JPH07213773A - Superimposed sewing control method and device for sewing machine - Google Patents

Abstract

PURPOSE:To prevent the dispersion of the superimposed sewing width from the start point of a seam and invariably perform superimposed sewing at a constant width regardless of the presence of the expansion property of a texture. CONSTITUTION:A circular texture 5 and a circular rubber cord 6 are mounted on a bed 3 in the superimposed state, and they are sewn by a thread inserted into a needle 4 while the texture 5 and the rubber cord 6 are moved toward the moving direction A in the peripheral direction. The tip section 11 of an insertion member 7 angularly displaceable in the directions of arrows B1, B2 is inserted between the texture 5 and the rubber cord 6 via a pin bolt 20. When the tip portion 16 of the tip section 11 is pressed by the seam at the start point P1 and angularly displaced in the direction of the arrow B2, a control means 10 stops a motor 34 based on the output from a proximity sensor 8 and stops the vertical reciprocation of the needle 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling overlapped stitches which can be suitably applied to a chain stitch sewing machine for sewing rubber cords or the like onto clothes.

[0002]

2. Description of the Related Art Conventionally, a chain stitch sewing machine has been used to sew an annular rubber cord to clothes such as sweatpants. In this chain stitch sewing machine, the counter counts the pulse signal generated at each reciprocating motion in which the needle descends from the top dead center to the bottom dead center and then rises to the top dead center again, and this value is counted. A control device is provided, which is read as a number and controls so as to stop the reciprocating vertical movement of the needle when the count value of this counter reaches a predetermined value.

In such a conventional technique, when sewing sweat pants as a sewn product, for example, when an elastic cord is sewn to an annular waist, the cloth is stretched to such an extent that the waist of the cloth is not loosened. The rubber cord is sewn on in the state. The seams are formed by the preset number of stitches as described above. With this number of stitches, after the entire circumference is sewn from the starting point of the seam, the stitches are sewn over the starting point, but the distance between the end point and the starting point of the stitch after the sewn stitch However, there is a problem in that there is variation in the width. The reason is that the length in the circumferential direction in the stretched state of the cloth and the rubber cord is slightly different for each product. A label showing the quality of the product composition, handling, size, shrinkage ratio, flame retardancy, water repellency, etc. is usually sewn to such a lapped portion, but if the lap stitch width is too long, The seam on the end point side protrudes from the label. If the overlapped stitch width is too short, the thread is likely to be frayed. As described above, regardless of whether the overlapped stitch width is too long or too short, the quality of the product is deteriorated and the commercial value is significantly deteriorated.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the variation in the overlapped stitch width of the seam and enable the overlap stitch to always have a constant width regardless of the stretchability of the cloth. To provide a method and a device for controlling overlapped stitches.

[0005]

SUMMARY OF THE INVENTION According to the present invention, an annular first sewn object and an annular second sewn object are placed in a state of being stacked on a bed, and these first and second sewn objects are sewn. In a sewing machine in which an object is sewn with a thread inserted by a needle that reciprocates up and down while moving in the circumferential direction,
From the time when the seam on the starting point side abuts on the insertion member in the state where the thin plate-shaped insertion member is inserted between the first and second sewing objects on the upstream side in the moving direction of the second sewing object. This is a method for controlling overlapped stitching of a sewing machine, which is characterized in that the sewing operation is stopped after a predetermined number of stitches have been sewn.

The present invention also includes a needle that is reciprocally moved up and down,
A thin plate-shaped insertion member provided so as to be retractable in the movement path of the first and second sewn items, on the upstream side of the needle in the moving direction of the first and second sewn items to be oversewn by the needle. And a means for detecting the displacement of the insertion member, and a control means for operating the needles by a predetermined number of stitches in response to the output of the detecting means.

[0007]

According to the present invention, the first bed is provided on the sewing machine bed.
And the second sewn object is placed in a stacked state. Each of these first and second sewn objects is annular, and while the first and second sewn objects are moved in the circumferential direction, a thread is inserted by a needle that is reciprocally moved up and down. Items to be sewn are sewn to each other.

