JPH05253368A - Seam data composing device for sewing machine - Google Patents

Abstract

PURPOSE:To provide a data composing device automatically making stitching data for a required form by taking the errors in the longitudinally feeding direction of the applied cloth, caused by the arc oscillation of a zigzag sewing machine needle, into consideration. CONSTITUTION:A needle-location point memory is forced to memorize X, Y position data of the needle-location points for a stitching pattern. The lateral width H of the stitching pattern, a conversion coefficient (k) of the needle- oscillation position, and the X-abscissa Zp of the center of the lateral width are operated (S3-S5) in accordance with the X-position data and the needle- oscillation data (Nn) are operated (S7) in accordance with these data and X- abscissa data. And the longitudinally feeding data are operated (S11) in accordance with the Y-position data of the needle-drop point, and the laterally feeding data are operated (S12) in accordance with the X-abscissa data and the needle- oscillating position data (Nn). When the accumulated error of the longitudinally feeding direction resulting from the needle-oscillation and the feeding reaches one feed pitch, the longitudinally feeding data of the seam data are corrected (S13-S20).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on stitch data composed of a set of vertical feed data which defines the vertical feed amount of a feeding tool and needle swing position data which defines the swing position of a needle. , Of the sewing machine that moves the needle in the arc direction along the outer circumference of the horizontal shuttle and moves the needle drop point with respect to the work cloth to form a stitch pattern while moving the feeder in the vertical direction. The present invention relates to a stitch data creating device.

[0002]

2. Description of the Related Art First, a conventional sewing machine will be described. A bed for supporting a cloth, a feed dog for moving a work cloth supported on the bed in a vertical direction and a horizontal direction in a plane parallel to the bed, respectively. A needle bar having a needle at its lower end, which reciprocates vertically with respect to the bed, and which can take a plurality of swing positions on an arc locus along the outer circumference of the horizontal shuttle in the lateral direction with respect to the bed; A needle bar releasing device that releases the drive connection between the needle bar crank mechanism and the needle bar to stop the needle above the work cloth, and a plurality of needle drop points required to embroider a pattern on the work cloth. , Vertical feed data that defines the vertical feed amount of the feed dog, horizontal feed data that defines the horizontal feed amount, needle swing position data that defines the swing position of the needle, and the presence or absence of needle bar release by the needle bar release device. The stitch data that represents the needle drop data as a set A sewing machine including a controller that embroiders a pattern on a work cloth by controlling the amount of movement of a feed dog and a step motor that is a drive device thereof, the amount of rocking of a needle, and the vertical movement of the needle based on There is.

When embroidering with this kind of sewing machine, when the maximum size of the pattern in the lateral direction (hereinafter referred to simply as the lateral width) exceeds the swing range that the needle can take, the work cloth is laterally moved by the feed dog. By moving the needle, the shortage of the swinging amount of the needle is compensated. When the lateral feed amount of one feed tooth exceeds the predetermined maximum feedable amount, the needle bar releasing device is operated to laterally feed the work cloth only, and then the remaining lateral feed and the needle bar The release device is inoperative and the seams are formed.

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 the desired embroidery pattern is read out as necessary, the controller can feed the stitch length data, cross feed data, and stitch data for each stitch. The embroidery pattern is formed by reading the rocking position data and the needle drop data, moving the feed dog in the vertical and horizontal directions, and rocking and vertically moving the needle.

In the conventional data preparation device, in order to store the stitch data in a storage medium such as a ROM, the preparer makes longitudinal feed data, lateral feed data, needle swing position data, The needle drop data was decided and input. However, since the needle oscillates along an arcuate path along the outer circumference of the horizontal shuttle, the needle position in the vertical feed direction changes according to the oscillating position of the needle, and the needle falls when the work cloth is fed by the feed dog. A feed error in which the vertical movement amount of the point does not match the amount indicated by the vertical feed data occurs, and the shape of the embroidery pattern changes. As a cause of this feed error, when the work cloth is fed by the feed dog in the sewing machine, the feed amount in the first step is the next due to the slippage and slippage between the feed tooth and the work cloth, mechanical delay, etc. This is because the feed amount per subsequent step is smaller. Therefore, in order to obtain the desired shape of the embroidery seam, the creator calculates the error,
Corrected stitch data for the error is newly created and additionally input.

