JP2876884B2 - Sewing machine reverse feed stitching controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for reverse feed stitching of a sewing machine, and more particularly to a correction stitch for one stitch unit which enables reverse feed stitching in addition to normal forward feed stitching.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIG. 1 according to an embodiment, in an industrial lockstitch sewing machine or the like, a body cloth or the like is placed on a work table 10 and a foot pedal 13 is operated. Sewing work such as sewing a pocket cloth on the body fabric is performed. By the way, when sewing a corner portion of the pocket cloth piece during the sewing work of the pocket cloth piece, the stepping down of the pedal 13 is stopped just before the corner part, the sewing is interrupted, and the correction sewing provided on the head of the arm section is performed. The switch 6 is operated to sew forward to the corners in one stitch unit, and thereafter the body fabric direction is changed, while the foot pedal 13 is operated to continue sewing.

[0003] However, when the pocket cloth is sewn in a straight line after passing through the corner during the sewing operation, the sewing is stopped by depressing the pedal 13 and the sewing machine M is provided on the pillar of the sewing machine M. The foot pedal 13 is slightly depressed while the reverse stitch lever 9 is operated with the right hand, and reverse feed sewing (correction sewing) is performed up to just before the corner portion.
Thereafter, forward stitching is performed in units of one stitch to the corner in the same manner as described above.

[0004]

However, as described above, when the sewing is excessively performed after passing through the corner of the pocket cloth piece, the foot pedal 13 is slightly depressed while the reverse stitch lever 9 is operated with the right hand while the left hand is operated. In the state where the work cloth is held alone, the over-stitched stitches are to be corrected by reverse feed, and the depressing operation of the foot pedal 13 is rough. Therefore, the number of stitches of the reverse feed stitch may be 3 depending on the degree of depressing. There is a problem that the number of stitches increases to 4 stitches or 4 to 5 stitches, and the reverse stitching correction sewing work becomes very complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a sewing machine capable of performing correction stitching by reverse feed in units of one stitch and improving the operability of the correction stitching. To provide a reverse feed stitching control device.

[0006]

In order to achieve the above object, a reverse feed sewing control device for a sewing machine according to the present invention comprises a cloth feed mechanism for feeding a work cloth and a cloth feed mechanism for reversing the cloth feed direction of the cloth feed mechanism. A reverse feed mechanism, and an electric actuator for driving the reverse feed mechanism, a reverse feed setting means for setting a reverse feed mode for operating the reverse feed mechanism via the electric actuator; A reverse stitching instruction means for instructing the correction stitching for one stitch, and a reverse feed for controlling the sewing machine motor to perform the reverse stitching for one stitch when the correction stitching is instructed by the correction stitching instruction means in the reverse feed mode. Sewing control means.

The cloth feed mechanism has a feed amount variable mechanism for changing the feed amount via the square pieces, and the reverse feed mechanism is configured to reverse the inclination direction of the square pieces by the driving force of the electric actuator. Is also good.

The reverse feed stitching control means, after the reverse feed stitching for one stitch, returns to the position set by the needle position setting switch based on the detection signal from the detection switch for detecting the position of the needle bar. You may comprise so that a needle bar may be stopped.

[0009]

In the reverse feed stitching control device of the sewing machine of the present invention, correction stitching for one stitch is instructed in a state where the reverse feed mode for operating the reverse feed mechanism via the electric actuator is set by the reverse feed setting means. When the correction stitching is instructed by the correction stitching instructing means for performing the stitching, the sewing machine motor is controlled by the reverse feed stitching control means to perform the reverse stitching for one stitch, and the correction stitching by the reverse feed is performed. on the other hand,
When the correction stitching is instructed by the correction stitching instruction means in a state where the reverse feed mode is not set, the sewing machine motor is controlled so as to perform forward stitch by one stitch without operating the reverse feed mechanism. Correction sewing by forward feed is performed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an industrial lockstitch sewing machine. The lockstitch sewing machine M will be described. Since the sewing machine M is the same as a general industrial sewing machine, it will be briefly described.

The lockstitch sewing machine M is mounted on a work table 10 as shown in FIG.
And a pillar 2 erected from the right end of the bed 1
And an arm 3 extending leftward from the pillar 2 so as to face the bed 1. Bed part 1
Includes a feed dog vertical movement mechanism (not shown) for moving the feed dog 42 up and down, and a feed dog longitudinal movement mechanism (not shown) for moving the feed tooth 42 back and forth.
And a reverse feed mechanism 50 for switching the forward movement of the feed dog 42 to the backward movement, a thread wheel catcher (not shown), and the like. The arm 3 has a needle bar drive mechanism for vertically moving a needle bar 4 on which a sewing needle 5 can be mounted at the lower end, and a balance drive mechanism for moving the balance up and down by adjusting the needle bar 4 up and down (shown in the figure). Omitted)
And so on. The vertical movement mechanism, the forward / backward movement mechanism, the needle bar drive mechanism, and the balance drive mechanism of the feed dog 42 are driven by the sewing machine motor 12.