On the upstream side of the needle in the moving direction of the first and second objects to be sewn, there is provided a thin plate-shaped insertion member to be inserted between the objects to be sewn. In a state in which the insertion member is inserted between the objects to be sewn, the sewing operation is controlled so as to stop after the sewing is advanced by a predetermined number of stitches from the time when the stitch on the starting point side comes into contact with the insertion member. Therefore, the seam at the starting point touches the insertion member without being affected by the variation in the length of the length section where the seam in the circumferential direction between the end point and the starting point of the seam at the time when the starting point abuts on the insertion member. It is possible to sew a predetermined number of stitches from the time when they come into contact with each other to make the overlapped stitching width between the start point and the end point constant.

Further, according to the present invention, a needle that is reciprocally moved up and down and an insertion member that is arranged upstream of the needle in the moving direction of the first and second workpieces are provided. The insertion member is a thin plate and is provided so as to be retractable in the movement path of the first and second sewn objects, and the displacement of the insertion member is detected by the detection means. Based on the output of the detecting means, the control means operates the needles by a predetermined number of stitches. In this way, the stitches on the starting point side of the first and second sewn objects come into contact with the insertion member by the sewing operation, whereby the insertion member is displaced, and the displacement causes the first and second sewn objects to have a predetermined needle. You can sew as many as you can. By presetting such a predetermined number of stitches to a value corresponding to the desired overlapped stitch width, it is possible to always perform overlapped stitches with a constant width.

[0010]

1 is a plan view showing a sewing machine control device 1 for sewing machine according to an embodiment of the present invention, and FIG. 2 is a side view showing a part of the control device 1 as seen from below in FIG. is there. For example, the control device 1 provided on the bed 3 of the chain stitch sewing machine is
Basically, a plurality of (4 in this embodiment) needles 4 which are reciprocally moved in the vertical direction perpendicular to the plane of FIG. 1, and a material 5 which is a first sewn object and is oversewn by these needles 4, Second
The thin plate-shaped insertion member 7 provided so as to be retractable in the movement path of the cloth 5 and the rubber cord 6 on the upstream side (the lower side in FIG. 1) of the movement direction of the rubber cord 6 which is the sewn object, and the insertion member 7. Double-acting pneumatic cylinder 9 with proximity sensor 8 for detecting displacement
And a control means 10 for operating the needle 4 by a predetermined number of needles in response to the output from the proximity sensor 8.

The insert member 7 is made of a rigid metal material such as stainless steel or aluminum.
It has a thickness T of about 5 to 2.0 mm. When the thickness T is less than 1.5 mm, when the tip 11 is inserted between the fabric 5 and the rubber cord 6, the rubber cord 6 contracts in a state in which the fabric 5 is pulled without slacking. The vicinity of the tip 11 is easily bent by the force. As a result, as shown in FIG. 3, the elastic cord 6 is pressed against the surface 13 of the bed 3, a large frictional force acts in the direction against the elastic cord 6 and the cloth 5, and the stitch pitch becomes uneven. It will cause a jump or skipped eyes.

If the thickness T is larger than 2.0 mm, the cloth 5 and the rubber cord 6 are largely separated from each other in the thickness direction (vertical direction in FIG. 3) at the insertion portion of the insertion member 7, and the cloth 5 and the rubber cord 6 are separated from each other. 6 is relatively displaced. Therefore, the thickness T of the insertion member 7 is selected to be 1.5 to 2.0 mm.

A guide surface 14 is formed on the peripheral edge of the insertion member 7 which faces the upstream side in the moving direction A and which is smoothly curved and becomes tapered toward the upstream side in the moving direction A. The guide surface 14 is formed in the distal end portion 11 of the insertion member 7 over a range including at least a portion protruding from the guide plate 15 fixed to the bed 3. Such a guide surface 1
4, the tip portion 16 of the guide surface 14 is brought into contact with the exposed portion 17a of the thread 7 exposed between the material 5 and the rubber cord 6 at the start point P1 of the seam, and the start point P1 can be accurately detected.

