JP2687589B2 - Sewing machine tape feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a tape feeding device for shirring sewing using a step motor.

[Prior Art] An elastic sewing tape such as a rubber tape is sewn into a work cloth in an extended state to form an appropriate wavy shape on the work cloth,
"Sewing sewing", which is a sewing method that gives a work cloth a three-dimensional shape and elasticity, is realized in a sewing machine as follows.

That is, it is realized by detecting the rotation speed of the sewing machine main shaft and adjusting the rotation speed of the tape supplying step motor so that the rotation speed becomes a predetermined relative feeding speed. Here, the relative feeding speed means the ratio of the tape feeding speed to the rotation speed of the spindle, and since the rotation speed of the spindle and the moving speed of the work cloth are proportional, the relative feeding speed is It also means the ratio of the tape feeding speed to the moving speed of the work cloth.

This relative feeding speed is set to less than 100% of the moving speed of the work cloth. That is, the absolute feeding speed of the tape is always set lower than the moving speed of the work cloth. As a result, when the tape is sewn into the work cloth at the sewing position, the tape in the sewn portion moves at the same speed as the work cloth, and therefore the speed of the relative feeding speed and the moving speed of the work cloth. The tape will be stretched according to the difference between the two. Moreover, it is sewn into the work cloth in the stretched state. Therefore, after sewing, the tape tends to shrink to its original length, forming wavy wrinkles on the work cloth.

The relative adjustment of the feeding speed is because the rotation speed of the main spindle is not constant and is changed by the operation. Therefore, regardless of the main spindle speed, that is, the work cloth speed, the elastic sewing tape is used. Is to be supplied as a constant elongation rate so that the amount of shirring of the work cloth is constantly adjusted.

As a mechanism for adjusting the feeding speed of the tape, a roller for holding the tape and a step motor for rotating the roller are generally used. The rotation speed of the step motor can be accurately controlled by the input drive pulse number and pulse width, so the rotation speed of the spindle that changes in an analog manner is detected and controlled to a predetermined relative speed with respect to that speed. it can.

[Problems to be Solved by the Invention] Particularly when sewing with a large amount of shirring, it is necessary to increase the elongation rate of the tape. For that purpose, the relative feeding speed of the tape must be sufficiently reduced. At that time, the number of drive pulses per one rotation of the main shaft becomes extremely small. For example, it becomes about "5" per one rotation of the main shaft.
In this state, for example, if you try to reduce the amount of bullying,
The number of pulses per spindle revolution must be increased.
Since the minimum increase amount of the pulse number is "1", it increases from "5" to "6".

However, when increasing from “5” to “6”, the rotation speed of the step motor increases by 20% at a time. Therefore, the relative feeding speed of the tape is 20% stepwise.
Will also rise. For this reason, even if it is desired to slightly reduce the amount of shirring (for example, 2%), it is impossible to adjust the amount to 20% or less, so that the desired amount of shirring cannot be realized. The same applies when you want to increase the amount of shirring. "5"
From 4 to 4, the relative feeding speed decreases by 20% at a time.

Of course, an expensive step motor with a small step angle may be used, but if the rotation speed of the main shaft is extremely high, the pulse width becomes too small and there is a risk of step out.
In addition, by reducing the diameter of the holding roller,
There is also a method of reducing the amount of change in the tape feeding speed in the step, but a certain diameter or more is required to pinch and accurately feed the tape, and there is a limit to the reduction of the roller diameter. Further, if the diameter of the roller is reduced and the rotation speed of the main spindle becomes high, the rotation speed of the step motor cannot follow and there is a risk that the tape cannot be sufficiently fed.

The present invention has been made in view of the above problems, and even if a conventional inexpensive step motor having a large step angle is used, it is not restricted by the size of the step angle and a sufficiently small relative feeding speed is obtained. The purpose of the adjustment is to realize a desired amount of shirring.

