JP4809538B2 - sewing machine - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a sewing machine having an automatic backstitch function that automatically performs backtacking to prevent fraying at the end of sewing.
[0002]
[Prior art]
FIG. 3 shows an outline of an external view of a conventional sewing machine having an automatic self-stitching function for industrial use as viewed from the front. A sewing machine body indicated by reference numeral 10 is installed on a sewing machine table 12, and the table A sewing machine motor 16 that rotates the sewing machine main shaft via a belt 14 is installed under the belt 12. Below the table 12, a control box 18, a power switch 20 for connecting and disconnecting commercial power to the control box 18, and a pedal 22 used during sewing are installed. An operation panel 24 and a touchback switch 26 are installed.
[0003]
The above-mentioned sewing machine will be described in detail. In recent industrial sewing machines, the sewing machine main body 10 is equipped with an actuator including an electromagnetic solenoid, an air cylinder, and the like, and automation of sewing operations such as thread trimming and back stitching is realized by the actuator. .
[0004]
In such a sewing machine, the needle bar position of the sewing machine and the rotational speed of the sewing machine are controlled by the sewing machine motor 16, and in recent years, such a motor is maintenance-free, has a long service life and a comfortable working environment. In general, inverter motors, AC servo motors, and the like are used.
[0005]
The control box 18 has a circuit for supplying electric power from a commercial power source to the sewing machine motor 16 and a circuit for driving an actuator built in the sewing machine body 10 and controls these circuits. It is composed of a microcomputer or the like.
[0006]
The pedal 22 is used by a sewing manufacturer (operator) to control the sewing machine during sewing. When the pedal 22 is depressed, the pedal sensor attached to the control box 18 controls the movement of the pedal 22. The control box 18 performs control according to the depression amount of the pedal 22 and drives the actuator provided in the sewing machine motor 16 and the sewing machine body 10 to perform the control operation instructed by the operator. It has come to be realized.
[0007]
The operation panel 24 is used when an operator sets sewing conditions including various sewing patterns, and information such as the sewing conditions set here is sent to the control box 18. The touch-back switch 26 is used when manually performing backtack sewing. When the switch 26 is pressed, an actuator such as an electromagnetic solenoid built in the sewing machine body 10 is operated. By driving a known feed mechanism (feed means) connected to the actuator, the feed direction of the sewing product can be changed from the normal feed to the reverse feed direction. In other words, the operator can reversely feed the sewing product by depressing the pedal 22 while pressing the switch 26 at the time of sewing, and can return to the normal feed by stopping the operation. Stop sewing can be performed at the position.
[0008]
Here, the function of the automatic backstitch which the conventional sewing machine has is demonstrated concretely. This automatic backstitch function sets the desired number of stitches on the operation panel 24, counts the number of stitches at the start or end of sewing in the control box 18, and automatically turns on / off the actuator for backtacking. In this function, the sewing can be automatically performed without the operator operating the touch-back switch 26 by sending the sewing product by the number of stitches.
[0009]
FIG. 4 shows a stitch pattern formed when this automatic backstitch sewing is executed. Since the actual stitches are overlapped on a straight line, it is easy to determine the needle drop position. Therefore, the sewing product is shown in a state in which it is moved in the left-right direction.
[0010]
The operation surface of the operation panel 24 shown in FIG. 5 includes the number of stitches Na, Nb, Nc, and Nd at each of the stitch points A, B, C, and D in FIG. 4 (Na = Nb = Nc in FIGS. 4 and 5). = Nd = 4 stitches) are provided with numerical indicators La, Lb, Lc, Ld, each of which displays LEDs, and the number of stitches Na, Nb, Nc, Nd is configured to increase by one stitch by pressing each of the Ap, Bp, Cp, and Dp switches, and to decrease by one stitch by pressing each of the Am, Bm, Cm, and Dm switches.
