JPH05277273A - Cloth end position control device for sewing machine - Google Patents

Abstract

PURPOSE:To accurately detect the end position of a cloth to be processed, and feed the cloth without any influence by a fluff and a notch existing at the end of the cloth. CONSTITUTION:The notch N of a cloth W to be processed can be detected with a notch detecting sensor 26 laid at a position along the width W of the cloth, relative to a cloth end near both sides of a cloth end detecting sensor 24. Also, a fluff K extending from the end of the cloth W can be detected with a fluff detecting sensor 28 laid at a position opposite to the cloth W, relative to a cloth end near both ends of the sensor 24. As a result, the end of the cloth W can be detected with the sensor 24 without any influence by the notch N and fluff K and on the basis of the detected cloth end, the cloth W is caused to move on the operation of a cloth travel motor, so that the end of the cloth W is faced to the vicinity of the bed surface of a sewing machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth edge position control device for a sewing machine, and more particularly to a cloth edge detecting sensor for detecting a cloth edge of a work cloth, a notch detecting sensor and a fluff detecting sensor. And (3) are additionally provided to accurately detect the cloth edge position without being affected by notches and fluff.

[0002]

2. Description of the Related Art Heretofore, various electronic sewing machines have been proposed and put into practical use, which detect a cloth edge of a work cloth with a cloth edge detecting sensor and follow a sewing position at a predetermined distance from the cloth edge. There is. By the way, when the body cloth cut based on the pattern is sewn along the cloth edge, the body edge of the body cloth often has a fluff extending from the body cloth. When the profile stitch is sewn along the edge of the cloth, it is not possible to perform accurate profile stitching on the edge of the cloth having the fluff, so a cloth edge position control device for detecting the edge of the cloth without being affected by the fluff is proposed. There is.

For example, as described in Japanese Patent Publication No. 60-28516, when the light receiving amount of the cloth edge detecting sensor is smaller than a preset light receiving amount due to fluff,
Reduce the amplification factor of the drive voltage that drives the motor for moving the work cloth in the direction orthogonal to the cloth feed direction, and increase the amplification factor of the drive voltage when the received light amount exceeds the preset value. As a result, a cloth edge position control device has been proposed which enables copy stitching without being affected by fluff.

[0004]

By the way, in general, not only fluffs but also notches (triangular notches) necessary for sewing are formed on the cloth edge portion of the body cloth cut based on the pattern paper. In many cases. That is, Japanese Patent Publication 60-285
In the cloth edge position control device described in No. 16, the copying sewing can be performed without being affected by the fluff, but when the light receiving amount of the cloth edge detecting sensor is increased due to the notch, the amplification factor of the drive voltage is largely controlled. Therefore, there is a problem that the work cloth largely moves to the side opposite to the work cloth, and accurate copy stitching cannot be performed on the cloth end portion having the notch.

The present invention has been made to solve the above problems, and its purpose is to accurately detect the cloth edge position without being affected by fluff and notches existing at the cloth edge of the work cloth. An object of the present invention is to provide a cloth edge position control device for such a sewing machine.

[0006]

In order to achieve the above object, a cloth edge position controller for a sewing machine according to the present invention controls the position of a cloth edge of a work cloth sewn by a sewing machine, which is substantially parallel to the cloth feeding direction. In order to do so, the cloth edge detection sensor is provided near the bed surface of the sewing machine so as to face the cloth edge of the cloth, and the cloth on the bed can be driven to move in the direction orthogonal to the cloth feed direction. A cloth moving means, and a control means for controlling the cloth moving means based on a detection signal from the cloth edge detecting sensor so that the cloth edge becomes a predetermined position set in advance with respect to the cloth edge detecting sensor, Further, among the positions near both sides of the cloth edge detection sensor, a notch detection sensor for detecting the notch of the work cloth at a position on the work cloth side with respect to the cloth end and a position on the opposite side to the work cloth with respect to the cloth end. , And a fluff detection sensor for detecting fluff extending from the edge of the work cloth, respectively. Those digits.

The control means may be configured to correct the detection signal from the cloth edge detection sensor based on the detection signal from the notch detection sensor and the detection signal from the fluff detection sensor. ..