[Means for Solving the Problems] To achieve the above object, a tape feeding device for a sewing machine according to the present invention has a step motor M1 as shown in FIG.
When the relative feeding speed of the elastic sewing tape M2 and the tape feeding means M3 for feeding the elastic sewing tape M2 to the sewing position by the rotation of Arrangement by selecting one or two integers from an integer that is closest to the number of pulses that is greater than or equal to the number of calculated pulses per revolution of the sewing machine spindle M4 and an integer that is less than or equal to the number of pulses that is closest to the number of pulses. The average value of the integer array thus obtained is an integer array acquisition means M5 for obtaining an integer array that is the same as or approximate to the calculated pulse number, and the sewing machine spindle in the drive signal of the step motor M1.
The pulse number adjusting means M6 for sequentially adjusting the number of pulses per one rotation of M4 according to the integer array obtained by the integer array obtaining means M5, thereby providing a resolution of the rotation speed of the step motor M1. Further, the resolution of the relative feeding speed of the elastic sewing tape M2 can be finely adjusted.

[Operation] For example, when it is desired to increase the number of pulses by 2% from the feeding speed of "5" per revolution of the sewing machine spindle M4, the calculated number of pulses is "5.1". This calculated number of pulses cannot be achieved with the step motor M1. Therefore,
The integer array acquisition means M5 is composed of an integer "6" that is greater than or equal to the calculated number of pulses "5.1" and the closest number "5" that is less than or equal to the calculated number of pulses "5.1". Is obtained. The average value of this integer array is `` 5.
It is set to be "1". For example, "5,5,5,5,
It is an integer array of "5,6,5,5,5,5".

Then, the pulse number adjusting means M6, the pulse number is adjusted so as to be an integer array pattern of "5,5,5,5,5,6,5,5,5,5" over 10 revolutions of the sewing machine spindle M4. Step motor
The drive signal of M1 is sequentially output for each revolution of the sewing machine spindle M4, and this is repeated.

When the drive signal of the step motor M1 is controlled in this manner, particularly, since the tape to be supplied is the stretchable sewing tape M2, the buffering action thereof causes "5" to "6".
The change in the feeding speed at a moment when the pulse number changes from “6” to “5”
It absorbs by itself and produces the effect of averaging the entire feeding speed. As a result, the actual feeding speed of the elastic sewing tape M2 can be increased by 2%.

In this way, the control by the pattern of the integer array of the step motor M1 and the synergistic action with the elastic sewing tape M2 enable the control of the shirring amount with a fine resolution.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a sewing machine 1 equipped with a tape feeding device as an embodiment. The sewing machine 1 has a drive motor 3
Is provided, and its output is transmitted via the belt 5 and the pulley 13 to the lower shaft 7 arranged in the bed portion 1a, and further transmitted via the belt 9 to the main shaft 11 arranged in the arm portion 1b. . The lower shaft 7 drives a mechanism such as a feed dog and a thread catcher provided on the bed portion 1a. The main shaft 11 drives a mechanism such as a needle provided on the arm portion 1b. These mechanisms are well-known general ones and will not be described in detail. still,
The rotation speed of the drive motor 3 is adjusted according to the depression amount of the foot switch 3a provided at the foot of the operator.

A needle position detector 15 also serving as a rotation speed detector is provided facing the pulley 13 of the lower shaft 7. This needle position detector 15
Optically detects the movement of a plurality of reflection marks provided on the pulley 13 to detect the rotation speed of the main shaft 11 which is interlocked with the lower shaft 7, and by another reflection mark, is interlocked with the main shaft 11 to move vertically. The position of the driven needle is detected. The signal from the needle position detector 15 is input to the controller 17.

A roller A18 and a roller B19 are provided at the tip of the arm portion 1b. One roller A18 freely rotates, and the other roller B19 is rotated by the step motor 21 via the joint 23 and the shaft 25. Therefore, if a stretchable sewing tape, here a rubber tape 27, is supplied between the roller A18 and the roller B19 from a tape supply source (not shown) provided above the arm portion 1b and held, the rotation of the step motor 21 is rotated. Speed and roller B1
At a speed corresponding to the diameter of 9 and the rubber tape 27,
Can be supplied to

At the sewing position 29, as shown in FIG. 3, the presser foot 33 attached to the tip of the presser bar 31 is attached to the rubber tape 27 and the work cloth 35.
And are pressed against the needle plate 37. A guide hole 33a for the rubber tape 27 is provided at the tip of the presser foot 33, and the rubber tape 27 fed by the roller B19 is provided in the guide hole 33a.
By passing through the
Are regulated. The details of the sewing machine 1 at the sewing position 29 are shown in FIG. 3 and are omitted in FIG.