[0011]
Further, the switch SWs and the switch SWe are switches for selecting whether or not to perform the back stitching at the start of sewing and the backstitch sewing at the end of the sewing, respectively, and the selection state can be alternately switched every time the operation is performed. The indicator Ls and the indicator Le arranged in the vicinity of each of the switches are indicators that indicate that the corresponding backtacking is set to execute when the switch is lit. The back stitch at the start of sewing (hereinafter also referred to as the start back stitch) and the back stitch at the end of sewing (hereinafter also referred to as the end stop stitch) are effective for preventing fraying of the thread at the start and end of sewing, respectively. However, some sewing products must not be sewn, and in such cases, the operator selects these functions by operating the switches SWs and SWe provided on the operation panel 24 each time. I am using it.
[0012]
4A and 4B show the stitches formed by the start stitches, that is, the stitches formed by the first stop stitches. When the pedal is depressed, if the execution of the first stop stitches is selected by the switch SWs, the stitches are shown. When the sewing machine rotates with the back stitch actuator turned off by several Na, a normal stitch A is formed, and when the sewing machine rotates with the back stitch actuator on for the number of stitches Nb, A reverse stitch seam B is formed so as to overlap the seam, thereby forming a back stitch at the start of sewing. On the other hand, if the execution of back-tacking is not selected at the start of the switch SWs, the stitches A and B are not formed and normal sewing is started immediately.
[0013]
C and D indicate the stitches formed by the end sewing at the end of the sewing, that is, the end sewing, and when the pedal is turned back during the normal sewing (when the pedal is stepped backward), the switch SWe If execution of end backtacking is selected, reverse sewing seam C is formed by rotating the sewing machine with the backtack actuator on for the number of seams Nc, and further backtack actuators for the number of seams Nd. When the sewing machine is rotated in the OFF state, a seam C is formed as a normal seam D by overlapping with the seam C, thereby forming an end-sewing stitch, and then a thread trimming solenoid or the like built in the sewing machine 10 is formed. A known thread trimming mechanism (thread trimming means) is driven by the thread trimming actuator to perform thread trimming. If execution of end-stop sewing is not selected by the switch SWe, the stitches C and D are not formed, and immediate thread trimming is performed.
[0014]
A conventional sewing machine having an automatic backstitch function is configured as described above, and an operator operates the above-described switch SWs and switch SWe to perform sewing start sewing sewing or sewing end stopping sewing before sewing. By setting it to be effective, it is possible to automatically form a fixed stitch with a predetermined number of stitches at the start of sewing or at the end of sewing.
[0015]
[Problems to be solved by the invention]
However, the above-described conventional sewing machine has the following problems. In other words, if an abnormality occurs where the bobbin thread is lost or sewing must be interrupted, an extra needle hole is opened in the workpiece (cloth) and the workpiece is damaged. In order to prevent the sewing thread and to make it easier to release the sewing thread, it is necessary to perform only the thread trimming without performing the end sewing, but if the execution of the end sewing is set to be effective, the operator It was necessary to operate the switch SWe on the panel to set the end stop stitching to be invalid, and then return the pedal to perform thread trimming. This operation is not only inefficient in sewing because the switch SWe is far from the hand, but it is necessary to operate the switch SWe again after thread trimming, so forgetting to re-operate the switch SWe. There was a possibility that after the resumption of sewing, there was a possibility that thread trimming would be performed without executing end sewing at the end of sewing.
[0016]
On the other hand, in order to solve this problem, it is possible to temporarily execute only thread trimming by newly adding a switch around the sewing machine jaw and turning the pedal back while operating this switch. Although the area around the sewing machine jaw is an important space for the operator to operate the sewing object during sewing, a new problem that the added switch hinders sewing occurs, There was also a problem that the cost of the sewing machine increased.
[0017]
The present invention has been made to solve the above-mentioned conventional problems, and even if the setting is made to execute the back-end stitching at the end of sewing without adding a new switch, it can be temporarily performed with a simple operation. Another object of the present invention is to provide a sewing machine that prohibits back-end sewing at the end of sewing and can perform only thread trimming.
