CN1358896A - Sewing machine for sewing bottonhole - Google Patents

Abstract

The buttonhole sewing machine M of the present invention is provided with a solenoid actuator (45), which is used to drive the thread cutting and holding mechanism (40) to switch from the closed position to the open position, and the solenoid is actuated by the control device. The device (45) is driven and controlled so that the thread cutting holding mechanism (40) for holding the upper thread is switched from the closed position to the open position immediately after sewing starts. Like this, the thread end part Ta that extends to the surface side from the 1st pin drop point on the processing cloth just pulls up with the thread take-up lever and shortens after the above-mentioned 1st pin drop. Therefore, the present invention provides such a buttonhole sewing machine which, when sewing buttonhole stitches of various shapes and sizes, continuously sews buttonhole stitches after sewing reinforcement stitches In the case of patterns other than buttonhole stitches, etc., for all these occasions, the above-mentioned thread ends can be prevented from being exposed to the outside of the stitches, and the quality of the pattern can be improved.

Description

Buttonhole Sewing Machine

technical field

The present invention relates to buttonhole sewing machines, and more particularly to a buttonhole sewing machine provided with an actuator for actuating a thread cut holding mechanism from a closed position to an open position.

current technology

The buttonhole sewing machine has a cloth feeding mechanism for feeding the processed cloth, and a stitch forming mechanism including a sewing needle forming a stitch on the processed cloth, a thread take-up lever and a thread catcher (rotary needle cylinder) now. Generally, the cloth feeding mechanism feeds the processed cloth pressed on the cloth feeding frame integrally with the cloth feeding frame forward and backward, and the stitch forming mechanism drives the sewing needle (needle bar) up and down, and can also swing drive left and right.

Accordingly, it is possible to sew, for example, a buttonhole stitch 100 including zigzag portions 100a, 100b and locking portions 100c, 100d shown in FIG. 20 on the processed cloth. The thread take-up lever of the stitch forming mechanism is the same as that of ordinary sewing machines. It moves up and down at a phase (for example, 70 to 120 degrees) that is slightly behind the up-and-down movement of the sewing needle. Pull up the upper thread to tighten the stitches formed on the processed cloth.

With existing buttonhole sewing machines, it is possible to sew buttonhole stitches of various sizes and shapes, and in addition to buttonhole stitches, it is also possible to sew various stitches including practical patterns such as straight stitches. It is also well known to form reinforcement stitches (for example, straight stitches) on the planned sewing portion before sewing the buttonhole stitches for reinforcement, and then to sew the buttonhole stitches. In this case, generally, the buttonhole stitches are continuously formed after the reinforcing stitches are formed.

As a conventional buttonhole sewing machine, as shown in FIGS. 17 to 19 , a sewing machine provided with a thread cutting holding mechanism 110 and an opening and closing mechanism 115 is widely used. The thread cutting and holding mechanism 110 is structured such that the thread cutting blades 111, 112 can be opened and closed according to the open state of FIG. 19 and the closed state of FIGS.

After sewing is finished, utilize this opening and closing mechanism 115, the thread cutting blade 111,112 of thread cutting holding mechanism 110 is switched into closing state from open state, as shown in Figure 17, cuts off from sewing needle 101 and extends and is connected in processing. The upper thread 102 on the cloth, and keep the end of the upper thread 102 on the sewing needle 101 side, when the next sewing starts, as shown in Figure 18 and Figure 19, the thread cutting blades 111, 112 of the thread cutting and holding mechanism 110 start from the closed The state is switched to the open state, and the held upper line 102 is released.

In particular, the switching of the thread cutting holding mechanism 110 from the closed state to the open state is after the engaging member 116, which moves integrally with the cloth feeding frame 105, moves a few stitches after the sewing starts, and the engaged portion of the thread cutting blade 111 is closed. 111a is engaged to rotate the thread cutting blade 111 (see FIG. 18 ). In this way, the thread cutting blades 111, 112 are half-opened to let go of the upper thread 102, and at the same time, retreat and move away from the needle 102 side to become a fully opened state (see FIG. 19). When sewing then, as shown in FIG. 20, the thread end portion 102a extending from the needle drop point of the first needle of the processed cloth to the surface side is sewn into the inside of the buttonhole stitch 100 (mainly the zigzag stitch 100a).

In the above-mentioned buttonhole sewing machine, after the thread cutting holding mechanism is switched to the open state and the upper thread is released at the start of sewing, most of the thread end part is in a free state, and the buttonhole stitch is sewn in this state. In addition, the buttonhole sewing machine disclosed in JP-A-11-9874 discloses a technique in which a movement drive mechanism is provided to move and drive the thread cutting holding member in the cloth feeding direction, and the movement drive mechanism is used to start sewing. Move the thread cutting and holding mechanism in the same direction as the cloth feeding direction, and after most of the above-mentioned thread ends are sewn into the buttonhole stitches, switch the thread cutting and holding mechanism from the closed state to the open state to release the upper thread.

