JPH043235B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a control device for an automatic sewing machine,
More specifically, the present invention relates to a control device capable of automatically changing the cloth feeding period in an automatic cloth feeding sewing machine that sequentially reads out pre-programmed pattern data and creates stitches of a fixed shape according to the data. [Prior Art] Conventionally, there is a control device of this type as shown in FIG. In the figure, 1 is the sewing machine head, 2
is a detector that rotates together with the upper shaft (not shown) of the sewing machine head 1 and generates a specific number of pulses, needle upper position and lower position signals, and a synchronization signal that can be output at any position during one rotation of the sewing machine. , 3 is a motor that rotates the sewing machine, 4 is a driver that drives motor 3, and 5 and 6 are presser feet (not shown), respectively.
7 and 8 are drivers that drive the pulse motors 5 and 6, respectively. 9 is the number of pulses corresponding to the cloth feed amount specified for each driver 7 and 8. 10 is a sewing machine start switch, 11 is a switch for raising and lowering the presser foot, 12
is the central processing unit (hereinafter abbreviated as CPU),
13 and 14 are data input/output ports, and 15 is a system control memory (hereinafter referred to as PROM).
), 16 is a data memory (hereinafter referred to as
17 is a pattern data memory, 18 is a data bus, 19 is an address bus,
20 is an XY drive mechanism section including an XY table and the like. Next, FIG. 11 is a block diagram schematically showing the internal configuration of the pulse train generation circuit 9 in FIG. 10.
In the figure, 21 is a one-shot pulse generation circuit triggered by the rising edge of synchronization signal c; 22
is a flip-flop (hereinafter abbreviated as F/F) circuit that is triggered by the rising edge of the synchronization signal c;
23 is an AND element that receives the pulse signal a from the detector 2 and the output e of the F/F circuit 22, and 24 uses the outputs AW, BW, CW, and DW of the input/output port 13 as count data setting inputs, and performs an AND operation. The output pulse f of element 23 is used as a countdown clock input.
Hexadecimal counter circuit, 25 is hexadecimal counter circuit 24
F/ which is triggered by the input of the count completion signal g of
F circuit, 26 is an AND element which receives the output h of the F/F circuit 25 and the output f of the AND element 23, 27
28 is a feed pulse distribution circuit for X-axis driving which uses the output pulse i of the AND element 26 as a clock input and outputs pulses corresponding to the output data from the input/output port 13 in synchronization with the clock i; 28 has the same function as 27; This is a feed pulse distribution circuit for driving the Y-axis. 29 is a 32-ary counter circuit which receives the output pulse i of the AND element 26 as a count up clock input; 30 is a one-shot pulse generating circuit which is triggered by the rising edge of the count completion signal of the 32-ary counter circuit 29. Further, FIG. 12 is a time chart of each pulse signal shown in FIG. 11. Next, the operation will be explained. When the presser foot switch 11 is stepped on, the presser foot (not shown) is lowered and the workpiece to be sewn is clamped by the presser foot. Next, when sewing machine start switch 10 is turned on, the CPU
Reference numeral 12 reads pattern data for one stitch from a data memory 17 into which sewing pattern data is input in synchronization with the falling edge of the synchronization signal c from the detector 2, and drives the motor 3 at a speed specified by the pattern data.
The sewing machine speed data is output to the driver 4 so that it rotates. At the same time, cloth feed data specified by the pattern data is output to the feed pulse train generation circuit 9 through the input/output port 13. The feed pulse train generation circuit 9 outputs pulses equivalent to the cloth feed amount in synchronization with the rotation of the sewing machine to the pulse motor drivers 7 and 8 for each axis of X and Y to drive the pulse motors 5 and 6 for each axis to produce a predetermined feed. Move the volume distribution presser. Next, this operation will be explained based on FIGS. 11 and 12. Pulse signal a is an input signal from detector 2, and 64 pulses are input to pulse train generation circuit 9 per one revolution of the sewing machine. Similarly, the synchronizing signal c is an input signal from the detector 2, and one pulse per revolution of the sewing machine is inputted to the pulse train generating circuit 9. The input/output port 13 outputs feed data for each of the X and Y axes to the pulse distribution circuits 27 and 28, and at the same time outputs counter set values AW, BW, CW, and DW to the hexadecimal counter 24 from each output line. When the rising edge of the synchronization signal c arrives, the output e of the F/F circuit 22 becomes high level, and the output d of the one shot pulse generation circuit 21 becomes low level. Count values are then set in the hexadecimal counter circuit 24 and the 32-decimal counter circuit 29, respectively. Since the input e becomes high level, the AND element 23 changes the pulse signal a to f.
