JPH0148787B2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention relates to a sewing machine that forms zigzag stitches on work cloth, and in particular, a sewing machine that is equipped with a cloth edge detector on the cloth feeding side from the needle drop point. The present invention relates to a sewing machine which automatically stops operation of the sewing machine after sewing a predetermined length after detecting a cloth end using a cloth end detector.

(Prior art) In this conventional sewing machine, for example, the 18th
As shown in Figures a and b, when sewing a cloth piece W2 such as a label or a name, which is another work cloth, on the work cloth W1, such as a work cloth W1 that is in its best season, when sewing one side edge of the cloth piece W2, After the cloth edge is detected by the cloth edge detector, a predetermined number of zigzag stitches corresponding to the distance L from the cloth edge detection point to the end of the piece of cloth W2 are formed, regardless of the zigzag amplitude 1 of the needle. , sewing machine operation is now stopped.

(Problem to be Solved by the Invention) Therefore, the needle stop position of the last needle of the zigzag stitch along one side edge of the cloth piece W2 is shown in FIG.
Whether the last needle is inside the piece of cloth W2 as shown at P2 in FIG. 18b or outside of the piece of cloth W2 as shown at P2 in FIG. The workpiece cloth W1 and When the cloth piece W2 is rotated to form a zigzag seam along the other side edge of the cloth piece W2, the zigzag seam is shifted outward at the other side edge of the cloth piece W2 as shown in FIG. 18a. There is a problem in that the value of the sewn product decreases because the threads are formed or are formed inwardly as shown in FIG. 18b.

Structure of the Invention (Means for Solving the Problems) The present invention has been made by paying attention to the above-mentioned problems. a stitch forming device that includes a needle 28 that swings left and right in synchronization with the vertical movement of the sewing machine, and forms a zigzag stitch on the work cloth on the work cloth support surface; A work cloth feeding device which is operated in synchronization and which transports the work cloth intermittently; a feed adjuster which adjusts the feed pitch of each workpiece by the work cloth feeding device; a cloth edge detector disposed on the feeding side for detecting the edge of the work cloth, a storage means for storing distance data between the cloth edge detector and the needle drop point, and the cloth edge 1/2 of the zigzag amplitude from the clothing edge at the time of detection
A control means is provided for controlling the operation of the feed adjuster based on the data stored in the storage means and the detection data from the swing direction detector so that the final needle falls at separated points.

(Function) Therefore, in the sewing machine of the present invention, when the fabric edge detector detects the fabric edge, the distance data between the fabric edge detector and the needle drop point stored in the storage means and the swing direction detector are used to detect the fabric edge. Based on the detection data of the needle swing direction, the feed amount of the work cloth by the feed adjuster is changed arbitrarily, for example, when sewing a piece of cloth such as a label or a name, which is another work cloth, on the work cloth. When sewing along one side edge of a piece of cloth in
The sewing machine operation is stopped precisely at a point one-tenth of a distance apart, and subsequent stitching is performed along the other side edge of the fabric piece so that the other side edge is located in the center of the zigzag stitch. It can be carried out continuously and easily, and sewn products with high product value can be obtained.

(Embodiment) Hereinafter, an embodiment of a sewing machine embodying the present invention will be described in detail with reference to the drawings.

Now, in the sewing machine of this embodiment, the first,
As shown in Figure 2, arm part 1 of sewing machine frame 1
A sewing machine main shaft 2 is rotatably supported within a, and a driven pulley 3 is attached to the right end thereof. A drive motor 4 is disposed below the bed portion 1b of the sewing machine frame 1, and a belt 6 is hung between the drive pulley 5 on the motor shaft and the driven pulley 3. Based on the depression of the operation pedal 7 provided below the sewing machine frame 1, the drive motor 4 is rotated at a rotational speed corresponding to the amount of depression, and the drive pulley 5, belt 6, and driven pulley 3 are accordingly rotated. The main shaft 2 of the sewing machine is rotated through the main shaft 2.