In a conventional buttonhole sewing machine having a thread cutting holding mechanism and an opening and closing mechanism, the thread cutting holding mechanism releases the upper thread at the start of sewing, and most of the thread end part becomes a free state, and the buttonhole is formed in this state. Therefore, as shown in FIG. 21 , the thread end portion 102 may not be sewn into the buttonhole stitch 100 but be exposed to the outside. Especially when buttonhole stitches (zigzag stitches) are narrow in width, and when buttonhole stitches are sewn on highly elastic processed fabrics such as knitwear, sew continuously after sewing reinforcement stitches (straight stitches). When making buttonhole stitches, etc., the end of the thread is not sewn into the buttonhole stitches and is easily exposed to the outside.

As shown in Figure 22, in the case of sewing buttonhole stitches on the processing cloth 107 with large stretchability, when the sewing needle 101 is pulled out from the processing cloth 107, the processing cloth 107 bulges and the thread end portion 102 is thrown away. As shown in FIG. 23, in the case where the buttonhole stitches are continuously sewn after the reinforcing stitches 108 are sewn, because during the formation of the reinforcing stitches 108, the thread end portion 102 is easy to move due to its vibration and the like and does not stay in the predetermined lock. Since the buttonhole stitch forming part 109 is inside, the thread end portion 102 is not sewn into the buttonhole stitch and is exposed to the outside. In the case of sewing patterns other than buttonhole stitches, there is also a problem that thread ends are not sewn into the buttonhole stitches, but are exposed to the outside.

In the buttonhole sewing machine disclosed in JP-A-11-9874, in order to sew the thread end into the buttonhole stitch, the entire thread cutting and holding mechanism is moved in the same direction as the feeding direction by moving the drive mechanism, and most of the thread end After sewing in the buttonhole stitch, switch the thread cut hold mechanism to the open position to let go of the upper thread. However, since the above-mentioned moving drive mechanism must be provided, the structure is complicated, which is not conducive to reducing the manufacturing cost, and the configuration of other components and mechanisms and the structure of the sewing machine may be restricted.

Furthermore, in the buttonhole sewing machine disclosed in JP-A-11-9874, when the buttonhole stitches (zigzag stitches) having a relatively narrow width are sewn, the thread ends may not be sewn into the buttonhole stitches with certainty. The phenomenon that the inside is exposed to the outside is easy to occur when sewing reinforcement stitches (straight stitches) and then sewing buttonhole stitches continuously, or when sewing other pattern stitches, as with existing buttonhole sewing machines. It is difficult to improve these problems due to the phenomenon that the thread end part is not sewn into the stitch but is exposed to the outside.

The object of the present invention is to provide a buttonhole sewing machine which, when sewing buttonhole stitches of various shapes and sizes (especially narrower widths), continuously sews the lock after sewing the reinforcement stitches. In the case of buttonhole stitches, when sewing patterns other than buttonhole stitches, etc., for all these occasions, it is possible to prevent the above-mentioned thread ends from being exposed outside the stitches, and to sew high-quality and beautiful buttonholes. stitches and other patterns, and the structure is not too complicated, which is advantageous in terms of manufacturing cost.

Contents of the invention

The buttonhole sewing machine of the present invention has a cloth feeding mechanism for feeding the processed cloth and includes sewing needles forming stitches on the processed cloth, a thread take-up lever, a thread catcher and a stitch forming mechanism, through the coordination of the cloth feeding mechanism and the stitch forming mechanism action, can sew buttonhole stitches on the processing cloth, the buttonhole sewing machine has the following parts: a thread cutting and holding mechanism, which is used to cut the upper thread extending from the above sewing needle and connected to the processing cloth, and can The closed position of the end of the upper thread on the needle side and the open position for releasing the held upper thread are opened and closed; the actuator can drive the above-mentioned thread cutting and holding mechanism to switch from the closed position to the open position; the control mechanism , which is used to drive and control the aforementioned actuators.

In this buttonhole sewing machine, locks can be sewn on the processed cloth through the coordinated action of the feeding mechanism that feeds the processed cloth and the stitch forming mechanism including the sewing needle that forms stitches on the processed cloth, the thread take-up lever and the thread catcher. Buttonhole stitching. After the buttonhole stitches are sewn, the thread cutting and holding mechanism switches from the open position to the closed position, cuts the upper thread extending from the sewing needle and connected to the processing cloth, and holds the end of the upper thread on the side of the sewing needle, at the beginning When sewing next time, the thread cutting and holding mechanism switches from the closed position to the open position, releasing the held upper thread.