This pulse output f is input to the countdown input of the hexadecimal counter circuit 24 and the AND element 26. At this time, the output h of the F/F circuit 25
Since is at a low level, no pulse signal is output to the output i of the AND element 26, and it remains at a low level. When the hexadecimal counter circuit 24 counts the pulses from f by the value set by the output from the input/output port 13, a low level pulse is output to the output g, and the output h of the F/F circuit 25 is set to a high level. shall be. As a result, the AND element 26 outputs the pulse signal a to i, which is input to the count-up input of the 32-ary counter circuit 29 and the clocks of the pulse distribution circuits 27 and 28, respectively. After counting 32 pulses, the 32-digit counter circuit 29 outputs a count completion signal to the one-shot pulse generation circuit 30, and the pulses output to j are sent to the F/F circuits 25 and 2.
2, their outputs h and e become low level, and the outputs of AND elements 23 and 26 become low level. On the other hand, the pulse distribution circuits 27, 2
8 outputs to each output a number of pulses specified by the input/output port 13 from the 32 pulse groups inputted from i, and this is X shown in FIG.
This serves as an input to the pulse motor drivers 7 and 8 for each Y axis. When the sewing machine completes one rotation and the next synchronization signal c is input, the same operation is started again. In Fig. 12, C is the period of one rotation of the sewing machine, W
is the counting period of the hexadecimal counter circuit 24, and P is 32
This is the counting period of the advance counter 29 and is also the cloth feeding period. D is the remaining period. During this period P, the cloth feed pulse k is output, and the actual stitches are formed. P also corresponds to the period when the needle of the sewing machine comes out of the workpiece, and during the period D, the cloth feed is not performed. This corresponds to the period during which a sewing machine needle remains stuck in the sewing material. Also, W is for synchronization signal c,
This is a period for adjusting the position of the cloth feeding period P. In this way, with the means shown in FIGS. 11 and 12, when the needle of the sewing machine moves up and down, when the needle is in the raised position, the workpiece is fed, and when the needle is stuck in the workpiece, the workpiece is fed. This is intermittent feeding where the feeding stops. Further, as an example of other conventional methods, there is one shown in FIG. These are the hexadecimal counter circuit 24, F/F circuit 25, and AND element 2 in FIG.
6 has been deleted, and the rest is the same as FIG. 11. In the figure, by inputting 32 pulses per revolution of the sewing machine to the pulse signal a, the feed that starts at the rising edge of the synchronization signal c becomes a feed period that spans the entire revolution of the sewing machine, so the fabric feed becomes continuous feed. be. [Problems to be Solved by the Invention] In the conventional control system described above, in the case of the former intermittent feed, the seam formation state is as shown in FIG. 14. In the figure, the cloth feeding period during which the cloth feeding pulses P1 to P5 are outputted is a period in which the material to be sewn is moving by the length of the stitch, and the other periods are periods in which it is stopped. Compared to the latter continuous feed method, this intermittent feed method requires twice the pulse rate (number of pulses per second) to feed the workpiece with the same rotation speed and the same feed pulse (that is, the same stitch length). As a result, a large load is placed on the pulse motor that drives the workpiece in each of the X and Y axes, causing the pulse motor to step out of synchronization, resulting in irregular stitches or the inability to increase the sewing speed, which also lengthens the cycle time. There is a problem. Furthermore, when the workpiece is moved along a stair-like trajectory as shown at 33 in FIG. The pulse motor has its own rotor,
Since there is a spring system between the stators or in the mechanism from the output shaft of the pulse motor to the cloth presser that clamps the workpiece, the actual movement trajectory moves while vibrating as shown at 34. Therefore, it has a wavy curve shape. Sewing machine needles are Q1 and Q, respectively.
