JP2629703B2 - Sewing machine ruler control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ruler control device for moving a ruler of a sewing machine.

[Prior Art] Conventionally, there has been disclosed a technique for retracting a ruler used for performing hem-stitching or the like in accordance with a step sewing portion of an object to be sewn (JP-A-52-60746).

In this technique, for example, as shown in FIG. 14, an edge overlock sewing machine guides a holder c for holding a folded fabric a in an S-shape and a bent portion of the fabric a in the direction of needle drop d. The present invention solves the following problems that occur when sewing is performed by attaching a guide plate e as the ruler so that the needle f just passes through the bent portion of the fabric a.

One of the problems is that, as shown in FIG. 15, for example, a "seam step" g (hereinafter, simply referred to as a step) formed by sewing a front body and a back body of an undershirt, a sports shirt, or the like. When entering h, the resistance of sending the fabric a becomes very large, and the fabric a near the needle drop d is stretched in the advancing direction by the feed dog, and the folded end of the fabric a is contracted in the lateral direction. The stitch comes off from the needle drop.

Also, for example, as shown in FIG.
Projecting from the fabric a, this projecting portion is
, A gap i is generated before and after that, and the sewing is similarly removed.

Therefore, conventionally, as shown in FIG. 17, the stepped portion g is detected and the guide body e is retracted to prevent the sewing from coming off.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, the timing for retracting the guide body e is shifted, and as shown in FIG. Occurred.

This is because, in the related art, the dispersion of the retreat timing is large, and the operating time of the solenoid or the like for retreating the guide body e is not considered.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to optimally form a stitch of a sewing machine on a work having a stepped portion.

[Means for Solving the Problems] As means for achieving the above object, a ruler control device for a sewing machine according to the present invention is disposed upstream of a needle drop section MA of the sewing machine as illustrated in FIG. , A ruler MC having a guide surface along the feed direction of the workpiece MB, and a corresponding ruler MC
A driving means MD for moving the workpiece away from the work MB,
A step sewing portion detecting means MF which is arranged upstream of the ruler MC by a predetermined distance and detects a step sewing portion ME of the sewing object MB, and a timing determined by the predetermined distance when the step sewing portion ME is detected. In the ruler control device for a sewing machine including the ruler control means MG for moving the ruler MC by controlling the driving means MD, a sewing speed detecting means MH for detecting a sewing speed of the sewing machine, The timing at which the ruler control means MG moves the ruler MC is corrected based on the operation time from the start of the operation of the driving means MD to the completion of the movement of the ruler MC, and the sewing speed. And moving timing correction means MI.

[Operation] The sewing machine ruler control device according to the present invention includes step sewing portion detecting means MF.
Detects the step sewing portion ME of the work MB, at a timing determined by the distance between the step sewing portion detecting means MF and the ruler MC, the ruler control means MG controls the driving means MD to set the ruler MC.
Is moved away from the work MB. Further, the movement timing correction means MI determines the timing based on the sewing speed detected by the sewing speed detection means MH and the operation time from when the driving means MD starts operating until when the movement of the ruler MC is completed. to correct.

Therefore, the timing at which the ruler MC retreats the step sewing portion ME is corrected in accordance with the change in the sewing speed and the operation time of the driving means MD, and the retraction timing of the ruler MC is accurately controlled according to the sewing. Is done.

Next, an embodiment in which the ruler control device for a sewing machine according to the present invention is applied to an overlock sewing machine will be described with reference to the drawings.

First, with reference to FIGS. 2 to 7, a description will be given of a mechanism 10 for preventing a hem pulling step from being attached to the front surface of an overlock sewing machine (not shown). FIG. 2 is a perspective view of the hem pulling step portion detachment prevention mechanism 10, FIG.
FIG. 5 is a sectional view taken along line AA, FIG. 5 is a sectional view taken along line BB, FIG. 6 is a sectional view taken along line CC, and FIG. 7 is a sectional view taken along line DD. A guide 14 is rotatably attached to the hem pulling base 12 of the hem pulling step portion prevention mechanism 10 by a step screw 16, and a holder 18 is fixed by a screw 20. Information body
A round groove 22 is formed at a position facing the tip of the holding body 18 of the 14, and a step detector 24 is fitted into the round groove 22. A step detecting shaft 26 (see FIGS. 5 and 7) is fitted to the hem pulling guide base 12, and the end of the shaft 26 is moved toward the guide 14 by a retaining ring 28 and a spring 30. Under the force, the step detector 24 is pushed through the through hole of the guide 14. Guide 14
The hole is provided adjacent to the round groove 22 into which the step detector 24 is fitted, and the detector stopper 32 is fitted therein.
Is provided with a set screw 33 (see FIG. 3) for fixing.
The detector stopper 32 has its tip bent in an L-shape, and is fitted into a notch on the side surface of the step detector 24. Thus, the step detector 24 serves as a rotation stopper and a stopper for preventing the step detector 24 from coming out of the guide body 14.
At the other end of the step detection shaft 26, a magnet holder to which a magnet 35 is bonded
36 is fixed with a set screw 38 (see FIG. 5).