[0008]

In the cloth edge position control device for a sewing machine of the present invention having the above-described structure, among the adjacent positions on both sides of the cloth edge detection sensor provided near the bed surface of the sewing machine so as to face the cloth edge of the work cloth. The notch detection sensor provided at the position on the side of the work cloth with respect to the cloth edge surely detects the notch of the work cloth. Then, the fluff detection sensor provided at the position opposite to the work cloth with respect to the cloth end reliably detects the fluff extending from the cloth end of the work cloth. This makes it possible to reliably control the cloth edge position of the work cloth to a predetermined reference position without being affected by these notches and fluffs.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is a case where the present invention is applied to an industrial lockstitch sewing machine. Since this lockstitch sewing machine M has the same structure as a known sewing machine provided with a sewing machine bed portion, a pedestal portion, an arm portion, and the like, a main part relating to the present invention will be described. As shown in FIGS. 1 and 2, a thin plate-like cloth base 14 on which a work cloth W is placed is disposed on the bed surface of the bed portion 10, and a front view is substantially L.
A cloth-shaped edge detector 20 is arranged, and this cloth-edge detector 20
Is fixed to the machine frame 18. The upper wall portion 20a of the cloth edge detector 20 faces the upper side of the cloth base 14, and the cloth edge detector 2
A portion of the cloth base 14 substantially facing 0 is cut out, and a thin plate-shaped reflection plate 16 is provided in the cutout portion at the same level as the cloth base 14.

On the lower surface side of the upper wall portion 20a, as shown in FIG. 2, a cloth detection sensor 22 for detecting the presence or absence of the work cloth W, and a cloth end for detecting the cloth end of the work cloth W. In addition to the detection sensor 24, a notch detection sensor 26 for detecting the notch N of the work cloth W is provided at a position near the work cloth W side with respect to the cloth edge detection sensor 24.
Further, a fluff detection sensor 28 for detecting a fluff K extending from the cloth edge of the work cloth W is provided in the vicinity of the cloth end detection sensor 24 on the opposite side to the work cloth W, and further,
The cloth edge detecting sensor 24, the notch detecting sensor 26, and the fluff detecting sensor 28 are provided with a projector 30 for projecting the irradiation light through the reflection plate 16, and a projector 32 for projecting the irradiation light to the cloth detection sensor 22. ing.

The cloth edge detecting sensor 24 is formed in a substantially square shape in a plan view, and has a notch detecting sensor 26 and a fluff detecting sensor 2.
The reference numeral 8 is formed in a substantially rectangular shape in plan view so that the notch N and the fluff K can be reliably detected. Although not shown, the bed 10 is provided with a feed dog up-and-down moving mechanism for moving the feed dog up and down, a feed dog forward-backward moving mechanism for moving back and forth, and a thread catcher. The cloth detection sensor 22, the cloth edge detection sensor 24, the notch detection sensor 26, and the fluff detection sensor 2
8 is a phototransistor, and the projectors 30 and 32 are light emitting diodes.

A needle bar 40 and a presser bar (not shown) are movably supported on the head 12 of the arm portion, and a presser foot (not shown) is attached to the lower end of the presser bar. A sewing needle 42 is attached to the lower end of the needle bar 40.
Although not shown, the arm portion is provided with a needle bar vertical movement mechanism for moving the needle bar 40 up and down, a balance drive mechanism for swinging the balance, and the like.

Next, the cloth moving mechanism 50 for moving and driving the work cloth W on the cloth table 14 in the lateral direction E orthogonal to the cloth feeding direction A will be described with reference to FIGS. A cloth moving motor 52 is disposed in the head portion 12 in the front-rear direction, and a drive shaft 52a thereof projects forward from the head portion 12. A drive pulley 54 is fixed to the drive shaft 52a, and upper and lower ends of a pair of front and rear swing plates 56 located on the front side and the rear side of the drive pulley 54 are rotatably supported by the drive shaft 52a. .. The pair of rocking plates 56 are integrally connected by a connecting plate 58, a driven roller 60 is rotatably supported at the lower end portion thereof, and a belt 62 is stretched around the drive pulley 54 and the driven roller 60. There is.