2, Q3, and Q4 pierce the material to be sewn, so there is a problem that the seams are not uniform as shown in FIG. 14A. Further, the feeding motion of the latter continuous feeding method is as shown in FIG. In the figure, the rising edge of the synchronization signal almost coincides with the point at which the needle exits the workpiece. P1 to P6 are each 1
This is the cloth feeding period in which a feed pulse for the number of needles is output, and the cycles C1 to C6 per revolution of the sewing machine coincide with the cloth feeding period. Now, when considering the C2 cycle, the length of the stitch formed in the C2 cycle corresponds to the number of pulses output during the P2 period, but since the needle pierces the workpiece in the middle of the period, the length of the stitch formed in the C2 cycle corresponds to the length of the D2 period. The seam will be shorter by the length of the seam. However, the actual stitch length is (P2 +
D1−D2), (P3+D2−D3), (Pn+Dn−1−Dn)
becomes. This is not much of a problem when the stitch lengths are equal and straight stitching is performed, but when there are corners where the stitching direction suddenly changes, there is a problem that the stitches will collapse at right angles or acute angles. FIG. 16 shows this state. In the figure, A shows a normal seam, and if it is a normal seam when sewing is performed at low speed and intermittently, then B shows a seam that occurs when sewing is performed with continuous feed. That is,
A, B to H indicated by dotted circles in the figure are regular stitches, but in the case of continuous feed, D1, D2,...D
Since the needle pierces the workpiece at a point shorter than the length shown by 7, the actual stitches will be A', B',...H',
In particular, there is a problem that the corners are D', E', and F', so regular seams cannot be seen. This tendency will be reduced if the synchronization signal position in Fig. 15 is changed so that the period D is shortened with respect to the needle bar motion.
It is extremely difficult to match the rising edge of the synchronization signal with the point where the needle pierces the workpiece for various types of workpieces having different thicknesses. In addition, with this continuous feed method, the object to be sewn moves while the needle is stuck in the object, so there is a problem that the needle may be bent or broken when sewing thick or hard materials, making it impossible to sew. Ta. As described above, there are two methods for moving the workpiece to form stitches: the conventional intermittent feeding method that outputs a feed pulse only when the needle is rising, and the conventional method that outputs a feed pulse regardless of the needle position. There are two types of continuous feeding methods, but with the intermittent feeding method, the load on the pulse motor is large, making it impossible to increase the sewing speed, and also making it impossible to obtain uniform stitches due to the vibration of the presser foot that holds the workpiece. There was a problem. In addition, with the continuous feed method, the load on the pulse motor is small and there is less vibration of the presser foot, so it is possible to increase the sewing speed, but it is difficult to sew thick or hard materials due to needle breakage, and it is difficult to sew corners neatly. There was a problem that I couldn't do it. The present invention was made to solve the above-mentioned problems, and automatically adjusts the feed width and sewing speed per revolution of the sewing machine depending on the presence or absence of sudden changes in the sewing direction or the condition of the sewing material. The object of the present invention is to obtain a control device for an automatic sewing machine that can switch to the automatic sewing machine. [Means for Solving the Problems] A control device for an automatic sewing machine according to the present invention is a control device for an automatic sewing machine that is controlled to sequentially read out pre-programmed pattern data and form stitches in accordance with the data. In the device,
a counter circuit for frequency-dividing a specific number of workpiece feed pulse trains synchronized with the rotation of the sewing machine by a specified value;