The switching of the wire cutting mechanism from the closed position to the open position is to use the control mechanism to drive and control the actuator, and use the actuator to drive the wire cutting and holding mechanism to switch from the closed position to the open position. Various settings can be made for the thread release time when the thread cutting and holding mechanism is switched from the closed position to the open position by the actuator and the control mechanism to release the thread. After starting, in this way, the thread end part extending from the needle drop point of the first needle of the processing cloth to the surface side can be pulled up with the thread take-up lever and shortened to the extent that it does not protrude from the processing cloth. The length of the thread end portion extending from the processing cloth is preferably several mm (1 to 3mm), and such a thread unwinding time can be set according to the needle curve and the thread take-up lever curve.

As mentioned above, since the thread end portion extending from the needle drop point of the first needle of the processed cloth to the surface side is shortened, it is not suitable for sewing various shapes and sizes (especially narrow width) of buttonhole stitches. Occasions, such as sewing reinforcement stitches and then sewing buttonhole stitches continuously, and sewing patterns other than buttonhole stitches, etc., can prevent the above-mentioned thread ends from being exposed to the On the outside, you can sew good-quality, attractive buttonhole stitches and other patterns. Moreover, in terms of hardware, the above functions can be realized as long as an actuator is provided. Therefore, the structure is not complicated, and it is also advantageous in terms of manufacturing cost.

In addition, the time to release the thread by the actuator can also be set to the original time, that is, the time to switch the thread cutting and holding mechanism from the closed position to the open position after the cloth is fed for several stitches after the sewing starts. Especially when sewing a buttonhole stitch (zigzag part) with a relatively wide width, the thread end can be sewn into the inner side of the buttonhole stitch without any problem even at the original time. Therefore, because the actuator is provided, the thread cutting and holding mechanism can be switched from the closed position to the open position according to the original time, so on the buttonhole sewing machine that is provided with the existing mechanical mechanism for this switching action, it can be ( partially) omit the mechanism.

According to the buttonhole sewing machine of the present invention, a thread cutting and holding mechanism, an actuator, and a control mechanism are provided. In this way, the control mechanism can be used to drive and control the actuator, and the thread cutting and holding mechanism can be driven by the actuator, so that it can be closed from the closed position. The position switches to the open position. Various settings can be made for the thread release time when the thread cutting and holding mechanism is switched from the closed position to the open position by the actuator and the control mechanism, and the thread release time is set to immediately after sewing starts , In this way, use the thread take-up lever to pull up the thread end part extending from the needle drop point of the first needle of the processing cloth to the surface side, and the degree of exposure from the processing cloth can be shortened.

Therefore, when sewing buttonhole stitches of various shapes and sizes (especially narrow widths), when sewing reinforcement stitches and then sewing buttonhole stitches continuously, and when sewing patterns other than buttonhole stitches, Sewing in all occasions such as occasions can prevent the above-mentioned thread ends from being exposed to the outside of the stitches, and can sew good-quality and attractive buttonhole stitches and other patterns. Moreover, the above-mentioned effect can be achieved only by providing the actuator in terms of hardware, so the structure is not complicated, which is advantageous in terms of manufacturing cost.

Especially in the case of sewing relatively wide buttonhole stitches, even with the conventional timing of switching the thread cut holding mechanism from the closed position to the open position after feeding a few stitches after the start of sewing, the thread end portion can be cut. It is sewn into the inside of the buttonhole stitching so there are no issues. That is to say, on the buttonhole sewing machine that carries out this switching action, is provided with existing mechanical structure, also can (partially) omit this mechanism.

A brief description of the drawings

Fig. 1 is a front view of a buttonhole sewing machine according to an embodiment of the present invention;

Figure 2 is a side view of the buttonhole sewing machine;

Fig. 3 is the front view of wire shearing and keeping release device;

Fig. 4(a) is a top view of the thread trimmer blade (closed state), solenoid actuator and opening and closing mechanism, and Fig. 4(b) is a diagram showing the position of the thread trimmer blade (thread release position);

Fig. 5 (a) is a top view of the thread trimmer blade (open state), solenoid actuator and opening and closing mechanism, and Fig. 5 (b) is a diagram showing the position of the thread trimmer blade (thread release position);

Fig. 6 (a) is a top view of the thread trimming blade (open state) and the solenoid actuator and the opening and closing mechanism; Fig. 6 (b) is a diagram showing the position (sewing position) of the thread trimming blade;

Fig. 7 (a) is a top view of the thread trimming blade (open state) and the opening and closing mechanism, and Fig. 7 (b) is a diagram showing the position (sewing position) of the thread trimming blade;

Figure 8(a) is a top view of the thread trimmer blade (open state) and the opening and closing mechanism, and Figure 8(b) is a diagram showing the position of the thread trimmer blade (thread cutting ready position);

Fig. 9 (a) is a top view of the thread trimming blade (closed state) and the opening and closing mechanism, and Fig. 9 (b) is a diagram showing the position of the thread trimming blade (thread cutting position);