A presser foot 8 is supported on the arm portion 1a of the sewing machine frame 1 so as to be movable up and down, and its lower end applies cloth presser pressure to the workpiece cloths W1 and W2 supported on the workpiece cloth support surface 9 of the bed portion 1b. A presser foot 10 is attached for this purpose. A feed dog 11 is disposed in the bed portion 1b of the sewing machine frame 1 so as to be retractable on the work cloth support surface 9 so as to cooperate with the presser foot 10 to constitute a work cloth feeding device. As the main shaft 2 rotates, the workpiece cloths W1 and W2 on the workpiece cloth support surface 9 are intermittently conveyed by a four-feed movement.

As shown in FIGS. 1 and 3, a feed adjuster 12 is rotatably supported within the sewing machine frame 1 via an adjustment shaft 13, and a feed dog 1 is connected via a connecting rod 14, etc.
It is linked to 1. An adjustment knob 15 is rotatably provided on the front surface of the arm portion 1a of the sewing machine frame 1, and as the adjustment knob 15 is rotated, the feed adjuster 12 is rotated, and the feed dog 11 adjusts the feed for each stitch. The setting of Pitch is starting to change.

A servo solenoid 16 is disposed within the sewing machine frame 1 near the feed adjuster 12;
The armature 17 is connected to one end of the adjustment shaft 13 via a connecting arm 18. When the servo solenoid 16 is operated, the feed adjuster 12 is rotated in accordance with the amount of protrusion of the armature 17, and the setting of the feed pitch for each stitch by the feed dog 11 is changed. A feed pitch detector 19 consisting of a potentiometer or the like is disposed in the sewing machine frame 1 near the feed adjuster 12, and its operating shaft 20 is connected to the adjusting shaft 13 and other parts via a pair of rotating levers 21 and 22. connected to the end. As the feed adjuster 12 rotates, the operating shaft 20 of the feed pitch detector 19 is rotated so that a detection signal corresponding to the feed pitch adjusted by the feed adjuster 12 is output. It's summery.

As shown in FIGS. 1 and 2, a sliding shaft 23 is supported in the arm portion 1a of the sewing machine frame 1 through a pair of bearing metals 24 so as to be movable left and right, and a needle bar support frame 25 is attached to the tip of the sliding shaft 23. is attached. A needle bar 26 is supported by the needle bar support frame 25 so as to be movable up and down, a needle bar holder 27 is fixed approximately at the center thereof, and a needle 28 is attached to the lower end. A crank body 29 is fixed to the left end of the sewing machine main shaft 2 above the needle bar support frame 25, and a needle bar connecting rod 30 is provided between the left side of the crank body 29 and the needle bar holder 27. When the crank body 29 is rotated with the rotation of the sewing machine main shaft 2, the needle bar 26 and needle 28 are moved up and down via the needle bar linking rod 30 and the needle bar holder 27.

On the sliding shaft 23, a swing linking rod 31 is rotatably attached at one end via a connector 32, and an adjustment piece 33 is rotatably supported at the other end.
An eccentric cam 34 is rotatably supported in the arm portion 1a of the sewing machine frame 1 below the swing link 31 via a rotating shaft 35, and a ring 36 that embraces the eccentric cam 34 is attached to the swing link 31. It is rotatably supported almost in the middle. As the sewing machine main shaft 2 rotates, the eccentric cam 34 is rotated via the gears 37 and 38, so that the swing linking rod 31 is provided with a swing motion via the ring 36.

An amplitude adjuster 39 is rotatably supported within the arm portion 1a of the sewing machine frame 1 below the other end of the swing linking rod 31, and the amplitude adjuster 39 is rotatably supported within the arm portion 1a of the sewing machine frame 1, and the amplitude adjuster 39 is provided between a pair of support arms 39a protruding from the rear surface. An adjustment pin 40 penetrating the frame 33 is installed. and,
When the vibration linking rod 31 is oscillated by the eccentric cam 34,
The adjustment piece 33 is moved up and down along the adjustment pin 40, and according to the inclination state of the adjustment pin 40, a lateral movement is caused in the connector 32 portion at one end of the swing linking rod 31, and the sliding shaft 23 and needle The needle bar 26 and needles 28 are designed to be swung in the left and right direction via the rod support frame 25.