[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 shape of the embroidery stitch is desired. In addition, it is a very time-consuming and error-prone task for the creator to calculate the error, and to newly create and additionally input the corrected stitch data for the error.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to eliminate an error in the vertical feed direction due to needle swing and a feed error when a work cloth is fed by a feed dog. (EN) Provided is a stitch data creation device for a sewing machine capable of automatically creating stitch data in which a set of vertical feed data of a feed dog and needle swing position data is set in a canceled state.

[0008]

In order to achieve this object, a stitch data creating device for a sewing machine according to a first aspect of the present invention, as shown in FIG. 1, has a plurality of needle drops forming stitches. A needle drop point data storage unit that stores vertical position data that defines the position of each point in the vertical direction and horizontal position data that defines the position in the horizontal direction, and feed from the vertical position data of the needle drop point. Stitch data calculation means for calculating vertical feed data of teeth for each needle drop point and needle swing position data for each needle drop point from lateral position data of the needle drop point, and a plurality of calculated needles The displacement error from the chord of each arc locus of the swing position is calculated, and the feed error between the feed amount calculated by the stitch data calculation means and the feed amount of the work cloth by the feed tool is calculated. Between the variation error and the feed error When the product value is calculated and the cumulative value of the variation error and the feed error exceeds a predetermined value, the stitch data created by the stitch data calculation means is corrected in order to eliminate the variation error and the feed error. And stitch data correction means for calculating.

In order to achieve this object, claim 2 of the present invention
In the stitch data creation device for a sewing machine according to the above, the stitch data corrected and calculated to eliminate the displacement error and the feed error is the stitch length data that defines the vertical feed amount of the feed tool. A data correction means is provided.

[0010]

In the stitch data creating device according to the first aspect of the present invention, the needle drop point data storage means defines the vertical position data and the horizontal position data that define the position of each of the plurality of needle drop points in the vertical direction. And lateral position data defining a position in the direction. 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 needle swing position data from the lateral position data of the needle drop point. Calculate each time. The stitch data correction means calculates the deviation error from the chord of the arc locus of each of the plurality of needle swing positions calculated by the stitch data calculation means, and the feed amount calculated by the stitch data calculation means. And the feed amount of the work cloth fed by the feed tool are calculated, the cumulative value of the variable error and the feed error is calculated, and the cumulative value of the variable error and the feed error exceeds the predetermined value. , The stitch data is corrected and calculated to eliminate the variation error and the feed error.

In the stitch data creating device according to the second aspect of the present invention, the stitch data correcting means defines the vertical feed amount of the feed tool in order to eliminate the variation error and the feed error. Compensate feed data.

[0012]

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. 2, the sewing machine according to the present embodiment has a needle which is moved up and down 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, a horizontal full rotary hook 13 which is arranged below the needle plate T and cooperates with the needle 11 to form stitches on the work cloth, and which is arranged in the opening of the needle plate T and appears on the upper surface of the needle plate. A feed dog 20 for transferring the work cloth in a vertical feed direction (Y direction in the drawing) and a horizontal feed direction (X direction in the drawing) at a predetermined feed pitch.
And have. The needle hole 10 is formed in an arc shape along the outer circumference of the horizontal shuttle 13, and the needle 11 is swung along the needle hole 10 on an arc locus about the rotation axis of the horizontal shuttle. 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. 3, the control device of the sewing machine is as follows.
CPU30, ROM31 and R, which are the core of the logical operation circuit
Stitch data memory 33 consisting of AM 32 and 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.

