JP2013052013A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewing machine capable of sewing while accurately monitoring the remaining amount of a bobbin thread.SOLUTION: A sewing machine comprises: a seam data storage device 2 for calculating the amount of bottom thread necessary for shape sewing or color change on the basis of data stored therein; a bottom thread remaining amount measuring device 3 for measuring the remaining amount of the bottom thread; a bottom thread shortage prediction device 4 for predicting a position at which the bottom thread runs out; and an alarming device 8 for alarming the fact that the remaining amount of the bobbin thread falls below the lower limit of the amount of the bobbin thread. If the remaining amount of the bobbin thread is greater than a necessary amount of the bobbin thread, the sewing machine automatically stops and terminates at a color change position in the similar way to the normal sewing. If the remaining amount of the bobbin thread is less than the necessary amount of the bobbin thread, a stop position determining device 5 determines a halfway stop position at which the sewing machine stops and the remaining amount of the bobbin thread is measured again.

Description

  The present invention relates to a sewing machine.

It has been conventionally performed to detect the lower thread amount of the sewing machine and notify the operator of the absolute shortage or the insufficient lower thread amount necessary for the color change accompanying the upper thread replacement.
The detection of the lower thread amount is difficult to perform while the sewing machine is in operation, and is usually configured to be performed while the sewing machine is stopped. The lower thread amount is detected at the start of sewing, and the lower thread shortage is predicted and notified based on the detected amount.

JP-A-5-329287 JP-A-6-182070

However, since it is a lower thread shortage prediction based on one lower thread amount detection at the start of sewing, there is a large error and a shortage notification is made even if there is a remaining amount. There were many bugs that didn't happen. For this reason, there has been a problem in that unnecessary lower thread replacement work is performed or empty stitching occurs.
The object of the present invention is to solve the problems of the prior art.

In order to achieve the above object, the present invention provides a stitch data adding device that provides stitch data necessary for sewing a shape to be sewn, a lower thread remaining amount measuring device that measures a lower thread remaining amount, and the lower thread remaining amount. When the amount is measured, whether or not the remaining amount of the lower thread is less than a predetermined lower limit lower thread amount, or more than the lower limit lower thread amount, the shape is further determined from the stitch data and the lower thread remaining amount. A lower thread shortage prediction device that predicts whether or not the lower thread is insufficient for sewing, and predicts the lower thread shortage position when it is insufficient, and determines the position where sewing should be stopped based on the lower thread shortage position. A stop position determining device, a midway stop control device for stopping the sewing machine halfway when the stop position is reached, a notification device for notifying that when the lower thread is less than a lower limit lower thread amount, and the lower The thread remaining amount measuring device measures the lower thread remaining amount at the start of sewing and at the middle stop. And a control device that operates the sewing machine when the lower thread is equal to or more than the lower limit lower thread amount, and releases the stop and restarts the sewing machine when the halfway stop is in progress. .
It is preferable that the stop position determination device determines the stop position at a front position where the number of stitches is smaller than the lower thread shortage position in the first time after the start of sewing. In the second and subsequent times, it is desirable to determine the lower thread shortage position as the stop position.

  According to the sewing machine of the present invention, when it is predicted that the lower thread will run short at the start of sewing, the sewing machine is automatically stopped halfway to measure the lower thread remaining amount, and according to the lower thread remaining amount at that time Since the notification or the continuation of the sewing is determined, it is possible to perform sewing while accurately grasping the remaining amount of the lower thread, and it is possible to prevent unnecessary lower thread replacement work and empty stitching.

The block diagram which shows one Embodiment of this invention. Explanatory drawing which shows the structure and operation | movement of one Embodiment of this invention. The flowchart figure which shows operation | movement of one Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
This embodiment is an example in which the present invention is applied to a sewing machine equipped with an embroidery device.
In FIG. 1, the control device 1 controls the entire sewing machine, and is connected to a DC motor driver 93, a DC motor 94, and a sewing mechanism 95 via an external input / output device 90, and executes sewing. In addition, the embroidery frame can be sewn by moving the embroidery frame by the XY motor driver 96 and the XY motor 97. Further, zigzag sewing can be performed by the amplitude / feed motor driver 98 and the amplitude / feed motor 99. Further, the display device 91 and the touch panel 92 are provided so that an operator can input various commands.