Fig. 10(a) is a top view of the thread trimmer blade (closed state) and the opening and closing mechanism, and Fig. 10(b) is a diagram showing the position of the thread trimmer blade (pressing and lifting);

Fig. 11(a) is a top view of the thread trimmer blade (closed state) and the opening and closing mechanism, and Fig. 11(b) is a diagram showing the position of the thread trimmer blade (thread release position);

Fig. 12 is a top view of the thread trimmer blade (half-open state) and the opening and closing mechanism, and is a diagram of the position of the thread trimmer blade (thread release position);

Fig. 13 is a plan view of the thread trimmer blade (open state) and the opening and closing mechanism, and is a diagram showing the position of the thread trimmer blade (position during sewing);

Fig. 14 is a block diagram representing a control system;

Fig. 15 is a diagram representing a sewing needle curve and a thread take-up lever curve;

Fig. 16 is a flow chart carried out with the control device;

Fig. 17 is the top view of the thread trimming blade (closed state) and the opening and closing mechanism of the thread releasing position of the prior art;

Fig. 18 is a top view of the thread trimming blade (half-open state) and the opening and closing mechanism in the line releasing position;

Figure 19 is a top view of the thread trimmer blade (open state) and the opening and closing mechanism in the sewing position;

Figure 20 is a top view of a normal buttonhole stitch;

Figure 21 is a top view of a bad buttonhole stitch;

Figure 22 is a top view of a reinforcing stitch for a buttonhole stitch;

Fig. 23 is a sectional view of a sewing needle for processing cloth.

Embodiment of the invention

Embodiments of the present invention will be described below with reference to the drawings.

This embodiment adopts this method on a buttonhole sewing machine that can sew buttonhole stitches and can sew various patterns (such as utility patterns, etc.) An example of an invention. In addition, the front, rear, left, and right of FIGS. 1 and 2 will be described as front, rear, left, and right.

As shown in FIGS. 1 to 3 , the buttonhole sewing machine M includes: a sewing machine main body 1 having a bottom 2, a leg portion 3 and an arm portion 4; a cloth feeding mechanism 5 for sending the processed cloth forward and backward; The stitch forming mechanism 6 of the stitch; the thread cutting, holding and releasing device 7 for cutting, holding and releasing the upper thread T extending from the sewing needle 20; the control device 8 for driving and controlling the mechanisms 5, 6 and the device 7 (refer to Fig. 14) etc.

The cloth feeding mechanism 5 has a cloth feeding frame 10 on which the processed cloth is placed, and a pressing frame 11 provided on the upper side of the cloth feeding frame 10 so as to be able to move up and down. In the state where the processing cloth is pressed against the cloth feeding frame 10 by the pressing frame 11, the cloth feeding motor 12 (see FIG. 14) is driven, and the processing cloth is fed forward and backward integrally with the frames 10 and 11. Stitches are formed inside the frames 10 and 11 on the processed cloth pressed against the cloth feeding frame 10 by the stitch forming mechanism 6 .

The stitch forming mechanism 6 includes a sewing needle 20, a needle bar 21, a thread take-up lever 22 and a thread catcher (not shown). The needle bar 21 (sewing needle 20) is driven up and down by the needle bar drive mechanism 26 (refer to FIG. Fig. 14) carry out left and right swing drive. The thread take-up 22 is driven up and down by a thread take-up drive mechanism 32 (see FIG. 14 ) using the sewing machine motor 25 as a driving source, as shown in FIG.

The thread catcher is rotated synchronously with the sewing needle 20 by the needle cylinder driving mechanism 36 (refer to FIG. 14 ) with the needle cylinder motor 35 as the driving source, and catches the upper thread T extending from the sewing needle 20 near the needle-down position. Cross with the lower line. Then, when the sewing needle 20 rises from the lower position of the needle, the upper thread T is pulled up with the thread take-up lever 22 to form a locked stitch. For the cloth feeding mechanism 5 and the stitch forming mechanism 6, various mechanisms other than the present embodiment may be employed. For example, the same mechanism as that of the buttonhole sewing machine disclosed in JP-A No. 2000-312793 filed by the applicant of the present invention can also be used.

As shown in FIGS. 1 to 13 , the thread cutting, holding and releasing device 7 includes: a thread cutting and holding mechanism 40, which is used to cut off the upper thread T extending from the sewing needle 20 and connected to the processed cloth, and hold the sewing needle 20 The closed position of the upper thread end Ta on the side and the open position of the held upper thread T are opened and closed; the solenoid actuator 45 drives the thread cutting and holding mechanism 40 to switch from the closed position to the open position; Opening and closing mechanism 50, which is set separately from the solenoid actuator, and it is linked with the cloth feeding action of the cloth feeding mechanism 5, can switch the thread cutting and holding mechanism 40 from the closed position to the open position, and when the sewing is completed, Afterwards, the thread cutting holding mechanism 40 is switched from the open position to the closed position.

