JPS625395A - Constant dimension stitching apparatus in sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention is configured to detect the actual feed amount of the work cloth by the feed dog and perform fixed-size sewing after detecting the edge of the cloth. This invention relates to a fixed-size sewing device for fabric edges in a sewing machine.

(Prior art) Conventionally, this type of fixed-size stitching device for fabric edges adds the counts after the fabric edge is detected by a fabric edge detector, and the count corresponds to a preset sewing length. A sewing machine is known in which the main spindle of the sewing machine is stopped when a match is made, and the end of the fabric is sewn to a fixed length.

<Problems to be Solved by the Invention> However, in general, when a sewing machine is operated at high speed, the responsiveness between each component in the cloth feed mechanism decreases due to inertia, and the cloth feed pitch tends to increase. . Therefore, when the operating speed of the sewing machine decreases after the cloth end is detected, the cloth feed pitch becomes slightly smaller than that during sewing before that point.

For this reason, the conventional stitch count control method has a problem in that even if the count after detecting the fabric edge matches the set number of stitches, the actual sewing length and the set line length do not exactly match.

In addition, when sewing a part with a large width such as the edge of a collar, a sewing jam occurs and the fabric feed is temporarily stopped, or the fabric to be processed stretches due to external force such as the force of the worker's presser foot. also had the same disadvantages as mentioned above.

Structure of the Invention (Means for Solving the Problems) This invention has been made to solve the above problems, and as shown in FIG. A stitch forming mechanism including a needle 5 that moves up and down, a feed dog 10 that intermittently transports the work cloth, a detection wheel 42 that rotates as the work cloth is transported, and the detection wheel 4.
a signal generator 44 that generates a signal synchronized with the rotation of No. 2;
A pitch changing means 38 that can reduce or change the cloth feed pitch during sewing, a cloth edge detector 51 that detects the edge of the work cloth on the cloth feed side from the needle drop point, and Setting means 4 for setting the sewing length to the position
9.53, a signal corresponding to the set line length, and a signal output from the signal generator 44 after detecting the cloth edge, and when the difference between the two reaches a certain value, the pitch changing means 38 so that at least the final needle stitch is executed at a reduced cloth feed pitch.

(Function) Therefore, in the fixed size sewing device for the edge of cloth according to the present invention,
As the detection wheel 42 rotates, the signal generator 44 outputs a signal that corresponds one-to-one to the actual cloth feed amount, and by comparing and calculating this signal with a signal corresponding to the set sewing length, the signal is detected immediately before the end of sewing. When the position is detected, the pitch changing means 38 is activated so that at least the last stitch is executed with a reduced cloth feeding pitch, so that the actual day length after the cloth edge detection and the set line length exactly match.

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 9, in which the present invention is embodied in a playback sewing machine capable of performing regenerated sewing work based on sewing data stored in advance through trial sewing work. do.

As shown in FIG. 1, a sewing machine main shaft 2 is rotatably supported within an arm portion a of a sewing machine frame 1, and a pulley 3 is attached to the right end thereof. Arm portion 1a of sewing machine frame 1
A needle bar 4 is supported so as to be movable up and down, and a needle 5 is mounted at the lower end of the needle bar 4.
is installed.

In addition, the bed portion 1 of the sewing machine frame 1 that constitutes the work cloth support surface
A motor 13 is installed below b and is connected to the pulley 3 via a belt 15.

Then, as the sewing machine main shaft 20 rotates due to the drive of the motor 15, the needle 5 is moved up and down through the workpiece cloth W on the bed section 1b in FIG. A lock stitch is formed on the work cloth W by cooperation with the catcher. Therefore, the needle 5
A seam forming mechanism is constituted by a thread loop catcher and the like.