A stitch data storage device 2 is connected to the control device 1, and stitch data such as a pattern to be sewn is stored. The stitch data includes the position information of the needle entry point, and the amount of lower thread necessary for sewing can be calculated from the stitch data.
The lower thread remaining amount measuring device 3 measures the amount of lower thread wound around the bobbin. In this embodiment, the measurement is performed mechanically, and the measurement can be performed when the sewing machine is stopped. The control device 1 issues a command to the bobbin thread remaining amount measuring device 3 to measure the bobbin thread amount at the start of sewing, and to measure the bobbin thread amount (remaining amount) at that point when stopping halfway. It is configured. The measurement at the midway stop will be described later.
Since the lower thread amount measured by the lower thread remaining amount measuring device 3 has an error, the lower thread remaining amount may be set to a value that is smaller by a predetermined percentage than the measured lower thread amount in advance. Is possible.

The lower thread shortage predicting device 4 first determines whether or not the lower thread remaining amount measured by the lower thread remaining amount measuring device 3 is less than the lower limit lower thread amount that cannot be continuously sewn. If the amount is lower than the lower limit lower thread amount, the shape of the pattern to be sewn is determined by the lower thread remaining amount based on the stitch data in the stitch data storage device 2 and the lower thread remaining amount measured by the lower thread remaining amount measuring device 3. Predict whether or not sewing can be completed. Also, it is predicted how much of the pattern can be sewn with the lower thread remaining amount. Specifically, the number of stitches (number of needle drop points) that can sew the pattern is predicted. That is, it predicts which part (position) of the pattern can be sewn. Hereinafter, the number of stitches that can be sewn and the number of needle drop points predicted by the lower thread shortage prediction device 4 are all expressed as “positions”. Further, a position where sewing can be performed based on the remaining amount of the lower thread, that is, a position where the remaining amount of the lower thread is insufficient is referred to as a lower thread insufficient position.
In this embodiment, the bobbin is not completely free of the lower thread, but a reference of a predetermined length, for example, 4 m, is set, and when the remaining amount of the lower thread becomes less than this length, this is reduced to the lower limit. The amount of yarn is used. When the lower thread remaining amount reaches the lower limit lower thread amount, it is determined that sewing is impossible, and the position at this time is determined as the lower thread shortage position.

The control device 1 is configured to stop the operation of the sewing machine halfway by controlling the DC motor driver 93 and the XY motor driver 96 at or before the position predicted by the lower thread shortage prediction device 4.
The stop position determination device 5 determines a position to be stopped halfway, and determines whether the position predicted by the lower thread shortage prediction device 4 is used as the stop position as it is or before it is stopped. In this actual embodiment, the first halfway stop after the start of sewing or after changing the color and restarting the sewing is determined before the shortage position predicted by the lower thread shortage prediction device 4. Specifically, the position 70% before the lower thread shortage position is set as the first stop position.

  The stitch position detection device 6 detects the stitch position of the pattern stitch that is in progress, and detects that the stop position determined by the stop position determination device 5 has been reached. The halfway stop / re-operation device 7 stops the DC motor 94 and the XY motor 97 via the control device 1 when the stop position is reached based on the detection of the stop position of the stitch position detection device 6, and the operation of the sewing machine is interrupted. It is configured to be stopped and restarted.

When the sewing machine is stopped halfway by the halfway stop / restart device 7, the control device 1 causes the lower yarn remaining amount measuring device 3 to measure the remaining yarn remaining amount, and the lower yarn shortage predicting device 4 measures the measured middle yarn remaining amount. It is predicted based on the amount whether or not the unsewn portion of the shape can be sewn.
When the lower thread remaining amount is less than the lower limit lower thread amount, the control device 1 determines that sewing cannot be continued, and notifies the notification device 8 to that effect, and prompts the operator to change the yarn.
If the remaining amount of the lower thread is equal to or greater than the lower limit lower thread amount, the sewing machine is restarted by the midway stop / restart device 7 so that the sewing is continued until the next midway stop position predicted by the lower thread shortage prediction device 4. It is configured.

