JP2681947B2 - Sewing machine actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an operating device of a sewing machine which detects an end portion of a work cloth and starts stitch formation from the end portion. is there. (Prior Art) Conventionally, for example, in a bead sewing machine, when a flap cloth is sewn together with a bead cloth on a cherry blossom cloth, a cloth sensor arranged at a predetermined distance from the needle passing point to the cloth feeding side. The seam formation is started from the time when the edge of the flap cloth is detected and the work cloths are integrally transferred by the predetermined distance after the detection. (Problems to be solved by the invention) However, in this conventional sewing machine, stitch formation is always started when the work cloth for a predetermined distance is transferred after the detection signal is output from the cloth sensor. Therefore, if there is a foreign substance such as dust in front of the edge of the flap cloth and the foreign substance is detected by the cloth sensor, the stitches will be separated by a predetermined distance from the detection point. However, there is a problem in that the formation of stitches does not start accurately from the end of the flap cloth. Structure of the Invention (Means for Solving the Problems) The present invention has been made in view of the above problems, and stitch formation including needles for forming stitches on a work cloth. A device, a cloth feeding device for transferring the work cloth through the passing point of the needle, a cloth pressing body which presses and holds the work cloth and through which a detection window is formed, and a passing point of the needle. It is arranged at a certain distance on the cloth feeding side,
The cloth is within the range from the time when the front end of the detection window reaches the cloth detection position to the time when the rear end of the detection window reaches the cloth detection position and when the work cloth is present in the detection window. When a cloth sensor that outputs a detection signal, and the end of the work cloth is fed to the passing point of the needle by the operation of the cloth feeding device,
First control means for operating and controlling the stitch forming device so that the stitch formation is started when the work cloth is transferred by the predetermined distance after the cloth detection signal is output from the cloth sensor. In response to the cloth detection signal from the cloth sensor, is the cloth detection signal continuously output from the cloth sensor while the work cloth is transported by the predetermined distance after the detection signal is output? If it is determined that the cloth detection signal is interrupted while the cloth is conveyed by the predetermined distance, the operation control of the stitch forming device by the first control means is invalidated, and the cloth is detected. The feeding device is controlled so as to wait for the cloth detection signal to be generated from the cloth sensor without making an emergency stop, and when the cloth sensor always outputs an incorrect cloth detection signal immediately after the start of the judgment operation, or when the judgment operation is performed. From the start of It is obtained by a second control means for controlling so as to emergency stop the cloth feed device when the fabric detection signal from the fabric sensor is not outputted by the end. (Operation) Therefore, in the sewing machine actuating device of the present invention, if there is a foreign substance such as dust in front of the end of the work cloth and the foreign substance is detected by the cloth sensor, the detection signal is output. Since the detection signal from the cloth sensor is interrupted while the work cloth is transferred by the predetermined distance, the stitch formation is not started even if the work cloth is transferred by the predetermined distance, and the cloth sensor is not used thereafter. Based on the detection of the end portion of the work cloth by, the stitches start to be formed at a predetermined distance. Therefore, even if foreign matter such as dust is present in front of the edge of the work cloth and a detection signal is temporarily output from the cloth sensor, there is no risk of accidentally forming stitches. It is possible to reliably detect the portion and accurately start the stitch formation from the end portion of the work cloth. Also, within the range from the time when the front end of the detection window reaches the cloth detection position to the time when the rear end of the detection window reaches the cloth detection position, and there is a work cloth in the detection window. Since the cloth sensor performs the detection when the cloth is pressed, the cloth sensor does not mistake the cloth pressing body for the work cloth, and the accurate stitch formation can be realized. Further, the second control means causes the cloth feeding device to make an emergency stop only when the emergency stop is really necessary, but does not make the emergency stop when the emergency stop is not so necessary, for example, when foreign matter is present. Control is performed so as to wait for the generation of the cloth detection signal from. Therefore, when resuming work after an emergency stop due to the presence of foreign matter, there is no need for the operator to reset and restart the emergency stop state by a switch operation, and thus workability can be prevented from lowering. . (Embodiment) Hereinafter, an embodiment of a bead stitch sewing machine embodying the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the sewing machine main body 1 is arranged on a sewing machine table 2. The needle bar 3 is provided on an arm portion of the sewing machine main body 1 so as to be vertically movable, and two needles 4 are attached to a lower end thereof. Then, the needle 4 constitutes a stitch forming device together with a thread catcher (not shown) provided in the head portion of the sewing machine main body 1, and the cooperation between the needle 4 and the work cloth causes 2
Parallel lock stitches of the book are formed. As shown in FIGS. 1 and 2, the clamp device 5 which constitutes the cloth feeding device is mounted on the sewing machine table 2 as follows.