The lower free end of the swing lever 64, which is pivotally supported by the machine frame 18 immediately above the cloth moving motor 52 and is substantially L-shaped in front view, is connected to a connecting plate 58. The free end of the other end is connected to the plunger of the solenoid 66 attached to the machine frame 18. Further, the swing spring 64, one end of which is locked to the machine frame 18 and the other end of which is locked to the swing lever 64, elastically biases the swing lever 64 in the counterclockwise direction in FIG. The driven roller 60 presses the work cloth W on the cloth base 14 through the rocking of the pair of rocking plates 56 connected to the moving lever 64. Here, on the outer peripheral surface of the driven roller 60, the work cloth W can be reliably moved in the lateral direction E as shown in FIG.
Unevenness (jagged) is formed.

Therefore, when the solenoid 66 is driven, its plunger moves downward and the swing lever 6 is moved.
Since 4 rotates in the clockwise direction by a predetermined angle, the swing plate 56 and the driven roller 60 simultaneously swing to the swing position indicated by the chain double-dashed line, and the driven roller 60 is separated from the work cloth W.
On the other hand, when the driving of the solenoid 66 is stopped, the swing lever 64 is rotated in the counterclockwise direction by the winding spring 68, and the driven roller 60 presses the work cloth W downward by the spring force of the winding spring 68. .. At this time, the cloth moving motor 5
2 is driven, the belt 62 and the driven roller 6
With the rotation of 0, the work cloth W is moved in the lateral direction E according to the rotation amount of the motor 52. As a result, the cloth edge detecting sensor 24
The cloth edge of the work cloth W corresponding to the sewing needle 42 moves rightward or leftward in FIG. 2 in cooperation with the cloth feeding operation of the work cloth W. The needle drop position of the sewing needle 42 in FIG. 2 is indicated by P _N.

Next, the control system of the lockstitch sewing machine M is constructed as shown in the block diagram of FIG. Start / stop switch 7 for instructing to drive and stop the sewing machine motor 75
0, an A / D converter 71 for A / D converting the detection signal (voltage signal) from the cloth detection sensor 22, and the cloth edge detection sensor 2
A / D for A / D conversion of cloth edge signal (voltage signal) from 4
The converter 72, the A / D converter 73 for A / D converting the notch signal (voltage signal) from the notch detection sensor 26, and the A / D conversion of the fluff signal (voltage signal) from the fluff detection sensor 28.
The A / D converter 74 for conversion is connected to the input / output interface 80 of the controller C, respectively. Further, the input / output interface 80 includes a drive circuit 76 for the sewing machine motor 75, a drive circuit 77 for the cloth moving motor 52,
A drive circuit 78 for the solenoid 66 is connected to each.

Further, the control device C has a CPU 81, an input / output interface 80, a ROM 82 and an RA connected to the CPU 81 via a bus 84 such as a data bus.
It is composed of M83. In ROM 82,
A drive control program for driving the sewing machine motor 75 based on a start / stop command from the stop switch 70, a control program for the cloth edge position control peculiar to the present application, which will be described later, and the like are stored.

The RAM 83 has a detection signal V _S from the cloth detection sensor 22 and a cloth end signal V _E from the cloth end detection sensor 24.
A work memory for storing the notch signal V _N from the notch detection sensor 26, the flicker signal V _K from the fluff detection sensor 28, and various memories for temporarily storing the calculation result calculated by the CPU 81 are provided.

It should be noted that the detection signal V _S is obtained by the cloth detection sensor 2
2 corresponds to 0 V when the amount of light received by 0 is 0%, and the cloth edge signal V _E is about 50% when the amount of light received by the cloth edge detection sensor 24 (as shown in FIG. When the central position of the sensor 24, that is, the reference position P0 is covered with the work cloth W), it is calculated by calculation control (not shown) so as to correspond to 0V. Further, the notch signal V _N is 0 V when the amount of light received by the notch detection sensor 26 is 0%.
In addition, the flash signal V _K is calculated by calculation control (not shown) so as to correspond to 0 V when the light amount received by the flash detection sensor 28 is 100%.