Further, in the sewing machine, when the work cloth is fed by the feed dog 20, the feed amount of the first step is the next due to a cause such as a slippage and a slip between the feed dog 20 and the work cloth, and a mechanical delay. It is smaller than the subsequent feed amount per step. The characteristic is shown in FIG. 4 of a graph with the vertical feed amount of the work cloth by the feed dog 20 as the vertical axis and the number of steps of the vertical feed step motor 43 as the drive device of the feed tooth 20 as the horizontal axis. .. It has been confirmed by experiments that the work cloth feed amount in the first step is 0.24 mm, and the work cloth feed amount in each subsequent step is 0.34 mm. Thus, every time the work cloth is fed in the vertical direction by the feed dog 20, one step vertical feed of 0.
The feed error data of 0.1 mm with respect to 34 mm corresponds to the forward and reverse of the feed, and negative feed error data is generated in the forward vertical feed, and positive feed error data is generated in the reverse vertical feed.

The needle bar releasing solenoid 45 controls a known needle bar releasing device. The needle bar releasing device releases the driving connection between the needle bar crank mechanism and the needle bar by exciting the solenoid 45, and the needle bar releasing device 45 releases the driving force. The (needle 11) is stopped above the work cloth to perform only relative feed between the needle and the work cloth, and the needle bar crank mechanism and the needle bar are connected by demagnetization to reciprocate the needle bar up and down. is there.

The stitch data stored in the stitch data memory 33 is read into the ROM 31 by one stitch in response to the detection of a specific rotation phase of the main shaft rotated by the sewing machine motor 41, and the needle swing step motor is read. 42, a program for driving and controlling the vertical feed step motor 43, the horizontal feed step motor 44, and the needle bar release solenoid 45 is stored. This stitch data is created for each feed control unit once as a 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. .. 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.

As the mechanical characteristics of this sewing machine, as shown in FIG. 5, the number of steps of the needle rocking step motor 42 is set to 14, and the needle rocking position data is-.
It is given as an integer value from 7 to 7 (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. 2, and when the value of the needle swing position data is 7, the needle 11 is swung to the rightmost position in FIG. 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.

In the sewing machine, the needle has a radius of 18 mm.
Although the rocking motion is performed in 14 steps along the arcuate locus, the position in the horizontal direction changes and the position in the vertical direction also changes for each step. That is, the swinging position of the needle changes from the chord of the arc locus at each step, and the displacement amount at each step becomes a value as shown in FIG. 6 with reference to both ends of the arc locus.

On the other hand, the feed amount per step of the vertical feed step motor 43 for moving the feed dog 20 in the Y direction in FIG. 2 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 0.5 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.

The needle bar release data indicates whether or not the needle 11 has dropped onto the work cloth. When the needle bar release data is 0, the needle bar release solenoid 45 of the needle bar release device of the sewing machine is not excited. Then, the needle bar crank mechanism and the needle bar are connected and the needle bar is driven up and down. When the needle bar release data is 1, the needle bar release solenoid 45 is excited to connect the needle bar crank mechanism and the needle bar. This means that the needle bar stops when it is released.

It is necessary to store the stitch data in the stitch data memory 33 before forming the embroidery stitch using the sewing machine configured as described above. The structure of the data creation device 50 for creating this stitch data will be described below.

As shown in FIG. 7, the data creating apparatus 50 includes a CPU 51, which is the center of a logical operation circuit, a ROM 52 storing a program for driving the CPU 51, and a RAM 53, via a common bus 54. They are connected to each other. It should be noted that the ROM 52 has a feed error due to the difference between the feed amount (= 0.24 mm) of the first first step of the vertical feed step motor 43 and the feed amount of each subsequent step (= 0.34 mm), and the difference therebetween. With reference to the data value (= 0.1 mm) and both ends of the arc locus in the swing of the needle 11, the amount of change in each step is
It is stored in advance in the ROM 52 in the form of a table of an error amount with respect to the needle swing position (referred to as a needle position error table). Further, the common bus 54 is connected to a digitizer 55 for inputting the needle entry point as position data in the XY directions, and a needle entry point memory (needle entry point memory for storing the needle entry point data input by the digitizer 55). A 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.

