JP3021507B2 - Multi-head embroidery sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-head embroidery sewing machine, and more particularly, to repairing an embroidery pattern defect caused by a broken thread of an embroidery thread on one of the heads. The present invention relates to a multi-head embroidery sewing machine that automates the processing of bobbin thread appearing on the surface of a fabric by an embroidery operation using a head that does not cause embroidery.

2. Description of the Related Art A multi-head embroidery sewing machine performs embroidery by tangling an upper thread passed through a sewing needle of each head and a lower thread stored in a bobbin of a shuttle provided for each head. Therefore, in order for the embroidery pattern formed on the surface of the fabric to be composed of all the upper threads selected in a desired color, the tension of the upper thread and the lower thread are adjusted to adjust the upper thread to the inside of the fabric. Or it is necessary to penetrate to the back. For this reason, in a multi-head embroidery sewing machine, an upper thread tension adjusting screw corresponding to the number of heads for adjusting the upper thread tension of each head and a lower thread tension adjusting screw provided on the bobbin are provided, and the embroidery pattern and the embroidery thread to be used are provided. The tension between the upper thread and the lower thread is adjusted according to the material of the thread.

However, the process of repairing an embroidery pattern defect performed when a thread breakage occurs in one of the heads causes a phenomenon in which the lower thread is exposed on the surface of the fabric in the other head.

Sew the exposed part of such bobbin thread by embroidery work,
Japanese Patent Publication No. Sho 63-32909 discloses a technique for improving the performance of an embroidery pattern by obscuring the embroidery pattern. FIG. 8A is a simplified illustration of this technique. If the normal head is embroidering at position P1 and the other head breaks the thread and the embroidery operation is interrupted, the embroidery frame is moved to the position where embroidery has already been completed to continue the embroidery operation of the head where the thread break occurred. A so-called stitch back, which is driven stepwise or linearly, is performed. However, in a normal head, the upper thread pulls the lower thread with a strong force due to this stitch back, and the lower thread is exposed on the surface of the fabric at the position P1. Therefore, according to the technique described above, in order to sew the exposed portion, the normal head embroidery operation is resumed from the position P2 slightly before the position P1 where the bobbin thread is exposed, and the position P1 is moved to the second position. It is characterized by stitching once.

[Problems to be Solved by the Invention] However, even if the above-described technique is used, the exposure of the lower thread cannot be completely covered and when the thread breakage occurs in any of the heads, the embroidery pattern is not included in the embroidery pattern. Exposed parts appear, impairing workmanship.

That is, the above-mentioned technique aims at the normal upper head thread pulling the lower thread at the thread breakage occurrence position P1, and sewing the lower thread exposed here. And this position
The exposure of the bobbin thread at P1 can be completely obscured.

However, there is a problem that the bobbin thread is exposed at a position P2 where the operation of sewing the bobbin thread exposed at the position P1 is started.

FIG. 8 (B) illustrates the cause of this problem.
It is. As shown in the figure, when the embroidery frame moves to the position P2 at which the embroidery operation for covering the lower thread exposed at the position P1 is started, the lower thread largely pulled out from the bobbin by the stitch back is in a hanging state. ing. That is, in this state, the adjusting action of the bobbin lower thread tension adjusting screw cannot be achieved as the actual lower thread tension, and the tension is almost zero.