It is movably arranged along a straight line passing through the preparation position on the front side of the needle 4 and the stitch forming position near the passage point of the needle 4. As is well known in the art, the clamp device 5 includes a pair of up-and-down movable presser plates 6 for pressing and holding the time cloth W1 as a work cloth on the surface of the table 2, and the work cloth placed on the time cloth W1. Wedge cloth W2 is folded from both sides and the best time cloth W1
A pair of laterally openable and closable folding plates 7 that are held above, and a pair of vertically movable fabrics that press and hold the flap cloth W3 as a work cloth placed on the beaded cloth W2 on the folding boards 7. A flap pressing body 8 as a pressing body is provided. The binder 9 is arranged above the sewing table 2 so as to be able to move up and down so as to extend from the preparation position of the clamp device 5 over the stitch forming device. As is well known in the art, the binder 9 has a substantially inverted T-shaped cross section, and
After the beaded cloth W2 is placed on W1, it is lowered onto the beaded cloth W2 prior to the folding operation of the folding plate 7 so that the beaded cloth W2 is pressed and held on the cloth W1. Has become. Then, in the state where the clamp device 5 is moved to the preparation position shown by the chain line in FIG. 1, the large presser plate 6, the folding plate 7, the flap presser body 8 and the binder 9 cooperate with each other. As shown in FIG. 3, the full bloom W1, the beaded cloth W2 and the flap cloth W3 are pressed and held on the sewing machine table 2, and in this holding state, each cloth W1 to W3 is moved from the preparation position to the stitch forming position as the clamp device 5 moves. When the flap cloth W3 is attached by the cooperation of the needle 4 and the thread catcher, the bead stitches of a predetermined number of stitches are formed. As shown in FIGS. 1 and 2, a pair of reflected light sensing type cloth sensors 10 are attached to the outer surface of the arm portion of the sewing machine body 1 by the attaching plate 11 corresponding to each needle 4, and are attached to the flap pressing body 8. A long hole-shaped detection window that is formed through and extends in the cloth feed direction
The presence of the flap cloth W3 on the folding plate 7 is detected via 12 and a cloth detection signal is output when the flap cloth W3 is present. In this embodiment, as shown in FIG. 4a, the cloth detection position S by each cloth sensor 10 is arranged at a predetermined distance D from the passing point N of the needle 4 toward the cloth feeding side. Next, the control circuit of the sewing machine configured as described above will be described with reference to FIG. 3. The central processing unit (CPU) 21
The CPU 21 has a read-on memory (ROM) 22 and a random access memory (RAM) 23 connected to it, which constitute a discriminating means, a first control means, and a second control means. ROM22
A program for controlling the operation of the sewing machine as a whole is stored in the RAM 23, and the RAM 23 is provided with various areas for storing, for example, feed amount data corresponding to the distance D. A start switch 24 operated by the cloth sensor 10 and a knee or the like is connected to the CPU 21 via an input interface 25, and various signals are input to the CPU 21 from them. Further, a motor 26 for moving the clamp device 5 and a sewing machine motor 27 are connected to the CPU 21 via an output interface 28 and drive circuits 29, 30, and a drive or stop signal is output from the CPU 21 to them. . Then, when the work cloths W1 to W3 are held by the clamp device 5, the CPU 21 sends the work cloths W1 to W3 from the preparation position shown in FIG. 4a to the passing point N of the needle 4 in accordance with the operation of the clamp device moving motor 26. , The flap holder 8 as shown in FIG. 4b.
The front end portion 12a of the upper detection window 12 is at the cloth detection position S of the cloth sensor 10.
When the movement of the clamp device 5 is started, the operation of determining the cloth detection signal from the cloth sensor 10 is started when
When the rear end portion 12b of the cloth 12 reaches the cloth detection position S, the operation of discriminating the cloth detection signal is completed. Also, CP
When the front end of the flap cloth W3 reaches the cloth detection position S and a cloth detection signal is output from the cloth sensor 10 as shown in FIG. 4c, U21 processes the predetermined distance D from the judgment of the cloth detection signal. Operation control of the sewing machine motor 27 is performed so that when the cloths W1 to W3 are transferred and the front end of the flap cloth W3 reaches the passing point N of the needle 4, stitch formation is started as shown in FIG. 4d. To do. Further, as shown in FIG. 4b, the CPU 21 has foreign matter R such as dust on the folding plate 7 in front of the flap cloth W3, and the foreign matter R is erroneously detected by the cloth sensor 10 as the front end of the flap cloth W3. When detected, in response to the detection signal from the cloth sensor 10, after the detection signal is output, the work cloth W1 ~
While W3 is transferred by the predetermined distance D, the cloth sensor 10
With the interruption of the detection signal from the sewing machine motor 27, the operation control of the sewing machine motor 27 is invalidated, and the cloth sensor 10 waits until the cloth detection signal for detecting the front end of the flap cloth W3 is generated. . Further, the CPU 21 is caused by the poor adjustment of the detection sensitivity of the cloth sensor 10, the poor adjustment of the detection position, the disconnection of the control circuit including the cloth sensor 10, etc., and the cloth sensor at the transfer position shown in FIG. 4b.