[0018]
[Means for Solving the Problems]
The present invention includes a feed means (not shown) capable of feeding a workpiece in forward and reverse directions, a feed actuating means (stop stitching solenoid 40) for electrically changing the feed direction or feed amount of the feed means, a sewing machine A thread trimming means (not shown) for cutting the sewing thread, a thread trimming actuation means (thread trimming solenoid 42) for electrically operating the thread trimming means, and a first that generates a stop signal and a thread trimming signal by different operations. The operation means (pedal 22), the second operation means (touch back switch 26) for generating a backstitch signal by operation, and the sewing machine is stopped when a stop signal is generated, and the sewing machine is driven when a thread trimming signal is generated. Further, the control means (CP) which operates the feed actuating means when the sewing machine is stopped after the threading actuating means is actuated after the feed actuating means is actuated and the predetermined number of stitches are formed, and the sewing machine is stopped. 28), in a sewing machine provided with a capital, with the proviso that thread cutting signal is generated during the sewing machine stopped and stitch signal generator according to the stop signal generator, the yarn without forming a stitch of the predetermined stitch count By providing a changing means (CPU 28 ) that acts on the control means so as to act only on the cutting operation means, the problem is solved.
[0019]
In other words, in the present invention, even if the end sewing at the end of sewing is set using the second operating means (touch back switch 26), the backtack switch is operated while the sewing machine is stopped during sewing. When the pedal is depressed in this state, only the thread trimming is executed.Therefore, without adding a new switch, the thread trimming is temporarily prohibited by simply prohibiting the back end sewing at the end of sewing. Can only run.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a sewing machine according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0021]
Since the appearance and operation panel of the sewing machine according to the present embodiment are the same as those of the conventional sewing machine shown in FIGS. 3 and 5, description will be made with reference to FIGS.
[0022]
FIG. 1 is a block diagram showing an outline of a control system centering on a control box 18 provided in the sewing machine of the present embodiment. The control box 18 supplies power to a CPU (Central Processing Unit) 28, a pedal sensor 30, a motor driver 32, a solenoid driver 34, a memory 36, and each part of the control box 18 connected to the CPU 28, respectively. Power supply circuit 38.
[0023]
Further, a pedal sensor 30 for detecting the depression state of the pedal 22 is connected to the CPU 28, and the operation panel 24 and the touchback switch 26 are connected to the CPU 28, respectively. Further, the power switch 20 is connected to the power circuit 36, and a motor driver 32 is connected thereto, and the sewing machine motor 16 is driven to rotate by the driver 32. The solenoid driver 34 is connected to a well-known sewing mechanism and a thread trimming mechanism (both not shown) incorporated in the sewing machine body 10 in accordance with a control signal input from the CPU 28. The non-feed stitch actuator) and the thread trimming solenoid 42 (thread trimming actuator) are appropriately driven.
[0024]
In addition, a motor encoder 44 and a needle position detector 46 are connected to the CPU 28. The motor encoder 44 is incorporated in the motor 16 and is used for generating a plurality of pulse signals per one rotation of the motor and detecting the motor speed. The needle position detector 46 generates one pulse per rotation of the sewing machine when the needle bar of the sewing machine 10 is at a predetermined vertical position, controls the vertical position of the needle bar when the sewing machine is stopped, and stops the start and end of sewing. The sewing machine is configured so that the number of stitches can be counted.
[0025]
With the above configuration, in the sewing machine according to the present embodiment, the setting contents of the operation panel 24 are read into the CPU 28 by the operation of the pedal 22 from the operator, the optimum motor driving and solenoid driving are performed, and the back stitching at the start of sewing is performed. The sewing operation of the sewing machine, the back end sewing at the end of sewing, the thread trimming and the like can be automatically executed.
[0026]
Next, the effect | action of this Embodiment performed by CPU28 is demonstrated with reference to the flowchart shown in FIG.
[0027]
First, when the power switch 20 is turned on, it is determined in step S1 whether or not the pedal 22 has been stepped forward by the operator. If the pedal 22 has been forwarded, the process proceeds to step S2.