Therefore, if an embroidery operation is performed on the head that is not broken at the position P2, the hanging lower thread is exposed on the fabric surface by the upper thread. That is, although the bobbin thread exposed at the position P1 can be covered and hidden, the bobbin thread is exposed at the position P2, which significantly deteriorates the performance of the embroidery pattern.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. When repairing an embroidery pattern defect due to a thread break of an embroidery thread is performed on one of the heads, an embroidery operation using a head having no thread breakage is performed. Not only the position P1 of the fabric but also the position
It is an object of the present invention to provide a multi-head embroidery sewing machine that automates processing of a bobbin thread appearing on a P2 cloth surface and improves the quality of an embroidery pattern.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the constituent means of the present invention comprises:
As shown in the basic configuration of the figure, in accordance with the embroidery data, the up and down movement of the sewing needles provided on each of the plurality of heads and the driving of the embroidery frame for changing the relative positional relationship between the plurality of heads and the embroidery cloth are controlled. In the multi-head embroidery sewing machine, a thread break occurs in one of the embroidery threads, and the stitch-back operation of the embroidery frame for repairing the thread break and continuing the embroidery operation interrupted by the thread break was performed. At the time, the initial embroidery work execution means C1 for executing embroidery only with the head where the thread break has occurred to the stitch back work start position or near the position, and after the embroidery work by the initial embroidery work execution means C1 is completed, The sewing operation by the plurality of heads is reduced at a position inside the pattern which can be finally covered by the embroidery pattern formed by the embroidery operation based on the embroidery data. A relay embroidery operation executing means C2 for executing at least the first stitch; and a stitch and an initial embroidery operation on which the sewing operation is performed by the relay embroidery operation executing means C2 after the sewing operation by the relay embroidery operation executing means C2 is completed. Returning to a position where both the final stitches of the embroidery operation performed by the head having no thread break before being executed by the execution means C1 can be covered, the embroidery operation based on the embroidery data is performed by the plurality of heads. And a continuous embroidery work executing means C3 for executing the multi-head embroidery sewing machine.

[Operation] The initial embroidery work execution means C1 in the multi-head embroidery sewing machine according to the present invention starts a stitch-back operation when an embroidery thread on one of the heads has a thread breakage and the embroidery pattern defect due to the thread breakage is repaired. Embroidery is executed only at the position or near the position where a thread break has occurred.

That is, the initial embroidery work executing means C1 executes the embroidery work only for the head where the thread break has occurred, and the state is almost the same for all the heads up to the stitch back work start position.

Subsequent to the control of the initial embroidery work execution means C1, the relay embroidery work execution means C2 includes a pattern inside which can be finally covered by an embroidery pattern formed by the embroidery work based on the embroidery data by all of the plurality of heads. , The sewing operation by the plurality of heads is executed at least for the first stitch or more.

As a result of the completion of the embroidery operation by the initial embroidery operation execution means C1, the relationship between the upper thread and the lower thread having no thread breakage is in the state shown in FIG. 8B as described above. Therefore, if the sewing operation is performed in this state, the hanging lower thread is pulled out by the upper thread and is exposed on the surface of the fabric.

Therefore, the relay embroidery work execution means C2 causes at least the first stitch to be sewn by a plurality of heads at a position inside the embroidery pattern formed by the embroidery work based on the embroidery data. Thus, the position where the lower thread is exposed is a position where sewing can be performed with an embroidery pattern based on the embroidery data.

Thus, the initial embroidery work executing means C1 after the stitch back of the head having the thread breakage is performed by the relay embroidery work executing means C2.
The lower thread slacks in the head where no thread break has occurred while performing embroidery stitching by embroidery sewing. By forming the position where the lower thread is pulled out at a position inside the pattern that can be finally sewn and hidden by the embroidery pattern, the lower thread is exposed when the embroidery is resumed for the head where the thread has not broken due to the slack of the lower thread. The position can be brought to a position where it can be covered by embroidery sewing by the continuous embroidery work executing means C3 described later. After performing the sewing operation of at least the first stitch by the relay embroidery operation executing means C2, the tension relationship between the upper thread and the lower thread is set by the tension adjusting screw, and then the continuous embroidery operation executing means C3 performs the following. Is executed.

The control target of the continuous embroidery work execution means C3 is, like the relay embroidery work execution means C2, a plurality of heads provided in the multi-head embroidery sewing machine, and the sewing work is completed by the relay embroidery work execution means C2. Return to the position where both the stitches and the final stitches of the embroidery work performed by the head without thread break before being executed by the initial embroidery work execution means C1 can be concealed, and the embroidery work based on the embroidery data is performed. To resume. Thereby, the exposed position of the lower thread generated at the time of stitch back by the initial embroidery work executing means C1 for coping with the thread breakage of any one of the heads, and the slack in the head where no thread break occurs during this stitch back. An embroidery pattern is formed so that both the positions where the lower thread exposed on the cloth by the sewing operation by the relay embroidery operation execution means C2 are covered. As a result, the embroidery operation interrupted due to the thread break is continued without exposing the lower thread at any point.

