JPS6366229B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a control device for a two-needle sewing machine, and particularly to a two-needle sewing state in which a stitch is formed by two needles spaced apart from each other on the left and right, and in a corner part. There is a needle bar mechanism that can be switched between a single-needle sewing state in which one of the needles pauses upward to form a stitch based on a preset number of stitches, and a needle bar mechanism that can be switched between a double-needle sewing state and a one-needle sewing state. The present invention relates to a control device for a two-needle sewing machine equipped with an electromagnetic switching means for switching between a main needle sewing state and a regular sewing state.

Conventional technology Conventionally, this type of two-needle sewing machine
A sewing machine disclosed in Japanese Patent No. 55-103895 is known. This conventional two-needle sewing machine has two needle bar mechanisms.
It is equipped with an electromagnetic switching means that switches between a full-needle sewing state and a single-needle sewing state, and the operation of this electromagnetic switching means is controlled by a control device, so switching of the needle bar is automated and work efficiency is improved. It is possible to improve

When corner stitching is performed using this two-needle sewing machine, the needle to be paused at the corner and the number of single-needle stitches in the front and rear parts of the corner are input in advance into the control device. Corner stitching was performed according to the stitch formation command from the control device. Then, for example, make a corner stitch as shown in Figure 1 with a width of 6.35 mm and a pitch.
To explain the case where sewing is performed from the upper left to the lower side with 3.18 mm, when corner stitching is performed at the right angle part shown in the same figure, after sewing up to points P ₁ and P ₂ with double needle stitching, the direction is set by the control device. Once the left hand needle is paused upward, the right hand needle is driven at low speed for a set number of stitches (in this case 2 stitches), and then stopped at the bottom of the needle on corner _C1 .

Then, the fabric is rotated 90 degrees around the right needle that is in the needle-down stop state, continues to be driven at low speed for the set number of stitches (2 stitches) in the single-needle sewing state, and then double-needle sewing is started again. By starting, a right-angled corner stitch as shown in the figure is formed.

However, when sewing an obtuse angle (110°) bent to the left with a two-needle sewing machine equipped with such a control device, for example, as shown in the lower part of the figure, the 2-needle sewing machine has two needles, similar to the corner sewing of the right-angled section described above. After operating the main needle up to points P ₁ and P ₂ , the right needle is driven at low speed before and after corner C ₂ by the same number of stitches while the left needle is resting upwards to perform corner stitching. When the number of stitches is set to 1, as shown in the same figure, and when the set number of stitches is set to 2, as shown in Fig. 2, a stitch is formed on the inside of the corner that deviates greatly from the desired obtuse angle, There was a drawback that beautiful corner stitches were not formed.

Purpose: In order to eliminate the drawbacks of the conventional example as described above, the present invention operates an electromagnetic switching means during sewing of the number of stitches in a single-needle sewing section set by the stitch number setting means, and changes the needle bar mechanism. By providing an operating member for switching from a single-needle sewing state to a double-needle sewing state, even obtuse corners can be sewn beautifully.
The present invention provides a control device for a full-needle sewing machine.

Embodiment Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. 3 to 7. A two-needle sewing machine 2 is placed on a table 1, and there are The needles 5 and 6 supported by the two needle bars 3 and 4, which are arranged at a distance from each other, perform two-needle operation to form straight stitches, and one of the needles rests in the needle-up position at the corner. to form a corner stitch 1
Needle bar mechanism (not shown) that enables regular needle operation
is installed. The detailed structure of this needle bar mechanism is disclosed in Utility Application No. 50-2387 (Utility Model Application No. 51-85862, Sewing Machine Needle Bar Movement Control Device) filed by the present applicant.
In addition, since various similar devices are known in addition to this application, a detailed explanation will be omitted.

A DC motor 7 is attached to the lower surface of the table 1, and is connected to a sewing machine main shaft (not shown) of the sewing machine 2 via a belt 9. A foot pedal 11 is supported on a support shaft 10 fixed to the table 1 so that it can be depressed forward (toe side) and backward (heel side), and is built into a switch box 13 fixed to the side of the DC motor 7. It is connected via a connecting rod 12 to a pedal switch 24 which will be described later.

On the lower surface of the bracket arm 2a of the sewing machine 2, there is a return type release switch 14 as an operating member.
15 is provided, and the rest state of the needle 5 or 6, which is stopped at the needle-up position in the single-needle sewing state during corner sewing, is released by pressing the needle.

Next, the electric circuit of the control device for driving and controlling the two-needle sewing machine 2 will be explained with reference to FIG.