An operating knob 4 is provided on the front surface of the amplitude adjuster 39 so as to protrude from the front surface of the arm portion 1a of the sewing machine frame 1.
1 is fixed, and by rotating and adjusting the amplitude adjuster 39 with this operating knob 41, the adjustment pin 40
The setting of the swing amplitude of the needle 28 is changed by changing the inclination state of the needle 28. An amplitude detector 42 consisting of a potentiometer or the like is disposed in the sewing machine frame 1 near the amplitude regulator 39, and its operating shaft 43 is connected to the amplitude regulator 39 via a pair of rotating levers 44, 45. has been done. As the amplitude adjuster 39 rotates, the operating shaft 43 of the amplitude adjuster 42 is rotated, and a detection signal corresponding to the swing amplitude of the needle 28 adjusted and set by the amplitude adjuster 39 is output. It's becoming like that.

As shown in FIG. 1, a thread loop catcher 46 is disposed in the bed portion 1b of the sewing machine frame 1 in correspondence with the needle 28. A forming device is configured. As the main shaft 2 of the sewing machine rotates, the needle 28 is moved up and down while being swung left and right, and the thread ring catcher 46 is operated, so that the work cloth support surface 9 is moved as shown in FIG. Zigzag stitches are formed on the upper work cloths W1 and W2.

As shown in FIGS. 1, 4, and 5, a light projector 47 is attached to the front surface of the arm portion 1a of the sewing machine frame 1. As shown in FIGS. On the other hand, a light receiver 48 is provided on the bed portion 1b of the sewing machine frame 1 so as to be located on the cloth feeding side with respect to the falling point of the needle 28. It is designed to output a detected signal.
And, with this light emitter 47 and light receiver 48,
A cloth edge detector 49 is configured to detect the edges of the work cloths W1 and W2. Moreover, as shown in FIGS. 1 and 2, the connector 32 on the sliding shaft 23
Correspondingly, a needle swing direction detector 50 consisting of a magnetic gap sensor or the like is disposed in the arm portion 1a of the sewing machine frame 1, and when the cloth edge detector 49 detects the cloth edge, the needle swing direction detector 50 detects the distance between the connector 32 and the Based on the change in the gap, a detection signal corresponding to the swinging direction of the needle 28 is output.

As shown in FIGS. 6 and 7, on the left side surface of the driven pulley 3, there is a first reflecting plate 51 having an arc-shaped notch 51a on the outer periphery, and a first reflecting plate 51 having a ring shape and having a notch 51 on the inner periphery.
2a is attached. A non-reflective portion 53 for detecting the needle top position is formed in a portion defined by the notch 51a and the inner peripheral edge of the second reflective plate 52, and
A non-reflective portion 54 for detecting the needle down position is formed in a portion defined by the outer peripheral edge of the reflecting plate 51. Further, on the surface of the second reflection plate 52, a large number of non-reflection surfaces 55 for generating synchronization signals (timing pulses) are formed at predetermined angular intervals.

A needle top position detector 56 is provided on the arm portion 1a of the sewing machine frame 1 so as to oppose the rotation locus of the non-reflective portions 53, 54 and the non-reflective surface 55 at positions close to the reflective plates 51, 52, respectively. A needle down position detector 57 and a synchronization signal generator 58 are respectively installed. Both detectors 56, 57 and synchronization signal generator 58 are light emitting elements 56a, 57, respectively.
a, 58a and light receiving elements 56b, 57b, 58b
The light from each of the light emitting elements 56a, 57a, and 58a is reflected by the reflecting plates 51 and 52, and is transmitted to the light receiving element 5.
6b, 57b, and 58b. As shown in FIG. 8, when the needle 28 reaches the needle up position and the needle down position, a needle up position detection signal and a needle drop are output from the detectors 56 and 57 in response to the non-reflective parts 53 and 54. A position detection signal is output, and as the driven pulley 3 rotates, the non-reflective surface 55 and the reflective surface alternately pass, so that a synchronizing signal generator 58 generates a synchronizing signal.

As shown in FIG. 1, a needle stop position setting switch 59 is provided in the arm 1a of the sewing machine frame 1, and a setting knob 60 that projects from the front of the arm portion 1a is provided at the front of the switch 59. For example, as shown in FIG. 5, when sewing a piece of cloth W2 such as a label or a name, which is another work cloth, on the work cloth W1, the needle stop position setting switch 59 is pressed.
By selecting and setting the inner stop position or the outer stop position with the setting knob 60, the stop position of the final needle of the zigzag stitch along one side edge of the cloth piece W2 can be set as follows:
A stop signal for moving the cloth piece W2 to the inside as shown by P1 in FIGS. 14 and 15, or a stop signal for moving the cloth piece W2 to the outside as shown by P2 in FIGS. It is designed to be output from the stop position setting switch 59.

