JP2001190881A - Bobbin thread feeder and sewing machine eqipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement accurate and easy replacement of bobbin case through accurate determination of bobbin replacement time. SOLUTION: It is determined whether the quantity of bobbin thread wound around a bobbin is sufficient for the quantity of bobbin thread required for one or more times of the next sewing pattern based on the quantity of bobbin thread to be used for every sewing pattern as well as the quantity of bobbin thread wound preliminarily around the bobbin, and if it is not, it is informed by a control means 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower thread supply device and a sewing machine provided with the same.

[0002]

2. Description of the Related Art In a conventional electronic cycle sewing machine,
The operator has determined the replacement time of the bobbin in which the bobbin thread has been consumed based on, for example, the count of each sewing pattern, the number of sewn parts, and the like.

[0003]

However, the electronic cycle sewing machine has the following problems. That is, as described above, the bobbin replacement time is determined based on the rule of thumb of the operator, and the bobbin winding amount on the bobbin is not constant, so that the determination of the bobbin replacement time must be inaccurate. In such a case, there is a problem that the bobbin thread is replaced while a considerable amount of bobbin thread remains, or that the bobbin thread runs out during sewing. Particularly, when changing the color of the thread, it is very difficult to grasp the time to replace the bobbin, since the bobbin used halfway is often used again.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a lower thread supply device in which the bobbin replacement time is always accurately determined, and a sewing machine having the same.

[0005] In addition to the first object, a second object is to provide a bobbin thread supply device in which bobbin exchange is automatically and easily performed.

[0006]

In order to achieve the first object, a lower thread supply device according to a first aspect of the present invention comprises a lower thread amount previously wound around a bobbin and a lower thread consumed for each sewing pattern. Based on the thread amount, after the end of one sewing pattern, the remaining amount of the bobbin thread wound on the bobbin is set to an amount obtained by adding a constant value α to the bobbin thread amount required for the next sewing pattern. A control means is provided for judging whether or not it is sufficient, and when it is insufficient, notifying that it is time to replace the lower thread.

In order to achieve the first object, a sewing machine according to a second aspect includes the lower thread supply device according to the first aspect.

According to a third aspect of the present invention, there is provided a bobbin thread supply device according to the first or second aspect, further comprising a bobbin attaching / detaching position for attaching / detaching a bobbin case to / from a shuttle. Move the bobbin case that houses the bobbin between other working positions related to the case,
A bobbin exchanging means for detachably attaching the bobbin case is provided. When the bobbin exchanging means is notified by the control means that the bobbin thread is to be exchanged, the bobbin in the shuttle is newly wound by the bobbin exchanging means. It has a configuration that is replaced with a turned bobbin.

According to such a lower thread supply device, the control means grasps the amount of the lower thread wound on the bobbin in advance, and controls the lower thread amount and the lower thread consumed for each sewing pattern. Based on the amount, it is determined whether or not the amount of bobbin thread wound on the bobbin is sufficient to add a fixed value α to the amount of bobbin thread required for the next sewing pattern. When it is determined that the lower thread is not enough, it is notified that it is time to replace the lower thread. The above determination is always accurate because it is made based on the amount of bobbin thread wound on the bobbin in advance and the amount of bobbin thread for one or more consumed sewing patterns.

Further, according to the sewing machine of the second aspect,
By providing the bobbin thread supply device according to claim 1, the remaining amount of the bobbin thread remaining on the bobbin is insufficient for the amount of the bobbin thread required for the next one or more sewing patterns. If it is determined, it is notified that it is time to replace the lower thread. Therefore, when sewing, unlike the conventional art, there is no need to replace the bobbin thread while a considerable amount of the bobbin thread remains, or to eliminate the bobbin thread during sewing.