A magnet guide plate 40 for preventing the magnet holder 36 from rotating is fixed to the hemming guide base 12.
Is made of a resin which is not affected by the lines of magnetic force from the magnet 35. At a position facing the magnet 35, there is a Hall IC 44 fixed to a case 42, and the case 42 has an IC mounting plate.
It is fixed to 46 with a screw 48. The above magnet 35 and Hall IC44
The combination of the two functions as a step sensor for detecting a step. In the upper part of the IC mounting plate 46, a long hole 50 and two grooves
52 (see FIGS. 2 to 5). The
An eccentric part of an eccentric knob 54 attached to the hem guide base 12 with a retaining ring 53 is fitted into the elongated hole 50 of the IC mounting plate 46. Thereby, the relative position of the IC mounting plate 46 with respect to the hemming guide base 12 is adjusted. Further, the IC mounting plate 46 is fixed to the hemming guide base 12 by a step screw 56 fitted in the groove 52.

A fixed base 58 supporting the hem pulling guide base 12 and the like (see FIGS. 2 to 4) is fixed to the sewing machine. A hem pulling base 60 is rotatably attached to the fixed base 58 with a stepped screw 62 and a nut 64. Mounting shaft on hem pull base 60
The bottom guide base 12 is fixed to one end of the mounting shaft 66. At the other end of the mounting shaft 66, a screw is formed, and a nut 68 fitted in the groove of the skirting base 60 is screwed. Thus, the nut 68 is rotated to move the mounting shaft 66, and the position of the hem guide base 12 can be controlled.

In the middle of the mounting shaft 66, the mounting shaft guide collar 70 is screwed.
Fixed by 72. A notch groove 74 is formed in the inner peripheral portion of the mounting shaft guide collar 70, and a guide pin 76 press-fitted into the hem pull base 60 is fitted. As a result, the rotation of the mounting shaft 66 is stopped.

Mounting springs 78 and 80 are fixed to the fixed base 58 and the skirt base 60 (see FIGS. 2 and 3).
Prevents rotation in the direction away from the fixed base 58. Guide plates 82 and 84 are fixed to the fixed base 58,
The guide plate 82 contacts the side surface of the hem pulling base 60 and functions as a stopper.

A plunger-type solenoid 88 is provided below the hem-pulling step portion prevention mechanism 10 (see FIGS. 2 to 4). Solenoid case of the plunger type solenoid 88
90 is fixed to a mounting plate 92 fixed to the mounting shaft 66. A set collar 96 is fixed to the plunger 94 of the solenoid 88 with a set screw 98, and a cushion 100 is fitted between the set collar 96 and the solenoid case 90. At the end of the plunger 94, a link 102 has a screw 104
The other end of the link 102 is
And is attached to the guide body 14. The guide body 14 is controlled by a torsion spring 108 (see FIG. 3) to operate the solenoid 88.
Is receiving a turning force in the left direction opposite to the direction in which the plunger 94 is pulled.

Next, the structure of the rotation sensor 110 that detects the rotation of the sewing machine will be described. As shown in FIG. 8, the rotation sensor 110 is a sewing machine pulley for driving a sewing machine spindle (not shown).
It comprises a magnet 114 fixed to 112 and a Hall IC 118 fixed to a sewing machine main body (not shown) by a mounting plate 116, and outputs one high-level signal pulse each time the sewing machine makes one rotation. is there.

As shown in FIG. 9, a controller 120 for controlling the above-mentioned hem-stepping-portion detachment prevention mechanism 10 includes a well-known CPU 122 and a clock.
124, a ROM 126, a RAM 128, an input interface 130, an output interface 132, a drive unit 134, and the like, the data detected by the step sensor 34, the rotation sensor 110, and the guide 14 provided on the front surface of a controller box (not shown). The state of the digital Na setting switch 136 for setting the needle value Na for starting the evacuation of the needle and the state of the Nb setting switch 138 for setting the holding needle value Nb for the evacuation of the guide body 14 are input via the input interface 130, and are stored in the ROM 126. Based on a program or the like stored in advance, the excitation state of the plunger solenoid 88 is controlled via the drive unit 134 as described below.