Hereinafter, in order to more specifically describe the present invention, examples will be described in detail.

[Embodiment] FIGS. 2 and 3 are explanatory views of the configuration of a multi-head embroidery sewing machine according to an embodiment of the present invention. As shown in FIG. A sewing needle is selected from the sewing needles 40 according to the embroidery pattern input from 20 and moved up and down, and the movement of the embroidery frame 50 in the X-Y direction is controlled in synchronization with the vertical movement.

FIG. 3 is a detailed configuration block diagram of the driver unit 30. In the figure, a needle changing motor 32 is a power source for selecting an arbitrary one of the multi-needles on each head. The sewing motor 34 is the needle changing motor 32
For moving the sewing needle 40 selected by
The main shaft connected to the selected sewing needle 40 via a crank mechanism is rotated, and the sewing needle 40 is moved up and down at a predetermined speed.

The electromagnetic actuators 35a and 35b have two heads (hereinafter, two heads).
The two heads are referred to as head a and head b respectively).
The mechanical connection between the main shaft rotated by 34 and the sewing needle 40 selected by the needle changing motor 32 is released, and the vertical movement of the a-head or b-head sewing needle 40 is stopped. Thus, a
An embroidery operation can be performed for only the head or the head b.

The X-axis motor 36 and the Y-axis motor 38, which are stepping motors, are power sources for moving the embroidery frame 50 in the X-axis direction and the Y-axis direction. As is well known, X-axis motor
36 moves the embroidery frame 50 by one unit distance in the X direction each time a step signal is input, and the Y-axis motor 38 moves the embroidery frame 50 by one unit distance in the Y direction each time a step signal is input. In such a manner, the belt for moving the embroidery frame 50 is rotationally driven via a pulley or the like.

As shown in FIG. 3, a driver unit 30 of the multi-needle multi-head embroidery machine is connected to a controller 20 operated by a user, and operates by analyzing a embroidery data input from the controller 20 while analyzing the embroidery data. It is configured as a digital logic circuit centered on a computer. Therefore, the driver unit 30 is provided with the CPU 3 that executes the logical operation.
0A, a ROM 30B for storing various programs, and a RAM 30C for temporarily storing information. The various motors described above, that is, the motor controllers 30D to 30F that output drive signals of the X-axis motor 36, the Y-axis motor 38, the needle changing motor 32, and the sewing motor 34 for moving the embroidery frame 30 in the XY directions, The excitation phase of the motor is appropriately changed according to the control signal from the CPU 30A, and the motor is rotated at a desired speed at a desired rotation angle. In addition, the excitation circuits 30Ga, 30G
“b” means that an exciting current is passed through each of the electromagnetic actuators 30a and 30b in response to a control signal from the CPU 30A, and the electromagnetic actuators 30a and 30b are appropriately excited.

The driver unit 30 configured as described above analyzes the embroidery data input from the controller 20 as the storage contents of the ROM 30B as is well known, and controls the various motors described above and the control signals of the excitation circuits 30Ga and 30Gb. To create
An embroidery work execution program for outputting the control signal to each controller and the excitation circuit at a predetermined timing is stored in advance.

FIG. 4 is a flowchart showing a schematic flow of the embroidery work execution program. As shown in the figure, when the processing by the embroidery work execution program is started by the CPU 30A, first, the embroidery data of the embroidery pattern requested this time is input from the controller 20 (step 100).
This embroidery data is converted into one-needle data suitable for the multi-head embroidery sewing machine of the present embodiment and stored in the RAM 30C (step 110). Then, the one stitch data thus stored in the RAM 30C is sequentially output to the various controllers 30D to 30F (step 120), and the embroidery operation is actually started.