The sewing machine is equipped with a pulse distribution circuit for generating a number of pulse trains corresponding to a specified stitch length from the pulse train after frequency division, and the sewing machine rotates by switching the specified frequency division value according to the condition of the stitch pattern or sewing material. The width of the sending pulse train for one cycle can be changed. [Operation] In the present invention, the pattern data memory in the PROM is read into the RAM in advance, and at the same time, the intersection angle is calculated every second from each stitch data, and when the angle is large, that is, the sewing direction suddenly changes. In this case, by writing data to change the fabric feed period and sewing speed, the switching data is determined when sewing is executed, and the continuous feed or intermittent feed is switched, and the sewing speed is also changed. For materials to be sewn, high-speed continuous stitching is used for straight sections, and low-speed intermittent stitching is used for corner sections.Also, when there are differences in the thickness of the fabric, high-speed continuous stitching is used for thinner areas, and low-speed intermittent stitching is used for thicker areas. It can be sewn. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing the internal configuration of a pulse train generation circuit in an embodiment of the present invention, and numerals 21 to 30 in the figure are the same as those shown in FIG. 11. 31 is the output AP, BP of the input/output port 13,
A frequency division counter for the pulse signal a that counts the pulse signal a by the number specified by CP and DP and outputs one pulse synchronized with the pulse signal a after the count is completed. 32 is the rising edge of the output from the counter 31. This is a one-shot pulse generating circuit triggered by the output signal B, and its output b is designed to set the count data of the counter 31. FIG. 2 is a timing chart of the signals a to k shown in FIG. 7 is a diagram illustrating an example of specifying a frequency division value of a signal of count output b corresponding to each bit value indicated by AP, BP, CP, and DP in the instruction data shown in the figure. FIG. FIG. 5 is a main flowchart showing the operation of the embodiment of the present invention, and FIG. 6 is a flowchart showing the sewing machine operation preprocessing subroutine in FIG. Next, the operation will be explained. The overall configuration is the same as that of the conventional example shown in FIG. be. Next, the operation of the sending pulse train generation circuit 9 will be explained based on FIGS. 1 and 2. pulse signal a
is the input signal from the detector 2, and a pulse signal of an integer multiple of 32 per revolution of the sewing machine is sent to the frequency dividing counter 31.
entered into the countdown. In the case of this embodiment, it is assumed that 128 (=32×4) pulses are input as the pulse signal a per one rotation of the sewing machine. The synchronizing signal c is also an input signal from the detector 2, and one pulse per revolution of the sewing machine is input to the one-shot pulse generating circuit 21 and the F/F circuit 22. The input/output port 13 outputs the feed data of each axis of X and Y to the pulse distribution circuits 27 and 28, and outputs the count set values AW, BW, CW, and DW to the hexadecimal counter 24 on each output line, and at the same time Round counter 31
Outputs count values AP, BP, CP, and DP to The frequency division counter 31 divides the pulse signal a into the AP,
After counting the values specified by BP, CP, and DP,
A pulse synchronized with the input pulse is output to the one-shot pulse generation circuit 32, and a one-shot pulse triggered by the rising edge of the pulse is output to the AND element 23. This one-shot pulse is also used to reset the count value of the frequency division counter 31 at the same time. The state of the output signal b of the frequency division counter 31 with respect to the set values of the count setting signals AP, BP, CP, and DP is shown in FIG. Other operations in FIG. 1 are similar to the conventional operations shown in FIG. 10. Next, in the timing chart shown in Fig. 2, the F/F determines the feed period during one rotation of the sewing machine.
The width of the valid period P of the output h of the circuit 25 is determined by the frequency division value shown in FIG. In other words, in Fig. 4, in the case indicated by (), the entire cycle of one rotation of the sewing machine becomes period P (frequency divided by 4), in the case of (), it is 3/4 (frequency divided by 3), and in the case of (), it is 1 /2 (divided by 2), () is 1/4 (input pulse as is)
becomes. Next, the operation of this embodiment will be explained with reference to the flowcharts of FIGS. 5 to 7 and the timing chart of FIG. 9. As shown in the main flowchart in Figure 5,
When the sewing machine is powered on, necessary initialization is performed in step 101. Next, move the material to be sewn.