According to the lower thread supply device of the third aspect, in addition to the operation of the first or second aspect,
When the bobbin exchanging means is notified by the control means that it is time to exchange, the bobbin exchanging means automatically moves the bobbin case in the shuttle to the bobbin case accommodating the bobbin wound with the new bobbin thread. Be exchanged. Therefore, the exchange is simple.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a general outline of a lower thread automatic supply device of a sewing machine to which a lower thread supply device according to the present invention is applied will be described with reference to FIGS.

The bobbin thread automatic supply device 17 is disposed in a space in which the bottom below a sewing machine bed MB provided in the sewing machine M is an oil reservoir, and a bobbin case attaching / detaching position A,
The remaining yarn removing position B and the bobbin winding position C are arranged at intervals of 120 ° around the guide shaft 4 as one axis, and the bobbin case attaching / detaching position A and the other working positions B and C correspond to the guide shaft 4.
Are divided into both ends. At the bobbin case attaching / detaching position A, the shuttle 16 is wound, at the remaining yarn removing position B, the residual yarn removing device 2 for removing the residual yarn of the bobbin 7, and at the lower yarn winding position C, the lower yarn is wound around the bobbin 7. Lower thread winding means 3 are provided respectively.

The guide shaft 4 is rotatably supported by a main base, and a pivot arm 5 slidable in the axial direction is supported on the guide shaft 4. That is, the cross section of the guide shaft 4 is non-circular, and the corresponding hole shape of the rotating arm 5 is also the same.
Can slide along the guide shaft 4 and
It can rotate with the guide shaft 4. The forward / backward movement of the rotary arm 5 along the guide shaft 4 is performed by a forward / reverse lever 6, and the forward or reverse rotation is performed in units of 60 ° by a driving device (not shown).

The pivot arm 5 extends slightly symmetrically to both sides from the center, and a bobbin case 8 containing a bobbin 7 is detachably supported near each end.
Regarding the bobbin case gripping mechanism in the rotary arm 5, for example, a lower thread automatic feeding device disclosed in Japanese Patent Application Laid-Open No. 5-192476 and Japanese Patent Application No. 5-1219 filed by the present applicant earlier.
For example, a pair of electromagnet suction heads described in the bobbin exchanging means of the sewing machine described in Japanese Patent Application No. 60-116, for example, described in the bobbin exchanging means of the sewing machine of Japanese Patent Application No. 5-116363 filed by the present applicant. An appropriate device such as a lever claw that has been used can be employed.

The mechanism for moving the rotating arm 5 forward and backward along the guide shaft 4, the mechanism for rotating the rotating arm 5 forward or backward, and the lower thread winding means 3 are also described in the above-mentioned publication and the specification. What is done can be suitably adopted.

The bobbin winding means 3 detects the number of rotations of a motor for rotating a bobbin shaft for winding the bobbin around the bobbin 7, for example. The bobbin thread length can be detected.
Then, the lower thread length is input to a RAM 10b described later, and when there are a plurality of bobbins, for each bobbin number (identification code) or in accordance with the order of the supplied bobbins,
Input the lower thread length.

Further, as the residual yarn removing device 2, for example, a bobbin residual yarn removing device disclosed in Japanese Patent Application No. 5-203610 previously filed by the present applicant may be appropriately used. it can.

A bobbin exchange comprising a bobbin case gripper capable of holding and opening the bobbin case 8 and a rotary arm 5 slidable in the axial direction while rotating the bobbin case gripper about the guide shaft 4. As shown in FIG. 1, a lower thread automatic supply device 17 whose main part is constituted by the means 1, the residual yarn removing device 2, and the lower thread winding means 3, is controlled by a CPU 9 comprising a microcomputer. The operation is controlled according to ROM and RAM as internal storage means. The lower thread automatic supply device 17 includes:
A control means 10 constituting a lower thread supply device of the sewing machine is provided.

