JP2733770B2 - Automatic embroidery sewing machine - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an automatic embroidery sewing machine, and more particularly, to detection of a thread break in an embroidery sewing machine which automatically performs embroidery according to a predetermined program, and executes the detection in response to the detection. It concerns control.

(Problems to be solved by the prior art and the invention) When a thread break occurs, the conventional automatic embroidery sewing machine detects the thread break and immediately stops on the spot, and restarts after the next thread break repair. Embroidery is executed from the data following the embroidery data at the time of occurrence. As a result, the seam of the embroidery may be poor and data may be missing in several stitches. Also, due to the detection error when detecting thread breakage,
There was a stoppage of erroneous operation without thread breakage.

To solve these problems, Japanese Patent Publication No. 61-5858
As in No. 4, etc., thread break detection is performed over multiple stitches, and any of them is judged to be a thread break at the time of detecting a thread break, returning to the position before the first thread break detection and restarting, poor seam, A device that prevents fraying or the like and prevents stoppage due to erroneous detection has been proposed.

In these cases as well, stopping the embroidery sewing machine immediately upon detection of the first thread break means stopping the sewing machine against the inertia of the mechanical section. When the sewing machine is restarted, it is returned by more than the amount of the empty sewing and restarted.

If the cause of the yarn breakage is, for example, the yarn being entangled with the needle, there is a high risk that the needle will break due to the movement of the cloth frame after the yarn breakage.

In addition, there is a drawback in that needle holes are formed on the cloth at the time of empty stitching and the finish is not clean.

Therefore, an object of the present invention is to improve these disadvantages and to provide an automatic embroidery sewing machine which confirms thread breakage by detecting a plurality of thread breaks and forms a clean seam.

(Means for Solving the Problems) For this reason, in the present invention, a stitch forming means including a needle which moves up and down and a needle thread catching means cooperating with the needle, and a stitch holding means for holding a cloth are provided in advance with respect to the stitch forming means. In an automatic embroidery sewing machine that automatically performs embroidery on an embroidery frame that moves relative to each other according to a predetermined program, when a thread break occurs during embroidery, reading of the embroidery data is stopped by detecting the thread break, and the stop position is determined. In the above, the detection of the yarn breakage is repeated n times, and the yarn breakage detecting means for determining the yarn break only when the yarn breakage is detected each time, and the embroidery frame is automatically moved from the stop position by the determination of the yarn breakage. It is constituted by means for returning several stitches.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

The automatic embroidery machine sets the cloth to be embroidered on the hoop, and places this hoop in accordance with the program.
The embroidery pattern is formed by the needle of the embroidery sewing machine and the needle thread catching means cooperating with the needle during the movement.

The program controls the movement in the X and Y directions and the vertical movement of the needle for each stitch.

FIG. 1 is a block diagram of the present invention, in which a central processing unit 6 as a control means is mainly used, and in an input unit 1 connected to the central processing unit 6, a pattern selection key 2 as a pattern selection means is operated to operate a desired pattern. To choose,
The selected patterns are displayed on the display means 10, and these displayed patterns are sequentially stored in the pattern storage means 9 by operating the storage key 11.

The start key 4 is sewing machine starting means for starting the sewing machine motor 15 via the sewing machine motor drive circuit 17.

The stop key 5 is a sewing machine stopping means for stopping the sewing machine motor 15.

The external storage data reading means 7 reads the embroidery data from the external storage means 8 such as a floppy disk for storing the embroidery data created based on the pattern to be embroidered, displays the embroidery data on the display means 10, and displays the displayed embroidery pattern. The pattern is stored in the embroidery data storage means 12 by operating the storage key 11.

Although not shown, the sewing machine according to the present invention includes a sewing machine drive shaft rotated by a sewing machine motor 15,
A needle that carries an upper thread and reciprocates up and down in conjunction with the sewing machine drive shaft; and a needle thread catcher that carries a lower thread and forms a stitch in a cloth that is sewn in conjunction with and cooperates with the needle. Seam forming means.

Reference numeral 13 denotes drive shaft rotation phase detection means, which detects the position of the needle by a known rotation phase detection means using a disk fixed to the sewing machine drive shaft and a photo interrupter (neither is shown) fixed by the sewing machine. .

14 is a pulse motor drive circuit, an embroidery frame beating device
A pulse motor for driving the motor 16 is connected to the central processing unit 6. During the phase in which the needle is positioned above the cloth by the rotation position detection signal of the sewing machine drive shaft by the drive shaft rotation phase detecting means 13, the central processing unit 6 transmits the embroidery data for each rotation of the sewing machine drive shaft. It operates based on the embroidery data read from the storage means 12 to drive an embroidery frame drive device 16 as embroidery frame drive means.

Reference numeral 18 denotes a yarn break detection circuit as a yarn break detection means, which is connected to the central processing unit 6.

Reference numeral 19 denotes an automatic back amount setting counter as a back amount setting means for counting and setting the automatic back amount of the embroidery frame after the thread breakage, and can set an arbitrary number of stitches of one or more stitches.

Next, the operation of the present invention will be described with reference to the flow chart from the detection of thread breakage to the restart in FIG.

In the step (a), the thread breakage detection circuit 18 detects a thread breakage. The detection of the breakage of the thread is checked when the thread tension is the highest during the reciprocation of the needle of the embroidery sewing machine, that is, when the thread is being pulled the most.

However, depending on the tension of the yarn, the detector may erroneously detect that the yarn is broken even though the yarn is not broken.

Since this erroneous detection is less likely to occur subsequently, as shown in the flowchart, it is confirmed by performing n detection checks.