As shown in FIG. 2, within the bed portion 1b of the sewing machine frame 1, a horizontal feed shaft 6 and a vertical feed shaft 7, which extend parallel to each other in the left-right direction, are rotatably supported. A feed table 8 is movably supported at the left end of the horizontal feed shaft 6 via a support arm 9, and a feed dog 10 that can be retracted from the upper surface of the bed portion 1b is attached to its upper surface. A two-pronged arm 11 is attached to the left end of the vertical feed shaft 7 and engages with an engaging portion 8a at the front end of the feed table 8. Then, as the horizontal feed shaft 6 and the vertical feed shaft 7 are reciprocated with the rotation of the sewing machine main shaft 2, the feed dog 10 is moved four times, and the work cloth on the bed portion 1b is intermittently touched in the horizontal direction. A special feed is now given.

That is, as shown in FIG. 3, an eccentric cam 12 for horizontal feeding is attached to the sewing machine main shaft 2, and the eccentric cam 12
← is fitted with the crank rod 14 at its upper end. The sewing machine frame 1 corresponds to the lower end of the crank rod 14.
A feed switching device 16 is rotatably supported on a support shaft 17 within the bed portion 1b. A rotating lever 18 is rotatably supported by a support bin 19 between the rear ends of the feed switching device 16, and its front end is rotatably connected to the lower end of the crank rod 14 by a connecting bin 20. .

A connecting arm 21 is fixed on the horizontal feed shaft 6 behind the feed switching device 16, and a connecting rod 22 is connected to the shaft 23 and the connecting bin 20 between the upper end of the connecting arm 21 and the front end of the rotating lever 18. It has been intervened.

Then, when the horizontal feed eccentric cam 12 is rotated with the support bin 19 set at a predetermined position by adjusting the rotation of the feed switching device 16, the rotation lever 18 is moved via the crank rod 14. It is reciprocated in the vertical direction around the support bin 19, and accordingly, depending on the set position of the support bin 19, a rotational force is applied to the connection arm 21 in the front and rear direction via the connection rod 22, and the horizontal feed shaft 6 is oscillated within a predetermined range. Therefore, as the horizontal feed shaft 6 swings, the feed dog 10 is given horizontal movement.

An eccentric cam (not shown) for vertical feeding is attached to the main shaft 2 of the sewing machine, and a crank rod for vertical feeding is connected between the eccentric cam and the vertical feeding shaft 7. As the eccentric cam for vertical feed rotates, the vertical feed shaft 7 is reciprocated within a predetermined range via the crank rod, thereby causing the feed dog 10 to move in the vertical direction via the feed table 8. It is now granted.

As shown in FIG. 4, a feed adjustment member 25 is rotatably supported in the arm portion a of the sewing machine frame 1 by a support shaft 26, and is rotated clockwise in the figure by the action of a spring (not shown). A 7-shaped feed control cam 27 is formed on the front side of the feed adjustment member 25. A connecting rod 28 is rotatably attached to the rear side of the feed adjustment member 25 with a screw 29 at the upper end. and its lower end is rotatably connected to the support bin 19 on the feed switching device 16 as shown in FIGS. 2 and 3. Also, as shown in FIG.
A manual operation member 30 is screwed onto the arm portion 1a of the sewing machine frame 1 at the front of the machine frame 1, and a feed adjustment member 2 is attached to the inner end of the manual operation member 30.
The feed adjustment member 2 engages with the feed control cam 27 of No.5.
A holding portion 32 is provided to restrict and hold 5 at a predetermined position against the action of the spring.

The feed adjusting member 25 is always controlled by the action of the spring.
is located at the position shown by the solid line in FIG. 4, and the connecting rod 28
is pushed down, and as shown in FIG. 3(a), the feed switching device 16 is placed in a lower rotating position where the cloth feed pitch is large. Therefore, in this state, when the feed adjustment member 25 is rotated counterclockwise as shown by the chain line in FIG. The feed changer 16 is rotated clockwise in FIG. 3(a) through the rise of the third
As shown in Figure (b), the cloth feed pitch becomes smaller as the axis of the support bin 19 on the feed changer 16 approaches the straight line L-1 connecting the connecting bin 20 and the axis of the shaft 23. As shown in Figure (C), the cloth feeding direction is reversed when the axis of the support bin 19 moves upward beyond the straight line LL.

As shown in FIG. 2, an operating shaft 34 is rotatably supported within the arm portion a of the sewing machine frame 1 so as to extend left and right above the feed switching device 16, and the arm portion 1
An operating lever 37 for discharging mist is attached to the outside of a.