Next, the control circuit of the sewing machine configured as described above will be explained with reference to FIG. A constituent random access memory (RAM) 63 is connected. The ROM62 stores programs for controlling the entire sewing machine, and the RAM6
3 shows data regarding the distance L between the light receiver 48 of the cloth edge detector 49 and the drop point of the needle 28 shown in FIG. 5, that is, the sewing length after the cloth edge is detected by the cloth edge detector 49, and the feed The amount of operation of the servo solenoid 16 corresponding to the detection signal of the pitch detector 19 is stored.

The detector CPU 61 also includes a needle stop position setting switch 59, a cloth edge detector 49, and a needle top position detector 5.
6, needle down position detector 57, synchronization signal generator 58,
The amplitude detector 42, the feed pitch detector 19, the needle swing direction detector 50, and the operating pedal 7 are connected via an input interface 64, and various signals from these are input to the CPU 61. Furthermore, the CPU61 has servo solenoid 1.
6 and motor 4 are connected via an output interface 65 and drivers 66, 67, and the CPU 6
1 outputs a drive or stop signal to the servo solenoid 16 and motor 4.

Next, the operation of the sewing machine configured as described above will be explained.

Now, with this sewing machine, when sewing a piece of cloth W2 such as a label or a name, which is another workpiece cloth, onto the workpiece cloth W1, such as the front end of the workpiece, as shown in FIG. Operation knob 4
1, the amplitude adjuster 39 is rotated to set the swing amplitude 1 of the needle 28, and the adjustment knob 15 is
Rotatingly adjust the feed adjuster 12 by adjusting the feed dog 11.
The feed pitch F of the work cloths W1 and W2 is set according to the following. After that, when you turn on the sewing machine, the 10th
The program shown in the flowchart in Figure
It is started under the control of CPU61, and first CPU6
1 waits for the needle stop position setting switch 59 to be set in step S1, and then the setting switch 59 is set.
is set to the inner stop position or outer stop position by the setting knob 60, the program returns to step S.
Proceed to step 2.

In step S2, the CPU 61 waits for the operating pedal 7 to be operated, and when the operating pedal 7 is pressed forward, the program advances to step S3, and the motor 4 is started at a rotational speed corresponding to the amount of depression of the operating pedal 7. Then, sewing operation of the sewing machine is started, and as shown in FIG. 5, a zigzag stitch of feed pitch F is formed along one side edge of cloth piece W2 on workpiece cloth W1 with the swing amplitude of 1. Ru. Then, in the next step S4, the swing amplitude 1 of the needle 28 is detected by the signal from the amplitude detector 42, and in step S5, the feed pitch F for each stitch is detected by the signal from the feed pitch detector 19. and those data are written into a predetermined data area of the RAM 63.

In the next step S6, the CPU 61 waits for the cloth edge detector 49 to detect the edge of the cloth piece W2 based on the change in the amount of transmitted light, and simultaneously proceeds to step S7 to detect the edge of the cloth W2 in the needle swing direction. detector 50
Based on the signal from W2, it is detected whether the swinging direction of the needle 28 when detecting the cloth edge is from the outside to the inside of the piece of cloth W2 or from the inside to the outside, and the data is written to a predetermined data area of the RAM 63. be included.

In the next step S8, the subroutine program shown in FIG. 11 is executed.
And in the scan around S10, the number of pulses of the synchronization signal from the synchronization signal generator 58 as shown in FIG. 8 after the cloth edge detection is counted, and the needle down signal from the needle down position detector 57 is detected. When this occurs, that is, at the time of the first needle drop after detecting the fabric edge, the process advances to step S11 and the counting of the synchronizing signal is stopped. In the next step S12, the CPU 61 compares the feed pitch data F stored in the RAM 63 with the count number and calculates the fifth
Processed fabric W1 shown in the figure and FIGS. 14 to 17,
The sending phase m of W2 is calculated and written into a predetermined data area of the RAM 63. The feed phase m is calculated as, for example, 0.5 as a ratio of the feed bit data F to 1, and the value is written in a predetermined data area. Note that the black circles and white circles shown in FIG. 5 and FIGS. 14 to 17 indicate the needle drop points before and after the stitch formation, respectively.