Move the XY table (not shown) to a predetermined position. Thereafter, the necessary processes are executed, and it is determined in step 103 whether the operation switch is ON or not. If it is OFF, the process jumps to after the return-to-origin process 102, and the necessary processes are executed again while the sewing machine is stopped. When the operation switch is turned on in step 103, a preparatory process 104 necessary before operation is executed, and a subroutine 105 for sewing machine operation is entered. When the sewing machine operation is finished, a return-to-origin process 102 is performed, and it is again determined whether or not to start operation based on ON/OFF determination of the operation switch. FIG. 6 shows a subroutine of the sewing machine operation preprocessing 104 in FIG. First, at 301
All pattern data memory 17 in PROM is RAM
Move within 16. Then, in step 302, the stitch number counter in the RAM working area is set to 0, and in judgment 303, the number of stitches read in step 301 is compared with the stitch number counter, and if they are equal, processing is completed and the process returns to the main routine. Conversely, if they are different, 1 is added to the stitch count counter in step 304, and data for four stitches is read in step 305 from the RAM data corresponding to the stitch count counter value. Then, in step 306, the crossing angles θ ₁ , θ ₂ , and θ ₃ for one stitch are calculated from the pattern data read in 305, respectively. This is illustrated in Figure 8. In the figure, C0, C1, C2, C3 and θ ₁ , θ ₂ , θ ₃ indicate the stitches and their intersecting angles based on the pattern data for each stitch, respectively. Now, when the stitch number counter indicates the data number corresponding to C0 in the RAM 16, the respective intersection angles θ ₁ , θ 2 , θ 3 are determined by the X and Y axis movement data corresponding to C0, C1, _C2 , _{and C3} . Calculate. Then, at 307, the absolute value of θ ₃ and the constant value θ _L1 are compared and determined, and if |θ ₃ | is larger, the RAM data is changed at 310 so that C0 is set to medium speed and C1 and C2 are set to low speed. . In addition, a divide-by-3 instruction is added between the data of C0 and C1, and
A divide-by-4 instruction is inserted between the data of C2 and C3, and between the data of C2 and C3. Next, when |θ ₃ | is smaller than the constant value θ _L1 , 3
At step 08, the value of |θ ₂ |+|θ ₃ | is compared with the constant value θ _L2 . If |θ ₂ |+|θ ₃ | is larger, the RAM data is converted in step 311 so that C0 and C1 are at medium speed and C2 is at low speed. Also, C0 and C1
A divide-by-3 instruction is inserted between the data of C1 and C2, and a divide-by-4 instruction is inserted between the data of C2 and C3. Also, when the value of |θ ₂ |+|θ ₃ | is smaller than θ _L2 , |θ ₁ |+|θ ₂ |+|θ ₃ | is compared with the constant value θ _L3 in 309, and |θ ₁ | If +|θ ₂ |+|θ ₃ | is larger, change the RAM data at 312 so that C0, C1, and C2 all have medium speed, and also change C0 and C1, C1 and C2, and C2. Insert a divide-by-3 instruction between all data in C3. Note that the constant values θ _L1 , θ _L2 , and θ _L3 are values set in advance based on the driving ability. Thereafter, the process returns to the step 303, where the stitch number counter and the number of pattern stitches read by the PROM are compared again, and if they are equal, the process is deemed complete and the process returns to the main routine. This makes it possible to read changes in the movement direction due to the shape of the pattern and set the sewing speed and feed period to accommodate the changes. FIG. 3 shows an example of pattern data in the RAM 16 as a result of the data processing shown in FIG. 6. In the figure, the frequency switching data indicated by FD is newly added to the pattern data in the process of FIG. 6. FIG. 7 shows a subroutine for sewing machine operation 105 in FIG. To explain the diagram, first, after processing the status detection of various switch sensors,
At 201, the data for one stitch indicated by the data pointer is
Read from RAM16. An example of the contents of the RAM 16 is shown in FIG. It is determined whether the data read in 202 is cloth movement data (stitch data), and if it is movement data, necessary data calculation processing is performed in a data calculation processing step 203. Each axis and Y axis movement data is output, and in step 205, a command value is output to the motor driver 4 shown in FIG. 10 so that the speed corresponds to the stitch data included in the movement data. This sewing speed data is SP1, SP0 shown in Figure 3.