Next, as conditions necessary for the embroidery operation to be continued satisfactorily, the self-diagnosis of the driver unit 30 and the occurrence status of the interruption command input by the operator when a thread breakage or the like occurs are confirmed ( In step 130), when it is determined that some trouble has occurred and the embroidery operation needs to be stopped (step 140), the state shifts to a “pause” state in which the embroidery operation is interrupted. Here, the "pause" state is a state in which the embroidery operation is stopped while various information necessary for resuming the embroidery operation, for example, the current output state of one stitch data, is stored in a predetermined storage area. This is distinguished from the "end" state at the end of the program to be executed.

If it is determined in step 140 that no stop request has been issued, then it is determined whether or not all stitch data has been output and the embroidery operation has been completed (step 140). 150) If it is determined that the processing has been completed, the stored one-needle data is cleared, and a transition is made to an "end" state in which the motor controllers 30D to 30F are initialized. On the other hand, when the result of the determination in step 150 is negative and it is determined that the embroidery operation has not yet been completed, the process proceeds to step 120 in order to output unstitched one-needle data, Repeat the embroidery work.

As described above, when an error such as a thread break occurs during the execution of the embroidery operation, the multi-head embroidery sewing machine sets the "pause"
Maintained in state. In this state, the operator repairs the broken thread of the head, head a or b, where the thread break has occurred, and performs embroidery in order to repair embroidery that is insufficient compared to other heads due to the thread break. The frame 50 is stitched back and an input for specifying the head where the thread break has occurred is performed.

FIG. 5A is a simplified illustration of such a normal repair work. That is, when a thread break occurs while embroidering the position Q1 on the head a, the thread break on the head a is repaired first. Then, in order to repair the embroidery portion (dotted line portion in the figure) which is insufficient compared to the head b due to the thread break, the embroidery is performed so that the sewing needle 40 is positioned at the needle slightly before the position Q1. The stitch-back of the frame 50 is executed, and an input indicating that a thread break has occurred at the head a is input.

Usually, during this operation, as described in the section of "Conventional Technology", in the case of the head b, which has not caused thread breakage,
The lower thread is pulled out at the position Q2 where the embroidery is completed by the stitch back of the embroidery frame 50, and a problem occurs in which the lower thread is exposed on the surface of the fabric.

When the operator executes a predetermined input after such a repair of the thread break and the stitch back work of the embroidery frame 50, the CPU 30a of the driver unit 30 executes the processing of the thread break processing program shown in FIG. Start. When this process is started, "pause" remains as it was when the thread break occurred.
From the stand-by state of each controller in the state, the thread breakage occurrence state, for example, confirmation of the position Q2 and confirmation of the current position where the embroidery frame 50 is placed by stitch back are executed (step
200), an input for specifying the head where the thread break has occurred is input by the operator (step 210). When the input of the head where the thread break has occurred is not performed, the process returns to step 210 again, and the input is prompted (step 220).

When the necessary information is obtained by the above-described processes, the Nth needle (the position Q2 in FIG. 5A) from the current position where the stitch-back of the embroidery frame 50 has been executed (the position Q2 in FIG. 5A) is performed. Until the second stitch), the embroidery operation is performed only by the head where the thread break has occurred. That is, in order to suspend the vertical movement of the embroidery needle 40 on the head where no thread break has occurred, the output of one stitch data is executed while outputting a control signal to the excitation circuit 30Ga or 30Gb (step 230).

If we explain based on the above illustrated example, this step
The embroidery work by head a and head b by the process of 230 is the fifth
The state shown in FIG. 8B is reached, and the sewing needle of each head temporarily stops at the position Q3.

In this way, after completing most of the repairs that were lacking due to thread breakage, the CPU 30a changes the “M stitch” and “M + 1” from Q2.
One-needle data of the stitch is read out, and the midpoint L of each stitch is calculated.

That is, if M = 1 is set in this embodiment and the explanation is given based on the above-described illustrative example, the calculated midpoint L is the position shown in FIG. 5 (B).

Subsequently, the CPU 30a creates and outputs one stitch data with the midpoint L calculated in step 240 as the current sewing position (step 250). That is, one-needle data for sewing the currently calculated midpoint L is added to the one-needle data created based on the embroidery data input from the controller 20, and this is executed.

