JPH08164285A - Automatic sewing machine - Google Patents

Abstract

PURPOSE: To maintain a constant margin to a seam in an automatic sewing machine by causing an end detection means to follow the end of a sewing workpiece in such a state as in contact therewith, and making a correction for a distance from the end of the workpiece to a needle location point on the basis of a position detection signal and a contact angle detection signal from the means. CONSTITUTION: An end detection signal regarding a workpiece W1 outputted from the potentiometer 22 of an end detection means 21, and a luminous energy detection signal from a detector arm 23 are respectively inputted to CPU. This CPU calculates a constant margin A from the end position of the workpiece W1 to a seam, on the basis of a signal detected for a position. Then, the CPU drives an X-Y feed mechanism and keeps the margin A constant. Also, the output shaft of the end potentiometer 22 is caused to advance and retreat on the operation of an air cylinder 26, and the arm 23 is pushed to the end of the workpiece W1 , so as to keep the arm 23 corresponding to the prescribed margin amount. Also, the detection means 21 is turned until the contact piece of the arm 23 orthogonally comes in contact with the end of the workpiece W1 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material to be sewn such as a natural leather, an artificial leather or a synthetic leather which is a constituent of a leather product, and a woven fabric, a non-woven fabric or a knitted fabric which is a constituent of a cloth product. The present invention relates to an automatic sewing machine in which a fixed seam allowance is automatically adjusted when performing the initial process sewing or combination sewing.

[0002]

2. Description of the Related Art Conventionally, various automatic sewing machines have been proposed in which the seam allowance is automatically adjusted. In order to adjust the seam allowance, it is necessary to detect the edge position of the material to be sewn. As the edge detecting means, a means utilizing transmission or reflection of detection light has been developed.

[0003]

However, when the first step sewing or combination sewing of the leather product as described above is performed, the conventional edge detecting means cannot be applied as it is. That is, first, when a plurality of objects to be sewn are overlapped and combined sewing is performed, transmission / reflection of detection light cannot be used, and it is difficult to detect the end position by the conventional edge detection means. Further, even when sewing one piece of the material to be sewn in the first step, the original edge position cannot be detected due to fluffing or the like formed on the edge of the material to be sewn, and a good sewing line cannot be obtained. There is a problem.

Further, in order to decorate the end portion of the sewn item neatly, when the end edge portion is manually folded inward to sew the seam allowance portion, variations in the end edge of the bent portion are likely to occur. Therefore, it is the actual situation that sewing to decorate the edges is almost manual. Further, even when performing manual work, there is a problem that skill is required in specific curve sewing and the like. Therefore, there has been a long-awaited demand for an automatic stitching device for an object to be sewn in the initial process or in combination sewing.
Automation is difficult.

According to the present invention, it is possible to accurately detect the edge of the sewing object of the initial process sewing or the combination sewing, and in particular, a certain seam allowance is applied to the sewing object having the annular sewing line. An object of the present invention is to provide an automatic sewing machine capable of performing good sewing while maintaining it, efficiently handling a material to be sewn, and automating manual work.

[0006]

SUMMARY OF THE INVENTION To achieve the above object, the present invention causes various kinds of sewn products to perform a predetermined feeding operation by an XY feeding mechanism, and the edges of the sewn products are sewn in a predetermined manner. In an automatic sewing machine that performs edge formation by sewing for a substitute, when the edge of the sewn object is formed, the sewn item moves in contact with the edge of the sewn object while pressing and moving toward the edge of the sewn object. An edge detecting means for generating a corresponding position detection signal and a detection signal of a contact angle with respect to the edge of the sewing object,
The rotation drive means for rotating the edge detection means around the needle bar and the rotation drive means based on the contact angle detection signal from the edge detection means drive the edge detection means with respect to the work. Control means for driving the XY feed mechanism so as to maintain the angle substantially constant and maintain a predetermined seam allowance and pitch based on the position detection signal from the edge detection means. Have

[0007]

In the device having such a structure, the edge detecting means has a structure in which the edge detecting means comes into contact with the edge of the sewn object and accurately follows and moves. Even if fluffing or the like is formed, it has good followability, and by correcting the distance from the edge of the workpiece to the needle drop point, a certain seam allowance is maintained and good sewing is performed.

Further, when the object to be sewn is set, the edge detecting means is retracted to the non-detecting position by the reciprocating means, so that the edge detecting means interferes with the setting and removing of the mold for the XY feed mechanism. It is supposed to be done without any effort.