Further, an actuation arm 35 is fixed to the left end of the actuation shaft 34,
The rear end is rotatably connected to the intermediate portion of the connecting rod 28 by a screw 36. When the operating shaft 34 is rotated clockwise in FIG. 2 by pressing the operating lever 37, the feed switching device 16 is rotated via the operating arm 35 and the connecting rod 28 as shown in FIG. 3(C). The cloth is rotated to the reverse position, and the cloth feeding direction is reversed.

Further, a servo solenoid 38 is disposed in the arm portion a of the sewing machine frame 1 behind the operating shaft 34, and the front end of the armature 39 is connected to the operating shaft 34 through a connecting body 40.
is operatively connected to. This servo solenoid 38 constitutes the pitch changing means in this embodiment, and as the armature 39 moves forward, the operating shaft 3
4 is rotated by a predetermined amount clockwise in FIG. 2, the feed switching device 16 is rotated in the direction of decreasing the cloth feed amount as shown in FIG. 3(b) via the operating arm 35 and the connecting rod 28. The cloth feed pitch is corrected by reducing the cloth feed pitch.

As shown in FIG. 1.5.6, a light projecting element 51a is mounted on the front surface of the arm portion 1a of the sewing machine frame 1 so as to be located on the work cloth feeding side rather than the needle drop point. Further, within the bed portion 1b on the cloth feeding side from the needle drop point, there is a light receiving element 51 for receiving the light emitted from the light projecting element 51a.
b is provided. And these light projecting elements 51a
A cloth edge detector 51 is configured by the light receiving element 51b,
The light-receiving element 51b directly receives the light from the light-emitting element 51a, and when the workpiece cloth W is sent between the two and the optical path is interrupted, the light-receiving element 51b receives the light from the light-emitting element 51a, and when the workpiece cloth W is sent between the two and the optical path is interrupted, the light-receiving element 51b receives the light from the light-emitting element 51a, and when the workpiece cloth W is sent between the two and the optical path is interrupted, the light-receiving element 51b receives the light from the light-emitting element 51a. End of knee cloth W or two pieces of processed cloth W
It is designed to detect the overlapping stepped portion of the cloth and output a cloth edge detection signal.

On the other hand, as shown in Fig. 5.6, a support plate 33 is attached to the lower end of the left side of the arm portion 1a, and a spring shaft 41 provided at the lower end is made of a magnetic material with an uneven surface. A detection wheel 42 is rotatably supported. This detection width 42 is determined by the biasing force of the spring shaft 41 in the bed portion 1b.
It is adapted to follow and rotate as the work cloth W is transferred while being in pressure contact with the work cloth W above. A magnetic sensor 4 is mounted on the support plate 33 so as to face the detection width 42 from above.
A signal generator 44 having a width of 3 is installed and outputs pulses synchronized with the rotation of the unevenness of the detection width 42. In addition, 24 shown in FIG. 5 is a presser foot, and 31 shown in FIG.
is the needle plate.

Next, the control circuit of the playback sewing machine in this embodiment will be explained based on FIG. A central processing unit (CPU) 46 serving as a control means receives, via an input interface 47, a start switch 48, the signal generator 44, and the needle down position and the counted position of the needle 5 in relation to the rotation of the sewing machine main shaft 2. A detectable needle position detector 50, the cloth edge detector 51, and a memory key 49 and a reproduction key 51 provided on the operation panel 45 are connected to each other. During trial sewing and regeneration sewing, the CPU 46 counts the number of pulses output from the signal generator 44 as the detection width 42 rotates after the fabric edge of the sewing machine main shaft 2 is detected. ing.

Further, the CPU 46 is provided with an output via an output interface 52.
A driving solenoid 55 for connecting and disengaging a clutch mechanism provided in the drive transmission system between the sewing machine main shaft 2 and the motor 13 is connected, and a driving solenoid 55 is connected to the clutch mechanism provided in the drive transmission system between the sewing machine main shaft 2 and the motor 13. The servo solenoid 38 is connected to the servo solenoid 38, which performs correction to reduce the stitch pitch in the entwined portion.