By this processing, the embroidery state of each head is as shown in FIG. 5 (C). The head a is embroidered from the position Q3 toward the middle point L, and the head b is embroidered from the position Q2 where the embroidery has been completed toward the middle point L. In the normal b-head where the thread break did not occur during the sewing operation of the middle point L, the bobbin thread having lost the tension due to the stitch back of the embroidery frame 50 as described above in the section of “Problems to be Solved by the Invention”. Are exposed on the fabric surface. That is, through the above-described processing, the lower yarn is exposed at the cloth surface at two positions: the position Q2 of the head b and the middle point L.

And as the last processing of the thread breakage processing program,
If the middle point L is obscured, or if there is a remaining embroidery portion from the Nth stitch to the stitch back start position, one stitch data is output from the position for repairing this portion (step 26).
0) The present program is ended, the process proceeds to step 120 of the embroidery work execution program to start the embroidery work which has been suspended in the “pause” state, and the “pause” state is released.

In other words, when the "pause" state is released, the embroidery work execution program shown in FIG. 4 is started again, and the embroidery work based on the normal one stitch data is started from the position where the embroidery repair work has been completed (position Q3). Is continued. Then, by this normal embroidery operation, two lower threads exposed in the embroidery pattern of the normal head which did not cause thread breakage are sewn into the newly formed embroidery pattern.

The state of the embroidery pattern formed by resuming the normal embroidery work is shown in FIG. 5 (D). As shown in the figure, the position Q2 and the midpoint L of the embroidery pattern of the b-head where the lower thread is exposed
Is reliably covered with the upper thread by executing the resumed embroidery work, and the embroidery pattern is in the best condition as when no thread break occurs.

FIGS. 5 (A) to 5 (D) illustrate the stitch pitch largely in order to illustrate complicated stitches. For this reason,
The embroidery thread covered by the resumed embroidery work, that is, the embroidery thread from head a position Q2 to midpoint L and the position of head b
Although the embroidery thread from Q3 to the middle point L is shown as being exposed, the embroidery thread is actually dense because the sewing pitch is small, and the embroidery thread in this portion is not exposed.

As described above in detail in the embodiment and the illustration of an example thereof, according to the multi-head embroidery sewing machine according to the present embodiment, when a thread break occurs in any of the heads in the multi-head embroidery sewing machine,
The two sewing positions where the lower thread is exposed in the normal head where no thread break has occurred are located at the lower part of the embroidery pattern, and the lower thread that is securely exposed is automatically covered by the upper thread. .

In the above-described embodiment, the operator has visually recognized the thread break, and has described a simple manual structure such as stitching back the embroidery frame 50. However, the multi-head embroidery sewing machine of the present invention is not limited to such a structure. Instead, it is embodied in various forms. For example, when a normal thread break sensor for detecting the occurrence of a thread break is provided, the position at which the thread break occurs in the illustrative description shown in FIG.
Q1 and the "pause" state position Q2 can be easily determined. Therefore, upon completion of the thread break repairing operation by the operator, it is possible to automatically automate the operation of stitching back the embroidery frame 50 to a position slightly before the thread break occurrence position Q1.

Further, in the above embodiment, “N =
2 "," M = 1 ", the embroidery operation is performed only on the head where the thread break has occurred up to the second stitch before the stitch back start position, and the first stitch and the second stitch from Q2 The data is read ahead and the midpoint L of each stitch is calculated. The variables N and M are arbitrarily selected and may be “0” or “negative number”. As an example, "N =
FIG. 7 shows a process of forming an embroidery pattern when the multi-head embroidery sewing machine of the above embodiment is configured with "0" and "M = -6".

(A) When a thread break occurs as shown in FIG.
Since it is "0", the repair position Q3 of the embroidery operation using only the head a where the thread break has occurred is executed until it matches the normal embroidery completion position Q2 of the head b as shown in FIG.

Subsequent sewing operations using the head a and the head b are described as “M = −
6, the processing is executed at the midpoint L between the "-6th stitch" and the "-5th stitch" just before the embroidery is completed as shown in FIG.