Further, even when the sewing line to the material to be sewn has an annular shape, the contact angle of the edge detecting means to the material to be sewn is kept substantially constant by the rotation driving means, so the amount of seam allowance. Is being maintained well.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a sewing machine for sewing leather products will be described in detail with reference to the drawings. First, as shown in FIG. 1, a sewing machine head 3 is provided on a sewing machine table 1 via a bed 2, and an XY feed is performed in the needle drop point region of the sewing machine head 3. A mechanism 4 is provided. The XY feed mechanism 4 includes a work holding mechanism that holds the works W ₁ and W ₂ as a workpiece to be sewn, a work feed mechanism that horizontally moves the work holding mechanism in the X and Y directions, have. The work holding mechanism is slidably arranged on the slide plate 5, and the work holding mechanism is moved back and forth by the drive device 6 of the work feeding mechanism so that the work holding mechanism reciprocates appropriately in the X direction and the Y direction. It is configured to be moved. The back of the presser base 7 is supported by a supporting mechanism 8.

A control device 9 for appropriately performing the sewing operation by the sewing machine head 3 and the drive device 6 is provided directly below the sewing machine table 1. This control device 9 is provided.
The control device 9 is operated by a signal from the sewing machine drive start switch 9A that is pulled out toward the feet from.

Further, as shown in FIG. 2, the work holding mechanism includes a lower presser plate 15 on which the workpiece is set so as to be slidably mounted on the slide plate 5, and the lower presser plate 1.
5 and an upper presser plate 16 which holds the sewing object from above. At this time, a set sensor 15b for detecting the presence or absence of the object to be sewn is embedded in the lower presser plate 15 if necessary. The set sensor 15b is configured to output a set detection signal to the control device 9 upon contact with a material to be sewn. The control system of the control device 9 will be described later.

The upper pressing plate 15 is held by an arm body 17 having a substantially U-shaped plane, and the tip of the pressing base 7 is attached via an attachment 18 provided on the base side of the arm body 17. Is attached to. A cylinder pressing means (not shown) is arranged inside the pressing base 7, and the arm body 17 is vertically rotated about the attachment 18 by the reciprocating movement of the cylinder pressing means. Thus, the opening / closing operation of the upper pressing plate 16 is performed.

Further, as shown in FIG. 3, the work holding mechanism is set in a so-called needle drop point vicinity region of the needle bar 19 extending from the sewing machine head 3. The edge detection means 21 is arranged in the area near the needle drop point. The edge detecting means 21 is an output shaft 22a of the potentiometer 22.
The detection arm 23 is attached to the tip of the potentiometer 22, and the potentiometer 22 is, for example, a resistance type, a magnetic type, or an optical type. The detection arm 2
Reference numeral 3 is bent and formed in a substantially L shape, and a contactor formed at the tip end thereof is in contact with the end edge of the work W _{1 on} the upper side. At this time, the output shaft 22a of the potentiometer 22
The coil spring 22b is mounted concentrically, by urging pressure of the coil spring 22b, the configuration contacts the detection arm 23, follow the movement as pushed along the edge shape of the workpiece W ₁ Has been done. In addition, the code | symbol 19a in FIG. 3 has shown the presser foot.

Further, the output shaft 22a of the potentiometer 22 moves in and out as shown by the arrow with the follow-up movement of the detection arm 23, and the potentiometer 22 outputs a detection signal proportional to the protrusion amount of the output shaft 22a, that is, the workpiece. A position detection signal corresponding to the edge position of W ₁ is output at a predetermined voltage. An example of the relationship between the output voltage of the potentiometer 22 and the pressing amount (stroke) of the contact of the detection arm 23 is shown in FIG. In FIG. 4, 0 (open) corresponds to the contact free position, B corresponds to the sewing position, C corresponds to the edge position, and the strokes corresponding to the output voltages b and c are 0-B and 0-C. The output voltage from the potentiometer 22, that is, the edge position detection signal is output to the control device 9.

Further, in FIG. 3, the potentiometer 22 is connected via a mounting plate 25 to an output shaft 24a of an air cylinder 24 which constitutes a vertically reciprocating means. The air cylinder 24 is arranged at a position directly above the potentiometer 22 so as to hang down substantially vertically, and the output shaft 24 a of the air cylinder 24.
And a shaft 25a extending upward from the mounting plate 25 of the potentiometer 22 are connected by a coupling (not shown). A coil spring 25b for pressing the potentiometer 22 downward is attached to the shaft 25a of the mounting plate 25.
Is installed. Then, the potentiometer 22 is moved up and down by the operation of the air cylinder 24, whereby the detection arm 23 comes between a detection position (a position shown in the drawing) where the detection arm 23 contacts the work side and a non-detection position which is separated upward from the work side. It is configured to reciprocate in.

