20 (described later), and error data (described later) are stored. The needle bar release data is set to 0 in advance for each of the needle drop points P1 to P37. When the needle bar release data is 0, the needle bar release solenoid of the sewing machine needle bar release device is set. When 45 is de-energized, the needle bar crank mechanism and the needle bar are connected to drive the needle bar up and down, and when the needle bar release data is 1, the needle bar release solenoid 45 is excited to form the needle bar crank mechanism. This means that the connection with the needle bar is released and the needle bar stops.

Next, the creation of stitch data using this data creation device 50 will be described.

First, the longitudinal feed direction is set to the Y-axis (1 scale 0.3
4 mm), and the coordinate system shown in FIG. 6 in which the lateral feed direction is the X axis (1 scale 0.5 mm) is set, and the desired needle drop point of the pattern “A” is determined in the coordinate system. That is, points P1 to P37 in FIG. 7 are designated by the digitizer, and the position data of each point in the XY directions is stored in the needle drop point memory 60 as needle drop position data. The position data in the XY directions of these points P1 to P37 are as shown in the table of FIG.

Thereafter, when a data processing start switch (not shown) is turned on, the CPU 51 starts the data creation program shown in the flowchart of FIG.

First, the CPU 51 uses the needle drop point memory 6
The position data of the needle drop point is read from 0 and stored in a predetermined area of the RAM 53 (step S1; the following step is abbreviated as S). Then, the maximum value Xmax of the X coordinate and the minimum value Xmin of the X coordinate are detected from the read position data of the needle drop point (S2). Here, the value of point P14 (= 38) is detected as the maximum value Xmax of the X coordinate, and the values (= 0) of points P3 and P22 are detected as the minimum value Xmin of the X coordinate. Then, in S3, the horizontal width H of the embroidery pattern is calculated by subtracting the minimum value Xmin from the maximum value Xmax. In the case of the pattern “A” in FIG. 7, the width H is calculated as 38.

Thereafter, in S4, between each of the plurality of X coordinate points assumed on the X axis within the width H of the embroidery pattern of this time and each of the plurality of swing positions of the needle 11. Correspondence is determined. The correspondence between each X coordinate point and each needle swing position is such that when the needle 11 penetrates the central X coordinate point between the maximum X coordinate point and the minimum X coordinate point of the cloth, the needle swing position is the neutral position. And when the needle 11 penetrates the maximum X coordinate point of the cloth, the needle swing position is at the right end position, and when the needle 11 penetrates the minimum X coordinate point of the cloth, the needle swing position is As the X coordinate point is located at the left end position and the X coordinate points are farther from the central X coordinate point, the needle 1
It is determined so that the swing amount from the neutral position of 1 increases. Specifically, the lateral width H of the embroidery pattern is divided by the needle swing range Wm (= 14) (the remainder is not rounded off) to convert the X coordinate value Xn of the X coordinate point into the needle swing position Nn. k is calculated.

Next, in S5, the X coordinate value Z of the center coordinate of the lateral width of the embroidery pattern (the point where the needle swing position data becomes 0).
p is obtained by dividing the sum of the maximum value Xmax and the minimum value Xmin by 2 (the remainder is not rounded).

Next, the counter n is initialized to 1 (S
6) Calculate the needle swing position Nn with respect to the needle drop point Pn. That is, the X coordinate value Zp of the center coordinate is subtracted from the X coordinate value Xn of the needle drop point Pn, the value is divided by the coefficient k obtained in step S4, and the fractions below the decimal point are rounded off to obtain the needle of the point Pn. The swing position data Nn is calculated and R
The data is stored in the stitch data area of AM53 (S7). It is determined whether or not this calculation has been performed for all needle drop points Pn (S8), and if NO, the counter n is incremented (S9) and the process returns to step S7. If the determination in S8 is YES, the CPU 51 proceeds to step S10. Here, the needle swing position Nn when the value of the X coordinate is from 0 to 38 in the process of step S7 is shown in the table of FIG.

Thereafter, the counter j is initialized (S1
0), longitudinal feed data by the feed dog 20 at the needle drop point Pj is calculated. Here, when the needle drop point is the point P1, the vertical feed data is set to 0, and in other cases, the needle drop point P is set.
The Y-coordinate data of j is read, and the feed amount F that must be moved by vertical feed for each stitch is set to the current needle drop point P.
It is obtained by subtracting the Y coordinate value of the preceding needle drop point Pj−1 from the Y coordinate value of j, and the number of steps of the vertical feed step motor 43 corresponding to the feed amount F is converted. It is stored in the stitch data area of the RAM 53 as vertical feed data for the needle drop point Pj (S11).

Next, the CPU 51 calculates the lateral feed data of the feed dog 20 at the needle drop point Pj. Here, when the needle drop point is the point P1, the lateral feed data is set to 0. In other cases, the X coordinate data of the needle drop point Pj is read and the needle feed point is moved by the lateral feed. The required feed amount S is subtracted from the X coordinate value of the current needle drop point Pj by the X coordinate value of the immediately preceding needle drop point Pj−1, and further the needle drop point Pj.
Obtained by subtracting the needle swing amount from -1 to the needle drop point Pj,
The number of steps of the lateral feed step motor 44 corresponding to the feed amount S is converted and stored in the stitch data area of the RAM 53 as lateral feed data of the needle drop point Pj (S12).