FIG. 2 is an explanatory view schematically showing the sewing operation, and the above configuration will be described in further detail based on this.
A case will be described as an example where 260 stitches are required until sewing of a certain color having a shape such as a pattern to be sewn is completed, that is, until the color is changed.
As shown in (A), it is assumed that the lower thread remaining amount measurement value in the lower thread remaining amount measuring device 3 is 15 m, and the lower thread shortage predicting device 4 predicts that the target shape can be sewn up to 150 stitches. That is, the 150th stitch is the lower thread shortage position. For the first stop, the stop position determination device 5 determines the midway stop position at a predetermined position before the 150th stitch. The first time is because an error is likely to occur in the lower thread remaining amount measurement value in the lower thread remaining amount measuring device 3. If the midway stop position is determined at the 70% position, the 105th stitch is the midway stop position.
After the measurement by the lower thread remaining amount measuring device 3, the midway stop / restart device 7 restarts the sewing machine and resumes sewing.
In addition, when the lower thread remaining amount at the start of sewing exceeds the 260th stitch until the color change, the control device 1 is configured to continue the sewing until the sewing is completed (color change) without stopping midway. ing.
In addition, when comparing the lower thread remaining amount and the necessary lower thread amount, it is preferable to compare based on a value equal to or less than a predetermined percentage of the lower thread remaining amount in consideration of an error or the like.

  When the stitch position detecting device 6 detects the 105th stitch as shown in (B), the midway stop / restart device 7 stops the sewing machine at this position. After the stop, the control device 1 causes the lower thread remaining amount measuring device 3 to measure the remaining lower thread remaining amount, and it is assumed that the remaining lower thread remaining amount is 8 m. Based on the lower thread remaining amount, the lower thread shortage prediction device 4 predicts the lower thread shortage position again, and this is the 185th stitch. The stop position determining device 5 now determines the lower thread shortage position as it is as a midway stop position. After the measurement by the lower thread remaining amount measuring device 3, the midway stop / restart device 7 restarts the sewing machine and resumes sewing.

As shown in (C), when the stitch position detecting device 6 detects the 185th stitch next time, the midway stop / restart device 7 stops the sewing machine at this position. After the stop, the control device 1 causes the lower thread remaining amount measuring device 3 to measure the lower thread remaining amount on the way, and this lower thread remaining amount is 5 m. Based on the lower thread remaining amount, the lower thread shortage predicting device 4 predicts the lower thread shortage position again, and if this is the 235th stitch, the stop position determining device 5 now uses the lower thread shortage position as it is as a midway stop position. decide.
After the measurement by the lower thread remaining amount measuring device 3, the midway stop / restart device 7 restarts the sewing machine and resumes sewing.

Next, as shown in (D), when the seam position detection device 6 detects the 235th stitch, the midway stop / restart device 7 stops the sewing machine at this position. After the stop, the control device 1 causes the lower thread remaining amount measuring device 3 to measure the lower thread remaining amount on the way, and this lower thread remaining amount is assumed to be 2 m. Since the bobbin thread shortage predicting device 4 has a lower bobbin thread remaining amount lower than the lower limit bobbin thread amount of 4 m, the control device 1 does not restart the midway stop / restart device 7 and notifies the notification device 8 to that effect. And prompt the operator to change the thread.
At this time, if there is a sufficient remaining amount of lower thread, for example, if the lower thread shortage position exceeds 260 stitches at 4 m or longer, the midway stop / restart device 7 restarts the sewing machine operation. In this case, the stitch data ends at the color change position, the sewing machine stops as usual, and sewing ends.

  According to the above configuration, since the lower thread shortage position is predicted, and the lower thread remaining amount is measured while stopping at that position, accurate sewing becomes possible. In other words, there is an effect that the lower thread is lost during sewing and the empty stitch is generated or the lower thread replacement operation is not performed even though the lower thread remaining amount is present.

The operation of the embodiment will be described with reference to the flowchart of FIG.
First, a lower thread amount necessary for sewing or color change of a shape such as a pattern to be sewn is calculated based on the data in the stitch data storage device 2 (step S1), and the lower thread remaining amount measuring device 3 calculates the lower thread remaining amount. The amount is measured (step S2), and the lower thread shortage prediction device 4 predicts the lower thread shortage position (step S3).

