JP5038480B2 - Multi-color embroidery sewing machine thread breakage detector - Google Patents

Description

  The present invention relates to a thread breakage detection device for a multicolor embroidery sewing machine suitably used for detecting thread breakage of an embroidery sewing machine, for example.

  In general, multi-color embroidery that realizes a multi-colored embroidery pattern on an embroidery object such as a cloth using a multi-color upper thread (embroidery thread) by driving and controlling the spindle of the sewing machine according to the embroidery data Sewing machines are known.

  A multicolor embroidery sewing machine according to this type of prior art includes a sewing machine main body provided with a drive source for rotationally driving a main shaft, a head portion provided in the sewing machine main body and reciprocatingly driven by rotation of the main shaft, A plurality of needle shafts which are provided in the head portion so as to be able to reciprocate and are driven up and down by a driving portion of the head portion, and upper threads (embroidery threads) which are respectively attached to the distal ends of the needle shafts are inserted. A plurality of sewing needles, an upper thread storage unit that stores each upper thread in a wound state so as to supply the upper thread to each sewing needle, and sending an upper thread that is supplied from the upper thread storage unit to the sewing needle In order to perform tightening and thread tightening, a plurality of balances are provided on the head portion corresponding to each sewing needle and are swung up and down by the driving portion.

  Here, the head unit is provided with a color changing mechanism, and the color changing mechanism selectively drives one sewing needle and the balance among the plurality of sewing needles and the balance according to the embroidery data. In addition, the sewing machine main body is positioned below the head portion to hold the embroidery cloth in a stretched state, and the holding frame is moved relative to the head portion together with the embroidery cloth. And a frame moving mechanism.

  When performing an embroidery work or the like, while rotating the main shaft by a drive source of the sewing machine, the head drive unit is reciprocated to drive the sewing needle up and down via the needle shaft. By moving the holding frame in the X-axis and Y-axis directions with a frame moving mechanism, the sewing needle is moved with respect to the embroidery cloth, and the upper thread of the desired color is sewn on the embroidery cloth to realize the embroidery pattern. To do.

  In this case, every time the main shaft rotates once, the sewing needle reaches the bottom dead center from the top dead center and is inserted into the embroidery cloth, and the balance reaches the top dead center from the bottom dead center while the upper thread is entangled with the lower thread. The upper thread is pulled out from the embroidery cloth so as to be sewn onto the embroidery cloth. However, if the thread breakage of the upper thread occurs during the needle movement of the sewing machine, the creation of the embroidery pattern is interrupted. This is detected by the thread breakage detection device and the surrounding operator is notified of the thread breakage of the upper thread. Like to do.

  For this reason, in the thread breakage detection device of the prior art, an electrical contact or the like is attached to a thread tension spring provided on the head of the sewing machine that is located between the upper thread storage section and the balance to supply the upper thread. The swing of the associated thread take-up spring is detected by opening and closing an electrical contact, and the yarn breakage of the upper thread is detected by this detection signal (see, for example, Patent Document 1).

JP-A-63-242299

  By the way, the above-described conventional yarn breakage detecting device has a configuration in which a sensor including an electrical contact is individually provided for each thread take-up spring of a thread tension arranged for each upper thread. For this reason, when applied to a multicolor embroidery sewing machine, it is necessary to attach electrical contacts and printed circuit boards to each of the thread take-up springs for a plurality of upper threads, which increases the number of parts and increases the work during assembly. There is a problem that the performance is lowered.

  In addition, such yarn breakage sensors not only increase the number of wires in proportion to the number of electrical contacts, but also cause false detection due to the influence of static electricity, etc. easy. Furthermore, the detection waveform may be changed by being influenced by the amount of yarn consumed on the upper yarn storage section, and there is a problem that the detection accuracy at the time of yarn breakage is poor.

  On the other hand, in another prior art (for example, JP-A-5-177080), a movable yarn path is provided between a balance and a sewing needle, and a plurality of upper threads are individually inserted into the movable yarn path. Dedicated to multi-color embroidery sewing machines with multiple thread insertion holes and a configuration that detects this vibration with a magnetoresistive element, etc., by vibrating the movable yarn path according to the movement of the upper thread accompanying the swing of the balance. A yarn breakage detecting device is described.

  However, in this case, the upper thread is individually inserted into each thread insertion hole of the movable thread path, and the movable thread path is vibrated finely according to the movement of the upper thread accompanying the swing of the balance. Immediately after that, vibration remains, and there is a problem that it is difficult to detect when yarn breakage occurs at an early stage.