[0028]
In step S2, it is determined whether or not the switch SWs of the operation panel 24 is operated and the setting is made to execute the back stitching. If it is set to execute, the process proceeds to step S3, and the operation panel 24 is also set. The set stitch numbers Na and Nb of the first back stitch set in step S4 are read, and the process proceeds to step S4. Next, in step S4, the sewing machine is driven while the backtack solenoid 40 is driven at a predetermined timing based on the above-described number of stitches set and the count value of the pulse signal from the needle position detector, so that the start backtack is formed. The process proceeds to step S5.
[0029]
In step S5, it is determined whether or not a stop signal is generated due to the suspension of pedaling in front of the pedal. If not interrupted, the process proceeds to step S6, where it is determined whether or not the touchback switch 26 is turned on and a backtack signal is output. If the touch-back switch 26 is not turned on, the process proceeds to step S7, and the sewing machine rotates and performs sewing while the cloth feed is in the normal feed state. When the touchback switch 26 is turned on and a backtack signal is output, the backtack solenoid 40 is driven to operate the backtacking mechanism of the sewing machine, and the sewing machine rotates with the cloth feed reversely fed. Sewing is performed. And after step S7 and step S8, it returns to step S5 in any case, and it is determined again whether pedal depression is interrupted.
[0030]
If it is determined in step S2 that the setting is not to be performed at the beginning, the process proceeds to step S6 as it is, and the processes of steps S6 to S8 are performed as described above, and the process proceeds to step S5.
[0031]
If it is determined in step S5 that the front pedal depression has been interrupted and a stop signal has been generated, the process proceeds to step S9 and deceleration for stopping the sewing machine motor 16 is started. It is determined whether or not a backward stepping is performed and a thread trimming signal is output.
[0032]
If it is determined in step S10 that the pedal is not depressed backward, the process proceeds to step S5 again, and it is determined whether or not the pedal front depression is continued. In addition, when the loop of step S5, step S9, step S10, and step S5 is repeated here, it is a case where the pedal 22 is maintained in the neutral state and the generation of the stop signal is continued. Deceleration is repeated and the sewing machine stops.
[0033]
On the other hand, if it is determined in step S10 that the pedal 22 has been stepped back and a thread trimming signal has been generated, the process proceeds to step S11 where it is determined whether the sewing machine is stopped. This stop determination determines whether the thread trimming signal generated by stepping on the back of the pedal 22 is generated before the sewing machine stops or after the stop. In other words, when the deceleration is started and stopped in step S9 and then the backward stepping is performed in step S10 and the backtack signal is generated, it is determined that the sewing machine is stopped, and the sewing machine is stopped even if the deceleration is started in step S9. It is determined that the sewing machine is not stopped if the front pedal is stepped again before stopping or the pedal 22 is stepped immediately after deceleration and the pedal is stepped back in step S10 before the sewing machine stops. Is done. This stop determination is performed, for example, by determining that the pulse signal output from the motor encoder 46 is not output for a predetermined time.
[0034]
If it is determined in step S11 that the sewing machine is not stopped, that is, if the sewing machine has stepped backwards before the machine is stopped and a thread trimming signal has been generated, the process proceeds to step S12 and the switch on the operation panel 24 is switched. It is determined whether or not the setting by SWe is set to execute end backtack sewing. If it is not set to execute, the process proceeds to step S16, and the thread trimming solenoid 42 is driven to perform thread trimming by the thread trimming mechanism. Is performed, and the sewing machine is stopped and the sewing is finished.
[0035]
On the other hand, if it is determined in step S12 that the end backtacking is set to be executed, the process proceeds to step S13, and the set end stitches Nc and Nd set by the operation panel 24 are read. Subsequently, in step S14, the sewing machine is driven to form the end backtack of the number of stitches set in the same manner as in the case of start backtacking, and then the process proceeds to step S16 to perform thread trimming. The sewing machine is stopped and sewing is finished.