  If the lower thread remaining amount is less than the lower limit lower thread amount (step S4), it is determined that sewing is impossible and the notification device 8 is notified (step S20).

Next, it is determined whether or not the lower thread remaining amount is greater than the necessary lower thread amount (step S5). If the lower thread remaining amount is smaller than the necessary lower thread amount, it is determined whether or not the first lower thread remaining amount measurement is to be performed. (Step S6) If it is the first time, the stop position determination device 5 determines the position before the lower thread shortage position (70% of the lower thread shortage position) as the midway stop position (Step S7).
If the lower thread remaining amount measurement is not performed at the beginning of sewing, the stop position determination device 5 determines the lower thread shortage position as a midway stop position (step S8).

Sewing is started after the above processing (step S9), and the midway stop / re-operation device 7 stops the operation of the sewing machine at the determined midway stop position (step S10).
Then, returning to step S2, the same operation is repeated.

  If the lower thread remaining amount is larger than the necessary lower thread amount in step S5, sewing is started (step S11) and automatically stopped at the color change position (step S12).

1: control device, 2: seam data storage device, 3: lower thread remaining amount measuring device, 4: lower thread shortage predicting device, 5: stop position determining device, 6: stitch position detecting device, 7: midway stop / restart Device: 8: Notification device, 90: External input / output device, 91: Display device, 92: Touch panel, 93: DC motor driver, 94: DC motor, 95: Sewing mechanism, 96: XY motor driver, 97: XY motor, 98: Amplitude / feed motor driver, 99: Amplitude / feed motor.

Claims (4)

A stitch data giving device for giving stitch data necessary for sewing the shape to be sewn;
A lower thread remaining amount measuring device for measuring the lower thread remaining amount;
When the lower thread remaining amount is measured, whether the lower thread remaining amount is less than a predetermined lower limit lower thread amount or not less than the lower limit lower thread amount, the stitch data, the lower thread remaining amount, A lower thread shortage prediction device that predicts whether or not the lower thread is insufficient to sew the shape from
A stop position determining device for determining a position where sewing should be stopped based on the lower thread shortage position;
A midway stop control device for stopping the sewing machine halfway when the stop position is reached;
When the lower thread is less than the lower limit lower thread amount, a notification device for notifying that effect,
When the bobbin thread remaining amount measuring device measures the bobbin thread remaining amount at the start of sewing and at the midway stop, when the bobbin thread is equal to or greater than the lower limit bobbin thread amount, the sewing machine is operated, To release the stop and restart the sewing machine,
A sewing machine characterized by comprising: The stop position determination device determines a stop position at a near position where the number of stitches is smaller than the lower thread shortage position in the first time after the start of sewing,
The sewing machine according to claim 1. The stop position determination device determines the stop position at the lower thread shortage position in the second and subsequent times after the start of sewing,
The sewing machine according to claim 1. A stitch data giving device for giving stitch data necessary for sewing the shape to be sewn;
A bobbin thread remaining amount measuring device that measures the bobbin thread remaining amount when sewing starts,
It is determined whether or not the lower thread remaining amount is less than a predetermined lower limit lower thread amount, and whether or not the lower thread is insufficient to sew the shape from the stitch data and the lower thread remaining amount. A lower thread shortage predicting device that predicts the lower thread shortage position in case of shortage,
A stop position determining device for determining a position where sewing should be stopped based on the lower thread shortage position;
A midway stop control device for stopping the sewing machine halfway when the stop position is reached;
A bobbin thread remaining amount measuring device for measuring the bobbin thread remaining amount at the time of the midway stop and obtaining the midway bobbin remaining amount;
It is determined whether the midway thread remaining amount is less than a predetermined lower limit bobbin thread amount, and the remaining sewing of the shape is completed from the midway thread remaining amount and the stitch data. A lower thread shortage predicting device that predicts whether or not the lower thread is short, and predicts a lower thread shortage position in the case of shortage;
A notification device for notifying that when it is determined that the amount is less than the lower limit lower thread amount;
When it is determined that the amount is not less than the lower limit lower thread amount, a control device that releases the midway stop and restarts the sewing machine;
A sewing machine characterized by comprising:

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