Further, a stitch data area and an error area are set in the RAM 53, and in this stitch data area, the vertical feed data of the feed dog 20 and the feed tooth 20 are associated with each needle drop point. Lateral feed data, needle bar release data indicating the presence / absence of needle drop of the needle 11, and needle swing position data of the needle 11 are stored. The needle bar release data is set to 0 in advance for each needle drop point. On the other hand, in the error area, error data is stored corresponding to each needle drop point, which is a standard for whether or not to correct the stitch.

Next, creation of stitch data by the data creating device 50 will be described with reference to the flow chart of FIG.

First, the coordinate system shown in FIG. 9 is set based on the Y axis in the longitudinal feed direction of 0.34 mm per scale and the X axis in the transverse feed direction of 0.5 mm per scale, and the pattern " The desired needle drop points P1 to P37 of "A" are determined.
That is, points P1 to P37 in FIG. 10 are designated by the digitizer 55, 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.

First, the CPU 51 reads the position data of the needle drop point from the needle drop point memory 60 and stores it in a predetermined area of the RAM 53 in step 1 (step S1; the following step is abbreviated as S).

Next, in S2, the CPU 51 determines the maximum value Xma of the X coordinate from the read position data of the needle drop point.
The x and the minimum value Xmin of the X coordinate are detected. In this embodiment, the CPU 51 determines the point P14 as the maximum value Xmax of the X coordinate.
Value (= 38) is detected, and the value (= 0) at points P3 and P22 is detected as the minimum value Xmin of the X coordinate.

Then, the CPU 51 subtracts the minimum value Xmin from the maximum value Xmax in S3,
The width H of the embroidery pattern is calculated. Then, the CPU 51 obtains the lateral width H (= 38) in the case of the pattern "A" in FIG.

Next, the CPU 51 sets a distance between each of a plurality of X coordinate points assumed on the X axis within the width H of the embroidery pattern of this time and each of a plurality of swing positions of the needle 11. The work for determining the correspondence relationship of is performed after S4. The correspondence between each X coordinate point and each needle swing position is that the needle swing position is the neutral position when the needle 11 penetrates the center X coordinate point of the maximum X coordinate point and the minimum X coordinate point of the cloth. 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 It is determined that the swing amount from the neutral position of the needle 11 increases 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.

First, in S4, the CPU 51 divides the lateral width H of the embroidery pattern by the number of needle swing steps (= 14) to convert the X coordinate value Xn of the X coordinate point into the needle swing position Nn. The coefficient k (= 2.714 ...) Is calculated. If there is a decimal point for this coefficient k, the decimal point is left.

Next, in S5, the CPU 51 determines the center coordinates of the lateral width of the embroidery pattern (the point where the needle swing position data becomes 0).
X coordinate value Zp of the maximum value Xmax (= 38) and the minimum value X
By dividing the sum with min (= 0) by 2, the X coordinate value Zp (= 1 of the center coordinate of the width of the pattern “A” this time.
9) is required. If there is a decimal point for this X coordinate value Zp, the decimal point is left.

Next, the CPU 51 calculates the needle swing position Nn for each needle drop point Pn of the pattern "A".

First, the CPU 51 initializes the counter n to 1 in S6.

Next, in S7, the CPU 51 subtracts the X coordinate value Zp of the center coordinate from the X coordinate value X1 of the needle drop point P1, divides it by the coefficient k obtained in S4, and rounds off to the right of the decimal point. By doing so, the needle swing position data N1 at the point P1 is calculated and stored in the stitch data area of the RAM 53.