At the head of the arm 3, a correction sewing switch 6 (correction sewing instructing means) for executing correction sewing in units of one stitch by driving the needle bar 4 up and down one stroke is provided.
While the correction stitching switch 6 is operated, the correction stitching in units of one stitch can be repeatedly performed. still,
A presser bar 7 is supported on the machine frame F on the rear side of the needle bar 4 so as to be vertically movable, and a presser foot 8 is attached to a lower end of the presser bar 7. Is provided with a reverse stitch lever 9 for performing the following.

A sewing machine motor 12 is provided immediately below the work table 10 and is attached to a work table 11 that supports the work table 10. The work table 11
A foot pedal 13 for operating the sewing machine is swingably supported at a lower end portion of the control box 15. An upper end portion of a connecting rod 14 connected to the foot pedal 13 operates the control box 15 attached to the worktable 11. It is connected to a switch (see FIG. 5) 70.

On the front face of the control box 15, a correction sewing setting switch 1 for setting whether or not to execute correction sewing is provided.
6. Correction sewing direction setting switch 17 for setting the cloth feed direction for the correction sewing to forward or backward, needle stop position changeover switch 18 for switching the stop position of the needle bar 4 to needle up or needle down, feed for correction sewing A feed pitch change switch 19 for changing the pitch to a predetermined reduced pitch is provided.

Next, the feed dog driving mechanism 20 for driving the feed dog 42 in the front-rear direction and the vertical direction will be described with reference to FIGS. As shown in FIG. 2, an eccentric cam 22 is fixed to a sewing machine main shaft 21 provided in the arm portion 3, and the upper end of a vertically extending crank rod 23 is rotatable on the eccentric cam 22. Fitted outside. On the other hand, a horizontal feed shaft 24 is rotatably supported by the machine frame F in the bed portion 1, and a swing arm 25 is fixed to the horizontal feed shaft 24. As shown in FIG. A pair of first links 28 are respectively connected between the fixed support shaft 26 and the support shaft 27 fixed to the lower end of the crank rod 23. As shown in FIG. 2, the front ends of a pair of second links 29 are rotatably supported by the support shaft 27, and the rear ends of the second links 29 are connected to a switch 31 by a support shaft 30. Have been. A pulley 32 for manual operation is provided at one end of the main shaft 21 of the sewing machine.

A feed amount setting member 33 provided below the main shaft 21 is rotatably supported by inserting a pivot shaft 34 parallel to the main shaft 21, and is provided at a front end portion of the feed amount setting member 33. Is formed with a bifurcated portion having a substantially rectangular shape in side view, and a pair of upper and lower feed amount adjusting surfaces 35 are formed on the bifurcated portion, respectively. A vertically extending tension spring 36 is stretched between the rear end of the feed amount setting member 33 and the machine frame F, and the feed amount setting member 33 is always elastically urged in the counterclockwise rotation direction in FIG. I have. The rear end of the feed amount setting member 33 is connected to the upper end of a connecting rod 37 extending vertically, and the lower end of the connecting rod 37 is connected to a connecting arm 39 via a pin 38 substantially coaxial with the support shaft 30. The connecting arm 39 is connected to the switch 3
1 is fixed to the left end.

A feed adjusting knob 40 for arbitrarily adjusting the feed amount is provided on the machine frame F of the arm portion 3 with its screw portion 40.
a, and a substantially hemispherical engagement piece 40b formed at the rear end of the feed adjustment knob 40 is connected to the feed amount setting member 33.
Of the feed amount setting member 33, that is, the advance of the feed tooth 42 by the forward or backward movement of the engagement piece 40 b accompanying the turning operation of the feed adjustment knob 40. The cloth feed amount in the cloth feed operation is changed. The feed dog 42 is fixed to a feed base 41 rotatably supported near the left end of the horizontal feed shaft 24. As shown in FIG. 2, the left end of an upper and lower feed shaft 43, which is disposed in parallel with the horizontal feed shaft 24 and swings via an eccentric cam and a connecting rod (not shown) by the rotation of the main shaft 21, has a bifurcated position. The arm 44 is fixed, and the fork 4
1 is engaged, and the feed dog 42 reciprocates in the vertical direction by swinging the vertical feed shaft 43.