Next, the cloth edge position control routine executed by the controller C of the sewing machine M will be described with reference to FIGS. 5 to 8 based on the flowchart of FIG. In the figure, reference numeral Si (i = 10, 11, 12, ...) Indicates each step. By the way, the outline of the cloth edge position control will be described. When the cloth edge of the work cloth W has no fluff K or notch N and the cloth edge moves to the opposite side of the work cloth W, as shown in FIG. , Flash signal V _K and notch signal V _N
Since there is no change in (0V) and the cloth edge signal V _E decreases,
Based on this reduced cloth edge signal V _E , the cloth moving motor 52
Is driven in the normal direction to move the work cloth W to the work cloth side. Similarly, when there is no fluff K or notch N at the cloth edge and the cloth edge has moved to the work cloth side, as shown in FIG.
There is no change in _K or notch signal V _N (0 V), and cloth end signal V
_{Since E} increases, the cloth moving motor 52 is reversely driven based on the increased cloth end signal V _E , and the work cloth W is moved to the opposite side of the work cloth W. However, the allowable range of the cloth edge control is that the output voltage of the cloth edge signal V _E is 3V ≧ V _E ≧ −3V,
If it is outside the allowable range, the sewing machine and the cloth moving motor 52 are stopped.

On the other hand, when the cloth edge has a fluff K,
As shown in FIG. 7, the fluff signal V _K of the fluff detection sensor 28
And the cloth edge signal V _E respectively decrease, and the notch signal V _N does not change. At this time, the cloth edge signal V _E has not changed, that is, is corrected as “0 V”, and the work cloth W is not moved. Similarly, when the cloth end portion has a notch N, as shown in FIG.
, The notch signal V _N of the notch detection sensor 26
And the cloth edge signal V _E respectively increase, and the flicker signal V _K does not change. Also at this time, the cloth edge signal V _E is not changed, that is, is corrected as “0 V”, and the work cloth W is not moved.

When the sewing machine M is turned on, this control is started and the solenoid 66 is driven first (S1).
0). Therefore, as described above, the swing plate 56 and the driven roller 60 swing to the swing position shown by the two-dot chain line in FIG. 1, and the driven roller 60 separates from the work cloth W. Next, as shown in FIG. 1, when the work cloth W is set by inserting it on the cloth table 14 deeper than the reference position P0 of the cloth end detection sensor 24, the detection signal V _S ≈0 V, the cloth end signal V _E ≤ 0 V (S1
(1: Yes, S12: Yes), the driving of the solenoid 66 is stopped (S13). As a result, as mentioned above,
The driven roller 60 descends and presses the work cloth W by the spring force of the winding spring 68.

Next, the sewing machine motor 75 is driven (S1
4), each cloth edge signal V _E , fluff signal V _K, and notch signal V _N
And the detection signal V _S are read and stored in the work memory (S15). Next, when the deviation of the cloth edge is within the allowable range based on the cloth edge signal V _E (S16: Yes), the sewing point is not the end portion of the work cloth W (S17: No), and the fluff K exists. That is, when the flash signal V _K <0 V (S18: Yes), the cloth edge displacement amount d is calculated (S18).
19). Here, as shown in FIG.
The length of 8 is Hk, its width is Sk, the length of the cloth edge detection sensor 24 is Eh, its width is Ew, the displacement amount of the cloth edge from the reference position P0 is d, and the average width of the fluff K is Kw, A calculation for obtaining the cloth edge displacement amount d will be described. The drive voltage E of the cloth moving motor 52 at the time of detecting the fluff K is basically the drive voltage Ek at the time of detecting the fluff K = cloth edge signal V _E −A
-It is obtained by the flicker signal V _K. A is a constant.

