JPS6118474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing machine, and more particularly to a fixed position stopping device for a sewing machine for correctly stopping the sewing machine at the end of a cloth to be sewn during sewing work using a sewing machine.

Normally, when sewing with a sewing machine, a part of the sewing work is often completed at the end of the workpiece, but when the sewing machine is operated at a high speed of about 4000 rpm, Correctly stopping at the end of the fabric is an extremely difficult task. As a result, the sewing machine often ends up sewing past the end of the fabric, or it becomes necessary to run the sewing machine again to make additional stitches in order to stop before the end of the fabric is reached, resulting in poor quality of the material being sewn. It was unavoidable that this would lead to a decline in productivity and work efficiency.

One method currently being considered to eliminate these drawbacks is to detect the end of the cloth using an optical sensor or the like and automatically stop the cloth.

This has the disadvantage that, due to the large inertia of the sewing machine and the driving device, the stopping position of the sewing machine changes greatly depending on the speed of the sewing machine immediately before it stops, that is, the speed of the sewing machine operated by the sewing worker. Furthermore, in such sewing machines that automatically stop, the needle top position is usually stopped automatically, or the sewing machine's thread trimming device is often linked to ensure that the sewing machine stops at the correct position at the end of the fabric. If they do not match, performing additional sewing has the disadvantage that the quality of the product to be sewn is significantly degraded.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above.The sewing machine is operated at a predetermined low speed from the time when the end of the cloth is detected by an optical sensor, etc., and then the sewing machine is operated at a specified low speed. The object of the present invention is to provide a sewing device that can be stopped at a certain point.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of the sewing device of the present invention, in which 101 is a sewing machine for sewing, 102 is a sewing machine that supports the sewing machine 101 and a variable speed motor 103 that is a driving device for the sewing machine 101, and also serves as a sewing workbench. Table 103 is sewing machine 101
104 is a variable speed motor for the operation of the sewing machine 1.
105 is a control device for controlling the sewing machine 101 and the variable speed motor 103;
6 is a detection device for generating a position detection signal for stopping the sewing machine 101 at a fixed position and a speed detection signal for detecting the operating speed of the sewing machine; 107 is a belt for connecting the sewing machine 101 and the variable speed motor 103; , 108 is an operation unit for controlling the operation pattern of the sewing machine 101, 109 is a negative edge detection device for detecting the end of the fabric of the sewing product, and 110 is a reflection plate for reflecting the optical signal from the fabric edge detection device. be.

Next, the effect will be explained. First, when a workpiece is set on the sewing machine 101 and the operation pedal 104 is operated, the control device 105 controls the sewing machine 101 and the variable speed motor 103 according to the signal from the operation pedal 104, and the sewing machine 101 sews the workpiece. do. When the sewing progresses and the end of the material to be sewn is detected by the cloth edge detection device 109, the signal is transmitted to the control device 105.
causes the variable speed motor 103 to operate at a predetermined low speed. After the end of the workpiece is detected by the cloth edge detection device 109, the sewing machine 101 continues sewing at low speed so that the needle of the sewing machine 101 approaches the final end of the workpiece, which is the end of the workpiece. is being done. When the needle of the sewing machine 101 reaches the terminal end, the operator operates the operating pedal 104 to stop the sewing machine 101. The detection device 106 provides the control device 105 with a signal for controlling the operating speed of the sewing machine 101 and a signal for determining the stop position of the sewing machine 101.

Next, a configuration diagram of the main parts of this invention is shown in FIG.
The operation will be explained with reference to the time chart shown in FIG.
In Figure 2, 101, 103, 104, 10
5,106 is equivalent to that shown in Figure 1, and 2
Reference numeral 01 indicates that a sewing object 109 set in a sewing machine 101 is a fabric edge detection device, which is a reflective type optical sensor, which reflects light from a light emitting element 109A on a reflecting plate 110 and receives the light on a light receiving element 109B. . In this case, the construction is such that the object to be sewn passes between the light emitting element 109A and the reflecting plate 110.
Reference numeral 202 denotes a one-shot circuit composed of a semiconductor IC, which generates a pulse signal for operating the flip-flop 203 at the next stage when the signal from the cloth edge detection device 109 changes from the H level to the L level. 204 is a flip-flop 203
A transistor 205, which becomes conductive when the output of the sewing machine becomes H level, responds to an input signal from the operating pedal 104 and generates an output for the sewing machine 101 and a speed command, run, and stop command output for the variable speed motor 103. A sewing machine control circuit 206 is a signal from the detection device 106 and a sewing machine control circuit 205 for
This is a motor control circuit that controls the variable speed motor 103 to operate, stop, and operate at a speed proportional to the magnitude of the speed command voltage in response to an output signal from the variable speed motor 103. FIG. 3 is a time chart explaining the operation of FIG. 2.