The control means 10 includes the lower thread winding means 3
The bobbin thread amount wound on the bobbin 7 is determined based on the bobbin thread length (bobbin thread amount) wound around the bobbin 7 and the bobbin thread length as the bobbin thread amount consumed for each sewing pattern. Judge whether the amount of bobbin thread required for the next sewing pattern is sufficient,
If not enough, the bobbin replacing means 1 (actually, the CPU
9), an exchange signal is sent out, and the bobbin exchange means 1
This is a so-called microcomputer that functions to replace the bobbin in the shuttle 16 with a bobbin on which a bobbin thread is newly wound.

More specifically, the control means 10
As shown in FIG. 1, for example, the thread consumption length (thread consumption) corresponding to, for example, the pattern number inputted by the sewing pattern input means 12 on the operation panel of the sewing machine M or a known external storage means or internal storage means And a RAM 10b as a storage means for storing the length of the bobbin wound on the bobbin in the bobbin winding means 3 and an end signal issued each time one sewing pattern ends from the sewing machine control means 11. From the RAM 10b, the bobbin thread length (unused) wound around the bobbin 7 and the thread consumption length corresponding to the sewing pattern are called, and the thread consumption length is subtracted from the bobbin thread length, and the bobbin bobbin thread is removed. The remaining amount is obtained, the value is stored in the RAM 10b, and when the next end signal is received, the lower thread length and the corresponding sewing pattern are subtracted from the RAM 10b. A computing means 10a for calling a thread consumption length, further subtracting the thread consumption length from the subtracted lower thread length, and storing the value in the RAM 10b; Is smaller than the thread consumption length of the next or predetermined number of sewing patterns, the CPU of the lower thread automatic feeding device 17
9, a bobbin exchange means 1 sends an exchange signal to
The comparison / judgment means 10c for exchanging the bobbin in the lower bobbin 6 with a bobbin wound with a lower thread in the lower thread winding means 3
And

Further, in the RAM 10b, the bobbin thread length at that time corresponding to the bobbin number can be stored by, for example, an identification number or the like input by the bobbin identifying means 15, and the bobbin identification is performed again. When the identification number or the like is input from the means 15, for example,
In a, the lower thread length corresponding to the number is called instead of the lower thread length (unused) wound on the bobbin 7.

Next, the operation of the lower thread automatic supply device will be described. First, the lower thread is wound around the empty bobbin by the lower thread winding means 3. As described above, the winding length can be determined, for example, by detecting the number of rotations of a motor that rotates a bobbin shaft in order to wind a bobbin thread around the bobbin 7. The lower thread length information is sent to the control means 10 via the CPU 9 of the automatic lower thread supply device 17, and the control means 10 stores the lower thread length.

Next, when the operator inputs, for example, a sewing pattern number or the like by using the sewing pattern input means 12 on the operation panel of the sewing machine M, sewing corresponding to the sewing pattern number is performed on the electronic cycle sewing machine.

The sewing pattern number and the like are also transmitted to the control means 10, and the control means 10 recognizes the thread consumption length corresponding to the previously stored sewing pattern number. When one sewing pattern is completed, the sewing machine control means 11
When the control means 10 receives this end signal, the stored lower thread length (unused) and the thread consumption length corresponding to the sewing pattern are called, and the lower thread length is read. While subtracting the thread consumption length from the
Store that value.

If the subtraction value is smaller than the thread consumption length of the next sewing pattern, it is determined that it is time to replace the bobbin thread during the next sewing operation. A signal is transmitted (details will be described later).

On the other hand, if the subtraction value does not become smaller than the thread consumption length of the next sewing pattern, the control means 10 determines that sewing can be continued and does not send an exchange signal.

Then, when the sewing in accordance with the second sewing pattern is completed and the control means 10 receives the second end signal, the control means 10 causes the control unit 10 to perform the lower thread length subtraction and stored. Then, the thread consumption length corresponding to the sewing pattern is called, the thread consumption length is further subtracted from the subtracted lower thread length, and the value is stored.