Therefore, in the next step (b), the reading of the embroidery data from the embroidery data storage means 12 is immediately stopped in response to the detection of the thread breakage, and the operation of the pulse motor is stopped.

Next, data of the number of times of detection is set in the step (c).

Then, in the next step (d), the needle is moved up and down at the above-described detection position (a), and the thread breakage detection circuit 18 checks whether or not a thread breakage has occurred.

When the crystal thread is not broken again, it is determined that the first detection of the thread break was erroneous, and the embroidery data is read out from the embroidery data storage means 12 stopped in the step (b) in the step (e). Resumes and performs embroidery.

If a yarn break is detected in the above step (d), the number of detections n set in the next step (f) is set to 1
pull.

Next, the number of detections n set in step (g) is 0.
If it is not 0, jump to the input side of the step (d) and move the needle up and down again at the detection position of the above (a). Confirm whether or not.

As a result, when the yarn break is continuously detected, the steps (f) and (g) are executed as described above, and the number of detections n becomes 0.
Is determined.

If n becomes 0, it is determined that the thread is broken, and the next (h)
The number m of return steps of the program is set in the step.
Since the detection position remains at a fixed position regardless of the number of times of detection, the magnitude of the number m of return steps can be set to one or more acceptable numbers in advance.

Next, the sewing machine motor 15 is stopped with the needle held at the top dead center side, and in steps (i), (j), and (k), m steps from the point where reading from the embroidery data storage means 12 is stopped. The embroidery data is read out, and the embroidery frame driving device 16 is driven by operating the pulse motor based on the embroidery data.

Next, in step (l), the embroidery frame drive device 16 is stopped at the position before the m stitches.

Next, in step (p), the process waits until the start key 4 is operated.

Next, in step (q), the operation is started from the moving position by operating the start key 4.

In the present embodiment, the reading of the embroidery data is stopped at the time of the detection of the thread breakage described in (a) above, and the needle is moved up and down for n times of the thread breakage detection at that position.
As shown in the control block of the figure and the flow chart of FIG. 4, the reading of the embroidery data is stopped at the time of the detection of the thread breakage, and the embroidery frame is moved up and down based on the data for separately confirming the detection of the thread breakage. Prevents the needle from penetrating into the same needle hole by fine drive to affect the sewing thread,
It may be one that confirms the detection of thread breakage.

That is, the data for confirming the thread breakage does not affect the embroidery pattern and is finely driven. For example, the data may be based on the stitching pattern of Japanese Patent Application Laid-Open No. 59-199472 filed by the present applicant. .

That is, suitable pattern data is read out from the thread breakage detection position and the embroidery data one stitch before, and the embroidery frame driving device is minutely driven.

(Effects) As described above, according to the present invention, yarn breakage detection is performed a plurality of times, and any of them determines that a yarn breakage has occurred when a yarn breakage is detected, thereby preventing erroneous detection of yarn breakage detection. By restarting from the position where the number of stitches is returned from the first thread breakage detection position, an embroidery stitch with a good seam can be formed.

In addition, the detection of the thread breakage a plurality of times is to stop reading out new embroidery data when the first thread breakage is detected, and to detect the thread breakage by the vertical movement of the needle at the same place or a minute movement place. Further, it is possible to prevent the occurrence of needle breakage due to the movement of the embroidery frame when the thread breaks due to thread entanglement as in the related art.

[Brief description of the drawings]

1 is a control block diagram of an embroidery sewing machine according to the present invention, FIG. 2 is a flowchart, FIG. 3 is a control block diagram of a sewing machine according to another embodiment, and FIG. 4 is a flowchart thereof. It is.

Claims (2)

(57) [Claims] 1. A needle carrying an upper thread and reciprocating up and down in conjunction with the rotation of a sewing machine drive shaft, and a needle carrying a lower thread and forming a stitch on a cloth which is sewn in conjunction with and in cooperation with said needle. An automatic embroidery sewing machine including a seam forming means including a thread catcher and an embroidery frame driving device for moving a embroidery frame holding a cloth relative to the needle to form a seam pattern on the cloth;
A sewing machine motor that rotates the sewing machine drive shaft, a sewing machine starting unit that starts the sewing machine motor, a storage unit that stores embroidery data of an embroidery pattern, and a pattern selection unit that selects a desired embroidery pattern from the storage unit. A pulse motor which operates based on embroidery data of an embroidery pattern which is selected by the pattern selection means and is read from the storage means for each rotation of the sewing machine drive shaft to drive the embroidery frame driving means; A thread break detecting means for detecting a thread break in relation to a vertical reciprocating motion during sewing; and a control means for reading embroidery data of an embroidery pattern from the storage means for each rotation of the sewing machine drive shaft. It operates in response to the detection of the thread break by the break detecting means, stops reading the embroidery data from the storage means, stops the pulse motor, and reciprocates the needle up and down by the sewing machine motor. By the operation, when the thread breakage detecting means detects the thread breakage n times, the sewing machine motor is stopped at the top dead center position of the needle, and one or more embroidery data are read backward from the stop position of the embroidery frame. Control means for operating the pulse motor, operating the pulse motor to stop the pulse motor at a position where the embroidery frame is retracted by m stitches by the embroidery frame driving means, and setting the number of reverse reading stitches of the embroidery data. Back amount setting means, wherein after the embroidery frame has stopped at the retreat position, the sewing machine motor is started in response to the operation of the sewing machine starting means to rotate the sewing machine drive shaft. Embroidery sewing machine. 2. The control means according to claim 1, wherein when said detection means does not detect a thread break among said n times of thread breakage, said control means restarts reading of subsequent embroidery data from said storage means to drive a sewing machine motor and a pulse motor. 2. The automatic embroidery sewing machine according to claim 1, wherein the embroidery sewing is continued.