Five stitch count setting switches 21 as stitch count setting means are provided on the surface of the switch box 13, and are used to set the number of stitches for single-needle sewing of the front and rear parts of each corner (in this embodiment, the number of stitches is The number of stitches in the second half is the same)
It is used to set the number of stitches and outputs the set number of stitches as a digital signal. Five corner stitching direction selection switches 22 are also provided on the surface of the switch box 13 in pairs with the number of stitches setting switch 21, and are used to set the corner stitching direction, whether the corner stitching is clockwise or counterclockwise. , the set corner sewing direction is output as a digital signal. The number of stitches setting switch 21 and the corner stitching direction selection switch 22 are used to sequentially set the number of stitches and the direction of corner stitching at five locations.

The needle position detector 23 is composed of a permanent magnet piece (not shown) that rotates in conjunction with the main shaft of the sewing machine, and a plurality of Hall elements arranged around the permanent magnet piece, and detects the upper needle position of the needles 5 and 6. , the needle down position and the thread trimming position are detected, and the detection signals are output.

The pedal switch 24 is a switch box 1.
3, and is adapted to output a front depression signal and a rear depression signal when the foot pedal 11 is depressed.

Corner stitch selection switch 25 is switch box 13
It is provided on the surface of the machine and is used to set the mode for corner stitching using single needle stitching, and when operated, a digital signal is output.

The control circuit 26 is provided in the switch box 13, and has a memory for storing the outputs of the stitch number setting switch 21, the corner stitching direction selection switch 22, and the corner stitching selection switch 25, and also includes a memory for storing the outputs of the stitch number setting switch 21, the corner stitching direction selection switch 22, and the corner stitching selection switch 25. 25 and the outputs of the needle position detector 23 and pedal switch 24, outputting a signal to a motor drive circuit 27 to drive the DC motor 7 at high or low speed;
The power transistors 28 and 31, which will be described later, are biased and turned on.

Power transistor 28 is switch box 1
3, its base is connected to the control circuit 26, and its emitter is electrically grounded,
A solenoid 29 and the release switch 14 are connected in series between the collector and the collector power supply Vcc. Further, a diode 30 for absorbing surge current is connected to the solenoid 29 and the release switch 14. The power transistor 31 is also disposed within the switch box 13, its base is connected to the control circuit 26, its emitter is electrically grounded, and a solenoid 32 and the release switch are connected between its collector and the collector power supply Vcc. 15 are connected in series.
Further, a diode 33 for absorbing surge current is connected to the solenoid 32 and the release switch 15.

This solenoid 29 constitutes an electromagnetic switching means for stopping the needle bar 3 and the needle bar 4 upward, and when the release switches 14 and 15 are closed, the power transistors 28 and 31 are connected to the control circuit. When the solenoids 29 and 32 are biased by 26 and turned ON, the solenoids 29 and 32 are excited by the collector currents of the power transistors 28 and 31, and based on this electromagnetic force, the needles 5 and 6 of the needle bar mechanism are stopped at the needle upper position. It is becoming more and more common.

Next, the operation of the control device for the two-needle sewing machine constructed as described above will be explained with reference to the flowchart shown in FIG.

_Now , to explain the case where the two-needle sewing machine 2 performs corner stitching at an obtuse angle of 110° as shown in Fig. 6 from top to bottom in the same figure, first, The number of each stitch for single needle sewing is set by the number of stitches setting switch 21. Now, let this number of stitches be 2. Next, the corner sewing direction selection switch 22
is operated to set the corner stitch that bends to the left as shown in the figure, and this back corner stitch selection switch 25 is operated to control the digital signal for setting the mode for corner stitching. It is stored in the memory within the circuit 26.

When the foot pedal 11 is depressed forward in this state, the control circuit 26 detects the forward depression signal from the pedal switch 24 and outputs a signal to the motor drive circuit 27 for causing the DC motor 7 to operate at high speed. Then, after double-needle stitching has been performed to positions P ₃ and P ₄ shown in FIG.
The control circuit 26 detects that the output of the corner sewing direction selection switch 2 is stored in the memory.
2 is read out from the memory, and the power transistor 31 is read out from the memory.
is biased to turn it ON. Then, the solenoid 32 is excited by the collector current of the power transistor 31, and the needle 6 is stopped at the needle-up position.

Next, the control circuit 26 activates the release switches 14 and 15.
It is determined whether at least one of the two is open. Since both release switches 14 and 15 are now closed, the control circuit 26 operates the right hand 5 at a low speed using the DC motor 7 while the left hand 6 is resting at the needle up position. Then, when the number of stitches set by the number of stitches setting switch 21 (in this case 2) is operated, the control circuit 26 causes the number of stitches to 5 on the corner _C3 .
to stop at the needle down position.