If the subtraction value is smaller than the thread consumption length of the next sewing pattern, it is determined that it is time to replace the thread because the lower thread runs out during the next sewing. That is, as shown in FIG. 2, the thread consumption by the sewing pattern is subtracted from the bobbin length wound on the bobbin (unused), and the subtracted bobbin thread length is calculated. The method of subtracting the thread consumption by the sewing pattern is sequentially repeated, and in the process, when the subtraction value becomes smaller than the thread consumption length of the next sewing pattern (the tenth time in FIG. 2 is completed). ), The CPU 9 of the lower thread automatic feeding device 17
An exchange signal is sent to the user.

This exchange signal is sent to C of the automatic lower thread supply device 17.
When the PU 9 receives the data, the bobbin exchanging means 1 is driven.
That is, the bobbin case 8 is not held at one end of the rotating arm 5, and the bobbin 7 on which the bobbin is wound by the bobbin winding means 3 at the other end (the bobbin length of the bobbin is also detected as described above. The information is sent to the control means 10) from the state where the built-in bobbin case 8 is held and one end not holding the bobbin case 8 is waiting at a position D (see FIG. 4) between A and C. Then, the rotating arm 5 is rotated counterclockwise in FIG. 3 by 60 ° and is advanced to the shuttle 16 side, so that the bobbin case 8 with the remaining bobbin with the remaining thread is moved from the shuttle 16 at the bobbin case attaching / detaching position A to the rotating arm 5. At one end.

Then, the bobbin 7 on which the bobbin thread has been wound is mounted in the shuttle 16 by the bobbin exchanging means 1. That is, the rotating arm 5 is retracted to the retracted position of the guide shaft 4 and
The bobbin case 8 with the bobbin wound and held at the other end of the rotating arm 5 is mounted on the shuttle 16 at the bobbin case attaching / detaching position A, and the rotating arm 5 is retracted. .

Then, the remaining yarn removing device 2 and the lower yarn winding means 3 are driven. That is, the rotating arm 5 is rotated clockwise by 60 °, and the bobbin case 8 with the built-in bobbin with the remaining thread held at one end of the rotating arm 5 is moved to the remaining thread removing position B.
The bobbin 7 is removed by the remaining yarn removing device 2 there, and the bobbin 7 becomes an empty bobbin without a yarn.
After that, when the rotating arm 5 is rotated counterclockwise by 120 ° and moved forward, the bobbin case 8 with the empty bobbin from which the remaining thread has been removed advances to the lower thread winding position C, and the lower thread winding means 3 thereat. A bobbin thread is wound around an empty bobbin. At this time,
Similarly to the above, the lower thread length of the bobbin is also detected as described above, and the information is sent from the CPU 9 to the R
It is sent to AM 10b. Then, the above operation is repeated.

Depending on the sewing, for example, the sewing may be performed by changing the thread color, or the sewing pattern may be changed. In such a case, the bobbin used halfway may be used again. It is not unusual, and in the past, it was extremely difficult to grasp the replacement time. However, in the present embodiment, even in such a case, the replacement time can be accurately grasped. .

That is, an input means 15 such as an identification number is provided as a bobbin identification means on, for example, an operation panel.
At 0, the current bobbin thread length corresponding to the identification number is stored, and when the identification number is input from the input means 15 when reusing, the bobbin thread wound around the bobbin 7 Instead of the length (unused), call the lower thread length corresponding to the number, subtract the thread consumption length corresponding to the sewing pattern from this lower thread length, and thereafter, Since the method of sequentially subtracting the thread consumption length corresponding to the sewing pattern from the subtracted lower thread length is sequentially repeated, even when the bobbin used halfway is used again, In addition, it is possible to accurately grasp the bobbin replacement time.

As described above, in the present embodiment, the control means 10 determines whether or not to replace the bobbin based on the amount of lower thread wound on the bobbin and the amount of lower thread for each sewing pattern consumed. This is accurate, and unlike the conventional case, there is no need to replace the bobbin thread while a considerable amount of the bobbin thread remains or to lose the bobbin thread during sewing.