Thereafter, the program returns to the main routine shown in FIG. 10 and proceeds to step S13. In this step S13, it is determined whether the final needle stop position of the zigzag stitch set by the needle stop position setting switch 59 is inside the piece of cloth W2, and as shown by P1 in FIGS. If it is inside, the process advances to step S14, and the first
If it is outside, as shown by P2 in FIGS. 6 and 17, the process advances to step S15. Then, in step S14, the calculation subroutine program shown in FIG. 12 is executed, and in step S15, the calculation subroutine program shown in FIG. 13 is executed.

First, the subroutine program shown in FIG. 12 will be explained. In step S16, the swinging direction of the needle 28 at the time of detecting the cloth edge detected by the needle swinging direction detector 50 is from the outside to the inside of the piece of cloth W2. It is determined whether or not the first
As shown in FIG. 4, if the direction is from the outside to the inside, the process proceeds to step S17, and if the direction is from the inside to the outside, as shown in FIG.
Proceed to 18. These steps S17 and S18
In this case, the CPU 61 detects the cloth edge detector 4.
Distance data L between the light receiver 48 of No. 9 and the needle drop point
to 1/2 of zigzag amplitude 1 and feed pitch F
The calculation of subtracting the product of and the feed phase m and dividing the value by the feed pitch F is performed, and then the process proceeds to steps S19 and S20, respectively.

In steps S19 and S20, it is determined whether or not there is a remainder in the quotient of the calculation result, and if it is determined in step S19 that there is a remainder, then step S is performed.
21, if there is no remainder, the process proceeds to step S22, and if it is determined in step S20 that there is a remainder, the process proceeds to step S23, and if there is no remainder, the process proceeds to step S24. In steps S21, S22, S23, and S24, it is determined whether or not the quotient integer of the calculation result is an odd number. If the determination result in step S21 is an odd number or the determination result in step S23 is an even number, the step Proceed to S25 and step S21
If the result of the determination in step S23 is an even number, the process advances to step S26, and if the result of the determination in step S22 is an odd number, and the result of the determination in step S24 is an even number, the process advances to step S27. However, if the determination result in step S22 is an even number or if the determination result in step S24 is an odd number, the process proceeds to step S28.

Then, in steps S25 and S26, the quotient integer of the calculation result is set as the number of stitches with the preset feed pitch F as the basic pitch, and the data is written in a predetermined data area of the RAM 63 as being reduced. . Moreover, the step S
In step 27, the value obtained by subtracting 1 from the quotient integer of the calculation result is set as the number of stitches of the basic pitch, and the data is written as having been reduced. Further, in step S28, the quotient integer of the calculation result is set as the number of stitches of the basic pitch, and the data is written without reduction.

After the setting operation in step S25, the remainder of the quotient in the calculation result is set as the reduction pitch in step S29, and the number of reduction stitches is set as 1 in step S30.
These data are written into a predetermined data area of the RAM 63. After the operation in step S26, in step 31, 1/2 of the remainder of the quotient in the calculation result is set as the reduction pitch, and in step S32, the number of reduction stitches is set as 2, and these data are is written to a predetermined data area. Furthermore, the step S27
After the operation, in step S33, 1/2 of the feed pitch F is set as a reduction pitch, and in step S34, the number of reduction stitches is set as 2, and these data are written in a predetermined data area. Then, the program returns from steps S28, S30, S32, and S34 to the main routine shown in FIG. 10, and proceeds to step S55.

On the other hand, in the subroutine program shown in FIG. 13, it is determined whether the swinging direction of the needle 28 at the time of detecting the cloth edge detected by the needle swinging direction detector 50 in step S36 is from the inside to the outside of the piece of cloth W2. If the direction is from the inside to the outside as shown in FIG.
If the direction is from the outside to the inside as shown in FIG. 17, the process advances to step S38. In steps S37 and S38, the CPU
61, add 1/2 of the zigzag amplitude 1 to the distance data L between the light receiver 48 of the material edge detector 49 and the needle drop point, and subtract the product of the feed pitch F and the feed phase, and calculate the value. is divided by the feed pitch F, and then step S
39 and proceed to S40, respectively.