The thread cutting holding mechanism 40 has a fixed thread cutting blade 41 , a movable thread cutting blade 42 , and a blade holding member 43 holding the thread cutting blades 41 , 42 . The thread cutting blades 41, 42 can be switched to the following five positions by interlocking with the cloth feeding operation of the cloth feeding mechanism 5 or by operating the operation portion 60 (refer to FIG. 14 ) such as a foot switch. That is, the thread releasing position (starting sewing position) of Fig. 4, Fig. 5, Fig. 11, and the position in sewing of Fig. 6, Fig. 7, and the thread ready cutting position of Fig. 8, and the thread cutting position of Fig. 9, And the compression lifting position of Fig. 10.

The thread cutting blade 42 is pivotally supported by the blade holding member 43 , and the thread cutting blade 42 is provided with an engaged portion 42 a. The engaged portion 42a of the thread trimmer blade 42 is pushed to rotate by the solenoid actuator 45 and the opening and closing mechanism 50, and the thread trimmer blades 41, 42 can be switched between a closed state and an open state.

As shown in FIG. 3, a vertical mounting plate 47 is fixed to the lower left end portion of the arm portion 4 of the sewing machine main body 1, and the solenoid actuator 45 is mounted on the mounting plate 47 from the left side. The output shaft 45a of the solenoid actuator 45 passes through the mounting plate 47 and extends to the right thereof, where it is connected with the blade pushing member 46 . The blade pushing member 46 extends obliquely downward and rightward from the output shaft 45 a of the solenoid actuator 45 , and faces the engaged portion 42 a in a horizontal state at its right end.

In the state where the thread trimming blades 41, 42 are located at the thread release positions of Fig. 4 and Fig. 5, the solenoid actuator 45 is not driven, and the blade pushing member 46 is positioned to the left from the engaged portion 42a of the thread trimming blade 42. When the solenoid actuator 45 is driven, the blade pusher 46 is driven to move to the right. When the thread trimmer blades 41, 42 are in the closed state (closed position), the blade pusher 46 is engaged with the engaged portion 42a of the thread trimmer blade 42 to rotate the thread trimmer blade 42 clockwise and switch the thread trimmer blades 41, 42 to the open state (open position) (see FIG. 5 ).

The opening and closing mechanism 50 has: the engaged portion 42a of the above-mentioned thread trimmer blade 42, a first engaging member 51 capable of engaging with the engaged portion 42a from the left side, and a first engaging member 51 capable of engaging with the engaged portion 42a from the right side. The second engaging member 52 to be engaged. The first engaging member 51 is configured to move forward and backward integrally with the cloth feeding frame 10 of the cloth feeding mechanism 5 , and the second engaging member 52 is fixedly provided on the sewing machine main body 1 .

Under the premise of not driving the solenoid actuator 45, as shown in Figure 4, the thread trimmer blades 41, 42 are located in the thread release position in a closed state, and start sewing, as shown in Figure 12 and Figure 13, to When feeding several stitches in the front, the first engagement member 51 engages with the engaged portion 42a of the thread trimmer blade 42, and the thread trimmer blade 42 is rotated clockwise, and the thread trimmer blades 41, 42 are switched to the open state and Let go of the upper line T.

As shown in Figure 8, when the thread cutting blade 41,42 is positioned at the thread ready cutting position with the open state, as shown in Figure 9, when the thread cutting blade 41,42 moves to the right and switches to the thread cutting position, the second The engaging member 52 engages with the engaged portion 42a of the thread trimming blade 42 to rotate the thread trimming blade 42 counterclockwise, switch the thread trimming blades 41 and 42 to the closed state, and cut the upper thread T. In addition, this normal operation is the same as Japanese Patent Application No. 2000-219095 previously filed by the applicant of the present invention.

Next, the control system will be described based on the block diagram of FIG. 14 .

The control device 8 has a computer including a CPU 50, a ROM 51, and a ROM 52, an input interface 54, and an output interface 55, and these are connected to each other by a bus 56 such as a data bus.

An operation unit 60 including a foot switch, keys 61 , a phase detection sensor 62 , a needle up sensor 63 , a needle down sensor 64 , and the like are electrically connected to the input interface 54 . The motors 12 , 25 , 30 , 35 and drive circuits 70 to 74 for driving the solenoid actuator 45 are electrically connected to the output interface 55 .

The control program of setting control and the plug-in control program etc. are stored in the ROM, wherein the control program of setting control is used to sew the pattern (mainly the buttonhole pin 80) to the operation keys 61 or the pattern of the pattern. Various settings such as (selection) setting of shape and size are performed; the plug-in control program is used for input according to the data (including sewing data) set by the setting control and the operation part 60 or sensors 62 to 64, etc. signal, to the cloth feeding mechanism 5 (cloth feeding motor 12), stitch forming mechanism 6 (sewing machine motor 25, needle bar pendulum motor 30 and needle cylinder motor 35) and thread cutting and holding release device 7 (solenoid actuator 45 ) for drive control.