That is, in the controller 120, an interrupt routine based on the flowchart shown in FIGS. 10 and 11 and a control routine based on the flowchart shown in FIG. 12 are executed. 14 is evacuated.

First, the 0.1 (ms) interrupt routine shown in FIG. 10 is a routine started every 0.1 (ms) based on a signal from the clock 124, and calculates the reference integration time To by the following equation (1). This is the routine to be performed (step S180).

To ← To + 0.1 (ms) (1) In the rotation pulse interruption routine shown in FIG. 11, the rotation sensor 1 is turned on each time the sewing machine pulley 112 makes one rotation as shown in FIG.
10. A routine started by a pulse output from 10, in which a reference integration time To calculated by the routine of FIG. 10 is substituted into a rotation time T1 indicating a time required for one rotation of the sewing machine pulley (step S190) Then, the process of clearing the reference integration time To (step S195)
Perform

That is, the 0.1 (ms) interrupt routine shown in FIG.
The rotation time T1 referred to in the solenoid control routine of FIG.
Is calculated.

In the solenoid control routine of FIG. 12, first, it is determined whether or not the sewing machine has rotated and the stitch portion (step portion) of the cloth has reached the step sensor 110, that is, the step sensor 24 is pressed by the step portion, and the step sensor 34 It is determined whether the output has exceeded a predetermined value, as shown at time t1 in FIG. 13 (step S200). In the standby state of the detection of the step in the step S200, if the step is detected by the step sensor 34, then the Na setting switch
The setting state of 136 and the Nb setting switch 138, that is, the needle value Na for starting retreat and the needle value Nb for holding retreat are read via the input interface 130 (step S21).
0).

Next, based on the rotation time T1, the above value Na, and the value Nb, from the time t1 when the step sensor 34 detects the step portion to the time when the energization to the plunger type solenoid 88 is started by the following equations (2) and (3) The time Ta and the time Tb from the start of energization to the stop of energization are calculated (step S220).

Ta ← Na · T1−Tα (2) Tb ← Nb · T1 + Tα−Tβ (3) Tα ... Time from when the signal to start energizing the solenoid 88 is output until the guide 14 retreats (No. (See Fig. 13)
(For example, 20 [ms]) Tβ: Guide member after power supply to solenoid 88 is stopped
Time until 14 returns to the original position Na · T1 ... start time of evacuation at the current sewing speed Nb · T1 ... hold time of evacuation at the current sewing speed After calculating the above time Ta, Tb, the next step T is detected
It is determined whether or not the time Ta obtained from 1 by the above equation (2) has elapsed (step S230).
Set the operation signal of the solenoid 88 to “ON” and set the solenoid
The energization to 88 is started (step S240). This allows
At time t2 in FIG. 13, energization of the solenoid 88 is started, and at time t3, the retreat of the guide 14 is completed.

Next, after the energization of the solenoid 88 is started, it is determined whether or not the time Tb (ms) obtained by the above equation (3) has elapsed (step S250). Is turned off, and the energization of the solenoid 88 is stopped (step S260). Thus, the power failure to the solenoid 88 is stopped at the time point t4 in FIG. 13, and the guide body 14 returns to the original normal position at the time point t5.

After the energization of the solenoid 88 is stopped, the process enters the standby state for step detection in step S200 described above, and the processes in steps S200 to S260 are repeated.

As described above based on the solenoid control routine and the like, according to the present embodiment, the step sensor as shown in FIG.
The guide body 14 is held at the regular position from the time when the step 34 detects the step to the time when the time Na.T1 elapses, and the guide body 14 is kept at the regular position from the time when the time Na. Part is retracted, and after the evacuation time ends, it returns to the normal position. That is, until the time Na · T1 elapses and the time Na · T1 +
After Nb ・ T2, keep the folded end of the fabric in the proper position,
By moving the bent end of the fabric with the retreat of the guide body 14 from the time when the time Na.T1 has elapsed until the time Nb.T1 has elapsed, the needle drop is deepened, and the gap between the front and rear of the step is prevented. To prevent. Therefore, prevention of the front and rear gaps due to the retreat of the guide body 14 is caused by the set value Na of the Na setting switch 136, the set value Nb of the Nb setting switch 138, and the rotation time as the sewing speed.
It is actually performed based on T1.