When an incorrect cloth detection signal is judged immediately after starting the judgment operation of the detection signal from 10, or the rear end portion 12b of the detection window 12 on the flap pressing body 8 reaches the cloth detection position S, Even if the judgment operation is completed, when the cloth detection signal from the cloth sensor 10 is not judged, the clamp device moving motor 26 is stopped to control the sewing machine operation. Next, the operation of the sewing machine configured as described above will be described. Now, as shown by the chain line in FIG. 1, by the cooperation of the large presser plate 6, the folding plate 7, the flap presser body 8 and the binder 9 of the clamp device 5 which has been moved to the preparation position, the best cloth W1,
When the start switch 24 shown in FIG. 3 is turned on while the beaded cloth W2 and the flap cloth W3 are pressed and held on the sewing machine table 2, the operation of the flowchart shown in FIG. First, in step S1, the clamping device 5 is moved forward by driving the clamping device moving motor 26, and the work cloths W1 to W3 are fed from the preparation position shown in FIG. 4a to the passing point N of the needle 4. When the front end portion 12a of the detection window 12 on the flap pressing body 8 reaches the cloth detection position S of the cloth sensor 10 as shown in FIG. 4b by moving the clamp device 5 by a predetermined amount, step S2 in FIG. Then, the operation of determining the cloth detection signal from the cloth sensor 10 is started, and the operation of determining the cloth detection signal is performed until the rear end portion 12b of the detection window 12 reaches the cloth detection position S. And
Immediately after the start of this discriminating operation, if there is a cloth detection signal from the cloth sensor 10 in step S3, the clamping device moving motor 26 is stopped in step S4, and the sewing machine operation is interrupted. The error is displayed with. Therefore, due to the poor adjustment of the detection sensitivity of the cloth sensor 10 or the disconnection of the control circuit including the cloth sensor 10,
When the wrong cloth detection signal is always output from 10, there is no possibility that the sewing machine operation is immediately stopped and the stitch formation is started from the wrong position. On the other hand, when the cloth detection signal is not judged immediately after the start of the judgment operation and the front end of the flap cloth W3 reaches the cloth detection position S as shown in FIG. 4c, the cloth detection signal from the cloth sensor 10 is detected in step S6. To be determined. Then, in the next step S7, it is determined whether or not the cloth detection signal is continuously output from the cloth sensor 10, and in step S8, between the passing point N of the needle 4 and the cloth detection position N of the cloth sensor 10. The work cloths W1 to W3 corresponding to the distance D are fed to determine whether or not the front end of the flap cloth W3 has reached the passing point N of the needle 4, and as shown in FIG. When the front end reaches the passing point N of the needle 4, the sewing machine motor 27 is activated in step S9 to start stitch formation. Also, as shown in FIG. 4b, when there is a foreign substance R such as dust on the folding plate 7 in front of the flap cloth W3 and the detection signal of the foreign substance R from the cloth sensor 10 is discriminated in step S6. Means that the detection signal from the cloth sensor 10 is interrupted between the foreign material R and the flap cloth W3 while the work cloths W1 to W3 are transferred by the predetermined distance D, and therefore the determination in step S7 is NO. Then, the process returns to step S6 and waits for the cloth sensor 10 to generate the front end detection signal of the flap cloth W3. Therefore, based on the detection signal accompanying the passage of the foreign matter R, there is no possibility that the stitch formation is erroneously started from a position spaced a predetermined distance D from the determination of the detection signal. Further, at step S10 in FIG. 5, even when the rear end portion 12b of the detection window 12 on the flap pressing body 8 reaches the cloth detection position S and the cloth detection signal determination operation is completed,
If the cloth detection signal from the cloth sensor 10 cannot be determined,
In step S11, the clamp device moving motor 26 is stopped to interrupt the sewing machine operation, and an error message is displayed in step S12. Therefore, if there is a case where the cloth sensor 10 does not output the cloth detection signal due to poor adjustment of the detection sensitivity of the cloth sensor 10 or disconnection of the control circuit including the cloth sensor 10, the sewing machine operation may be stopped. To be done. Further, it is within the range from the time when the front end 12a of the detection window 12 reaches the cloth detection position to the time when the rear end 12b of the detection window 12 reaches the cloth detection position, and the flap cloth is placed inside the detection window 12. The fabric sensor 10 is configured to detect when W3 is present.