Accordingly, the rotation of the main shaft 21 causes the eccentric cam 2 to rotate.
Since the crank rod 23 reciprocates in the vertical direction via the second shaft 2, the first link 28 swings about the support shaft 26 as a center, and the second link 29 and the switch 31 rotate the support shaft 30. Swinging motion as the center. At this time, when the support shaft 30 is not located on the line connecting the support shaft 26 and the support shaft 27, the rotation center position of the two links 28 and 29 is 1
Since they are not on a straight line, a oscillating motion occurs in the oscillating arm 25, and the feed dog 42 via the horizontal feed shaft 24 and the feed base 41.
Moves forward and backward. In addition, the feed dog 42 is moved in the front-rear direction, and reciprocates in the vertical direction by the swing of the vertical feed shaft 43. As a result, the work cloth can be fed in the forward feed direction. Further, the feed adjustment knob 4
By the rotation operation of 0, the feed amount of the forward feed operation can be changed.

Next, a reverse feed mechanism 50 for switching the cloth feed direction of the feed dog 42 from forward feed to reverse feed will be described with reference to FIGS. Below the main shaft 21, the main shaft 2
A feed adjusting shaft 51 parallel to 1 is rotatably supported by the machine frame F, a front end of a connecting lever 52 is fixed to one end of the feed adjusting shaft 51, and is fixed to a rear end of the connecting lever 52. The pin 53 is fitted in a long hole 37 a in the front-rear direction formed in the connecting rod 37. The reverse stitch lever 9 is fixed to the right end of the feed adjusting shaft 51 at the base end.

On the right side of the connecting rod 37, a solenoid (hereinafter, referred to as a first solenoid) 54 is attached to the machine frame F. The front end of the plunger 55 of the first solenoid 54 is fixed to the feed adjusting shaft 51. The connecting arm 56 is rotatably connected to the connecting arm 56. When the first solenoid 54 is not driven, the plunger 55 is retracted into the first solenoid 54 by the spring force of the tension spring 36. Therefore, the feed adjustment shaft 51 is at a predetermined forward feed rotation position, and the connecting rod 37 is moved up and down according to the inclination of the feed amount setting member 33. However, when the first solenoid 54 is driven, its plunger 55 protrudes forward, so that the feed adjusting shaft 51 is connected via the connecting arm 56 in FIG.
At the same time, the connecting rod 37 is moved upward by the upward swing of the connecting lever 52 at the same time. At this time, the connecting rod 37 is
0b moves upward until it engages with the upper feed amount adjusting surface 35 of the feed amount setting member 33.

As a result, the second link 29 and the switch 31
Is changed. That is, since the switch 31 is inclined to the angle for inverting the feed amount as shown in FIG. 3, the support shaft 30 moves above the straight line connecting the support shaft 26 and the support shaft 27, A swinging motion for feeding occurs, and the feed dog 42 moves backward.

Next, the feed pitch changing mechanism 60 for reducing the forward feed amount will be described with reference to FIGS.
On the right side of the feed amount setting member 33, a plate-shaped pitch adjusting plate 61 is rotatably supported by the pivot shaft 34. A feed amount setting member is provided at the lower end of the rear end of the pitch adjusting plate 61. 33
A protrusion 61a is formed at the rear end of the cover 61 so as to be contactable from below. On the other hand, below the pitch adjusting plate 61, a rotary solenoid (hereinafter, referred to as a second solenoid) 62 is attached to the machine frame F via a support plate 64, and a plunger 63 of the second solenoid 62 As shown in FIG. 4, the base end of the drive lever 65 is fixed, and the third link 66 is connected to the tip end of the drive lever 65 and the pitch adjusting plate 61.

Therefore, the second solenoid 62 is driven,
When the drive lever 65 is rotated by a predetermined angle in the counterclockwise direction in FIG. 4, the pitch adjustment plate 61 is rotated clockwise about the pivot shaft 34 via the third link 66. . At this time, the protrusion 61a is
The rear end portion is pivoted upward by a predetermined amount, so that the feed amount setting member 33
As shown by the two-dot chain line in FIG. 4, is rotated to a reduced feed position for reducing the cloth feed amount by the feed dog 42 (for example, about 0.5 mm to 1.0 mm). This is the same as setting the reduction pitch. As a result, regardless of the setting of the feed amount by the rotation operation of the feed adjustment knob 40,
It is forcibly changed to a predetermined reduced pitch.