As a result, regardless of the rotation speed of the sewing machine and the operation time (Tα, Tβ) of the solenoid 88, the guide body is moved for the number of stitches corresponding to the values Na and Nb set by the Na setting switch 136 and the Nb setting switch 138. Since the step 14 accurately retreats the stepped portion, there is no gap between the front and rear of the stepped portion and the seam is not too deep, so that an extremely excellent effect that a guided seam can be obtained is obtained.

In the above embodiment, based on the time required for the latest one stitch when the step is detected, that is, the rotation time T1,
The configuration is such that the energization start time Ta and the energization stop time Tb are calculated and the energization to the solenoid 88 is controlled, but instead of the time T1, the rotation speed of the sewing machine after detecting the stepped portion is replaced. May be used. That is, the time required for one rotation from a few stitches before the step is detected may be stored, and the rotation time T1 after the detection of the step may be calculated from the amount of change in the time. Thereby, a more stable seam can be obtained.

Further, by changing the equations (2) and (3) to the following equations (4) and (5), the time until the guide body 14 actually retreats and the time during which the guide body 14 retreats can be accurately determined. Can be set.

m: predetermined number That is, the rotation time T1 becomes 1 / m (1 / m needle), and the time T
Since a and Tb are controlled in 1 / m stitch units, sewing machine pulley 1
The same high-precision control as when m magnets 114 are attached to 12 can be performed.

Although the embodiment and the modified example of the present invention have been described above, the present invention is not limited to this, and various embodiments can be implemented without changing the gist.

[Effect of the Invention] The ruler control device for a sewing machine according to the present invention is configured such that the retreat timing of the ruler is set according to a value set in advance in consideration of, for example, an operation state of a driving unit, according to a change in a sewing speed of the sewing machine. Since the correction is performed, the ruler can be moved in accordance with the traveling speed of the step sewing portion. As a result, there is an extremely excellent effect that the seam of the sewing machine can always be optimally formed with high precision by preventing the deep portion of the step stitch portion from being shifted back and forth due to a change in the sewing speed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating the basic configuration of a ruler control device for a sewing machine according to the present invention. FIG. Is its plan view,
4 is a sectional view taken along line AA, FIG. 5 is a sectional view taken along line BB, FIG. 6 is a sectional view taken along line CC, FIG. 7 is a sectional view taken along line DD, and FIG. Configuration diagram showing a rotation sensor of FIG.
FIG. 10 is a block diagram of the controller of the embodiment, and FIG.
FIG. 11 is a flowchart of a 0.1 (ms) interrupt routine, FIG. 11 is a flowchart of a rotation pulse interrupt routine of the embodiment, and FIG.
FIG. 13 is a flowchart of a solenoid control routine of the embodiment, FIG. 13 is a graph showing an operation state of the embodiment, and FIGS. 14 to 18 are explanatory diagrams of a conventional example. MA: Needle drop, MB: Workpiece, MC: Ruler MD: Drive means, ME: Step sewing part MF: Step sewing part detection means MG: Ruler control means MH: Sewing speed detection means MI: Movement timing correcting means 10: Hem-pulling stepped part detachment prevention mechanism 14: Guide body, 34: Step sensor 88: Plunger solenoid 110: Rotation sensor, 120: Controller

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Mamoru Suzuda 9-35, Hotta-dori, Mizuho-ku, Nagoya-shi Inside Brother Industries, Ltd. (56) References JP-A-59-200691 (JP, A) JP-A-54 -117263 (JP, A) Japanese Utility Model Showa 61-160875 (JP, U) JP-B 54-38545 (JP, B2) JP-B 56-49151 (JP, B2) JP-B 54-6944 (JP, B2) Japanese Patent Publication No. 56-74 (JP, B2) Japanese Patent Publication No. 56-49152 (JP, B2) Japanese Utility Model No. 57-1900 (JP, Y2) Japanese Utility Model No. 63-14785 (JP, Y2)

Claims (1)

(57) [Claims] 1. A ruler disposed upstream of a needle drop portion of a sewing machine, the guide ruler having a guide surface along a feed direction of a workpiece, and a driving unit for moving the ruler in a direction away from the workpiece. A step sewing portion detecting means for detecting a step sewing portion of an object to be sewn, which is arranged on the upstream side separated by a predetermined distance from the ruler; and when the step sewing portion is detected, the driving means at a timing determined by the predetermined distance. And a ruler control means for moving the ruler.The ruler control device for a sewing machine comprising: a sewing speed detecting means for detecting a sewing speed of the sewing machine; and And movement timing correction means for correcting the timing at which the ruler control means moves the ruler based on the operation time until the movement of the ruler is completed, and the sewing speed. Features a ruler control device for sewing machines.