Then, the CPU 51 determines in S8 that this calculation is not performed for all needle drop points Pn, the counter n is incremented in S9, and the process returns to S7. Then, in S7, as with the needle drop point P1, for the needle drop point P2 and thereafter, the needle swing position data N
2 (= -7) is calculated and stored in the stitch data area of the RAM 53. When the calculation for all needle drop points is completed, YES is determined in S8, and the CPU 51
Proceeds to S10. The needle swing position data for each needle drop point calculated in S7 is shown in the tables of FIGS. For reference, the needle swing position calculated in S7 is shown in the order of the X coordinate values (0 to 38) in FIG.
It is shown in the table of No. 5.

Next, the CPU 51 calculates the stitch data for forming the stitch at each needle drop point and the error data which is a standard for determining whether or not to correct the stitch, and determines the stitch data area and the error in the RAM 53. Store in the area. The error data includes the displacement error data of the needle 11 caused by the needle 11 swinging along the needle hole 10 on an arc locus centering on the rotation axis of the horizontal shuttle, and the initial value of the vertical feed step motor 43. Is calculated by calculating the feed error data resulting from the fact that the feed amount of the first step is smaller than the feed amount per subsequent step.

First, the CPU 51 initializes a counter j to 1 in S10.

Next, in S11, the CPU 51 sets vertical feed data (= 0) for the needle drop point P1, and S1 is set.
2 sets the horizontal feed data (= 0), and RAM5
Store in 2.

Next, in S13, in the case of the needle drop point P1, the CPU 51 uses the needle swing position data set in S7 to determine the actual needle drop point for the work cloth when the needle is swung and the needle drop point. The needle deviation error data stored in the point memory 60 with respect to the target needle drop point P1 is converted into needle swing position data N0 (= -7) and N1 from the relative positional relationship of the needle 11.
It is calculated as the difference between the error amounts in FIG. 6 corresponding to (= −6). Therefore, the needle drop point P1 is the first time, so CPU5
1 is the difference (= 0-0.0919 = -0.0919m
m) is stored in the error area of the RAM 53 as error data that is a standard for determining whether to correct the stitches.

Next, the CPU 51 proceeds to S14, where S1
It is calculated that the feed error data does not occur from the vertical feed data (= 0) calculated in 1. Then, the CPU 51 uses the error data that has been calculated in S13 as the feed error data as RA
It is stored in the error area of M53.

Next, the CPU 51 sets a correction boundary value as a condition for correcting the stitch data. This is because the feed amount in the first step of the vertical feed motor 43 is different from the feed amount in each subsequent step, so that when the vertical feed data is corrected from 0 to 1 or from 0 to -1, This is because the correction value of the error data is different except for.

First, the CPU 51 determines in S15 that the vertical feed data is 0, and in S16, RO
0.24m by calling the feed amount (= 0.24mm) for the first step of the vertical feed motor 43 from M52.
Set m as the correction boundary value.

Next, the CPU 51 proceeds to S18, where S1
The absolute value (= 0.091 mm) of the error data (= -0.0919 mm), which is the total error between the variable error data calculated in 3 and the feed error data calculated in S14.
9) is the correction boundary value set in S16 (= 0.24 m
Judge that it is not larger than m). Then C
In S21, the PU 51 determines that the stitch data has not been created for all needle drop points Pj,
In S22, the counter j is incremented to S1.
Return to processing of 1.

Next, in S11, the CPU 51 reads the Y-coordinate data (= 4) of the needle drop point P2 and sets the feed amount F, which must be moved by vertical feed for each stitch, to the current needle drop point P2. The needle drop point P1 immediately before the Y coordinate value
It is obtained by subtracting the Y coordinate value (= 0) of. Since the feed amount F (= 4) corresponds to the number of steps of the vertical feed step motor 43, the CPU 51 stores the feed amount F in the RAM.
It is stored in the stitch data area 53 as vertical feed data for the needle drop point P2.