When the bobbin exchange means 1 receives an exchange signal from the control means 10, the bobbin exchange means 1
Since the bobbin in the shuttle 16 is automatically replaced with a bobbin on which a new bobbin is wound, the replacement can be easily performed.

As shown in FIG. 5, for example, in a cycle sewing in which a sewing pattern (Y1, Y2) using a black thread and a sewing pattern (X1, X2, X3) using a red thread are alternately performed, a flowchart shown in FIG. Is controlled in accordance with

That is, when the completion of one sewing pattern is confirmed in step 1, the remaining amount of the lower thread (La) is calculated based on the thread consumption length in step 2, and the lower thread length in the next pattern of the same color is calculated in step 3. Data (Lb) is read out. Then, in step 4, it is determined whether or not the next pattern is the same color. If it is the same color, the process proceeds to step 5, and when La ≦ Lb + α (α: a constant number based on the sewing condition) is satisfied, that is, when the pattern is mounted on the shuttle If the remaining amount of thread in the bobbin case is small, an alarm is displayed in the next step 6, and the bobbin thread replacement operation including bobbin replacement of the same color by bobbin identification in step 7 is performed in step 8,
In the next step 9, it is started by a start signal.

On the other hand, if the next pattern is not the same color in step 3 above, an alarm is displayed in step 10 and the bobbin of the next pattern is replaced in step 12 by the bobbin identification in step 11. Then, in the next step 13, it is activated by the activation signal,
The next pattern is sewn.

On the other hand, when La ≦ Lb + α (α: a constant number) is satisfied in step 14 with respect to the bobbin case removed from the shuttle, that is, when the remaining amount of yarn in the bobbin case removed from the shuttle is small, the process proceeds to step 15. According to the bobbin identification, a thread of the same color is replenished in the bobbin case taken out in step 16. Then, the previous remaining amount La is stored in the storage means (RAM) 10a in step 17.
Is stored.

When sewing a sewing pattern of a different color as shown in FIG. 5 by the control according to the flowchart, first, a black thread corresponding to the sewing pattern (Y1) is applied to the shuttle. The wound bobbin case is attached, and the next sewing pattern (X
A bobbin case around which a red thread corresponding to 1) is wound is arranged. Then, when the sewing of the first sewing pattern (Y1) is completed, the next sewing pattern (X1) is red, so the black thread bobbin case attached to the shuttle is taken out, and the red bobbin case previously disposed at the winding position is removed. Attached to the kettle.

Next, the sewing of the next sewing pattern (X1) is started by a start signal, the lower thread remaining amount of the black thread bobbin case taken out during that time is detected, and the detected lower thread remaining amount is determined by the next sewing pattern. (X2) When the length is smaller than the bobbin thread length, the remaining thread is removed, and then the black thread is newly wound to replenish the bobbin thread.

The same processing is performed at the end of the second sewing pattern (X1) and the third sewing pattern (Y2). On the other hand, at the end of the fourth sewing pattern (X2),
Since the next sewing pattern (X3) is the same color, when the lower thread remaining amount of the red thread bobbin case attached to the shuttle is low, the remaining thread of the bobbin case removed from the shuttle is removed and then the red thread is wound. , The bobbin case is mounted on the shuttle.

When three or more bobbin case holding portions of the above-mentioned rotating arm 5 are provided, at the end of the fourth sewing pattern (X2), another bobbin case in which a red thread has been wound in advance. May be attached to the shuttle.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and can be variously modified without departing from the gist of the invention. Needless to say, for example, in the above-described embodiment, the exchange signal is sent to the bobbin exchange means, and the bobbin in the shuttle 16 is automatically exchanged for a bobbin on which a new bobbin thread is wound. Figure 1
As shown in FIG.
A display or the like as the display means 14 may notify the worker of the fact and replace the bobbin manually.