Therefore, unlike the configuration in which the detection is started when the needle 4 starts idling, the cloth sensor 10 does not confuse the flap pressing body 8 with the flap cloth W3, and extremely accurate stitch formation can be realized. Further, the CPU 21, which is the second control means, controls the clamp device 5 to make an emergency stop only when an emergency stop is really necessary. On the other hand, when the emergency stop is not so necessary as when there is the foreign matter R, the emergency stop is not performed and the cloth sensor 10 waits for the cloth detection signal to be generated. Therefore, when restarting the work after the emergency stop due to the presence of the foreign matter R, it is possible to surely eliminate the complexity of the operator resetting and restarting the emergency stop state by the switch operation. Therefore, according to the apparatus of the present embodiment, there is a great advantage that it is possible to prevent a decrease in workability. It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and may be embodied by arbitrarily changing the configuration of each unit without departing from the spirit of the present invention. EFFECTS OF THE INVENTION As described in detail above, according to the present invention, even when a foreign material such as dust is present in front of the end portion of the work cloth and the detection signal is temporarily output from the cloth sensor, the sewing error is erroneously performed. There is no possibility that eyes will start to be formed, and there is an effect that the edge of the work cloth can be reliably detected and stitch formation can be accurately started from the end of the work cloth. Further, since the cloth sensor performs detection when the detection window is at the cloth detection position, the cloth sensor does not mistake the cloth pressing body for the work cloth, and it is possible to realize accurate stitch formation. Play. Further, since the emergency stop is controlled so that it is stopped only when it is really necessary, the complexity at the time of restarting the work can be eliminated, and the workability can be prevented from lowering.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a bead sewing machine embodying the present invention, and FIG. 2 is a partially enlarged sectional view showing a clamped state of a work cloth by a clamp device and a binder. , Fig. 3 is a block diagram of the control circuit, Figs. 4a to 4d are partial plan views sequentially showing the cloth detection position of the cloth sensor and the transfer state of the flap cloth to the passing point of the needle, and Fig. 5 is the cloth detection. It is a flowchart which shows operation | movement and its related operation | movement. 4 ... Needles constituting stitch forming device, 5 ... Clamping device as cloth feeding device, 8 ... Flap pressing body as cloth pressing body, 10 ... Cloth sensor, 12 ... Detecting window, 21 ... First and second CPU that constitutes the control means.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yuji Tagawa               9-35 Horitadori, Mizuho-ku, Nagoya-shi, Aichi               Within Brother Industries, Ltd. (72) Inventor Hideo Kawaguchi               9-35 Horitadori, Mizuho-ku, Nagoya-shi, Aichi               Within Brother Industries, Ltd.                (56) References Japanese Patent Publication Sho 60-40311 (JP, B2)

Claims (1)

(57) [Claims] A stitch forming device including a needle (4) for forming a stitch on a work cloth (W1, W2, W3) and a work cloth (W1 to W3) are transferred through a passing point of the needle (4). Cloth feeding device (5) for pressing and holding the work cloth (W3) and detecting window (12)
And the cloth presser body (8) formed by penetrating the cloth, and a front end portion (12a) of the detection window (12) which is arranged at a predetermined distance closer to the cloth feeding side than the passing point of the needle (4). The work cloth (W3) exists within the range from the time when the position reaches the position to the time when the rear end portion (12b) of the detection window (12) reaches the cloth detection position and within the detection window (12). And a cloth sensor (10) that outputs a cloth detection signal when the cloth feeding device (5) operates to feed the end of the work cloth (W3) to the passing point of the needle (4). 10) The operation of controlling the stitch forming device so that the stitch formation is started when the work cloth (W1 to W3) is transferred by the predetermined distance after the cloth detection signal is output from the first section.
In response to the cloth detection signal from the control means (21) and the cloth sensor (10), while the work cloth (W1 to W3) is transferred by the predetermined distance after the detection signal is output, It is determined whether or not the cloth detection signal from the cloth sensor (10) is continuously output, and when it is judged that the cloth detection signal is interrupted while the cloth detection signal is being transferred by the predetermined distance, the first The operation control of the stitch forming device by the control means (21) is invalidated so as to wait for the generation of the cloth detection signal from the cloth sensor (10) without stopping the cloth feeding device (5) in an emergency. At the same time, when the cloth sensor (10) always outputs an incorrect cloth detection signal immediately after the start of the judgment operation, or when the cloth sensor (10) does not output the cloth detection signal from the start to the end of the judgment operation. Emergency stop of the cloth feeding device (5) And a second control means (21) for controlling the sewing machine.