Next, in step S13, the CPU 51 reads out the needle swing position data Nj at the needle drop point Pj obtained in step S7, and stores the error amount in the vertical feed direction corresponding to the needle swing data Nj in the ROM 51. The needle is swung based on the needle swing position data, the vertical feed data, and the horizontal feed data, which are read out with reference to the needle position error table, and calculated with respect to the needle drop point Pj in steps S7, S11, and S12, and The actual needle drop point and the needle drop point memory 60 for the work cloth when the feed dog 20 is operated.
The error with respect to the target needle drop point Pj stored in is calculated and stored in the error area of the stitch data storage memory (FIG. 11) of the RAM 53.

As for the error with respect to the needle drop point P1, since both the vertical feed data and the horizontal feed data are 0, and only the error in the vertical feed direction due to the needle swing occurs, the needle swing position data is obtained. The value of the error (vertical feed direction) corresponding to (-6) is -0.0919 from the needle position error table. The sign of the error value is negative in FIG.
It means that an error due to the needle swing occurs in the negative direction in the coordinate system of. Here, as will be described later, if the vertical feed data is corrected by ± 1, a plus or minus error correction amount associated with the vertical feed of the feed dog is also generated, so an error (0 or a negative value) associated with needle swinging is generated. The error at the needle drop point is obtained by adding the error correction amount to.

Then, in step S14, the CPU 51 sends the amount of error corresponding to one step of the vertical feed step motor 43 of the feed dog 20 (0.3 in the case of this embodiment).
4 mm) or more (one longitudinal feed step, that is, whether +0.34 mm or more or −0.34 mm or less) is determined. And step S14
If the result of the determination is YES, the CPU 51 rewrites the vertical feed data for the needle drop point Pj of the stitch data storage memory (FIG. 11) and also the error data (S15; details will be described later), and NO. In this case, step S15 is skipped and the process proceeds to step S16.

In step S15, the CPU 51
Indicates that the needle drop point indicated by the stitch data has changed by one step or more in the vertical feed direction from the target needle drop point, so if the error amount becomes -0.34 mm or less, the vertical feed data 1 is added, and when the error amount becomes +0.34 mm or more, 1 is subtracted from the vertical feed data, and the error data is also corrected by adding or subtracting 0.34 mm depending on both cases.

Thereafter, the CPU 51 causes all needle drop points Pj
It is determined whether or not the processes of steps S11 to S15 are completed (S16), and if NO, the counter j
Is incremented (S17), and the process returns to step S11. If YES, the data creation process ends.

Now, the needle drop points P1 to P37 of the stitch pattern "A" shown in FIG. 7 will be described. The stitch data creation and error correction are as follows.

That is, in the case of the needle drop point P1, the values of the vertical feed data and the horizontal feed data are set to 0, respectively, and since the needle swing position data is -6, the actual needle drop point and the target needle drop point are set. The error between and is calculated to be −0.0919. This value is because the work cloth is at the position indicated by the vertical and horizontal feed data, and therefore only the error due to the needle swing is present.
Then, since the error data is smaller than one step of vertical feeding, no correction is performed (S14; NO).

In the case of the needle drop point P2, as is apparent from the data table of FIG. 8, the amount of movement of the needle drop point in the Y direction is 4 (that is, 1.36 mm), so the vertical feed data is calculated as 4. , The amount of movement of the needle drop point in the X direction is -3 (that is, -1.5 m
m), and the needle swing position moves by -1 step (-0.
5 mm), the lateral feed data is calculated as -2 to move the remaining -1 mm. At this time, the error data becomes 0.

In the same manner, the stitch data at the needle drop point is calculated until it is determined in S14 that the error data is larger than one vertical feed step. That is, the needle drop point P3
The stitch data up to P17 is created as shown in FIG.

At the next needle drop point P18, the vertical feed data is calculated as -1 and the horizontal feed data is -as in the same manner as described above.
3 and the error data is calculated as -0.3436 (see FIG. 11). Here, the error data is -0.34m
Since it becomes m or less, the determination in step S14 is YES, and the stitch data is corrected (corrected) in step S15. That is, the vertical feed data is incremented by 1 to become 0, and correspondingly, the error data is also incremented by the feed amount (0.34 mm) for one step of the vertical feed, and is -0.00.
36.

For the next needle drop point P19, the vertical feed data is calculated as -1, the horizontal feed data is calculated as -3, and the error data is transferred from the needle position error table to the needle swing position (-2). The value 0.0242 is calculated by adding the corresponding value −0.3158 to the added value 0.34 at the needle drop point P18. Since this error data is smaller than one vertical feed step, the determination in S14 is NO and the next needle drop point P
The stitch data of 20 and P21 are calculated as shown in FIG.