In the above embodiment, the replacement time of the bobbin is determined based on the subtraction value. For example, if the same sewing pattern is used, the amount of the lower thread wound on the bobbin is determined by the sewing pattern. It is also possible to divide by the number of times, and to sew until the divided value is an integer, and to transmit the exchange signal when the integer value is completed.

Further, the method of detecting the length of the bobbin wound around the bobbin 7 by the bobbin winding means 3 is not limited to the above-described embodiment. For example, an encoder may be provided in the bobbin thread supply path. Thus, a method of detecting the lower thread length may be performed.

[0048]

As described above, according to the bobbin thread supplying device according to the first aspect, the control means grasps the bobbin thread volume wound on the bobbin in advance, and determines the bobbin thread volume and the sewing pattern The amount of bobbin wound on the bobbin, based on the amount of bobbin consumed in the next sewing pattern, is equal to or less than the amount obtained by adding a constant value α to the amount of bobbin required for the next sewing pattern. Is determined. When it is determined that the lower thread is not enough, it is notified that it is time to replace the lower thread. The determination of the replacement time is made based on the amount of the bobbin wound on the bobbin and the amount of the bobbin thread for one or more sewing patterns consumed, so that it can always be accurately performed.

According to a second aspect of the present invention, there is provided a sewing machine comprising the lower thread supply device according to the first aspect.
If the remaining amount of bobbin thread remaining on the bobbin is determined to be insufficient for the amount of bobbin thread required for the next one or more sewing patterns, it is configured to notify that it is time to replace the bobbin. Therefore, unlike the related art, there is no possibility that the lower thread is replaced while the lower thread remains, or that the lower thread does not disappear during sewing.

Further, in the bobbin thread supplying device according to the third aspect, in addition to the first or second aspect, when the bobbin exchanging means is notified by the control means that it is time to exchange, the bobbin exchanging means may be used. Then, the bobbin case in the shuttle is automatically replaced with a bobbin case accommodating a bobbin wound with a new bobbin thread. Therefore, the exchange can be easily performed.

[Brief description of the drawings]

FIG. 1 is a control block diagram of an automatic lower thread supply device of a sewing machine to which a lower thread supply device according to an embodiment of the present invention is applied.

FIG. 2 is an explanatory diagram of a determination principle in a control means in FIG. 1;

FIG. 3 is an overall perspective view of a lower thread automatic supply device arranged below a sewing machine and a sewing machine bed;

FIG. 4 is an explanatory perspective view showing a transport state in the upper and lower thread automatic supply device.

FIG. 5 is an explanatory plan view showing an example of cycle sewing of a sewing pattern using different lower threads.

FIG. 6 is a flowchart showing a procedure for performing the cycle sewing of the sewing pattern shown in FIG. 5;

[Explanation of symbols]

 1 bobbin exchange means 3 bobbin winding means 7 bobbin 8 bobbin case 10 control means 16 shuttle M sewing machine MB sewing machine bed A bobbin attaching / detaching position C bobbin winding position Y1, Y2, X1, X2, X3 sewing pattern

Claims (3)

[Claims] An amount of bobbin thread wound around a bobbin after completion of one sewing pattern is determined based on an amount of bobbin thread wound in advance on a bobbin and an amount of bobbin thread consumed for each sewing pattern. A control means for judging whether or not an amount obtained by adding a constant value α to the amount of the lower thread required for the next sewing pattern is sufficient, and in the case of being insufficient, notifying that it is time to replace the lower thread. A lower thread supply device comprising: 2. A sewing machine comprising the lower thread supply device according to claim 1. 3. The bobbin thread supply device according to claim 1, wherein the bobbin case is attached to and detached from the shuttle and a bobbin case is attached to and detached from another bobbin case. A bobbin case accommodating the bobbin therein, and a bobbin exchanging means for detachably attaching the bobbin case. The bobbin exchanging unit is notified by the control unit that it is time to exchange the bobbin thread. A bobbin in the shuttle which is replaced by a bobbin on which a lower thread is wound by means.