In the program from steps S39 to S54, the same program as steps S19 to S34 in the flowchart shown in FIG.
From S54, the process returns to the main routine shown in FIG. 10 and proceeds to step S55.

In this step S55, after the cloth edge detector 49 detects the cloth edge, it is determined whether sewing has been performed corresponding to the number of stitches of the basic pitch, and at the same time as the sewing is completed, the process proceeds to step S56 to reduce the feed pitch. It is determined whether or not it is necessary. If reduction is necessary, proceed to step S57.
A drive signal according to the reduced feed pitch data is output from the CPU 61 to the servo solenoid 16, and the feed adjuster 12 is rotationally adjusted by the protrusion of the armature 17 of the servo solenoid 16.
1, the feed pitch per stitch is reduced. In the next step S58, it is determined whether sewing has been performed for the specified number of stitches using the reduced feed pitch. If NO, the process returns to step S57 and the scan continues through steps S57 and S58. be done.

Then, if it is determined in step S56 that it is not necessary to reduce the feed pitch, and if it is determined in step S58 that sewing of the specified number of stitches using the reduced feed pitch has been completed, the program advances to step S59 and the CPU 61 A stop signal is output to the motor 4, and the sewing operation of the sewing machine is stopped with the needle 28 penetrating the work cloths W1 and W2 on the finger support surface 9 of the work cloth and being located at the bottom dead center.

Therefore, for example, as shown in FIG. 14, the final needle stop position is inside the piece of cloth W2 on the workpiece cloth W1, and the swinging direction of the needle 28 when detecting the cloth edge is from the outside of the piece of cloth W2 to the inside. In this case, there is a remainder in the quotient of the operation result in step S17 of the subroutine shown in FIG.
→S25→S29→S30, as shown in Fig. 14a, 5 stitches are sewn with the quotient integer as the basic pitch stitch number, and then 1 stitch is sewn with the remainder as the reduced pitch. The last needle drops to a point P1 which is separated by half of the zigzag amplitude 1 toward the inner side of the cloth piece W2, and in this state, the sewing operation of the sewing machine is stopped. Therefore, after rotating the work cloth W1 and the cloth piece W2 from this state around the final needle drop point P1, when continuing sewing along the other side edge of the cloth piece W2, A zigzag seam can be formed such that the other side edge is centered.

Furthermore, in the case of FIG. 14 described above, if there is a remainder in the quotient of the calculation result and the quotient integer is an even number, the program of FIG.
21→S26→S31→S32, as shown in FIG. 14b, after 6 stitches are sewn with the quotient integer as the basic stitch number, the remaining half is used as the reduced pitch. Two stitches worth of sewing is performed, and the final needle drops to the same point P1 as described above.
Then, if there is no remainder in the quotient of the operation result and the quotient integer is an odd number, the program starts at step S.
19→S22→S27→S33→S34, as shown in FIG. Two stitches of sewing are performed using the reduced pitch of 1, and the final needle falls at point P1. Furthermore, when there is no remainder in the quotient of the calculation result and the quotient integer is an even number, and the program progresses from step S19 → S22 → S28,
As shown in Fig. 14d, only 6 stitches are sewn with the quotient integer as the basic pitch stitch number, and the final stitch is P.
Fall to 1 point.

On the other hand, as shown in FIG. 15, when the final needle stop position is inside the cloth piece W2 and the swinging direction of the needle 28 at the time of cloth edge detection is from the inside to the outside of the cloth piece W2, the 12th If there is a remainder in the quotient of the operation result in step 18 in the figure and the quotient integer is an even number, the program will proceed to steps S20→S23→
When progressing from S25 → S29 → S30, the first
As shown in Figure 5a, after six stitches are sewn using the quotient integer as the basic pitch stitch number, one stitch is sewn using the remainder as the reduced pitch, and the final stitch is the same as above. It falls to point P1. Then, if there is a remainder in the quotient of the calculation result and the quotient integer is an odd number, the program proceeds to steps S20→S23→S2.
When the process progresses from 6 to S31 to S32, as shown in Fig. 15b, 5 is set with the quotient integer as the basic pitch stitch number.
After the stitches have been sewn, two stitches are sewn using the remaining 1/2 as the reduction bit, and the final needle drops to the point P1.