For the next needle drop point P22, the vertical feed data is calculated as -1 and the horizontal feed data is calculated as -3, and the error data is transferred from the needle position error table to the needle swing position (-7). A value of 0.34 is calculated by adding the added value of 0.34 at the needle drop point P18 to the corresponding value of 0. Since this error data corresponds to one step of vertical feeding, S14
Is YES, and the stitch data is corrected (corrected) in step S15. That is, the vertical feed data is subtracted by 1 to become -2, and correspondingly, the error data is also subtracted by the feed amount for one step of vertical feed (0.34 mm) to become 0 (FIG. 11).

In the same manner, the stitch data of the needle drop points P23 to P37 are created as shown in FIG.

When the creation of the stitch data is completed in this way, the worker mounts the stitch data memory 33 mounted on the sewing machine on the PROM writer 61 and causes the stitch data memory 33 to store the stitches in the RAM 53. The stitch data in the data area is stored. In this way, if the stitch data memory 33 storing the stitch data is attached to the sewing machine, the stitch pattern (the pattern "A" in this embodiment) can be formed without losing its shape.

Here, in step S7 of the CPU 51,
The processing of S11 and S12 corresponds to the stitch data calculating means of the present invention, and the processing of steps S13 to S15 corresponds to the stitch data correcting means of the present invention.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in this embodiment, as a condition for rewriting the vertical feed data of the feed dog,
When the error is one step of the vertical feed step motor 43, the condition is, for example, when the vertical feed is one half of the step, and if the vertical feed data is rewritten, the point is closer to the target needle drop point. Obviously, it is possible to create data such as a needle drop.

[0046]

As is clear from the above description,
According to the present invention, if the needle drop point data storage means stores the vertical position data that defines the vertical position and the horizontal position data that defines the horizontal position of each of the plurality of needle drop points, The stitch data calculating means calculates the vertical feed data of the feed dog for each needle drop point from the vertical position data of the needle drop point, and the lateral feed data and the needle swing position from the horizontal position data of the needle drop point. The data is calculated for each needle drop point, and the stitch data correction means calculates the deviation error amount from the chord of each arc locus of the plurality of needle swing positions calculated by the stitch data calculation means. Since it is configured to correct and calculate the stitch data in order to eliminate the variation error amount, the vertical feed data, lateral feed data and needle of the feed dog in the state where the error in the vertical feed direction due to needle swing is eliminated. The swing position data and Has the effect that it is possible to create in a short time a stitch pattern data of stitch patterns forming the desired shape.

[Brief description of drawings]

FIG. 1 is a block diagram of a data creation device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a sewing machine operated by stitch data.

FIG. 3 is an explanatory view showing a relationship among a needle, a feed dog, and a shuttle of the sewing machine.

FIG. 4 is an explanatory diagram showing a swing locus and a swing position of a needle.

FIG. 5 is an explanatory diagram showing a relationship between a swing position of a needle and an error amount.

FIG. 6 is an explanatory diagram showing a coordinate system used when creating stitch data.

FIG. 7 is an explanatory diagram showing a needle drop position of a stitch pattern “A”.

FIG. 8 is a table showing position data of needle drop positions of a stitch pattern “A”.

FIG. 9 is a flowchart showing the operation of the CPU 51 of the data creation device.

FIG. 10 is a table showing needle swing position data for each X coordinate of the needle drop position of the stitch pattern “A”.

FIG. 11 is a table showing stitch data before and after error correction stored in a stitch data area of a RAM 53 of the data creation device.

FIG. 12 is a table showing stitch data before and after error correction stored in a stitch data area of a RAM 53 of the data creation device.

[Explanation of symbols]

 10 Needle hole 11 Needle 13 Horizontal hook 20 Feed dog 33 Stitch data memory 42 Needle swing step motor 43 Vertical feed step motor 44 Horizontal feed step motor 50 Data creation device 51 CPU 52 ROM 53 RAM 60 Needle entry point memory

Claims (1)

[Claims] 1. A set of vertical feed data that defines a vertical feed amount of a feed dog, lateral feed data that defines a lateral feed amount of the feed tooth, and needle swing position data that defines a swing position of a needle. Based on the represented stitch data, the feed dog is moved in the vertical and horizontal directions, and the needle is swung on an arc locus along the outer circumference of the horizontal shuttle to move the needle drop point with respect to the work cloth and stitch. A stitch data creation device for a sewing machine configured to form a pattern, wherein vertical position data defining a position in the vertical direction of each of the plurality of needle drop points and a position in the horizontal direction are defined. The needle feed point data storage means for storing the horizontal position data, and the vertical feed data of the feed dog is calculated for each needle drop point from the vertical position data of the needle drop point, and the lateral position of the needle drop point is calculated. Directional position data Stitch data calculating means for calculating the lateral feed data and the needle swing position data for each needle drop point, and a change error from the chord of the arc locus of each of the calculated plurality of needle swing positions. And a stitch data correcting means for correcting and calculating the stitch data created by the stitch data calculating means in order to eliminate the variation error amount. Data creation device.