Next, in S12, the CPU 51 reads the X-coordinate data (= 1) of the needle drop point P2 and sets the feed amount S, which must be moved laterally for each stitch, to the current needle drop point P2. The needle drop point P1 immediately before from the X coordinate value
X coordinate value (= 4) is subtracted, and the needle swing amount (= -1) from the needle drop point P1 to the needle drop point P2 is subtracted. The feed amount S (= -2) is the lateral feed step motor 4
Since it corresponds to the number of steps of 4, the CPU 51 sends the feed amount S
Is stored in the stitch data area of the RAM 53 as the lateral feed data of the needle drop point P2.

Next, in S13, the CPU 51 obtains needle displacement error data between the actual needle drop point and the target needle drop point P2 by the needle swing position data N1 (= -6) and N2 (=
-7) and the error amount difference of FIG. 6 corresponding to (= 0.0919
-0 = + 0.0919mm), and the needle drop point P
Add the deviation data (= + 0.0919mm) of the needle to the error data (= -0.0919mm) obtained in 1, and
Error data recalculated in the error area of the RAM 53 (= 0
mm) is memorized.

Next, the CPU 51 proceeds to S14, where S1
Since the vertical feed data (= 4) calculated in 1 is in the plus direction, the feed error data (= -0.1 mm) is calculated. Then, the CPU 51 adds the feed error data (= -0.1 m) to the error data (= 0 mm) calculated in S13.
m) is added to recalculate the error data and R
Error data (= -0.1 mm) is stored in the error area of AM53.

Next, the CPU 51 determines in S15 that the vertical feed data (= 4) is not 0, and in S17, calls the feed amount (= 0.34 mm) for one step of the vertical feed motor 43 from the ROM 52. , 0.34m
Set m as the correction boundary value.

Next, the CPU 51 determines in S15 that the absolute value (= 0.1) of the error data (= -0.1 mm) is S1.
It is determined that it is not larger than the correction boundary value (= 0.34 mm) set in 7. Next, the CPU 51 executes S
In 21, it is determined that the stitch data has not been created for all needle drop points Pj, and in S22, the counter j is incremented and the process returns to S11.

Explaining the case of the needle drop point P4 by performing the same calculation, the CPU 51 determines in S11 that
Read the Y coordinate data (= 14) of the needle drop point P4,
By subtracting the Y coordinate value (= 10) of the needle drop point P3 from the Y coordinate value of the current needle drop point P4, the feed amount F (=
4) is obtained and the needle drop point P is set in the stitch data area of the RAM 53.
The feed amount F is stored as the vertical feed data of 4.

Next, in S12, the CPU 51 reads the X coordinate data (= 4) of the needle drop point P4, and from the X coordinate value of the current needle drop point P4, the X coordinate value (= 0) of the needle drop point P3. Is subtracted, and the needle drop point P3 to the needle drop point P4
Feed amount S (= 3) by subtracting the needle swing amount (= + 1) up to
Then, the feed amount S is stored in the stitch data area of the RAM 53 as the lateral feed data of the needle drop point P4.

Next, in S13, the CPU 51 obtains needle displacement error data between the actual needle drop point and the target needle drop point P4 by the needle swing position data N3 (= -7) and N4 (=
-6) and the difference in the error amount of FIG. 6 (= 0-0.09
19 = -0.0919 mm), and the needle drop point P
The error data of the needle (= -0.0919 mm) is added to the error data (= -0.2 mm) obtained in 3, and RAM5
The error data (= -0.2919 mm) is stored in the error area of 3.