[0036]
If it is determined in step S11 that the sewing machine is stopped, that is, it is determined that the pedal has been stepped backward after the sewing machine has stopped and a thread trimming signal has been generated, the process proceeds to step S15, and the touchback switch 26 is turned on. If it is determined whether or not it is turned on, the process proceeds to step S12, and the processes of step S13, step S14, and step S16 are subsequently performed to perform end-stop sewing and thread trimming. Is performed, the sewing machine is stopped and sewing is completed.
[0037]
In step S15, if it is affirmative, that is, if it is determined that the touch back switch 26 is turned on and a backtack signal is generated, the process proceeds to step S16 and only thread trimming is performed without performing end backtacking. The sewing machine is stopped and sewing is completed.
[0038]
As a result of the above processing, if the thread trimming signal is generated while the backtack signal is being generated after the sewing machine has stopped due to the stop signal, control is performed so that only the thread trimmer acts without forming the backtack of the predetermined number of stitches. The operator can change the sewing machine, and even if the end sewing is set by the switch SWe, the operator temporarily stops the sewing machine in the middle of sewing, and depresses the pedal 22 while turning on the touchback switch 26. By performing the return (backward stepping) operation, the end sewing can be temporarily prohibited to perform only thread trimming.
[0039]
Although the present invention has been specifically described above, the present invention is not limited to that shown in the above embodiment, and various modifications can be made without departing from the scope of the invention.
[0040]
For example, in the above embodiment, as shown in FIG. 4, the start backtack and the end backtack are applied to a sewing machine that drives the backtack solenoid 40 and feeds the cloth reversely by a predetermined number of stitches. Although described, the present invention is not limited to this. For example, the present invention is also applicable to a sewing machine that can automatically form a condensed seam as a slight feed in the forward direction or in the reverse direction by driving the backlock solenoid 40. Of course, it is possible.
[0041]
Further, a selection means using a switch or the like may be provided in a control box or the like so that the validity of the temporary stop sewing function described above can be selected according to the sewing environment.
[0042]
【The invention's effect】
As described above, according to the present invention, when an abnormality occurs in which the sewing has to be interrupted without adding a new switch, it is possible to temporarily stop sewing at the end of sewing with a simple operation. And a sewing machine capable of performing only thread trimming can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an outline of a control system of an embodiment of a sewing machine according to the present invention. FIG. 2 is a flowchart showing control of the sewing machine of an embodiment according to the present invention. FIG. 4 is an explanatory view showing a pattern of seams formed by the sewing machine. FIG. 5 is a schematic front view showing an operation surface of the operation panel 24 of the sewing machine according to the embodiment of the present invention.
DESCRIPTION OF SYMBOLS 10 ... Sewing machine main body 12 ... Sewing machine table 14 ... Belt 16 ... Sewing motor 18 ... Control box 20 ... Power switch 22 ... Pedal 24 ... Operation panel 26 ... Touch back switch 28 ... CPU
DESCRIPTION OF SYMBOLS 30 ... Pedal sensor 32 ... Motor driver 34 ... Solenoid driver 36 ... Memory 38 ... Power supply circuit 40 ... Stop sewing solenoid 42 ... Thread trimming solenoid 44 ... Motor encoder 46 ... Needle position detector

Claims (1)

A feeding means capable of feeding the workpiece in forward and reverse directions;
Feed actuating means for electrically changing the feed direction or feed amount of the feed means;
Thread trimming means for cutting the sewing thread,
Thread trimming operation means for electrically operating the thread trimming means;
First operating means for generating a stop signal and a thread trimming signal by different operations;
A second operating means for generating a backtack signal by operation;
When the stop signal is generated, the sewing machine is stopped, and when the thread trimming signal is generated, the sewing machine is driven and the feed operation means is actuated, and after the predetermined number of stitches are formed, the thread trimming operation means is actuated and then the sewing machine is stopped. , In a sewing machine provided with a control means for causing a feed actuating means to act when a backtack signal is generated,
On condition that the thread cutting signal is generated during the sewing machine stopped and stitch signal generator according to the stop signal generator, said to act only Itosetsu actuating means without forming a stitch of the predetermined stitch count A sewing machine comprising a changing means acting on the control means.

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