First, the cloth edge signal V _E and the fluff signal V _{K that} are output are proportional to the areas of the cloth edge detection sensor 24 and the sensor portion of the fluff detection sensor 28 covered with the fluff K. , And the covered area is M, the driving voltage E
k = G · M. Therefore, the drive voltage Ek at the time of detecting the fluff K is obtained by the following equation. Ek = G {-Kw (Ew / 2-d) -d * Eh-A * Kw * Sk} ... (1 expression). Here, A is a constant, and this constant A is A = Ew / (2 · Sk) according to the equation 1 under the condition that the drive voltage Ek = 0 when the cloth edge displacement amount d = 0. Substituting the value of the constant A into the equation 1, Ek = G {-d * Eh-Kw (Ew / 2-d) + Ew * Kw / 2}, that is, Ek = G {-d (Eh-Kw). } (Equation 2)

Here, the drive voltage Ek is related to the width Kw of the fluff K, and Kw = flicker signal V _K / Sk, so Ek = G
[-D · Eh {1-flicker signal V _K / (Eh · Sk)}]
.. (3 types) That is, G, Eh, Sk, and Sn are constants, respectively, and the driving voltage Ek and the flicker signal V _K are also obtained, so that the cloth edge displacement amount d is obtained by the equation (3). next,
The drive voltage E is calculated according to the cloth edge displacement amount d (S
20). That is, the drive voltage E = for driving the motor 52
It is calculated by G (-d · Eh). Then, the drive voltage E drives the cloth moving motor 52 in the forward direction or in the reverse direction for a predetermined time (S21), and the process returns to S15.

Next, when the notch N exists based on the read cloth edge signal V _E , the fluff signal V _K , the notch signal V _N and the detection signal V _S , that is, when the notch signal V _N > 0V. (S15, S16: Yes, S17, S18: N
o, S22: Yes), the cloth edge displacement amount d is calculated (S
23). Here, as shown in FIG. 10, the length of the notch detection sensor 26 is Hn, the width thereof is Sn, the average width of the notch N in the cloth edge detection sensor 24 is Nw, and the average width of the notch N in the notch detection sensor 26 is Ns cloth edge reference position P
A calculation for obtaining the cloth edge displacement amount d will be described with the displacement amount from 0 as d. The drive voltage E of the cloth moving motor 52 when the notch N is detected is basically obtained by the drive voltage En when the notch N is detected = cloth edge signal V _E −B · notch signal V _N. B is a constant.

As described above, the output cloth end signal V _E
Since the notch signal V _N and the notch signal V _N are proportional to the areas of the cloth edge portion and the sensor portions of the cloth edge detecting sensor 24 and the notch detecting sensor 26 covered with the notch N, if the covered area is M, the driving voltage is En = G · M. Therefore, the drive voltage En at the time of detecting the notch N is En = G {Nw (Ew
/ 2 + d) -d (Eh-Nw) -B * Sn * Ns} ...
(Formula 4) Here, B is a constant, and this constant B is B = Ew · Nw / (2 · Ns · Sn) from the condition that the drive voltage En = 0 when the cloth edge displacement amount d = 0, according to the equation (4). ). By substituting the value of the constant B into the equation 4, En = G {-d (Eh-2 · Nw)} ... (Equation 5) is obtained.

Here, the driving voltage En is the width Nw of the notch N.
And Nw / Ns = r (average width of notch), Nw = r · notch signal V _N / Sn, so En = G
[-D · Eh {1-2 · r · notch signal V _N / (Eh ·
Sn)}] ... (Equation 6) That is, G, Eh, and Sn are constants, respectively, and the drive voltage En and the notch signal V _N are also obtained. Therefore, the cloth edge displacement amount d can be obtained by Equation 6. Next, in the same manner, the drive voltage E corresponding to the cloth edge displacement amount d is calculated (S20), and the cloth moving motor 52 is driven to rotate in the forward direction or the reverse direction for a predetermined time (S21). Return to S15.

On the other hand, when there is no fluff K or notch N based on the read cloth edge signal V _E , fluff signal V _K , notch signal V _N and detection signal V _S , that is, fluff signal V _K ≈
When 0 V and notch signal V _N ≈0 V (S15, S1
6: Yes, S17, S18, S22: No), and similarly, the cloth edge displacement amount d is calculated (S24). In this case,
For example, the flicker signal V _K = 0V is obtained by the above equation 3. Then, the process returns to S15 through S20 and S21. In this case, S24 and S20 may be skipped and the cloth moving motor 52 may be driven by the drive voltage E proportional to the cloth edge signal V _E.