In general, the CPLI46 has random access memory (R
AM) 53 and read only memory (ROM) 54 are connected. Then, the RAM 53 and the memory key 4
9 constitutes a setting means, and when the sewing of one pattern is completed during trial sewing and the memory key 49 is operated, the CPU 46 receives the signal from the signal generator 44 after the cloth edge detector 51 detects the cloth edge. The added value of the number of pulses is stored and set in the RAM 53 as sewing length data for the edge of the fabric during trial sewing. Furthermore, when the regeneration key 51 is operated, the regeneration sewing mode is set, and the CPU 46
subtracts the number of pulses output by the signal generator 44 after detecting the fabric edge during resewing from the memorized number of pulses, and when the subtracted value reaches a certain value, causes the servo solenoid 38 to reduce the fabric feed pitch. It is designed to output a drive signal for this purpose. Note that the ROM 54 contains a program for controlling the entire playback sewing machine.

Next, the operation of this playback sewing machine will be explained based on FIG. 8. In step S1, it is determined whether or not the playback sewing mode has been set by operating the playback key 51. Then, when the reproduction key 5-1 is not operated, that is, when the trial sewing mode is set, step S
When the operation of the start switch 48 is confirmed at step 2, the hand 5
At the same time, sewing is performed using the sewing machine 1, and cloth feeding is performed using the feed dog 10. When the cloth edge is detected by the cloth edge detector 51 in step S3, the number of pulses from the signal generator 44 corresponding to the cloth feed amount after the cloth edge detection is added in step S4. Then, in step S5, 1
When the sewing of the pattern is completed and the operation of the memory key 49 is confirmed in step S6, in step S7 the pulse corresponding to the sewing length after the fabric edge detection at the trial date and time added in step S4 is After the number is stored in the RAM 53, the process returns to step $1.

Subsequently, in step S1, the regeneration sewing mode is set by operating the regeneration key 51, and when the operation of the start switch 48 is confirmed in step S8, regeneration stitching is executed based on the sewing data from the trial sewing. Then, in step S9, based on the number of pulses output by the signal generator 44 between the needle up signal from the needle position detector 50 and the next needle up signal, the number of pulses (-th 9) is detected and its value is stored in the RAM 53. Subsequently, when the cloth edge is detected by the cloth edge detector 51 in step S10 (the state shown in FIG. 9), step 811
After the cloth edge is detected, the pulses output by the signal generator 44 are subtracted from the number of stored pulses, and then in step 312, the needle down position of the needle 5 is determined based on the needle down signal from the needle position detector 50. is confirmed.

In step S13, it is determined whether the remaining number of pulses after being subtracted in step S11 is equal to or less than the number B of pulses per cloth feed pitch, and if not, the process returns to step S11 and the calculation is performed. and confirmation of the needle down position is repeated. Next, in step S14, it is determined whether or not the remaining number of pulses matches the number B of pulses per cloth feed pitch. If they match, the process proceeds to step S16, and the mu of the last needle is moved at the same cloth feed pitch as before. After this is executed, thread trimming is performed, and in step 817 a drive stop signal is output to the drive solenoid 55 to stop the rotation of the sewing machine main shaft 2.

On the other hand, if the remaining number of pulses is less than 8 pulses per cloth feed pitch, the process proceeds to step S15, where a drive signal based on the remaining number of pulses is applied to the servo solenoid 3.
The armature 39 of No. 8 is driven to protrude, and the feed switching device 16 is rotated in the direction of decreasing the cloth feed amount as shown in FIG. Cloth feed pitch is reduced. Next, step S1
The cloth feed pitch reduced to the workpiece cloth W in step 6 (B' in Fig. 9)
) after the final needle stitch is executed, thread trimming is performed,
In step S17, the rotation of the sewing machine main shaft 2 is stopped.