The combinations are shown in Table 1.

[Table] Next, after executing the sewing machine main shaft drive motor control processing 205, other processing necessary for sewing is performed, and the process returns to the starting point of the sewing machine operation subroutine 105, and the same processing is performed thereafter. If it is not movement data in determination 202,
At step 206, it is determined whether the data is the end data or not, and if the data is the end data, the process returns from the sewing machine operation subroutine 105 to the main routine. If it is determined in step 206 that the data is not end data, it is determined in step 207 whether or not it is frequency switching data. If the data is not switching data, determination of other various commands (thread trimming command, stop command, etc.) and data processing are performed. The frequency switching data is the data indicated by FD in the sewing data shown in Fig. 3, and is 4-bit frequency switching data (AP,
BP, CP, DP) and the synchronization signal c shown in Figure 2.
and count setting value data (AW, BW, CW, DW) for the counter 24 that determines the period W for adjusting the position of the feed period P. Judgment 20
If 7 is switching data, 208 is AP, BP,
It reads the data of CP and DP and outputs it to the input/output port 13 at 209. Then AW at 210,
The BW, CW, and DW data are read, and the delay timing set value is output to the input/output port 13 at 211, and the process returns to the starting point of the sewing machine operation subroutine 105. If the above operations are executed in accordance with the data order shown in FIG. 3, the motion shown in FIG. 9 will be obtained. This is an example of sewing the corner shown in FIG. 16A. P1, P2,...P shown in FIG.
8 indicates a cloth feeding period, which corresponds to P1, P2, . . . P8 shown in FIGS. 3 and 16A. 9th
In the figure, C1 to C8 are the sewing cycles of one rotation of the sewing machine, W3 to W6 are the feed adjustment periods, and L3 to L6 are the remaining time of one cycle after the end of feed. To explain this operation based on FIG. 9, C1,
In the cycle C2, the frequency of the pulse signal from the detector 2 is divided into four and used as a feed pulse, so that the entire cycle is a feed period, and the feed motion of each cycle is a continuous feed, and the sewing speed can be increased. When transitioning from the C2 cycle to the C3 cycle, as shown in FIG. 3, the divide-by-3 command data is inserted between the data of P2 and P3.
The feed period P3 is 3/4 of the cycle period C3.
period. At the same time, if the speed data also specifies medium/low speed, the number of rotations of the sewing machine will be half of the speed of the C1 and C2 cycles. Also, from C3 cycle
When shifting to the 4th cycle, the frequency division by 2 command data is inserted, so the sending period P4 becomes 2/4 (=1/2) period of the cycle C4. If the speed data also specifies low speed at the same time, the sewing machine rotation speed becomes the preset low speed rotation. Thereafter, sewing is performed in the same manner as C4→C5→C6→C7→C8. In this case, C3 has the same conditions as C6, and C7 and C8 have the same conditions as C1 and C2.
In other words, up to C1 and C2, continuous stitching is performed at high speed.
3. At the same time as lowering the sewing machine rotation speed with C4, change the feed period ratio P/C during one cycle period to 3/4 and 2/4, and set the intermittent feed to move the fabric when the needle is rising, C5, Conversely, the feed period ratio P/C is switched to 2/4, 3/4, and 4/4 at C6 and C7,
Change from intermittent feeding to continuous feeding again. This operation eliminates the collapse of corner sewing as shown in FIG. 16A, and enables beautiful sewing as shown in FIG. 16A. At the same time, by gradually decreasing the sewing speed, it is possible to prevent the pulse motor from falling out of synchronization and the presser foot from vibrating, thereby preventing the seams from becoming disordered. In the above embodiment, the number of pulses per revolution of the sewing machine from the detector 2 attached to the main shaft of the sewing machine was 128 pulses (=32×4), but this is 32
Various feeding periods can be set by increasing the integer multiplier. Here, the number 32 is the number of pulses corresponding to the maximum stitch length for one stitch. Furthermore, in this embodiment, all the pattern data in the PROM is read into the RAM 16, and the sewing speed data is corrected and the frequency switching data is inserted all at once. However, if a CPU with high calculation processing speed is used, In this case, the data pre-reading process shown in Figure 6 is performed during sewing, and the data can be read directly without reinstalling the RAM.