In this way, the rubber tape 27 and the work cloth 35 fed to the sewing position 29 are moved up and down with the rotation of the main shaft 11, the needle 41 provided at the tip of the needle bar 39 and the needle 41 with the rotation of the lower shaft 7. It is sewn in cooperation with a thread catcher (not shown) that is driven in synchronization with 41, and is sent out backward on the bed surface 47 by the feed dog 45.

The control device 17 is configured as a computer, and includes a CPU 51, a ROM 53, a RAM 55, an input / output interface 57 and a bus line 59 for transmitting signals between them as shown in FIG. 2, and the CPU 51 stores programs and programs stored in the ROM 53. A predetermined process is executed according to the data. The predetermined processing is performed by the needle position detector 15, the knee switch 61 provided at the position of the operator's knee, the toggle switch 62, the digital switch A63, the digital switch B65, and the digital switch C6.
The signal from 7 is input through the input / output interface 57, necessary arithmetic processing is performed based on the input data, and as the calculation result, the light emitting diode A71, the light emitting diode B73, and the light emitting diode B73 are emitted through the input / output interface 57. One of the diodes C75 is selected and turned on, and a pulse signal for controlling the rotation of the step motor 21 is output to the step motor 21.

The front view of the controller 17 is as shown in FIG. A digital switch A63 and a light emitting diode A71 are arranged in the standard sewing setting portion 17a, and a digital switch B65, a digital switch C67, a toggle switch 62 and two light emitting diodes B73 and a light emitting diode C75 are arranged in the barbed sewing setting portion 17b. ing.

The digital switches A63 to C67 display decimal numbers on their display units 63a to 67a and 63b to 67b, respectively. This decimal number is set by pressing the "+" keys 63c-67c, 63d-67d and "-" keys 63e-67e, 63f-67f arranged above and below the display units 63a-67a, 63b-67b. It For example, the value on the display 63b is currently set to "8", but you can change it to "9" by pressing the "+" key 63d once, and the number of presses will increase, and if it is "9" or more, it will be displayed again. Return to 0 ". Conversely, the "-" key 63f is decreased by the number of times it is pressed, and when it is "0" or less, it returns to "9" again. The same applies to other display units.

The light emitting diode A71 is controlled so that it is turned on when the knee switch 61 is turned off and turned off when the knee switch 61 is turned on, and both the light emitting diode B73 and the light emitting diode C75 are turned off when the knee switch 61 is turned off and the knee switch 61 is turned on. When is turned on, the side of the toggle switch 62 on which the knob portion 62a is tilted is turned on, and the opposite side is turned off.

The pulse signal setting and output processing executed by the CPU 51 in the ROM 53 based on the program and data will be described with reference to the flowcharts of FIGS. 5 (A) and 5 (B). The process shown in FIG. 5 (A) is a pulse signal setting process performed after the power of the sewing machine 1 is turned on, and FIG. 5 (B) shows the process when the needle position signal from the needle position detector 15 is output. Is a pulse output process that is executed by interruption. The time when the needle position signal is output is the time when the needle comes out of the needle hole (not shown) formed in the needle plate 37 and the tip just comes to the needle hole.

When the pulse signal setting process is started by turning on the power of the sewing machine 1, it is first determined whether or not the knee switch 61 is on (S110). If it is not on, the light emitting diode A71 is turned on, and the other light emitting diodes 73 and 75 are turned off (S12
0). This indicates to the operator that the set value of the digital switch A63 has been selected. And digital switch
The set value of A63 is read (S130). This set value is a value set in advance by the operator as the relative feeding speed for standard sewing, and the value "98" is read in the example of FIG.

If the knee switch 61 is in the ON state in step S110, that is, if the operator has pressed the knee switch 61, it is next determined whether or not the toggle switch 62 is on (S140). 4th
In the figure, turning the knob 62a of the toggle switch 62 to the left turns it off, and turning it to the right turns it on. If it is not on, the light emitting transistor B73 is turned on, and the other light emitting diode 7
1,75 are turned off (S150). This indicates to the operator that the set value of the digital switch B65 has been selected.
Then, the first set value for the pseudo-sewing sewing (here, “49”) of the digital switch B65 is read (S160).