By the way, in the playback sewing machine of this embodiment, sewing is performed for a predetermined sewing length A) in FIG. 9 from the cloth edge detection position detected by the cloth edge detector 51 to the tangling position. Therefore, even if the sizes of the sewn products W are different, a constant seam allowance (C in FIG. 9) can always be obtained. In this case, since the detection width 42 is rotated to follow the feed of the work cloth W, a nearly one-to-one response is obtained between the number of pulses output by the signal generator 44 and the amount of cloth feed. Based on the number of pulses from the signal generator 44, the actual cloth feed amount by the feed dog 10 can be accurately detected. Moreover, since the final needle stitching is performed at a reduced cloth feed pitch, the regenerated sewing can be completed at an accurate entangled position that is neither too much nor too little compared to the entangled position at the time of trial sewing. In the above description of the operation, the servo solenoid 38 is activated when the number of remaining pulses reaches less than 8, which corresponds to one pitch. The larger the setting is, the greater the number of stitches to be reduced, making it possible to perform fixed-size stitching with beautiful entangled parts.

(Second Embodiment) Next, the second embodiment embodies this invention into a playback sewing machine.
Examples will be described based on FIGS. 10 to 12. This second
This embodiment differs from the first embodiment only in the structure of changing the cloth feed pitch of the final needle.

That is, as shown in FIG. 10, a two-pronged arm 11 fixed to the vertical feed shaft 7 has a pivot lever 57 supported via a shaft 56, and a two-pronged portion 59 at one end thereof.
is fitted into the engaging portion 8a of the feed table 8, and one end of a link 61 is pivotally attached to the other end by a pin 60. Further, an actuating lever 64 is rotatably supported at an intermediate portion of a support shaft 62 fixed in the bed portion 1b of the sewing machine frame 1, and is always urged counterclockwise in the figure by a spring 63. ing. The other end of the link 61 is connected to the upper end of the operating lever 64 via a pin 65, and the lower end is connected to the armature 66 of the feed stop solenoid 58 disposed in the bed portion 1b by the action of the spring 63. They are in pressure contact.

The armature 66 of the feed stop solenoid 58 is always in the retracted position, and when the vertical feed shaft 7 is reciprocated in conjunction with the sewing machine main shaft 2 in this state, the rotary lever 57 is moved against the two-pronged arm 11. The feed dog 1 is moved through the feed table 8 by being swung up and down at a fixed angle position.
α appears and disappears from the upper surface of the bed portion 1b, and this movement of appearing and disappearing,
The workpiece cloth W is intermittently transferred in cooperation with the horizontal movement of the feed dog 10 accompanying the reciprocating rotation of the horizontal feed shaft 6. In addition, during resewing, the signal generator 4 is activated after detecting the fabric edge.
When the number of pulses output by C 4 reaches the number of pulses corresponding to the set line length of the edge of the cloth, as shown in FIG.
A drive signal is output from PL, 146 to the feed stop solenoid 58, causing the armature 66 to protrude, and as the operating lever 64 rotates clockwise in FIG. By rotating clockwise, the engaging portion 8a of the feed bar 8 is pushed down and the feed dog 10 is lowered from the upper surface of the bed portion 1b, and the cloth feeding action of the feed dog 10 is disabled and processing is performed. The feeding of the cloth W is immediately stopped.

Next, the operation of the playback sewing machine in the second embodiment will be explained based on FIG. 12.

In steps 821 to 827, sewing data associated with the trial sewing work is stored in the same manner as in the first embodiment. Next, in step 821, the regeneration sewing mode is set by operating the regeneration key 51, and when the operation of the start switch 48 is confirmed in step S28, regeneration sewing is started.

When the edge of the cloth is detected in step S29, the pulses output by the signal generator 44 during the regenerated stitching are subtracted from the number of stored pulses corresponding to the set line length in step 830. Next, in step 831, it is checked whether the remaining number of pulses after the subtraction has become 0. When the remaining number of pulses has become O, in step 832, a drive signal is output to the feed stop solenoid 58, and the feed dog 10 is sinks and the feeding of the work cloth W is immediately stopped. Subsequently, when a total of five needle down positions are confirmed by the needle position detector 5o in step 833, thread trimming is executed in step S34, and then a drive stop signal is output to the drive solenoid 55. The rotation of the sewing machine main shaft 2 is stopped.