Next, the CPU 51 advances to S1 in S14.
Since the vertical feed data (= 4) calculated in 1 is in the plus direction, the feed error data (= -0.1 mm) is set. The error data calculated in S13 (= -0.2
This feed error data (= -0.1 mm)
Is added to recalculate the error data and RAM
Error data in the error area of 53 (= -0.3919 mm)
Memorize

Next, in S15, the CPU 51 determines that the vertical feed data (= 4) is not 0, and in S17, calls the one-step feed amount (= 0.34 mm) of the vertical feed motor 43 from the ROM 52. , 0.34m
Set m as the correction boundary value.

Next, the CPU 51 determines in S18 the absolute value (= 0.39) of the error data (= -0.3919 mm).
19) is the correction boundary value set in S17 (= 0.34 m
It is judged that it has become larger than m).

Next, in S19, the CPU 51 rewrites the stitch data for one vertical feed pitch in the direction opposite to the direction in which the error occurs. To this end, the CPU 51 determines that the needle drop point P4
The sign of the error data (= -0.3919 mm) is determined, it is determined that the error occurs in the negative direction, and 1 is added to the vertical feed data (= 4).

Next, in S20, the CPU 51 adds in accordance with the rewriting direction of the vertical feed data in S19, so the error data calculated in S14 (= -0.
One pitch of positive vertical feed to 3919 mm (= 0.34)
mm) is added. And CPU51 is RAM53.
Error data (= -0.0519)
mm) is memorized.

Next, in S21, the CPU 51 determines that the stitch data has not been created for all needle drop points Pj, and in S22, the counter j is incremented and the process returns to S11.

In the following, the same calculation is performed and the case of the needle drop point P22 will be described.
For vertical feed data (= -1), for S12 horizontal feed data (= -3), for S13 variable error data (= + 0.1691 mm) and error data (= + 0.42).
mm), feed error data in S14 (= +0.1 m
m) and error data (= + 0.52 mm) are calculated, and RA
Each is stored in the stitch data area and the error area of M53.

Next, in S15, the CPU 51 determines that the vertical feed data (= 4) is not 0, and sets a correction boundary value (= 0.34 mm) in S17.

Next, in S18, the CPU 51 confirms that the absolute value (= 0.52) of the error data (= + 0.52 mm) becomes larger than the correction boundary value (= 0.34 mm) set in S17. to decide.

Next, in S19, the CPU 51 rewrites the stitch data for one vertical feed pitch in the direction opposite to the direction in which the error occurs. To do this, the CPU 51 sets the needle drop point P22.
The sign of the error data (= + 0.52 mm) is determined, it is determined that the error occurs in the plus direction, and 1 is subtracted from the vertical feed data (= -1).

Next, in S20, the CPU 51 subtracts in accordance with the rewriting direction of the vertical feed data in S19, so the error data calculated in S14 (= + 0.
52 mm), which is one vertical pitch (= 0.34 m)
Subtract m). Then, the CPU 51 recalculates error data (= + 0.18 mm) in the error area of the RAM 53.
Is stored, and similarly, through S21 and S22, the process returns to S11.

After this, similarly, stitch data at the needle drop points are created as shown in FIGS. 12 to 14, and the following vertical feed data is rewritten at the following needle drop points.

At the needle drop point P4, 1 is added to the vertical feed data.

At the needle drop point P5, 1 is added to the vertical feed data.

At the needle drop point P8, 1 is added to the vertical feed data.

At the needle drop point P22, 1 is subtracted from the vertical feed data.

At the needle drop point P30, 1 is subtracted from the vertical feed data.

At the needle drop point P36, 1 is added to the vertical feed data.

After creating the stitch data of the needle drop point P37, the CPU 51 determines in S21 that the creation of the stitch data has been completed for all the needle drop points Pj and creates the stitch data. Exit the program for.

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

Here, the processes of S7 and S12 of the CPU 51 correspond to the stitch data calculation means of the present invention, and S13 to S2.
The processing of 0 corresponds to the stitch data correcting means of the present invention.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the present embodiment, it is assumed that the error in the condition for rewriting the vertical feed data of the stitch data is equal to the correction boundary value, and the correction boundary value is the feed amount of one step of the vertical feed step motor 43. By rewriting the vertical feed data by using this corrected boundary value as, for example, half the feed amount of one step of the vertical feed step motor 43, it is clear that data can be created such that the needle falls to a point closer to the target needle drop point. is there.