On the contrary, if the toggle switch 62 is on, the light emitting transistor C75 is turned on and the other light emitting diodes 71, 73 are turned off (S170). This indicates to the operator that the set value of the digital switch C67 has been selected. Then, the second setting value for false stitch sewing (here, "02") of the digital switch C67 is read (S180).

In this way, one of the digital switches 63 to 67 is selected according to the state of the switches 61 and 62 and the set value is read. Table 1 summarizes the on / off states of the switches 61 and 62 and the selection status of the set values.

Next, it is determined whether or not the change of the set value was between the previous processing (S185). If this setting process has just been started, an affirmative decision is made that the set value has been newly read, and the flag F is set to "1" (S187). Next, the array pattern of the corresponding portion of the data table prepared in the ROM 53 is read based on the set value. This data table corresponds to the pulse number array pattern (corresponding to an integer array) with respect to the set value as shown in FIG. The array pattern corresponding to the set value is read from this table into a predetermined area in the RAM 55 (S190).

For example, if the setting value is "98", "23,23,23" (1
An array pattern with a needle average of 23.00) is read. Similarly, if the set value is "49", "11,12,12,11,12,1
2 ”(one stitch average 11.67) array pattern is read,
If the setting value is "02", it is "6,6,6,6,6,5,6,6,6,6,6,
An array pattern of 6 "(average of 5.92 per stitch) is read.

 After this, the process returns to step S110 again.

After that, if it is determined in step S185 that the set value has not been changed, it is not necessary to read the array pattern, and therefore the process directly returns to step S110.

On the other hand, when the pulse output process is started by the generation of the needle position signal, it is first determined whether or not the flag F is "1" (S210). If the above step S187 is executed, F =
Since it is 1, the first pulse number is read from the pulse number array pattern that has been affirmatively determined and already read (S220). For example, if the set value is "49", the first pulse number is "11". Next, the flag F is set to "0" (S230). Next, the pulse width is determined from the spindle rotation speed and the number of pulses (S250). That is, the rotation speed of the spindle 11 is calculated by a rotation speed detection routine (not shown) based on the rotation speed signal from the needle position detector 15. The pulse width is determined in inverse proportion to the value of the rotation speed and the number of pulses.

Next, a pulse signal having the determined number of pulses and pulse width is output to the step motor (S260). Thus, the process is once ended.

Next, when the pulse output process is started again without changing the set value, a negative determination is made in step S210, and the next pulse number is read (S240). If the set value is "49", the next pulse number is "12". After that, the above-mentioned steps S250 and S260 are executed, and the pulse with the pulse number “12” is output.

Then, unless the set value is changed, the read array pattern is sequentially executed as "12", "11", "12", "12". If the end of the array pattern, step S240
Then, it will be repeated from the first "11" of the array pattern again.

If the set value is changed in the middle of this array pattern, for example, if it is "02", an affirmative decision is made in step S185,
F = 1 is set (S187), and a new pulse number array pattern is read (S190). And on the pulse output processing side,
A positive determination is made in step S210, and output processing is performed from the first pulse number (S220, S230, S250, S260).

As described above, the pulse number output according to the pulse number array pattern selected by the set value is performed. FIG. 7 shows a timing chart of the pulse number arrangement pattern output when the set value is "00". Here, 1 of the spindle 11
This means that an average of 5.75 pulses of rotation is realized with respect to the rotation. The average values of the other set values are shown in FIG. In Fig. 6, when the set value increases by "1", the average number of pulses is 1.5%.
It is set to increase.

In this way, when the set value is "98", the step motor 21
Realizes standard sewing by feeding the rubber tape 27 at the same speed as the movement speed of the work cloth 35, and the set value is "49" or "02".
In the above, the rubber tape 27 is fed at a speed lower than the moving speed of the work cloth 35 to realize the desired shirring sewing. The amount of shirring is larger at the set value "02" where the relative feeding speed is slower.