The following description will be given with reference to these figures. When a workpiece 201 is set on the sewing machine 101 and the operating pedal 104 is placed in the first operating position, the variable speed motor 103 is activated and the sewing machine 101 begins sewing. At this time, the material to be sewn 201 disables the operation of the cloth edge detection device 109, and sets the output of the light receiving element 109B, that is, the potential at point A to the H level. Therefore, the output of the one-shot circuit 202 remains at the L level, the output Q of the flip-flop 203 remains at the L level, the transistor 204 becomes non-conductive, and the potential at point B is maintained at the potential controlled by the sewing machine control circuit 205. Then, the variable speed motor 103 rotates at a predetermined speed, and the sewing machine 101 continues sewing work.

Next, the operating pedal 104 continues to be operated on the same first pedal as described above.
When the cloth end detection device 109 detects the end of the cloth of the workpiece 201 when the sewing machine 101 is in the operating position of
The cloth end detection device 109 is set so as to be a predetermined distance from the end of the cloth 01], and the light receiving element 109B receives the light from the light emitting element 109A reflected by the reflection plate 110 conduction,
The potential at point A is set to L level. When the potential at point A changes from H level to L level, one shot circuit 202 generates a predetermined pulse signal and transmits it to the set input (S terminal) of flip-flop 203 at the next stage. Flip-flop 203 inverts its output (Q terminal) from L level to H level based on this signal. The operation timing during this period is 3rd.
They are shown at 2, 4, 5, and 6 of the timing chart in the figure. Next, when the output (Q terminal) of the flip-flop 203 becomes H level, the transistor 2
04 conducts and the speed command voltage at point B is set to OV.
Since this point B is forced to 0V, no matter how much the speed command voltage from the sewing machine control circuit 205 is, the speed command voltage to the motor control circuit 206 is
0V, the motor control circuit 206 sets the speed of the variable speed motor 103, that is, the operating speed of the sewing machine 101 to a predetermined low speed operation. At the time when this low-speed operation is performed, the cloth edge detection device 10
9 is the point at which the end of the object to be sewn 201 has just been detected, and the needle of the sewing machine 101 that is actually sewing is still a predetermined distance from the end of the object to be sewn 201, and during this time it is operated at a predetermined low speed. Can do sewing. Therefore, the needle of the sewing machine 101 is connected to the workpiece 2.
The operator of the sewing machine 101 can easily determine the point at which the end of the sewing machine 101 is reached, and can stop the sewing machine 101 accurately at the end of the sewing product. sewing machine 10
To stop 1, use the operation pedal 1 shown earlier.
04 in the second operating position, and when it is necessary to stop the needle in the up position or to perform thread cutting operation, this can be accomplished by placing the operating pedal 104 in the third operating position. The operation timing during this period is shown at 1, 3, 7, and 8 in FIG. Flip-flop 203 is reset for subsequent operation by the thread trimming solenoid energization signal.

In the above embodiment, a reflection type detection device sensitive to light is used as the cloth edge detection device 109, but this can also be realized by a transmission type detection device or one using a mechanical contact.

As described above, according to the present invention, it is possible to automatically operate the sewing machine at a predetermined low speed when the end of the object to be sewn is detected, and to stop the sewing machine after accurately sewing up to the end of the object to be sewn. It is possible to reduce worker fatigue and perform work with stable quality, and this effect can be realized with inexpensive equipment.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a sewing machine according to an embodiment of the present invention, FIG. 2 is a configuration diagram showing the main parts of the invention, and FIG. 3 is a time chart diagram for explaining the operation of FIG. 2. . In addition, the same reference numerals in the figures indicate the same parts, and 101
1 is a sewing machine, 103 is a variable speed motor, 104 is an operating pedal, 105 is a control device, and 109 is a fabric edge detection device.

Claims (1)

[Scope of Claims] 1. In a sewing device in which driving and stopping of a motor are controlled according to the operating position of an operating device, there is provided a cloth edge detection device for detecting the terminal end of a workpiece to be sewn, and a position for stopping at a fixed position. It is characterized by comprising a position detection device that generates a detection signal, and a control device that drives the motor at low speed when the cloth edge detection device detects a cloth edge, and stops the motor when the operating device is operated to a stop position. sewing equipment. 2 The first operating position of the operating device controls the operation of the sewing machine, the second operating position controls the stopping of the sewing machine in the needle down position,
2. The sewing device according to claim 1, wherein the third operating position is a needle-up stop position of the sewing machine.