However, as shown in FIG. 15, the phase of the thread take-up lever curve in which the thread take-up lever 22 moves up and down is about 70 to 120 degrees behind the phase of the needle (needle bar) curve in which the sewing needle 20 (needle bar 21) moves up and down. . When the phase of the sewing needle 20 at the needle-up position is set to 0 degrees (360 degrees), when the phase is 30 degrees, the needle-up signal is input from the needle-up sensor 63, and when the phase is 215 degrees, the signal is input from the needle-down sensor 63. 64 input needle down signal.

Next, a series of controls performed by the control device 8 will be described based on the flowchart of FIG. 16 , and a series of operations performed by the control will be described based on FIGS. 4 to 13 .

This control starts when the power is turned on, and after the initial setting (S1), various settings can be made (S2). When carrying out various settings, as mentioned above, the pattern (mainly the buttonhole pin 80) and the shape and size of the pattern can be set with the key class 61 (selection). Whether to drive the solenoid actuator 45 immediately after the start of braking. In addition, the keys 61, the control device 8 for executing S2, and the like correspond to setting means.

Here, it is set to sew a buttonhole stitch, and it is set to drive the solenoid actuator 45 immediately after sewing starts. Then, the operation part 60 is operated to start sewing (S3: Yes), but before the sewing starts, as shown in FIG. , at the thread release position (sewing start position).

As soon as the sewing starts, the sewing process (S4) is executed to control the stitching of one needle, and then the signals sent by the sensors 62 to 64 are read (S5), and when the sewing is not completed (S6: No), it is judged Is it the solenoid driving time (S7). When it is not the solenoid driving time (S7: No), return to S4, and when it is the solenoid driving time (S7: Yes), drive the solenoid actuator 45, and return to S7.

Here, the solenoid driving time will be described.

The solenoid driving time is set to a time for driving the solenoid actuator 45 such that the thread cutting holding mechanism 40 holding the upper thread T is switched from the closed position to the open position immediately after sewing starts. Specifically, the upper thread release time for switching the thread cutting holding mechanism 40 from the closed position to the open position to release the upper thread T is the thread end portion extending from the needle drop point of the first needle of the processed cloth to the surface side. Ta is pulled up by the thread take-up lever 22 immediately after the above-mentioned first needle drop and shortens to a time of about several mm (for example, 1 to 3 mm).

Regarding the thread release time when the thread end part Ta is pulled up by the thread take-up lever 22 to leave a few mm on the surface side of the processed cloth, it can be based on the needle curve and the thread take-up lever curve in Figure 15, and according to the processed cloth and the upper thread Material, etc., ye experience settings. Therefore, the set thread release time, more specifically, is during the formation of the first stitch immediately after sewing, as shown in FIG. The phase time between 195° and 135°, that is, the time when the phase of the sewing needle 20 is between 195° and 315°.

In the case of this embodiment, the thread unwinding time can be set in advance, for example, to be 75 degrees behind from the phase in which the sewing needle 20 is located at the needle-down position during the stitching of the first stitch immediately after the sewing starts. During this period, the thread release time can also be changed and set so that the phase of the sewing needle 20 is between 195 degrees and 315 degrees. In this case, it may be performed with various settings of S2.

When the solenoid actuator 45 is driven according to the above time (S8), as shown in Figure 5, the thread cutting holding mechanism 40 is switched from the closed position to the open position, and the held upper thread T is released, and the upper thread T is held by the thread take-up lever. 22 is pulled up and shortened to about several millimeters. Then, S4→S5→S6→S7→S4 is repeated to form the buttonhole stitch 80 . At this time, as shown in Figure 6, after the upper thread has just been released, the thread trimmer blades 41, 42 retreat to the left from the thread release position and switch to the sewing middle position, and continue to sew, and can be sewed into the sewing machine shown in Figure 7. buttonhole pin 80 shown.

Then, after the sewing of the buttonhole stitch 80 is completed (S6: YES), the needle thread cutting process is performed (S9). This upper thread cutting process, for example, can be started by the upper thread cutting operation of the operation part 60. Like this, as shown in FIG. Shown, the thread cutting blades 41, 42 are switched to the thread cutting position.

When the thread cutting blades 41, 42 are switched from the thread cutting ready position to the thread cutting position, the second engagement member 52 is engaged with the engaged portion 42a of the thread cutting blade 42, and the thread cutting blade 42 turns counterclockwise, and the thread cutting The blades 41 and 42 are switched to the closed state to cut off the upper thread T extending from the sewing needle 20 and connected to the processing cloth, and hold the upper thread end T on the sewing needle 20 side.