Then, since the position Q2 where the lower thread is exposed and the middle point L are sewn with the embroidery thread, and the embroidery operation is restarted from the needle before the middle point L by the embroidery data, the work quality is good as shown in FIG. Embroidery is completed.

In the above embodiment, the midpoint L is calculated as a position at which the lower thread, which has lost tension due to the stitch back of the embroidery frame 50, is exposed on the fabric surface. This position can be arbitrarily determined as long as it is within the range covered by the upper thread in the subsequent embroidery operation, and may be any point of 1/3 or any other point.

As described above, the multi-head embroidery sewing machine of the present invention can be embodied in various modes without departing from the gist thereof.

[Effects of the Invention] The multi-head embroidery sewing machine according to the present invention is characterized in that a thread break occurs in an embroidery thread of one of the heads, and the embroidery frame for repairing the thread break and continuing the embroidery operation interrupted by the thread break is continued. When the stitch-back operation is performed, first, embroidery is performed only on the head where the thread break has occurred to the stitch where the thread break has occurred or in the vicinity thereof. Next, a sewing operation with a plurality of heads is executed at least at the first stitch at a position inside the pattern that can be finally covered by an embroidery pattern formed by the embroidery operation based on the embroidery data, and no thread break has occurred. Restoring the tension of the lower thread that has slackened on the head with stitch back. Then, the sewing is executed by the stitches and the initial embroidery work executing means C1 where the sewing operation has been executed by the relay embroidery work executing means at the position where the lower thread may be exposed on the head where the thread break did not occur. The continuous embroidery operation execution means returns to a position where it is possible to cover both the stitches, so that both the last stitches of the embroidery operation previously performed by the head having no thread break are sewn again, and interrupted. The embroidery operation based on the embroidery data is performed by a plurality of heads.

Therefore, even when the repair of the broken thread of the embroidery thread is performed on any one of the heads, the processing of the lower thread exposed on the surface of the fabric by the embroidery work by the head that has not been broken is automated, and the embroidery is performed. The quality of the pattern can be improved.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram showing a basic configuration of a multi-head embroidery sewing machine of the present invention, FIG. 2 is a schematic configuration diagram of a multi-head embroidery sewing machine according to an embodiment, FIG. 3 is a block diagram of its driver unit, and FIG. Is a flowchart of an embroidery work execution program executed in the multi-head embroidery sewing machine, FIG. 5 (A).
7A to 7D are explanatory diagrams illustrating an example of an embroidery pattern formed by the embodiment, FIG. 6 is a flowchart of a thread breakage processing program executed in the embodiment, and FIG.
(D) is an explanatory view of a seam constituted by another embodiment,
FIGS. 8 (A) and 8 (B) show explanatory views of the lower thread tension lost by the thread breaking process. 20: Controller, 30: Driver unit 36: X-axis motor, 38: Y-axis motor 35a, 35b: Electromagnetic actuator 40: Needle, 50: Embroidery frame

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Patent 2583088 (JP, B2) JP-B-63-32909 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) D05B 1/00 -83/00 D05C 5/00-5/06

Claims (1)

(57) [Claims] 1. A multi-head embroidery machine for controlling a vertical movement of sewing needles provided on each of a plurality of heads and a drive of an embroidery frame for changing a relative positional relationship between the plurality of heads and the embroidery frame in accordance with embroidery data. In the above, when a thread break occurs in any one of the embroidery threads and a stitch back operation of the embroidery frame for repairing the thread break and continuing the embroidery work interrupted by the thread break is performed, An initial embroidery operation executing means for executing embroidery only by the head where the thread break has occurred to or near the operation start position; and an embroidery operation based on the embroidery data after the embroidery operation is completed by the initial embroidery operation executing means. At least one sewing operation by the plurality of heads at a position inside the pattern that can be finally covered by the embroidery pattern formed by
After the sewing operation by the relay embroidery operation executing means is completed, the stitching operation is executed by the relay stitching operation executing means and the initial embroidery operation executing means. Returning to a position where both the last stitches of the embroidery work that was previously performed by the head having no thread breakage can be covered, and performing the embroidery work based on the embroidery data on the plurality of heads. Means, comprising: a multi-head embroidery sewing machine comprising: