JP5116924B2 - Thread breakage detection method for embroidery sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thread breakage detecting method for automatically detecting thread breakage occurring during sewing processing.
[0002]
[Prior art]
As a conventional yarn breakage detection method, a method used in the yarn breakage detection device disclosed in Japanese Patent Publication No. 6-30708 can be exemplified. This yarn breakage detecting method includes a yarn progress amount detecting device that detects the amount of progress of the yarn, and the amount of progress of the yarn detected by the yarn progress amount detecting device while the needle moves up and down a predetermined number of times is a reference value. When it is smaller, the thread breakage is judged to have occurred. A predetermined value is used for the predetermined number of times from the start to the end of the embroidery process and is not changed during the embroidery process.
[0003]
The predetermined number of times is, for example, a case where a yarn progress detection device having a resolution of about 2 mm is employed, and when the minimum stitch length is 1 mm, it is necessary to set the number of times at least three times.
[0004]
[Problems to be solved by the invention]
However, the length of the stitches included in one embroidery pattern is not constant, and in a place where the length is large (for example, 10 mm), if the predetermined number of times is 3, the length of the stitch is 30 mm. However, the drive frame may move. For this reason, for example, when the lower thread is broken, the upper thread is pulled strongly, and the leading end side of the broken lower thread may come out to the front side of the fabric.
[0005]
An object of the present invention is to solve the above-described problems and to provide a thread breakage detection method for a sewing machine that can efficiently detect thread breakage.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the thread breakage detection method for an embroidery sewing machine of the present invention has the following configuration.
The used embroidery machine generates a pulse when the needle (21), the drive frame (23), and the upper thread (T) corresponding to the needle (21) are pulled out, and detects the amount of advance of the upper thread (T). The yarn progress amount detecting device (7), the pulse edge detecting portion (28) for detecting the rise or fall of the pulse output from the yarn progress amount detecting device (7), and the pulse edge detecting portion (28) are connected. A control unit (26),
The control unit (26) includes a storage unit (32). In the work area of the storage unit (32), a one-needle data pointer that points to any one stitch data (41) in the embroidery data (36); When the advancement of the upper thread is not detected for a predetermined number of stitches, the detection stitch number setting value for setting the predetermined stitch number when determining that thread breakage has occurred, and the number of stitches for the determination are counted. Count the number of detected stitches and set the predetermined length when it is determined that thread breakage has occurred when the sum of the lengths of one or two or more consecutive stitches where the progress of the upper thread is not detected exceeds a predetermined length The detection distance setting value and the detection distance count area for counting the stitch length for making the determination are secured, and the detection distance setting value is set as the initial value of the detection distance count.
The embroidery processing (S110) performed using the embroidery sewing machine includes:
First, a step (S111) of initializing the detected stitch number count,
Thereafter, a step of starting an embroidery processing operation (S112),
Next, a step of reading one stitch data (41) pointed to by the one stitch data pointer (S113),
Next, a step (S114) of driving the drive frame (23) according to the contents of the one-needle data (41) while the needle (21) is moving up,
Next, a detection signal check step (S117) for checking whether the detection signal of the pulse edge detection unit (28) is ON or OFF,
When the detection signal of the pulse edge detector (28) is OFF in the detection signal check step (S117), a step of incrementing the detection stitch number count by 1 (S123);
Next, a detection stitch number check step (S124) for checking whether or not the detection stitch number count is equal to the detection stitch number setting value;
If the detected stitch number count is not equal to the detected stitch number setting value in the detected stitch number check step (S124), a step of subtracting the frame movement amount for one stitch from the detected distance count (S125);
Next, a detection distance check step (S126) for checking whether the detection distance count is greater than 0 or less than 0,
When the detected stitch number count is equal to the detected stitch number setting value in the detected stitch number check step (S124), or the detected distance count becomes 0 or less in the detected distance check step (S126). And a step of executing thread breakage processing (S127).
[0008]
The yarn progress amount detection device can also determine that the progress of the upper yarn is not detected when the advance amount of the upper yarn is a predetermined amount or less.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
1 to 8 show a thread breakage detecting method for a sewing machine according to an embodiment of the present invention. FIG. 1 shows a multi-needle type embroidery sewing machine 1 which is provided above a table 24 and selectively drives one of a plurality of needles 21; A yarn path device 3 that is provided above the sewing head 2 and applies tension to the upper thread T that is supplied to the needle 21, and a table 24 that is substantially flush with the table 24 corresponding to the sewing head 2, and has a built-in shuttle 22. A bed 25, a drive frame 23 movably provided on the table 24, and an operation panel 27 for inputting operation instructions and the like for the embroidery sewing machine 1. As shown in FIG. 2, the yarn path device 3 includes a frame portion 4 and does not entangle a plurality of upper threads T attached to the frame portion 4 and corresponding to the plurality of needles 21 of the sewing machine head 2. The upper thread entanglement prevention unit 5 that guides in this way, the thread guide 6 with a small knob as the first tension member, the yarn progress amount detection device 7 that detects the progress amount of the upper thread T, and the second tension member A thread tension 8 with a knob and a thread guide member 9 having a guide hole 9a for guiding a plurality of upper threads T are provided. Then, when the embroidery process is started, the upper thread T is moved in accordance with the vertical movement of the needle 21, the upper thread entanglement prevention unit 5, the thread guide 6, the thread advancement detection device 7, the thread tension 8, and the thread guide member 9 is supplied to the sewing machine head 2 through 9 guide holes 9a.
[0010]
The yarn progress amount detecting device 7 includes a bearing 11 attached to the frame portion 4, a rotary shaft 12 rotatably provided on the bearing 11, and a frame portion front side of the rotary shaft 12. A rotating wheel 13 wound once or twice and an encoder 14 for detecting a yarn progress amount connected to the back side of the frame portion of the rotating shaft 12 are provided. The encoder 14 includes a slit plate 16 attached to the rotary shaft 12 via a connector 15, and a projector 18 and a light receiver 19 attached to the frame part 4 via an attachment part 17. In the present embodiment, for example, the circumferential length of the yarn passage portion of the rotating wheel is 36 mm. As shown in FIG. 3, the slit plate 16 includes a plurality of slits 20 (12 in this embodiment at intervals of 30 °) arranged at equal intervals in the circumferential direction around the rotation shaft 12. Each slit 20 extends in the radial direction around the rotation shaft 12. The light projector 18 projects light onto the slit plate 16, and the light receiver 19 outputs a pulse signal each time light received through the slit 20 of the slit plate 16 is received. Specifically, as shown in FIG. 9, when the upper thread T is pulled out as the balance is lifted, the light receiver 19 generates a pulse.
[0011]
FIG. 4 is a block diagram showing a configuration of a portion related to the thread breakage detection method of the embroidery sewing machine 1. As shown in FIG. 1, the embroidery sewing machine 1 includes a control unit 26 incorporating a microprocessor (not shown). The control unit 26 includes an operation panel 27, a pulse edge detection unit 28 that detects the rise (or fall) of the pulse output from the light receiver 19 of the yarn progress amount detection device 7, and a frame drive that drives the drive frame 23. A mechanism 29, an upper shaft driving mechanism 30 for driving the needle 21 of the sewing head 2 up and down, and a lower shaft driving mechanism 31 for rotating the shuttle 22 that cooperates with the needle 21 are connected. The control unit 26 includes a control program including an initialization process (step S100), an embroidery process (step S110), and a thread breakage process (step S140) described later, a work area used by the control program, and embroidery data 36. And the like are stored. The control unit 26 operates according to the control program, and controls the mechanisms so as to form an embroidery pattern represented by the embroidery data 36 on the work cloth.
[0012]
When the pulse edge detection unit 28 detects the rise (or fall) of the pulse output from the light receiver 19 of the yarn progress amount detection device 7, the detection signal is turned ON as shown in FIG. As shown in the figure, the detection signal is turned OFF when a reset signal is input, and the ON state is maintained unless a reset signal is input. The yarn progress amount detection device 7 and the pulse edge detection unit 28 are means for detecting whether the upper yarn T is moving or not.
[0013]
For example, as shown in FIG. 5, the embroidery data 36 includes one stitch data 41, which is embroidery information for one stitch, for the number of stitches of the embroidery pattern. Each stitch data 41 includes XY data 42 and a jump stitch flag 43. (The data structure of the embroidery data 36 shown in the figure is an example, and is not limited to this.) Each XY data 42 includes a relative movement amount Δx in the X direction and a relative movement amount Δy in the Y direction from the needle drop position in the previous one needle data 41 to the needle drop position in the one needle data 41. Contains. In this example, each moving amount is set in units of 0.1 mm. The jump stitch flag 43 is ON when the jump stitch does not move the needle up and down, and is OFF otherwise.
[0014]
The work area of the storage unit 32 includes a one-needle data pointer that points to one of the one-needle data 41 in the embroidery data 36 and the number of jump stitches that counts the number of jump stitches that are processed while the progress of the thread is not detected. The count, the detection stitch number setting value for setting the predetermined stitch number when it is determined that yarn breakage has occurred if the progress of the yarn is not detected for a predetermined number of stitches, and the number of stitches for making the determination Count the number of detected stitches to be counted and set the predetermined length when it is determined that thread breakage has occurred when the sum of the lengths of one or two or more consecutive stitches in which the progress of the yarn is not detected exceeds a predetermined length Variable areas such as a detection distance setting value to be detected and a detection distance count for counting the stitch length for making the determination are secured. The detection distance setting value and the detection distance count are set in units of 0.1 mm. The detection distance count is subtracted and a detection distance setting value is set as an initial value.
[0015]
FIG. 6 is a flowchart showing the flow of the initialization process (step S100). This processing is executed before the embroidery processing (step S110), and various data and the like are initialized. First, 60, which means 6 mm, is set as the detection distance setting value (step S101), and the detection distance setting value is set as an initial value of the detection distance count to be subtracted (step S102). Next, 3 representing 3 stitches is set as the detection stitch number setting value (step S103). Next, the one-needle data pointer is set to point to the first one-needle data 41 of the embroidery data 36 (step S104). Next, a reset signal is input to the pulse edge detection unit 28 (step S105), and the process ends (step S106). Each set value is an exemplification, and is not particularly limited, and is appropriately changed according to the sewing machine, the thread, the cloth of the work cloth, and the like.
[0016]
FIG. 7 is a flowchart showing the flow of the embroidery processing (step S110). In this process, first, the detected stitch number count and the jump stitch number count are initialized to 0 (step S111), and then the spindle motor is turned on to start the embroidery processing operation (step S112). Next, one stitch data 41 pointed to by the stitch data pointer is read (step S113). Next, the drive frame 23 is driven according to the contents of the one-needle data 41 while the needle 21 is moving up (step S114). Next, the jump stitch flag 43 of the one-needle data 41 is checked. If the flag 43 is ON (step S115), the jump mechanism (not shown) built in the sewing machine head 2 is used to jump (the needle 21 is dropped). The jump stitch count is incremented by 1 (step S116), and the process returns to step S113. When the jump stitch flag 43 is OFF (step S115), the process proceeds to step S117.
[0017]
In step S117, the detection signal of the pulse edge detection unit 28 is checked. If the detection signal is ON, the detection signal is reset by outputting a reset signal to the pulse edge detection unit 28 (step S118), and the detection distance count is set. Is initialized to the detection distance setting value (step S119), and the detection stitch count and jump stitch count are each initialized to 0 (step S120). Next, the one-needle data pointer is set to point to the next one-needle data 41 in the embroidery data 36 (step S121). Next, when reading of all the one-needle data 41 in the embroidery data 36 has not been completed (step S122), the process returns to step S113, and when reading of all the one-needle data 41 has been completed (step S122). ), The spindle motor is turned off (step S128), and this process is terminated (step S129).
[0018]
If the detection signal of the pulse edge detector 28 is OFF in step S117, the detected stitch number count is incremented by 1 (step S123). Next, it is checked whether or not the detected stitch count is equal to the detected stitch count setting value (step S124). If they are not equal, the frame movement amount for one stitch is subtracted from the detected distance count (step S124). Step S125). The frame movement amount for one stitch is the frame movement amount from the previous needle drop position to the current needle drop position. Specifically, the “jump stitch number before one needle data 41 pointed to by one needle data pointer” This is the amount of movement by one stitch data for “count contents + 1”. This frame movement amount is (ΣΔx ² + ΣΔy ² ) ^1/2 ) where the X-direction component of the frame movement amount for one stitch is ΣΔx and the Y-direction component is ΣΔy. Next, when the detection distance count is greater than 0 (step S126), the process proceeds to step S121 described above.
[0019]
If both are equal in step S124, or if the detected distance count is 0 or less in step S126, the thread breakage process (step S140) is executed (step S127), and the process returns to step S111. It is like that.
[0020]
FIG. 8 is a flowchart showing the flow of the yarn breakage process (step S140). In this process, first, the spindle motor is turned off (step S141), and the thread breakage display (not shown) provided on the sewing head 2 (or the operation panel 27) is turned on (step S142). Next, the one stitch data pointer is returned by the number of stitches of “detected stitch count count + jump stitch count count + α”, and the drive frame 23 is moved to the coordinates for embroidery processing with the one stitch data 41 pointed to by the pointer. Move (step S143). Here, although it does not specifically limit as a value of (alpha), It can be illustrated that it is about 0 to several stitches, and it is illustrated that it is 1 stitch in this example. Next, initialization is performed by setting a detection distance setting value in the detection distance count (step S144). Next, the process waits until a start switch (not shown) provided on the operation panel 27 is turned on (step S145), and returns to the caller of this process (step S146).
[0021]
Next, a series of operation examples when yarn breakage occurs by the sewing machine will be described with reference to FIG. This figure shows that thread breakage occurs immediately after the nth stitch is formed, and the sum of the lengths of one or two or more consecutive stitches in which the progress of the thread is not detected exceeds a predetermined length, resulting in the occurrence of thread breakage. An example in the case of being detected is shown. In this example, it is assumed that the detection stitch number setting value is set to 3 and the detection distance setting value is set to 60 (6 mm). In addition, in order to simplify the description, it is assumed that the length of each stitch is 4 mm.
[0022]
Stitches before thread breakage (before the nth) are formed mainly by executing steps S111 to S122 of the embroidery processing (step S110). Specifically, at the time of forming each stitch, the light receiver 19 generates a pulse signal when the upper thread T is pulled out as the balance is raised, and this is detected by the pulse edge detector 28 to generate a detection signal. . In synchronization with this, steps S113 to S115 of the embroidery processing are executed, and the drive frame 23 is moved. At this time, since the detection signal is ON (step S117), the detection signal is reset (step S118), and steps S119 to S122 are executed to return to S113 to form the next stitch. It has become.
[0023]
If yarn breakage occurs immediately after the nth stitch is formed, no pulse signal is generated when the n + 1th stitch is formed, so the detection signal remains OFF (step S117), and steps S123 and after are executed. The detection stitch count is set to 1, and the frame movement amount (that is, stitch length) 40 is subtracted from the detection distance count initialized to 60, so that the detection distance count is 20 (steps S123 to 125). At this time, since the detection distance count is greater than 0, steps S121 and S122 are executed, and the process returns to S113 to form the next n + 2nd stitch.
[0024]
Since thread breakage has occurred, the detection signal remains OFF even at the (n + 2) th stitch (step S117), and step S123 and subsequent steps are executed. Then, the detection stitch count is set to 2, the frame movement amount 40 is subtracted from the detection distance count which is 20, and the detection distance count becomes −20 (steps S123 to S125). At this time, since the detection distance count is 0 or less (step S124), thread breakage processing is executed (step S127), and the embroidery process is stopped and stitch back is performed up to the (n-1) th stitch. Thereafter, the embroidery process is resumed from the (n-1) th stitch (steps S111 and S112).
[0025]
According to the yarn breakage detecting method of the sewing machine of the present invention configured as described above, the sum of the lengths of one or two or more consecutive stitches where the progress of the yarn is not detected is a predetermined length (in this example, 6 mm (detection distance). When the setting value is equal to or greater than 60)), it is configured so as to include a stage (steps S125 and S126) for determining that thread breakage has occurred. Thread breakage can be detected with a small number of stitches, and embroidery processing can be stopped. As a result, it is possible to reduce the pull-out amount of the lower thread by the upper thread T in the sewing machine head 2 where no thread breakage has occurred.
[0026]
Further, it includes a step (steps S123 and S124) of determining that a yarn breakage has occurred unless the progress of the yarn is detected for a predetermined number of stitches (three stitches in this example (detected stitch number setting value = 3)). Therefore, when the stitch length is short (less than 2 mm in this example), the yarn breakage can be detected as in the conventional case. And even if the number of detected stitches is increased in order to improve the accuracy of thread breakage detection when the stitch length is 1 mm or less, for example, the stitch length is long, the stitch length is the sum of the stitch lengths. By determining the yarn breakage (steps S125 and S126), the yarn breakage can be detected with a very small number of stitches. As described above, according to the present invention, it is possible to efficiently detect thread breakage corresponding to various stitches on the same embroidery pattern.
[0027]
In addition, this invention is not limited to the said embodiment, For example, it can also be suitably changed and embodied as follows, for example in the range which does not deviate from the meaning of invention.
(1) Changing the shape and number of the slits 20 of the slit plate 16 as appropriate.
(2) Change the encoder 14 to another structure or operating principle.
(3) Change the yarn progress amount detection device 7 to another structure or operating principle.
[0028]
(4) A counter that counts the number of pulse edges is provided in place of the pulse edge detector 28.
(5) The pulse edge detector 28 is configured to detect the falling edge of the pulse.
(6) A counter that counts the number of pulses is provided in place of the pulse edge detector 28.
[0029]
【Effect of the invention】
As described above in detail, according to the thread breakage detection method of the sewing machine of the present invention, it is possible to efficiently detect thread breakage corresponding to various stitches on the same embroidery pattern. Play.
[Brief description of the drawings]
FIG. 1 is a front view showing an embroidery sewing machine using a thread breakage detecting method according to an embodiment of the present invention.
FIG. 2 is a side view showing a yarn path device of the sewing machine.
FIG. 3 is a plan view showing a slit plate in the yarn progress amount detection device of the yarn path device.
FIG. 4 is a block diagram showing a configuration of a portion related to a thread breakage detection method of the embroidery sewing machine.
FIG. 5 is a diagram showing a structure of embroidery data of the embroidery sewing machine.
FIG. 6 is a flowchart showing a flow of initialization processing executed by the embroidery sewing machine.
FIG. 7 is a flowchart showing a flow of embroidery processing executed by the embroidery sewing machine.
FIG. 8 is a flowchart showing a flow of thread breakage processing executed by the embroidery sewing machine.
FIG. 9 is a timing chart showing a series of operation examples when thread breakage of the embroidery sewing machine occurs.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Embroidery sewing machine 7 Thread progress amount detection apparatus 28 Pulse edge detection part 36 Embroidery data S100 Initialization process S110 Embroidery process S140 Thread breakage detection process

Claims (1)

The used embroidery machine generates a pulse when the needle (21), the drive frame (23), and the upper thread (T) corresponding to the needle (21) are pulled out, and detects the amount of advance of the upper thread (T). The yarn progress amount detecting device (7), the pulse edge detecting portion (28) for detecting the rise or fall of the pulse output from the yarn progress amount detecting device (7), and the pulse edge detecting portion (28) are connected. A control unit (26),
The control unit (26) includes a storage unit (32). In the work area of the storage unit (32), a one-needle data pointer that points to any one stitch data (41) in the embroidery data (36); When the advancement of the upper thread is not detected for a predetermined number of stitches, the detection stitch number setting value for setting the predetermined stitch number when determining that thread breakage has occurred, and the number of stitches for the determination are counted. Count the number of detected stitches and set the predetermined length when it is determined that thread breakage has occurred when the sum of the lengths of one or two or more consecutive stitches where the progress of the upper thread is not detected exceeds a predetermined length The detection distance setting value and the detection distance count area for counting the stitch length for making the determination are secured, and the detection distance setting value is set as the initial value of the detection distance count.
The embroidery processing (S110) performed using the embroidery sewing machine includes:
First, a step (S111) of initializing the detected stitch number count,
Thereafter, a step of starting an embroidery processing operation (S112),
Next, a step of reading one stitch data (41) pointed to by the one stitch data pointer (S113),
Next, a step (S114) of driving the drive frame (23) according to the contents of the one-needle data (41) while the needle (21) is moving up,
Next, a detection signal check step (S117) for checking whether the detection signal of the pulse edge detection unit (28) is ON or OFF,
When the detection signal of the pulse edge detector (28) is OFF in the detection signal check step (S117), a step of incrementing the detection stitch number count by 1 (S123);
Next, a detection stitch number check step (S124) for checking whether or not the detection stitch number count is equal to the detection stitch number setting value;
If the detected stitch number count is not equal to the detected stitch number setting value in the detected stitch number check step (S124), a step of subtracting the frame movement amount for one stitch from the detected distance count (S125);
Next, a detection distance check step (S126) for checking whether the detection distance count is greater than 0 or less than 0,
When the detected stitch number count is equal to the detected stitch number setting value in the detected stitch number check step (S124), or the detected distance count becomes 0 or less in the detected distance check step (S126). And a step of executing thread breakage processing (S127).

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