Furthermore, in the case of FIG. 15 described above, if there is no remainder in the quotient of the calculation result and the quotient integer is an even number, the program of FIG.
24 → S27 → S33 → S34, as shown in Fig. 15c, after sewing is performed for 5 stitches with the basic pitch stitch number being the quotient integer -1, half of the feed pitch F is sewn. Two stitches are sewn with a reduced pitch of , and the final needle drops to point P1.
Furthermore, if there is no remainder in the quotient of the operation result and the quotient integer is an odd number, the program is executed at step S.
When progressing from 20 → S24 → S28, the 15th
As shown in FIG. d, only seven stitches of sewing are performed, with the quotient integer being the basic pitch stitch number, and the final stitch falls at point P1.

Next, as shown in FIG. 16, the final needle stop position is outside the cloth piece W2 on the workpiece cloth W1, and the swinging direction of the needle 28 when detecting the cloth edge is from the inside of the cloth piece W2 to the outside. In some cases, there is a remainder in the quotient of the calculation result in step S37 of the subroutine shown in FIG. 13, and the quotient integer is an odd number,
The program goes to step S39→S41→S45→
When the process progresses from S49 to S50, as shown in Fig. 16a, after seven stitches are sewn with the quotient integer as the basic pitch stitch number, one stitch is sewn with the remainder as the reduced pitch. Then, the final needle falls at a point P2 that is spaced by half of the zigzag amplitude 1 from the end of the cloth piece W2 to the outside.

Furthermore, in the case of FIG. 16 described above, if there is a remainder in the quotient of the calculation result and the quotient integer is an even number, the program of FIG.
41→S46→S51→S52, as shown in FIG. 16b, after eight stitches are sewn with the quotient integer as the basic pitch stitch number, the remaining half is used as the reduced pitch. Two stitches worth of sewing is then performed, and the final needle falls at the same point P2 as described above.
Then, if there is no remainder in the quotient of the operation result and the quotient integer is an odd number, the program starts at step S.
39→S42→S53→S53→S54, as shown in FIG. Sewing for two stitches is performed using the reduced pitch of 1, and the final needle drops to the point P2. Furthermore, when there is no remainder in the quotient of the operation result and the quotient integer is an even number, and the program progresses from S39 to S42 to S48, the first
As shown in Figure 6d, only eight stitches are sewn with the quotient integer as the basic pitch stitch number, and the final stitch is
It falls to 2 points.

On the other hand, as shown in FIG. 17, when the final needle stop position is outside the cloth piece W2 and the swinging direction of the needle 28 when detecting the cloth edge is from the outside to the inside of the cloth piece W2, the 13th If there is a remainder in the quotient of the operation result in step S38 in the figure and the quotient integer is an even number, the program will proceed from step S40 to S43.
→S45→S49→S50, as shown in Fig. 17a, 8 stitches are sewn with the quotient integer as the basic pitch stitch number, and then 1 stitch is sewn with the remainder as the reduced pitch. is performed, and the final needle drops to the same point P2 as above. Then, if there is a remainder in the quotient of the calculation result and the quotient integer is an odd number, the program proceeds to steps S40→S43→S.
When it progresses from 46 → S51 → S52, the 17th
As shown in Figure b, after 7 stitches are sewn with the quotient integer as the basic pitch stitch number, 2 stitches are sewn with the remaining 1/2 as the reduced pitch, and the final stitch is It falls to the point P2.

Furthermore, in the case of FIG. 17 described above, if there is no remainder in the quotient of the operation result and the quotient integer is an even number, the program of FIG.
44→S47→S53→S54, as shown in FIG. 17c, after 7 stitches are sewn with the basic pitch stitch number being the quotient integer minus 1, 1/2 of the feed pitch F is sewn. Two stitches of sewing are performed using the reduced pitch, and the final needle drops to the point P2. Furthermore, when there is no remainder in the quotient of the calculation result and the quotient integer is an odd number, and the program progresses from step S40 to step S44 to step S48, the quotient integer is used as the basic pitch stitch number as shown in FIG. 17d. Only nine stitches of sewing are performed, and the final needle falls at the point P2.