After the upper thread cutting process is performed in S9, the pressing and lifting process is performed (S10). This crimping and lifting process can also be started, for example, by the crimping and lifting operation of the operation part 60, so that, as shown in FIG. In the state where the processing cloth is pressed against the cloth feeding frame 10 by the pressing frame 11, the thread cutting blades 41, 42 are located on the upper side of the pressing frame 11, and the thread cutting blades 41, 42 are switched to the pressing lifting position , the pressing frame 11 can be raised and lowered without interfering with the thread cutting blades 41,42.

That is, the pressing frame 11 is raised, the processed cloth is decompressed, and the processed cloth can be moved or replaced; In addition, return to S2 after the pressing and lifting process is completed, and then transfer to S10 when sewing is not started (S3: No), and the lifting and lowering of the pressing grip 11 can be performed several times.

On the other hand, in the various settings of S2, if the solenoid actuator 45 is not driven, after the sewing starts (S3: Yes), the solenoid actuator 45 is not driven, and the process is repeated. S4→S5→S6→S7→S4 is performed. In this case, as shown in FIGS. 12 and 13 , the engaging member 51 that moves integrally with the cloth feed frame 10 engages with the engaged portion 42 a of the thread trimmer blade 42 after sewing starts and moves for several stitches. , so that the thread trimmer blade 42 is turned around.

Like this, thread cutting blades 41, 42 are half-opened to release upper thread T (refer to FIG. 12 ), and thread cutting blades 41, 42 move away from sewing needle 20 to become fully opened state (refer to FIG. 13 ). When sewing is performed thereafter, the thread end portion Ta extending from the needle drop point of the first needle of the processed cloth to the surface side is sewn into the inside of the buttonhole stitch 80 .

As described above, according to this buttonhole sewing machine M, by providing the thread cutting holding mechanism 40 and the solenoid actuator 45, the solenoid actuator 45 can be driven and controlled by the control device 8, and the solenoid can be used as the actuator. Actuator 45 drives wire shearing holding mechanism 40 to switch it from a closed position to an open position.

Various thread release times can be set, and the thread release time is the thread release time when the thread shear holding mechanism 40 is switched from the closed position to the open position by the solenoid actuator 45 and the control device 8 to release the thread T. time. As in this embodiment, by setting the thread release time as immediately after sewing starts, the thread end portion extending from the first needle drop point of the processed cloth to the surface side can be extended with the thread take-up lever 22. It is pulled up and shortened so that it does not protrude from the processing cloth.

In this way, when sewing buttonhole stitches 80 of various shapes and sizes (especially narrow ones), after sewing reinforcement stitches, and continuously sewing buttonhole stitches 80, sewing other than buttonhole stitches 80 The occasions of pattern etc., all these occasions can prevent thread end part Ta from being exposed to the outside of stitches, and can sew good quality, beautiful buttonhole stitches 80 and other patterns. Moreover, in terms of hardware, as long as the solenoid actuator 45 is provided, the above effect can be achieved, the structure is not complicated, and it is also beneficial to reduce the manufacturing cost.

Since the thread cutting holding mechanism 40 is switched from the closed position to the open position, the thread end portion Ta extending from the needle drop point of the first needle of the processed cloth to the surface side is used for the thread take-up immediately after the above-mentioned first needle drop. The time during which the lever is pulled up and becomes shorter, specifically, is the time during which the phase of the sewing needle 20 changes from the phase of the needle-down position to a phase lagging by 15 degrees to 135 degrees during the stitching of the first stitch immediately after the start of sewing , So use the thread take-up lever 22 to really pull up the thread end part Ta extending from the needle drop point of the 1st needle of the processed cloth to the surface side, and then it can be shortened to the extent that it does not expose from the processed cloth.

Switching separately from the solenoid actuator 45, the thread cutting holding mechanism 40 can be switched from the closed position to the open position in conjunction with the cloth feeding operation of the cloth feeding mechanism 5 by the opening and closing mechanism 50. Since it is possible to set whether to drive the solenoid actuator 45 immediately after sewing starts, switching of the opening and closing mechanism 50 of the thread cutting holding mechanism 40 and switching of the solenoid actuator 45 can be separately used depending on the situation. .

Especially in the case of sewing a relatively wide buttonhole stitch 80, it is set to not drive the solenoid actuator 45, and after the sewing starts and the cloth is fed for several stitches, even if the thread is cut by the opening and closing mechanism 50, the holding mechanism 40 Switching from the closed position to the open position also allows the thread ends to be partially sewn into the inside of the buttonhole stitching, so there will be no problems.

In addition, if various settings are made to the time for switching the thread cutting holding mechanism 40 from the closed position to the open position using the solenoid actuator 45, since the switching can be performed at the same time as the time of the mechanism, it is also possible to The thread cutting and holding mechanism 40 is partially omitted, that is, the first engaging member 51 and the like that move integrally with the cloth feeding frame 10 are omitted. The above-mentioned mechanism refers to the use of the opening and closing mechanism 50 to switch the thread cutting and holding mechanism 40 from the closed position to the open position. mechanism.