Next, the control system of the lockstitch sewing machine M is configured as shown in the block diagram of FIG. An operation switch 70 connected to the foot pedal 13, a correction sewing switch 6, a timing signal generator 71 for generating various timing signals such as a needle up position and a needle down position, a correction sewing setting switch 16, a correction sewing A direction setting switch 17,
The needle stop position changeover switch 18 and the feed pitch change switch 19 are respectively connected to the input / output interface 75 of the control device C. Here, the operation switch 70 outputs a drive stop signal for the sewing machine motor 12 to the neutral position of the foot pedal 13, and outputs a drive signal for the sewing machine motor 12 in response to the front depression of the foot pedal 13. The reverse feed setting means of this embodiment comprises a correction sewing setting switch 16 and a correction sewing direction setting switch 17. The input / output interface 75
Are connected to a drive circuit 72 for the sewing machine motor 12, a drive circuit 73 for the first solenoid 54, and a drive circuit 74 for the second solenoid 62, respectively.

The control device C comprises a CPU 76 and this CPU
An input / output interface 75 connected to a data bus 76 via a bus 80 such as a data bus;
And 8. The ROM 77 stores a drive control program for driving the sewing machine motor 12 based on a drive signal or a drive stop signal from the operation switch 70, a control program for correction sewing control unique to the present invention, which will be described later, and the like.

The RAM 78 has a correction sewing setting switch 1
The flag data of the correction sewing flag HF that is set (data of “1”) when the No. 6 is switched to the “execution” side and reset (“0” data) when the No. 6 is switched to the “non-execution” side; Set the correction sewing direction setting switch 17 to “reverse feed”.
The flag data of the correction sewing direction flag DF, which is set when switching to the "forward" side, and reset when switching to the "forward" side, and set when the needle stop position changeover switch 18 is switched to the "needle up" side. The flag data of the needle stop position flag PF, which is reset when switching to the "needle down" side, is set when the feed pitch change switch 19 is switched to the "change" side, and is switched to the "no change" side. There are provided a flag memory for storing flag data of the feed pitch change flag CF which is reset at the time, a work memory for storing the operation result calculated by the CPU 76 and various memories such as a counter and a pointer.

Next, a routine of the correction sewing control performed by the control device C of the lockstitch sewing machine M will be described with reference to a flowchart of FIG. In the figure, reference symbol Si (i = 3)
0, 31, 32,...) Are each step. Here, as a stage before starting this control, each of the switches 16 to 1 is executed by a flag data setting control program (not shown).
It is assumed that every time 9 is switched, the flag data of each flag HF, DF, PF, CF is updated and set each time based on the switching position.

When the correction sewing switch 6 is operated while the foot pedal 13 is switched to the neutral position and the driving of the sewing machine motor 12 is stopped, this control is started. First, based on the flag data in the flag memory, the control is started. When the correction sewing flag HF is set (S30: Yes) and the correction sewing direction flag DF is set (S30).
31: Yes), the first solenoid 54 is driven (S
32). As a result, as described above, the switch 31 is tilted to the reverse feed position shown by the two-dot chain line in FIG. 3 via the reverse feed mechanism 50. Next, the sewing machine motor 12 is driven at a low speed (S35), and the correction sewing is started by the reverse feed operation of the feed dog 42.

Next, when the needle stop position flag PF is set, that is, when this correction sewing is started from the needle upper position (S36: Yes), the timing signal output from the timing signal generator 71 When the signal is the next needle up timing (S37: Yes),
Since the correction sewing by the reverse feed for one stitch has been completed, the driving of the sewing machine motor 12 is stopped (S38), and the driving of the first solenoid 54 and the second solenoid 62 is stopped (S39). At this time, if the correction sewing switch 6 has not been operated (S40: No), this control ends. Therefore, every time the correction sewing switch 6 is operated, the correction sewing by the reverse feed of one stitch is performed. When the correction sewing switch 6 is continuously operated (S40: Yes), S30 and the subsequent steps are repeated. When the correction sewing switch 6 is no longer operated (S40: No), the control is terminated.

When the sewing machine motor 12 is driven at a low speed and the needle stop position flag PF is reset, that is, when the correction sewing is started from the needle lower position (S36: No), the output is performed. When the signal is the next needle down timing on the basis of the timing signal
41: Yes) Since the correction stitching for one stitch has been completed, the driving of the sewing machine motor 12 is stopped (S3).
8) The driving of both solenoids 54 and 62 is stopped (S3
9), this control ends.