The insertion member 7 is connected to a boss 19 fixed to a base 18 made of aluminum by a pin bolt 20 so as to be rotatable in the directions of arrows B1 and B2. The base 18 includes a substrate 21 supported on the surface 13 of the bed 3,
The side wall 23 which is bent and rises substantially at right angles to one end of the substrate 21 in the longitudinal direction and the side wall 23 fixed to the lower surface of the substrate 21.
And a mounting wall 24 at right angles. In this mounting wall 24,
Two elongated holes 25 extending in the vertical direction (direction perpendicular to the paper surface of FIG. 1) indicated by arrows C1 and C2 are formed.
The shafts of the bolts 26 are inserted into the respective shafts and screwed to the side portions of the bed 3. In a state where these bolts 26 are loosened, the base 18 can be displaced in the vertical directions C1 and C2, whereby the surface 1 of the bed 3 of the insertion member 7 can be displaced.
Adjusting the height with respect to 3, rubber string 6 arranged below
The height can be set to correspond to the thickness of the.

One end of a connecting rod 29 is pin-connected to the other end 27 of the insertion member 7 by a pin bolt 28, and the other end of the connecting rod 29 is pin-connected to an aluminum support 31 by a pin bolt 30. It This support 31
Can be displaced smoothly and freely on the surface of the substrate 21. One end of the support body 31 is connected to the piston rod 33 of the double-acting pneumatic cylinder 9. A piston (not shown) is fixed to the other end of the piston rod 33, and a permanent magnet piece is incorporated in this piston. When such a permanent magnet piece approaches the proximity sensor 8, the switching mode is switched by the change of the magnetic field, and the control means 10 controls on / off of the motor 34 provided in the sewing machine by the change of this signal. To be done. The proximity sensor 8 is realized by a limit switch, for example.

The tip portion 1 of the guide surface 14 of the insertion member 7
6 forms an angle θ1 with respect to a plane perpendicular to the movement direction A, and this angle θ1 is equal to an angle θ2 formed by a plane including each axis of each needle 4 with a plane perpendicular to the movement direction A. To be elected. These angles θ1 and θ2 are θ1 = 20 ° = θ2
To be chosen. By thus inclining the tip portion 16 of the insertion member 7, when the exposed portion 17a of the thread 17 at the starting point P1 comes into contact, the insertion member 7 is smoothly moved by the carrying force from the thread 17 to the arrow B1. It is possible to make an angular displacement in the direction to retract from the movement path of the seam.

Further, each needle 4 is reciprocated up and down at a high speed of 4000 to 4500 times / minute by the power from the motor 34. Furthermore, the distal end portion 16 of the insertion member 7 has a thread 17
The pressing force in the direction of the arrow B2 is selected to be about 200 to 400 g in the state of being in contact with the exposed portion 17a.
This prevents an excessive force from being applied to the exposed portion 17a of the thread 17 and the stitch from being displaced.

Piston rod 3 of the double-acting pneumatic cylinder 9
The axis of 3 exists in the space on the side opposite to the tip portion 11 with respect to the plane including the axis of the pin bolt 20 that pivotally locks the insertion member 7. Therefore, when the piston rod 33 extends in the arrow D1 direction, the insertion member 7 is angularly displaced in the arrow B2 direction,
The tip portion 11 retracts from the movement path of the cloth 5 and the rubber cord 6.

When the piston rod 33 retracts in the direction of arrow D2, the insertion member 7 is angularly displaced in the direction of arrow B1 and the tip portion 11 thereof projects into the movement path. The double-acting pneumatic cylinder 9 has two ports 35, 36.
Two conduits 37 and 38, which are realized by a flexible synthetic resin tube or the like, are connected to 36, respectively. The solenoid valve 40 selectively supplies compressed air from an air pressure source 39 to either one of the conduits 37 and 38.

This solenoid valve 40 is a two-position switching solenoid valve, and the electromagnetic solenoid is energized or de-energized in response to a control signal from the control means 10 to bring it to the first and second positions 41a and 41b. Can be switched alternately. First
When the position 41a faces the respective pipelines 37, 38, the compressed air from the air pressure source 39 is guided to the one pipeline 37, and the other pipeline 38 is opened to the atmosphere. Therefore, the piston rod 37 retracts in the direction of arrow D2, and angularly displaces in the insertion member 7 in the direction B, so that the tip portion 11 projects into the movement path. When the first position 41b faces each of the conduits 37, 38, the compressed air from the air pressure source 39 is guided to the other conduit 38, the one conduit 37 is opened to the atmosphere, and the piston rod 33 moves to the arrow. It extends in the D1 direction. As a result, the insertion member 7 has an arrow B
It is angularly displaced in two directions, and the tip 11 withdraws from the movement path.