Therefore, even in sewing where the final needle drops and stops outside the piece of cloth W2 on the workpiece cloth W1 as shown in FIGS. 16 and 17, the final needle's falling point P in this stopped state
After rotating the workpiece cloth W1 and the piece of cloth W2 around 2, when continuing sewing along the other side edge of the piece of cloth W2, zigzag stitching is performed so that the other side edge of the piece of cloth W2 is located in the center. Eyes can be formed.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments, and the configuration of each part can be arbitrarily changed and embodied without departing from the spirit of the invention.

Results of the Invention As detailed above, according to the present invention, when the cloth edge detector detects the cloth edge, the distance data and the swing direction between the cloth edge detector and the needle drop point stored in the storage means are detected. Based on the needle swing direction detection data from the machine, the feed amount of the work cloth by the feed adjuster is arbitrarily set and changed, for example, when sewing a piece of cloth such as a label or a name on another work cloth. When sewing along one side edge of a piece of cloth, the last needle of the zigzag stitch is always 2 times the zigzag amplitude from the edge of the cloth.
The sewing machine operation is stopped precisely at a point one-tenth of a distance apart, and subsequent stitching is performed along the other side edge of the fabric piece so that the other side edge is located in the center of the zigzag stitch. It can be carried out continuously and easily, and has excellent effects in that sewn products with high product value can be obtained.

[Brief explanation of drawings]

Fig. 1 is a front view showing a sewing machine embodying the present invention with the main control circuit added, Fig. 2 is a partial perspective view showing the swinging and vertical movement of the needle, and Fig. 3 is an adjustment of the feed pitch. FIG. 4 is a partial perspective view showing the sewing work section. FIG. 5 is a partial plan view showing the sewing work section. FIG. 6 is a partial perspective view showing the sewing work section. FIG. 6 is a partial perspective view showing the sewing work section. 7 is a partial sectional view showing the arrangement of the hand position detector and the synchronization signal generator; FIG. 8 is a time chart showing the generation status of the hand position detection signal and the synchronization signal; FIG. Figure 9 is a block diagram showing the control circuit.
Fig. 0 is a flowchart showing the sewing routine of the sewing machine, Fig. 11 is a flowchart showing the feed phase detection subroutine when detecting the fabric end, Fig. 12 is a flowchart showing the feed pitch calculation subroutine after detecting the fabric edge, and Fig. 13 is a flowchart showing the feed pitch calculation subroutine after detecting the fabric edge. The figure also shows a flowchart showing the calculation subroutine, Figures 14 to 17 are plan views showing examples of various seam formations when sewing pieces of cloth onto work cloth, and Figures 18a and b are views of a conventional sewing machine. FIG. 3 is a partial plan view showing an example of seam formation in FIG. 2... Sewing machine main shaft, 9... Work cloth support surface, 10... Presser foot forming work cloth feeding device, 11... Feed dog forming work cloth feeding device, 12... Feed adjuster, 2
8... Needle constituting the seam forming device, 46... Thread loop catcher constituting the stitch forming device, 49... Fabric edge detector,
50... Needle swing direction detector, 61... CPU constituting control means, 63... RAM constituting storage means.

Claims (1)

[Scope of Claims] 1. Includes a needle 28 which is moved up and down across the work cloth support surface 9 as the sewing machine main shaft 2 rotates, and which is swung left and right in synchronization with the up and down movement; a seam forming device for forming zigzag seams on the work cloths W1 and W2 on the support surface 9; and a seam forming device that is operated in synchronization with the rotation of the sewing machine main shaft 2;
Work cloth feeding devices 10 and 11 for intermittently transporting the work cloths W1 and W2, and a feed adjuster 12 for adjusting the feed pitch for each stitch by the work cloth feeding devices 10 and 11.
and a cloth edge detector 4 disposed on the cloth feeding side from the needle drop point and for detecting the edge of the work cloth W2.
9, a storage means 63 for storing distance data between the cloth edge detector 49 and the needle drop point, and a swing direction detector 50 for detecting the swing direction of the needle 28 when detecting the cloth edge. , The feed adjuster 12 is operated based on the data stored in the storage means 63 and the detected data from the swing direction detector 50 so that the final needle falls at a point spaced from the edge of the fabric by half the zigzag amplitude. A sewing machine comprising a control means 61 for controlling.