On the other hand, an air cylinder 26 is attached to the attachment plate 25 so as to be substantially horizontal. A connecting plate 26b provided at the tip of the cylinder rod 26a is arranged in front of the mounting portion 23c of the detection arm 23, and the detection arm 23 is spring 22 when not sewn.
It is configured to operate so as to pull in against b.

Further, the air cylinder 24 is attached to the outer ring 31 of the rotation driving means 30 via attachment arms 32. The rotation driving means 30 includes an outer ring 31 and an inner ring 33 which are arranged substantially horizontally just below the sewing machine head 3.
The inner ring 33 is fixed to the sewing machine head 3 via a mounting plate 34, and the outer ring 31 is rotatably mounted on the outer peripheral side of the inner ring 33. The timing belt 3 is provided on the outer periphery of the outer ring 31.
5, the outer ring 31 is rotated in an appropriate direction and angle by the output of the edge detector motor 36 hung on the opposite side of the timing belt 35, whereby the contactor of the detection arm 23 is rotated. The contact angle is adjusted appropriately.

Further, on the outer ring 31, at a position on the opposite side of the mounting arm 32, that is, on the opposite side of the potentiometer 22,
A lamp holder 37 is attached, and light emitted from a lamp 38 attached to the lamp holder 37 illuminates the tip of the contact 23b of the detection arm 23. At this time, as shown in FIG. 5, the contactor 23b of the detection arm 23 is formed by arranging a plurality of optical fibers 23d in parallel so that the light emitted from the lamp 38 can be taken in. ing.

At this time, the plurality of optical fibers 23d
Are arranged in parallel on a substantially arcuate line, and the arcuate tip end portion of the contactor 23b formed thereby is configured to be pressed against the edge portion of the sewn object. .
The light from the lamp 38 is blocked from entering the optical fiber at the portion where the arcuate contactor 23b is in contact with the workpiece, and the detection arm 23 is detected based on the light beam entering from the optical fiber at the non-contact portion. The contact angle with the material to be sewn is detected. That is, by detecting that the optical fiber at the tip portion is in contact, the contact piece 23b is in contact with the workpiece at a right angle.

Next, a control system of the automatic sewing machine having the above-mentioned structure will be described. As shown in FIG. 6, a central processing unit (hereinafter referred to as CPU) 41 is provided inside the control device (microcomputer) 9. The CPU 41 has a ROM 4 as a read-only memory in which a necessary sewing operation program is stored.
2, and a RAM 43 for reading or writing various data relating to sewing at any time is connected as a basic unit constituting the calculating means, and the edge detecting means 2 described above is used.
Workpiece W ₁ detected by potentiometer 22 of _{No. 1}
The XY feeding mechanism 4 is operated according to the edge position of the sewing machine, and the sewing operation is executed so that a constant seam allowance is always obtained.

On the input side of the controller 9, the sewing machine drive start switch 9A and keyboard 9B are connected to the CPU.
41, which is connected to the sewing machine drive start switch 9
The control device 9 is operated by a signal from A, and output voltage data and contact angle data with respect to the pushing amount of the edge detecting means when forming edges of various sewn objects through the keyboard 9B, etc. Various data required for sewing are input and stored in the RAM 43.

Further, the edge position detection signal S ₁ of the work W ₁ detected and output by the potentiometer 22 of the edge detection means 21 is input to the CPU 41 via the amplifier 44 and the A / D converter 45. Is configured. Further, the set detection signal S ₂ from the set sensor 15b for detecting the sewn object of the work holding mechanism, which is provided as necessary, is input to the CPU 41 of the control device 9.

The detecting arm 2 of the edge position detecting means 21
The light amount detection signal S ₄ received by the fiber bundle 23d of the contactor 23b in 3 is input to the CPU 41 via the amplifier group 46 and the A / D converter group 47.

On the other hand, on the output side of the control device 9, X-
Drive device 6 of Y feed mechanism 4, that is, X motor 51 and Y
Motor drive circuit 5 attached to each of the motors 52
3, 54 are connected. The CPU 41 calculates a constant seam allowance A (see FIG. 3) from the end edge position of the workpiece W ₁ detected by the potentiometer 22 of the end edge detecting means 21, and keeps the seam allowance A at all times. -Has a function of appropriately driving the X motor 51 and the Y motor 52 of the Y feed mechanism 4. The seam allowance A is set by the keyboard 9B.