Here, when the cloth is rotated around the needle 5 by an angle corresponding to the refraction angle of 110 degrees and the foot pedal 11 is depressed forward, the control circuit 26 determines that both the release switches 14 and 15 are in the closed state, right hand needle 5
Resume single needle sewing at low speed. Then, when the release switch 15 is pressed to open the circuit after sewing one stitch with the needle 5, the collector current of the transistor 31 is immediately cut off, and the excitation of the solenoid 32 is released. Then, the control circuit 26 runs the last stitch of the set number of corner stitches at low speed with two needles, and if the foot pedal 11 is continued to be depressed forward after this, the straight line section following the corner stitch is operated at high speed. Double needle stitching is performed to form beautiful square stitches as shown in FIG.

One corner stitch is formed by this procedure, and when forming multiple corner stitches, each stitch number setting switch 2 is
1 and the corner stitch direction selection switch 22 to set the number of stitches and corner stitch direction for each corner stitch, it is possible to sequentially form desired corner stitches. After all the corner stitches have been formed based on the set data, when the foot pedal 11 is pressed down, the control circuit 26 determines that all the corner stitches are completed and raises the needles 5 and 6. At the same time as stopping at the position, the thread is cut and the sewing operation is completed. In addition, if the foot pedal is released from the double-needle sewing state, needles 5 and 6
is stopped at the needle down position, and in this state new corner stitch data can be input to continue operating the sewing machine 2.

Further, this two-needle sewing machine 2 can also sew the same obtuse angle (110°) as described above by the following procedure.

That is, in the above procedure, from corner C ₃ , use one needle to
After the needle operation, the release switch 15 is pressed to release the needle 6 from its rest state, and the last stitch of the set number of stitches is operated with two needles, but in the same case, the set number of corner stitches is set to 2. , After operating the two needles to the P ₃ and P ₄ positions, press the release switch 15 to open the circuit, and operate the first stitch of corner stitching with the two needles, and the following stitch with the single needle of needle 5. After stopping at the corner _C3 position and rotating the cloth around the needle 5, one needle is operated for a predetermined number of stitches, and a corner stitch as shown in FIG. 7 is formed.

Therefore, in right-angle corner stitching, the control device of this two-needle sewing machine 2 performs sewing according to the number of stitches and the corner stitching direction set by the number of stitches setting switch 21 and the corner stitching direction selection switch 22, as in the conventional case. By operating a single needle, it is possible to form a desired corner stitch, and in the case of obtuse angle corner stitching, the release switch 14 or 15 is pressed and opened during the set single needle stitch operation, and the needle is stopped at the needle up position. By canceling the dormant state of needles 5 or 6, a desired number of stitches from the set number of stitches for single-needle operation can be operated with two needles to create a beautiful corner that approximates the desired obtuse angle. Sewing can be formed.

Effects As described in detail above, in a two-needle sewing machine in which the switching operation of the needle bar is automated, the electromagnetic switching means is set during sewing of the number of stitches in the single-needle sewing section set by the number of stitches setting means. By providing an operating member for operating the needle bar mechanism and switching the needle bar mechanism to a two-needle state, even when forming an obtuse corner, beautiful corner stitches that approximate a desired obtuse angle can be formed.

[Brief explanation of drawings]

FIGS. 1 and 2 show two conventional methods related to this invention.
Fig. 3 is a front view of a two-needle sewing machine embodying the present invention, Fig. 4 is a block diagram showing the electric circuit of the control device, and Fig. 5 is a calculation diagram of the control circuit. Flowcharts illustrating processing operations, FIGS. 6 and 7 are stitch patterns made by a two-needle sewing machine embodying the present invention. Needles...5, 6, Release switch...14, 15, Number of stitches setting switch...21, Corner sewing direction selection switch...2
2. Control circuit...26, Solenoid...29, 33.

Claims (1)

[Claims] 1. Two needles 5 arranged with a space between them on the left and right sides,
6, a needle bar mechanism 3 capable of switching between a two-needle sewing state in which a stitch is formed and a single-needle sewing state in which one of the needles is rested in an upper position at a corner to form a stitch; 4, electromagnetic switching means 29, 32 operatively connected to the needle bar mechanisms 3, 4 to switch the needle bar mechanisms 3, 4 between a double needle sewing state and a single needle sewing state; a stitch number setting means 21 for setting the number of stitches in a sewing section depending on the sewing state; and a control means 26 for controlling the operation of the electromagnetic switching means 29 and 32 based on the number of stitches set by the stitch number setting means 21. In the two-needle sewing machine equipped with the above, the electromagnetic switching means is activated during sewing of the set number of stitches by the stitch number setting means 21, and the needle bar mechanisms 3 and 4 are changed from a single-needle sewing state to a double-needle sewing state. A control device characterized in that it is provided with operation members 14 and 15 for switching.