On the other hand, when the correction sewing flag HF is set (S30: Yes), but the correction sewing direction flag DF is reset, that is, in the case of correction sewing of forward feed (S31: No), the feed pitch is changed. When the flag CF is reset, that is, when the feed pitch is not changed (S33: No), S35 and subsequent steps are executed, and the correction stitching by the forward feed for one stitch is performed.

However, in the case of forward stitching correction sewing (S
31: No), when the feed pitch change flag CF is set, that is, when the feed pitch is changed (S3)
3 :: Yes), the second solenoid 62 is driven (S
34). As a result, as described above, the feed amount setting member 33 is rotated to the reduced feed position via the feed pitch changing mechanism 60, and the forward feed is performed at a predetermined reduced pitch with the low-speed driving of the sewing machine motor 12 after S35. Is executed for one stitch. When the control is started and the correction sewing flag HF is reset (S30: No), the control is immediately terminated.

As described above, when the correction sewing direction flag DF is set when the correction sewing switch 6 provided on the head of the arm 3 is operated, the correction sewing for one stitch is performed by the reverse feed. Is executed. Further, when the correction sewing direction flag DF is reset, the correction sewing for one stitch is executed by the forward feed. Therefore, it is possible to perform the correction sewing in units of one stitch while securely holding the work cloth with both hands during the correction sewing of the forward feed or the reverse feed, and it is possible to greatly improve the operability of the correction sewing.

The reverse feed mechanism 50 and the feed pitch changing mechanism 60 are merely examples, and may have various structures. The feed dog driving mechanism 20 is configured to generate the reciprocating motion of the feed dog by the rotation angle of the square piece, and is configured to reverse the inclination direction of the square piece by the electric actuator of the reverse feed mechanism 50. You may.

[0035]

As described above in detail, according to the sewing machine reverse feed stitching control apparatus of the present invention, the reverse feed stitching means, the correction stitching instruction means, and the reverse feed stitching control means are provided, and the correction sewing instruction is provided. When the reverse feed mode is set when the correct sewing is instructed by the means, the correct sewing for one stitch is executed by the reverse feed, and when the reverse feed mode is not set, the correct stitch by one stitch by the normal feed. Is executed, the correction sewing can be performed in units of one stitch while securely holding the work cloth with both hands during the correction sewing, and the operability of the correction sewing can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an industrial lockstitch sewing machine.

FIG. 2 is a schematic perspective view showing an internal mechanism of the lockstitch sewing machine.

FIG. 3 is a vertical sectional side view of a main part showing a reverse feed mechanism in an internal mechanism of the lockstitch sewing machine.

FIG. 4 is a vertical sectional side view of a main part showing a feed pitch changing mechanism in an internal mechanism of the lockstitch sewing machine.

FIG. 5 is a block diagram of a control system of the lockstitch sewing machine.

FIG. 6 is a schematic flowchart of a routine of correction sewing control.

[Explanation of symbols]

 M Lockstitch sewing machine 6 Correction sewing switch 12 Sewing machine motor 16 Correction sewing setting switch 17 Correction sewing direction setting switch 20 Feed dog drive mechanism 23 Crack rod 24 Horizontal feed shaft 31 Switch 37 Connecting rod 42 Feed dog 43 Vertical feed shaft 50 Reverse feed Mechanism 51 Feed adjustment shaft 52 Connecting lever 54 First solenoid 76 CPU 77 ROM 78 RAM C Controller

Claims (3)

(57) [Claims] 1. A sewing machine comprising: a cloth feed mechanism for feeding a work cloth; a reverse feed mechanism for reversing a cloth feed direction of the cloth feed mechanism; and an electric actuator for driving the reverse feed mechanism. Reverse feed setting means for setting a reverse feed mode in which the feed mechanism is operated via an electric actuator; correction sewing instruction means for instructing correction sewing for one stitch by the sewing machine; and correction in the reverse feed mode. A reverse feed stitching control device for a sewing machine, comprising: a reverse feed stitching control means for controlling a sewing motor so as to perform reverse feed stitching for one stitch when a correction stitch is instructed by the sewing instructing means. 2. The cloth feed mechanism has a feed amount variable mechanism for changing a feed amount via a square piece, and the reverse feed mechanism is configured to reverse a tilt direction of the square piece by a driving force of an electric actuator. 2. The reverse feed stitching control device for a sewing machine according to claim 1, wherein: 3. The reverse feed stitching control means returns to a position set by a needle position setting switch based on a detection signal from a detection switch for detecting a position of a needle bar after reverse stitching for one stitch. The reverse feed sewing control device for a sewing machine according to claim 1, wherein the needle bar is stopped.