In addition to the solenoid actuator, various actuators such as air cylinders and electric motors can be used, and the structure in which the actuator is mounted on the sewing machine body is not limited to the mounting structure of the embodiment. In addition, various changes can also be implemented without departing from the scope of the present invention.

Claims (11)

1. sewing machine for binding buttonhole, this Sewing machines has to send into the processing cloth feeding mechanism used of cloth and be included in the stitch that forms suture needle, the thread take-up tension lever of stitch on the processing cloth and catch the line device and forms mechanism, form the coordination of mechanism by cloth feeding mechanism and stitch, can on processing cloth, make the buttonhole stitch, it is characterized in that possessing:

Line is cut off maintaining body, and this mechanism is used to cut off from above-mentioned suture needle extension and is connected in reaching the standard grade on the processing cloth, and can the closing position of thread end open and close with the open position of reaching the standard grade that relieving is kept on maintenance suture needle one side;

Actuator, it can drive above-mentioned line and cut off maintaining body, makes it switch to open position from closing position;

Controlling organization is used for the above-mentioned actuator of drive controlling.

2. sewing machine for binding buttonhole according to claim 1 is characterized in that, the above-mentioned actuator of above-mentioned controlling organization drive controlling makes the maintaining body of cutting off that keeps reaching the standard grade just begin the back and just switch to open position from closing position making.

3. sewing machine for binding buttonhole according to claim 2, it is characterized in that it is that line end part that the 1st pin needle falling point from processing cloth extends to a surperficial side just pulls with thread take-up tension lever and time of shortening from the time that closing position switches to open position that above-mentioned line is cut off maintaining body after above-mentioned the 1st pin has just fallen pin.

4. sewing machine for binding buttonhole according to claim 2, it is characterized in that it is to make just to begin the back suture needle becomes the arbitrary phase place more than 15 degree that lags behind from the phase place that is positioned at the pin upper/lower positions time from the time that closing position switches to open position that above-mentioned line is cut off maintaining body.

5. sewing machine for binding buttonhole according to claim 3, it is characterized in that, be provided with switching mechanism and set mechanism, wherein switching mechanism and above-mentioned actuator branch are arranged, the work feed action interlock of it and cloth feeding mechanism, line can be cut off maintaining body and switch to open position, and line be cut off maintaining body after finishing and switch to closing position making from open position from closing position; Whether set mechanism can be set in to make makes after just beginning actuator drive.

6. sewing machine for binding buttonhole, it comprises as the lower part:

Send into the cloth feeding mechanism of processing cloth;

Stitch forms mechanism, and it comprises suture needle, thread take-up tension lever and catch the line device, by with the coordination of above-mentioned cloth feeding mechanism, on processing cloth, form the buttonhole stitch;

Line is cut off maintaining body, and its effect is to be connected in reaching the standard grade on the above-mentioned processing cloth to extending from above-mentioned suture needle to cut off, and can the closing position of thread end switch with the open position of reaching the standard grade that relieving is kept on above-mentioned suture needle one side of maintenance;

Driver part, it is used to drive above-mentioned line and cuts off maintaining body, makes it switch to open position from closing position;

Controlling organization, it is used for above-mentioned driver part is carried out drive controlling, makes the above-mentioned line that keeps reaching the standard grade cut off maintaining body and just begins the back and just switch to open position from above-mentioned closing position making.

7. sewing machine for binding buttonhole according to claim 6, it is characterized in that, above-mentioned line is cut off maintaining body and with thread take-up tension lever line end part is pulled and when shortening, switches to open position from closing position from the 1st pin needle falling point of processing cloth after above-mentioned the 1st pin has just fallen pin.

8. sewing machine for binding buttonhole according to claim 7, it is characterized in that it is to make just to begin the back suture needle becomes the arbitrary phase place more than 15 degree that lags behind from the phase place that is positioned at the pin upper/lower positions time from the time that closing position switches to open position that above-mentioned line is cut off maintaining body.

9. sewing machine for binding buttonhole according to claim 7 is characterized in that: it is to make the time that the phase place that just begins the back suture needle becomes the arbitrary phase place more than 195 degree from the time that closing position switches to open position that above-mentioned line is cut off maintaining body.

10. sewing machine for binding buttonhole according to claim 6, it is characterized in that: above-mentioned sewing machine for binding buttonhole also has switching mechanism, the work feed of this switching mechanism and above-mentioned cloth feeding mechanism action interlock and above-mentioned line is cut off maintaining body switch to open position from above-mentioned closing position.

11. sewing machine for binding buttonhole according to claim 10 is characterized in that, above-mentioned switching mechanism is cut off maintaining body with above-mentioned line after finishing and is switched to closing position from open position making.

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