Further, a drive circuit MMD of the sewing machine motor MM is connected to the output side of the control device 9, and a motor detection signal S ₃ from a rotation position detection sensor 48 for detecting the rotation state of the sewing machine motor MM. Is input to the CPU 41 of the control device 9.

Further, a drive circuit 61 for operating the air cylinder 24 for vertically moving the potentiometer 22 of the edge detecting means 21 is connected to the output side of the control device 9, and an operation signal from the drive circuit 61 is connected. By solenoid valve 6
2 is opened and closed, and working fluid air from the air source 63 is made to flow into the air cylinder 24 side or stopped.

On the output side of the controller 9, a drive circuit 64 for operating the air cylinder 26 for inserting and removing the output shaft 22a of the potentiometer 22 is connected.
The solenoid valve 65 is opened and closed by an operation signal from the drive circuit 64, and the working fluid air from the air source 63 flows into the air cylinder 26 side or is stopped.

The operation of the apparatus of this embodiment will be described with reference to FIG. As shown in FIG. 7, in step 1,
When the sewing machine drive start switch 9A is turned on, first in step 2, the work holding mechanism is moved to a predetermined position (-X position) near the sewing position by the XY feed mechanism 4, and the workpiece is held by the work holding mechanism. Set inside. At this time, the edge detecting means 21 (see FIG. 3) is operated by the air cylinder 2
4 is retracted to the non-detection position on the upper side, whereby the sewing object can be set easily and surely without being disturbed by the edge detection means 21.

When a set signal (a signal from a set sensor 15b provided as necessary) for the sewing object is issued, the edge detecting means 21 is lowered by the air cylinder 24 in step 3. At this time, the output shaft 22a of the potentiometer 22 is connected to the air cylinder 26
However, the detection arm 23 of the edge detection means 21 is placed at the detection position. At this time, the tip of the contact piece 23b of the detection arm 23 has not yet come into contact with the workpiece side as a workpiece.

Next, in step 4, the cloth presser foot 19a of the sewing machine is lowered, and in step 5, X-
By the Y feed mechanism 4 appropriately moving the work holding mechanism in the X direction and the Y direction so that the initial sewing position becomes the needle drop point, in step 6, the detection arm 23 of the edge detection unit 21 serves as a work. The edge of the work is touched. Then, in step 7, the detection arm 23 of the edge detection means 21 is pressed against the edge of the sewn object, and is stopped when it is pushed to the position where the set voltage is output in step 8. This set voltage corresponds to the planned seam allowance amount and has a voltage value indicated by c in FIG. 4, for example.

Further, in the next step 9, the edge detecting means 21 is rotated and stopped until the contact 23b of the detecting arm 23 of the edge detecting means 21 comes into contact with the edge of the workpiece at a right angle. To do. Next, as in step 10, X- is reached until the set voltage corresponding to the planned amount of seam allowance is output.
The Y feed mechanism 4 pushes it in and stops.

Then, in step 11, the sewing operation is started, and in step 12, the contact 23 of the detection arm 23.
The work holding mechanism starts to move in the tangential direction of b by the XY feed mechanism 4, and it is determined in step 13 whether or not the edge detection means is disengaged from the corner of the sewing object. If it is off, it means that the sewing position is the final sewing position, so that the sewing is stopped at step 20, and if it is not off, the process proceeds to step 14 to determine whether or not the X and Y coordinates have both passed in the vicinity of the point once passed. That is, it is determined whether or not the sewing operation for one round has been completed, and if the sewing machine has passed the vicinity of the point that has passed once, it means that the sewing operation for one round has been completed, so that the sewing is stopped in step 20. If it has not passed the vicinity of the point that has passed once, it means that the sewing operation for one round has not been completed, so the movement of the work holding mechanism is ended in step 15,
The needle drop operation is executed in and after the next step 16 as shown in FIG.

That is, as shown in FIG. 8, in step 16, the edge detecting means 21 is rotated and stopped so that the edge detecting means 21 and the end of the sewing object are at a right angle,
X until the position where the set voltage is output as in step 17
It is pushed in by the Y feed mechanism 4 and stopped, and the needle drop operation is executed in step 18 thereafter.

Then, returning to step 12 again, it is detected whether or not the detection arm 23 of the end edge detecting means 21 is disengaged from the corner of the sewn product at the final sewing position, and if disengaged, the sewing is stopped in step 13. If not, steps 14 to 18 are repeated.