Such a solenoid valve 40 is provided in the control means 1 as described above.
Controlled by 0. The control means 10 controls the motor 3
A counter 43 for counting the number of pulses of a pulse signal corresponding to the number of stitches from 4 and a plurality of stitches for setting the number of stitches corresponding to the length L1 at which overlap stitching should be performed after the end point P2 of the stitch reaches the start point P1. The input means 44 realized by a numeral key or the like is compared with the signal corresponding to the number of stitches input by the input means 44 and the count value from the counter 43, and when they match, the motor 34 is stopped. And a processing circuit 45. The processing circuit 45 is realized by, for example, a central processing unit (CPU).

The counter 43 starts the counting operation when the signal from the proximity sensor 8 becomes low level, that is, when the piston rod 33 extends in the direction of arrow D1, and this count value is input to the processing circuit 45. It In the processing circuit 45,
The set value input from the input means 44 and the counter 43
The count value input from is input, and whether the two match or not is compared. When they match, that is, when lap stitching is performed for the lap stitch length L1, the motor 34 is stopped and the needle 4 moves up and down. Be stopped. To improve the quality of sewing,
Direction of movement A between the tip portion 16 of the insertion member 7 and the axis of the needle 4
The interval L2 in is selected from 20 to 40 mm, more preferably from 25 to 30 mm. Although it is preferable that the distance L2 be as short as possible, the sewing speed is as high as 4000 to 4500 times / minute, and the pressing plate 46 does not come into contact with the distal end portion 11 of the insertion member 7 angularly displaced in the arrow B2 direction. Considering that, at least 25
It is preferably ˜30 mm. Further, the lap stitch length L1 varies depending on the stitch pitch, but in the case of attaching a rubber cord to sweat pants, for example, it is 1
4 needles are selected.

With such a structure, it is possible to eliminate the variation in the overlapped stitch width of the seam and to always perform the overlap stitch with a constant width regardless of the stretchability of the cloth. Therefore, when sewing a label or the like to the overlapped stitch portion, it is possible to reliably avoid the problem that the overlapped stitches stick out from the label or are too short.

The present invention is not limited to the step of attaching the elastic cord to the waist of the sweat pants or the like, and can be suitably applied to the case where the sleeve rubber of underwear is attached, for example.

[0025]

As described above, according to the present invention, it is possible to eliminate the variation in the overlapped stitch width of the seams and to always perform the overlap stitch with a constant width regardless of the stretchability of the cloth.

[Brief description of drawings]

FIG. 1 is a plan view showing an overlapped stitching control device 1 for a sewing machine according to an embodiment of the present invention.

FIG. 2 is a side view in which a part of the control device 1 is cut away as viewed from below in FIG.

3 is an enlarged cross-sectional view taken along the section line III-III in FIG.

[Explanation of symbols]

 1 Control Device 3 Bed 4 Needle 5 Fabric 6 Rubber String 7 Insertion Member 8 Proximity Sensor 9 Double-acting Pneumatic Cylinder 10 Control Means 11 Tip Part 14 Guide Surface 16 Tip Part 17 Thread 40 Solenoid Valve 43 Counter 44 Input Means 45 Processing Circuit

Claims (2)

[Claims] 1. An annular first sewn object and an annular second sewn object are placed in a state of being stacked on a bed, and while these first and second sewn objects are moved in the circumferential direction. A sewing machine sewn with a thread inserted by a needle that is reciprocally moved up and down, wherein a thin plate is provided between the first and second sewn objects upstream of the needle in the moving direction of the first and second sewn objects. Overlap control of the sewing machine characterized by stopping the sewing operation after a predetermined number of stitches have been sewn from the time when the seam on the starting point side abuts on the insertion member in the shape of an insertion member Method. 2. A needle that reciprocates up and down, and a movement of the first and second sewn items upstream of the needle in the moving direction of the first and second sewn items sewn by the needle. It includes a thin plate-shaped insertion member that can be retracted into and out of the path, a means for detecting the displacement of the insertion member, and a control means for operating the needle a predetermined number of times in response to the output of the detection means. A sewing control device for sewing machines, characterized by.