As described above, normally, if the relative feeding speed is adjusted only by the number of pulses per one revolution of the main shaft 11, it can be set only at around 20 stages (5 to 24 pulses, maximum 20 stages). On the other hand, in this embodiment, the relative feeding speed control (here, 100 steps) with a finer average resolution is possible without changing the device by the output pulse number arrangement pattern between a plurality of rotations. Became. Moreover, due to the buffering action of the rubber tape 27, the actual relative feeding speed is also averaged over the entire pattern, and a uniform shirring state corresponding to each step is realized.

In the above-mentioned embodiment, the digital switch on the false stitching side
Although there are only two 65 and 67, three or more may be provided if necessary. In this case, not the toggle switch 62,
A dial switch that can be selected from three or more states is provided.

In the above embodiment, the step motor 21, the roller A18
And roller B19 correspond to tape supply means M3, and step S
130, S160, S180, and S190 correspond to the processing as the integer array acquisition means, and the pulse output processing of FIG. 5B corresponds to the processing as the pulse number adjustment means.

As described above in detail, in the present invention, when the integer array acquisition means M5 realizes the target relative feeding speed of the elastic sewing tape M2, the sewing machine corresponding to the relative feeding speed is provided. One or two integers are selected and arranged from an integer that is closest to the number of pulses that is greater than or equal to the number of calculated pulses per revolution of the spindle M4 and an integer that is less than or equal to the number of pulses that is closest to the number of pulses. The average value of the integer array obtained is an integer array that is the same as or approximate to the calculated pulse number, and according to this integer array, the pulse number adjusting means M6 sets 1 of the sewing machine spindle M4 in the drive signal of the step motor M1. The number of pulses for each rotation is adjusted sequentially. As a result, the resolution of the relative feeding speed of the elastic sewing tape M2 can be adjusted more finely than the resolution of the rotation speed of the step motor M1.

Therefore, the speed adjustment does not become rough even at a relatively low relative feeding speed, and the desired shirring state can be accurately set. Therefore, high quality sewn products can be provided.

[Brief description of the drawings]

FIG. 1 is a basic exemplification diagram of the present invention, FIG. 2 is a block diagram of a main portion of a sewing machine equipped with a tape feeding device as an embodiment, FIG. 3 is a side face configuration diagram in the vicinity of a sewing position, and FIG. Is a front view of the control device portion, FIG. 5 (A) is a flow chart of the pulse signal setting process, FIG. 5 (B) is a flow chart of the pulse output process, and FIG. 6 shows a pulse number arrangement pattern from set values. FIG. 7 is a timing chart showing an example of pulse output. M1 ... Step motor, M2 ... Elastic sewing tape M3 ... Tape supply means, M4 ... Sewing machine spindle M5 ... Integer array acquisition means, M6 ... Pulse number adjusting means 1 ... Sewing machine, 11 ... spindle, 15 ... Needle position detector 17 ... Controller 18 ... Roller A, 19 ... Roller B 21 ... Step motor, 27 ... Rubber tape 63 ... Digital switch A 65 ... Digital switch B 67 ... Digital switch C

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyasu Iwakoshi 9-35 Hotta-dori, Mizuho-ku, Nagoya, Aichi Prefecture Brother Industries, Ltd. (56) Reference JP-A-57-45894 (JP, A) Sho 62-159694 (JP, A) JP 59-201698 (JP, A) Actual development Sho 62-379 (JP, U)

Claims (1)

(57) [Claims] 1. A tape feeding means for feeding an elastic sewing tape to a sewing position by rotation of a step motor, and a relative feeding when realizing a target relative feeding speed of the elastic sewing tape. One or two integers are selected from an integer that is closest to the number of pulses that is greater than or equal to the number of calculated pulses per revolution of the sewing machine spindle that corresponds to the speed, and an integer that is less than or equal to the number of pulses that is closest to the number of pulses. The average value of the arranged integer arrays is an integer array obtaining means for obtaining an integer array having the same or an approximate number as the calculated pulse number, and 1 of the sewing machine spindle in the drive signal of the step motor.
The number of pulses for each rotation is sequentially adjusted according to the integer array obtained by the integer array obtaining means, and the pulse number adjusting means is provided, so that the elastic sewing can be performed from the resolution of the rotation speed of the step motor. A tape feeding device for a sewing machine, which is capable of finely adjusting the resolution of the relative feeding speed of the tape.