Finally, after thread cutting is performed in step 20, the cloth presser is raised in step 21. Then, in step 22, the output shaft 22a of the potentiometer 22 is pulled in by the air cylinder 26,
The edge detecting means 21 is pulled upward by the air cylinder 24, and in step 23, the workpiece is removed from the work holding mechanism. At this time, the edge detection means 2
Since No. 1 is retracted to the upper non-detection position by the air cylinder 24, the material to be sewn can be easily and surely removed without being disturbed by the edge detection means 21.

As described above, in the apparatus of this embodiment, since the edge detecting means 21 has a mechanical structure in which the edge detecting means 21 comes into contact with the edge of the workpiece W and moves following the edge, the edge of the workpiece W is detected. Even if fluffs or the like are formed, it has good followability, and at the time of setting and removing the sewing object W, it is retracted to the non-detection position by the air cylinder 26 so that the sewing object can be set and removed. ing.

Further, even when the sewing line to the material to be sewn has an annular shape, the rotation drive means 30 maintains the contact angle of the edge detection means 21 to the material to be sewn substantially constant (right angle). Therefore, the amount of seam allowance is maintained well.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, in the above-described embodiment, the edge detecting means is rotated and stopped so that the edge detecting means and the material to be sewn are substantially at a right angle, and the XY feeding mechanism is pushed to the position where the set voltage is output and stopped. However, it is also possible to obtain the X and Y coordinates moved by the sewing pitch in the angular direction rotated from the immediately preceding needle drop point at the same time as the rotation and send them to the X and Y coordinates. By doing so, the accuracy of the length of the sewing pitch can be improved. However, the control time in this case becomes slightly longer.

[0040]

As described above, in the automatic sewing machine according to the present invention, the edge detecting means is appropriately rotated by the rotation driving means while being brought into contact with the edge of the workpiece at a constant contact angle to follow the movement. As a mechanical structure, even if fluff is formed on the edge of the sewn object, good followability is obtained, and the edge detection means is set at the non-detection position by the reciprocating means when setting or removing the sewn material. The work piece can be set and removed without being disturbed by the edge detection means, and a predetermined seam allowance is maintained based on the position detection signal and the angle detection signal from the edge detection means.
-Because it has a control means for driving the Y feed mechanism, it is possible to accurately detect the edge even for a material to be sewn in the first step or combination sewing such as leather products. Good sewing can be performed while maintaining a constant seam allowance of the sewn object having an annular sewing line,
By automating the handling of the material to be sewn, efficient work is possible and productivity can be improved.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the overall structure of an automatic sewing machine according to an embodiment of the present invention.

FIG. 2 is an external perspective view of the main part of a work holding mechanism for XY feeding used in the sewing machine shown in FIG.

FIG. 3 is an external perspective view of an essential part showing an edge detecting means used in the sewing machine shown in FIG.

FIG. 4 is a diagram showing an example of the relationship between the output voltage of the edge detecting means and the amount of pushing by the edge of the sewing object.

5 is an external perspective explanatory view showing an enlarged contactor used in the edge detecting means shown in FIG.

6 is a block diagram of a control device used in the sewing machine shown in FIG. 1. FIG.

FIG. 7 is a flowchart showing the overall sewing procedure.

FIG. 8 is a flowchart showing a needle drop operation in a sewing procedure.

[Explanation of symbols]

 3 Sewing Machine Head 4 XY Feeding Mechanism 9 Control Device W Work (Sewn Material) 21 Edge Detection Means 22 Potentiometer 23 Detection Arm 23a Contact 24 Air Cylinder 30 Rotation Drive Means

Claims (2)

[Claims] 1. An automatic sewing machine for performing various feeding operations on various articles to be sewn by an XY feeding mechanism and sewing the edges of the articles with a predetermined seam allowance to form the edges. In the above, when the edge of the sewn object is formed, the sewn object is moved toward the edge of the sewn object while making contact with the edge of the sewn object. Edge detection means for generating a contact angle detection signal, rotation drive means for rotating the edge detection means around the needle bar, and rotation drive means based on the contact angle detection signal from the edge detection means. Is driven to maintain the contact angle of the edge detecting means with the workpiece to be substantially constant, and to maintain a predetermined seam allowance and pitch based on the position detection signal from the edge detecting means. Control means for driving the Y feed mechanism, Automatic sewing machine, characterized in that it includes. 2. The automatic sewing machine according to claim 1, wherein the control means has a storage means for storing the position detection signal and the contact angle detection signal from the edge detection means, and the storage value read from the storage means. The amount of displacement of the edge position of the sewn product is calculated from the above, and the distance from the edge position of the sewn product to the needle drop point is corrected to maintain the predetermined seam allowance and pitch.
-An automatic sewing machine having a function of driving a Y feed mechanism.