Therefore, in this second embodiment, as in the first embodiment, based on the signal that corresponds almost one-to-one with the cloth feed amount output by the signal generator 4.4, the Since the sewing length (A in Fig. 7) is accurately detected, when the sewing length matches the sewing length set at the time of trial sewing, the fabric feeding by the feed dog 10 is immediately stopped, and as shown in Fig. 9. As shown, by forming stitches with a reduced pitch B' on the tangled work cloth W, it is possible to perform regenerated stitching with just the right stitch length.

Note that the present invention is not limited to the configuration of the above-mentioned embodiments. For example, the signal generator may be configured with a detection width having a large number of slits and a corresponding photointerrupter, or the present invention may be configured with an operation panel. The configuration of each part can be arbitrarily changed without departing from the spirit of the invention, such as applying it to an input-type sewing machine that memorizes and sets the sewing length after detecting the fabric edge in advance by operating the setting key above. It is also possible to convert

Effects of the Invention As detailed above, according to the present invention, as the detection wheel rotates, the signal generator outputs a signal that corresponds one-to-one to the actual cloth feed amount, and based on that signal, the cloth feed amount of at least the final needle is This has the excellent effect of reducing the feed pitch and sewing the edges of the fabric with a sewing length that exactly matches the set line length.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the construction of a sewing machine according to the present invention. 2 to 9 show a first embodiment embodying this invention,
Figure 2 is a perspective view showing the horizontal feed mechanism, Figure 3 (a), (
b) and (C) are main part sectional views showing the configuration for adjusting the cloth feed amount;
Fig. 4 is a partial side sectional view of the sewing machine, Fig. 5 is a left side view of the sewing machine showing the signal generator, Fig. 6 is a plan sectional view of main parts, Fig. 7 is a control circuit diagram, and Fig. 8 is a flow chart diagram. , FIG. 9 is a plan view showing the seams. 10 to 12 show a second embodiment embodying the present invention, and FIG. 10 is a perspective view of the main part;
FIG. 11 is a control circuit diagram of the main part, and FIG. 12 is a flowchart. In the figure, 1 is the sewing machine frame, 1b is the bed part that constitutes the work cloth support surface, 2 is the main shaft of the sewing machine, 5 is the needle, 6 is the horizontal feed shaft, 8 is the feed base, 10 is the feed dog, and 13 is the motor. ,3
8 is a servo solenoid constituting pitch changing means; 42
44 is a signal generator, 46 is a CPU as a control means, 51 is a cloth edge detector, 53.49 is a RAM and memory key constituting a setting means, 51 is a reproduction key, and 58 is a pitch changing means. This is the feed stop solenoid that consists of the

Claims (1)

[Claims] 1. As the sewing machine main shaft (2) rotates, the work cloth support surface (1b
), the stitch forming mechanism includes a needle (5) that is moved up and down across the workpiece cloth support surface (1b) and forms a stitch in the workpiece cloth (W) on the workpiece cloth support surface (1b); A feed dog (10) for intermittently transporting the work cloth (W); and a feed dog (10) that contacts the work cloth (W) in the vicinity of the feed dog (10) and is rotated as the work cloth (W) is transferred. a detection wheel (42), a signal generator (44) that generates a signal synchronized with the rotation of the detection wheel (42), and a pitch that can reduce or change the cloth feeding pitch by the feed dog (10) during sewing. changing means (38, 58); a cloth edge detector (51) for detecting the end of the work cloth (W) on the cloth feed side from the needle drop point; and a cloth end detector (51) for detecting the end of the work cloth (W) from the end of the work cloth (W) Setting means for setting the sewing length up to (
49, 53), the signal corresponding to the set length, and the signal output from the signal generator (44) after the detection of the cloth edge, and when the difference between the two reaches a certain value, the signal corresponding to the set length is calculated. A fabric edge section in a sewing machine, comprising a control means (46) for activating the pitch changing means (38, 58) to control at least final needle stitching to be performed with a reduced fabric feed pitch. Fixed size sewing device.