[0076]

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 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 needle swing position data for each needle drop point from the lateral position data of the needle drop point. The stitch data correction means calculates the displacement error from the chord of the arc locus of each of the plurality of needle swing positions calculated by the stitch data calculation means, and is calculated by the stitch data calculation means. The feed error between the feed amount and the feed amount of the work cloth fed by the feed device is calculated, and the stitch data is corrected and calculated to eliminate the variation error and the feed error. Error in the vertical feed direction due to The effect that the vertical feed data and the needle swing position data of the feed dog in the canceled state can be automatically created, and the stitch pattern data of the stitch pattern having a desired shape can be created in a short time. Have.

[Brief description of drawings]

FIG. 1 is a block diagram showing the present invention.

FIG. 2 is an explanatory diagram showing a relationship among a needle, a feed dog, and a shuttle of the sewing machine.

FIG. 3 is a block diagram of a sewing machine operated by stitch data.

FIG. 4 is an explanatory diagram showing a relationship between a vertical feed amount of a work cloth by a feed dog and the number of steps of a step motor.

FIG. 5 is an explanatory diagram showing a swing locus and a swing position of a needle.

FIG. 6 is an explanatory diagram showing a relationship between a swing position of a needle and an error amount.

FIG. 7 is a block diagram of a data creation device according to an embodiment of the present invention.

FIG. 8 is a flowchart showing an operation of the CPU 51 of the data creation device.

FIG. 9 is an explanatory diagram showing a coordinate system used when creating stitch data.

FIG. 10 is an explanatory diagram showing a needle drop position of a stitch pattern “A”.

FIG. 11 is a table showing position data of respective needle drop positions of the stitch pattern “A”.

FIG. 12 is a table showing stitch data stored in a stitch data area of a RAM 53 of the data creation device.

FIG. 13 is a table showing stitch data stored in a stitch data area of a RAM 53 of the data creation device.

FIG. 14 is a table showing stitch data stored in a stitch data area of a RAM 53 of the data creation device.

FIG. 15 is a table showing needle swing position data for each X coordinate used when creating stitch data.

[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 (2)

[Claims] 1. A longitudinal direction of the feeding device is defined based on stitch data composed of a set of vertical feed data defining the vertical feed amount of the feeding device and needle rocking position data defining the rocking position of the needle. Stitches for a sewing machine in which the needle drop point for the work cloth is moved by moving the needle in a circular arc path along the outer circumference of the horizontal shuttle while forming a stitch pattern. A data creating device, wherein each of the plurality of needle drop points stores vertical position data that defines a position in the vertical direction and lateral position data that defines a horizontal position data that defines a position in the horizontal direction. The storage unit and the vertical position data of the needle drop point are used to calculate the vertical feed data of the feed tool for each needle drop point, and the needle swing position data is also dropped from the lateral position data of the needle drop point. Calculate point by point Stitch data calculation means for calculating the displacement error from the chord of the arc locus for each of the calculated plurality of needle swing positions, and the feed amount calculated by the stitch data calculation means and the When the feed error with the feed amount of the work cloth by the feed tool is calculated, the cumulative value of the variation error and the feed error is calculated, and the cumulative value of the variation error and the feed error exceeds a predetermined value. Stitch data for a sewing machine, the stitch data correcting unit correcting and correcting the stitch data created by the stitch data calculating unit so as to eliminate the variation error and the feed error. Creation device. 2. The stitch data corrected by the stitch data correcting means in order to eliminate the displacement error and the feed error is vertical feed data that defines the vertical feed amount of the feed tool. 2. A stitch data creating device for a sewing machine according to claim 1, wherein