By the way, when the deviation of the cloth edge is out of the allowable range (S16: No) or when the sewing point is the end portion of the work cloth W (S17: Yes), the driving of the sewing machine motor 75 is stopped (S25). , And returns to S10.

As described above, the cloth edge detecting sensor 24
A notch detection sensor 26 for detecting the notch N of the work cloth W is provided at a position on the work cloth side with respect to the cloth end among the positions in the vicinity of both sides of the work edge, and the position is opposite to the work cloth W with respect to the work edge. Since the fluff detection sensor 28 for detecting the fluff K of the cloth W is provided, the fluff K and the notch N can be surely detected by both of these detection sensors 26 and 28, and the cloth edge position is not affected by the fluff K and the notch N. Can be accurately position controlled.

The cloth moving mechanism 50 is merely an example.
It may be configured using various members.
The shapes of the cloth edge detecting sensor 24, the notch detecting sensor 26, and the fluff detecting sensor 28 are not limited to the rectangular shape. Instead of the control device C, the cloth edge position control device may be composed of an electronic circuit including a comparator and a resistor. The cloth edge detection sensor 24, the notch detection sensor 26, and the fluff detection sensor 28 may be configured by combining a plurality of small optical sensors.

[0033]

As described above in detail, according to the cloth edge position control device for a sewing machine of the present invention, the work cloth is located at a position on the work cloth side with respect to the cloth edge among the positions on both sides of the cloth edge detection sensor. Notch detection sensor that detects the notch of
Since a fluff detection sensor that detects fluff of the work cloth is provided at a position opposite to the work cloth with respect to the cloth edge, both of these detection sensors can reliably detect the fluff and notch, and affect these fluff and notch. Without this, the cloth edge position can be accurately detected.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional front view of essential parts of a lockstitch sewing machine.

FIG. 2 is a partial plan view of a sewing machine bed section.

FIG. 3 is a block diagram of a control system of a lockstitch sewing machine.

FIG. 4 is a schematic flowchart of a cloth edge position control routine.

FIG. 5 is a time chart of each detection signal of the cloth edge detector when the cloth edge of the work cloth moves to the side opposite to the work cloth.

FIG. 6 is a diagram when the cloth edge of the work cloth moves to the work cloth side.
FIG.

FIG. 7 is a view corresponding to FIG. 5 when a fluff of the work cloth is detected.

FIG. 8 is a view corresponding to FIG. 5 when the notch of the work cloth is detected.

FIG. 9 is an explanatory diagram for controlling the cloth edge position by ignoring the presence of fluff.

FIG. 10 is an explanatory diagram for controlling the cloth edge position by ignoring the presence of notches.

[Explanation of symbols]

 M Lockstitch sewing machine 20 Cloth edge detector 24 Cloth edge detection sensor 26 Notch detection sensor 28 Flank detection sensor 50 Cloth moving mechanism 52 Cloth moving motor 54 Drive pulley 60 Driven roller 62 Belt 81 CPU 82 ROM 83 RAM

Claims (2)

[Claims] 1. In order to control the position of the cloth edge of the work cloth sewn by the sewing machine in a direction substantially parallel to the cloth feed direction, the sewing machine is provided near the bed surface of the sewing machine so as to face the cloth end of the work cloth. Based on a cloth edge detection sensor, cloth moving means capable of driving the work cloth on the bed surface in the direction orthogonal to the cloth feed direction and the detection signal from the cloth edge detection sensor, the cloth edge is detected. A cloth edge position control device for a sewing machine, comprising: a control means for controlling the cloth moving means so that the cloth edge is located at a predetermined position set in advance with respect to the detection sensor. The notch detection sensor that detects the notch of the work cloth at the position on the work cloth side and the position opposite to the work cloth with respect to the cloth end, and the fluff detection that detects fluff extending from the cloth end of the work cloth. Edge position of the sewing machine characterized by being provided with a sensor for each The control device. 2. The control means is configured to correct the detection signal from the cloth edge detection sensor based on the detection signal from the notch detection sensor and the detection signal from the fluff detection sensor. The cloth edge position control device for a sewing machine according to claim 1, which is characterized in that.