It is also possible to run with data from PROM. [Effects of the Invention] As described above, according to the present invention, the ratio of the feed period in one sewing cycle can be automatically changed according to the sewing pattern or the condition of the sewing material, and the sewing speed can be set for each stitch. For example, for thin material to be sewn, high-speed continuous stitching can be performed on straight sections, and low-speed intermittent stitching can be performed on corner sections, and high-speed continuous stitching can be performed on thin sections when there is a difference in the thickness of the material. Sewing can be performed using low-speed intermittent stitching in thick areas. In other words, the pattern data is read before the sewing machine starts, and the switching data of continuous/intermittent and sewing speed is determined on the sewing machine side during sewing by performing arithmetic processing.
It is possible to automatically switch between continuous/intermittent sewing and sewing speed during each sewing process, so beautiful, uniform seams can be obtained even when sewing corners. This has the effect of preventing step-out and vibration of the presser foot, and shortening the cycle time of the sewing pattern.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the internal configuration of a pulse train generation circuit in an embodiment of the present invention, FIG. 2 is a timing chart of each pulse signal in FIG.
FIG. 4 is an explanatory diagram of an example of the structure of pattern data, FIG. 4 is an explanatory diagram of an example of specifying a dividing value in pattern data, FIG. 5 is a main flowchart in an embodiment of the present invention, and FIG.
FIG. 7 is a flowchart showing a sewing machine operation pre-processing subroutine, FIG. 7 is a flowchart showing a sewing machine operation subroutine, FIG. 8 is an explanatory diagram of an example of a pattern for explaining the operation in FIG. 6, and FIG. 9 is a flowchart showing a sewing machine operation subroutine. Timing chart showing example operation, No. 10
The figure is a block diagram showing the overall configuration of a conventional example.
12 is a circuit diagram showing the internal configuration of a conventional pulse train generation circuit. FIG. 12 is a timing chart of each pulse signal in FIG. 11. FIG. FIG. 14 is a timing chart during conventional continuous cloth feeding, FIG. 15 is an explanatory diagram showing a corner sewing state, and FIG. 16 is a circuit diagram showing the internal configuration of another example of the conventional pulse train generation circuit. 1...Sewing machine head, 2...Detector, 3...Motor, 4...Motor driver, 5...X-axis pulse motor, 6...Y-axis pulse motor, 7...X-axis pulse motor driver, 8 ... Y-axis pulse motor driver, 9 ... Pulse train generation circuit, 12 ... CPU,
13, 14...PPI, 15...PROM, 16...
RAM, 17...Data memory, 21...One shot pulse generation circuit, 22...F/F circuit, 2
3...AND element, 24...Hex counter circuit,
25... F/F circuit, 26... AND element, 2
7, 28... Pulse distribution circuit, 29... 32-decimal counter circuit, 30... One shot pulse generation circuit, 31... Frequency division counter, 32... One shot pulse generation circuit, and the same reference numerals in the figure indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. In a control device for an automatic sewing machine that is controlled to sequentially read out pre-programmed pattern data and form stitches according to the data, a specific number of workpiece feeds synchronized with the rotation of the sewing machine are provided. Equipped with a counter circuit for frequency-dividing a pulse train by a specified value, and a pulse distribution circuit for generating a number of pulse trains corresponding to a specified stitch length from the pulse train after frequency division, A control device for an automatic sewing machine, characterized in that the width of the feed pulse train for one cycle of sewing machine rotation can be changed by switching the designated frequency dividing value accordingly. 2 The above pattern data is prepared in advance before sewing.
The pattern data stored in the PROM is sequentially read out, the sewing speed is changed according to the change in the crossing angle of the sewing direction, and the specified frequency division value after the above switching becomes the format inserted between the stitch data. 2. A control device for an automatic sewing machine according to claim 1, wherein the control device is modified as follows and stored in a temporary storage memory.