  Also, even if thread breakage occurs while performing embroidery work by selecting one of the plurality of upper threads, other non-selected upper threads will move as the embroidery frame moves. If the tension of the yarn changes due to vibration, the movable yarn path may vibrate. In this case, it is difficult to immediately detect the occurrence of yarn breakage, which causes a false detection.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to detect the occurrence of yarn breakage at an early stage, without being affected by other non-selected upper yarns. An object of the present invention is to provide a thread breakage detection device for a multicolor embroidery sewing machine that can stably detect thread breakage.

  In order to solve the above-described problems, the present invention provides a plurality of sewing needles and balances for performing multicolor embroidery, and selectively drives any one of the sewing needles and balances. A head portion of the sewing machine, an upper thread storage means for storing a plurality of upper threads for supplying the upper thread to each sewing needle of the head portion via a balance, and between each sewing needle and each balance. The present invention is applied to a thread breakage detecting device for a multicolor embroidery sewing machine which is provided at the head portion and includes a detecting means for detecting the presence or absence of thread breakage.

The feature of the configuration adopted by the invention of claim 1 is that the detecting means extends so as to cross a plurality of upper threads supplied to the respective sewing needles from the upper thread accommodating means via the balances. A rotating body that rotates and displaces according to the thread tension applied to the upper thread by the balance, and a rotation detecting means that detects the breakage of the yarn by detecting the displacement of the rotating body. A thread contact bar that extends in the left and right directions of the head portion so as to cross the plurality of upper threads and contacts the upper thread on the outer peripheral surface, and the thread contact bars provided at both ends of the thread contact bar are eccentric. A connecting tool for pivotally connecting the thread hitting bar to the head part side at a position; and a connecting tool provided on the connecting tool located on at least one end side of both ends of the thread hitting bar; It is installed between the rotating plate that rotates integrally, and the connector and the head side. And an urging means for urging the thread contact bar in a direction to contact the upper thread. The head portion is provided with a protective cover that covers a plurality of balances so that the balance can be opened and closed from the outside. The rotation detecting means is configured to be attached to the protective cover .

By configuring in this way, when one balance selected by the color changing mechanism or the like among a plurality of balances swings up and down, the upper thread is pulled with the sewing needle along with this, Since it behaves so as to project in the rear direction, the rotating body can be rotationally displaced by utilizing this behavior, and the thread breakage of the upper thread can be detected at an early stage by detecting the displacement of the rotating body by the rotation detecting means. Can be detected. In addition, when the thread breakage occurs at the lower part of the needle point of the sewing needle due to the thread breakage of the lower thread or the consumption of the lower thread, the upper thread is not supplied to the sewing needle side, and the upper thread is removed from the balance. In this case as well, the rotating body is no longer rotationally displaced by the upper thread, and it is possible to detect a breakage of the lower thread.
In particular, since the thread pad of the rotating body is arranged at an eccentric position with respect to the rotation center of the coupler, the rotational force in the direction in which the thread pad is brought into contact with the upper thread is used to reduce the weight of the thread pad. It can be generated using. Further, by using the urging means, the force for rotating the thread hitting bar in the direction of contacting the upper thread can be adjusted in relation to the weight of the thread hitting bar, so that the movement of the entire rotating body becomes unbalanced. Can be suppressed. Then, the fact that the upper thread behaves forward and backward with the sewing needle as the balance swings is transmitted to the connecting member of the rotating body and the rotating plate via the thread pad. The entire rotating body can be stably rotated and displaced. Moreover, the head portion is provided with a protective cover that covers the plurality of balances so that they can be opened and closed from the outside, and the rotating body and the rotation detecting means are attached to the protective cover. Thus, the rotating body, the rotation detecting means and the like can be protected together with the plurality of balances using the protective cover, and the yarn break detecting operation can be automatically released when the protective cover is opened.

  According to a second aspect of the present invention, the rotation detecting means is constituted by a non-contact type sensor that detects the displacement of the rotating body in a non-contact state. As a result, the displacement of the rotating body can be detected using a non-contact type sensor, and the occurrence of yarn breakage can be determined with high accuracy from the signal from the non-contact type sensor.

Further, according to the invention of claim 3 , the connecting member of the rotating body extends in the left and right directions in parallel with the thread hitting bar, and the connecting bar is a support portion that rotatably supports the thread hitting bar at both ends. The connecting bar is provided on each support part side, and the connecting bar is configured by a rotating shaft that rotatably connects to the head part side together with a thread hitting bar.

  As a result, the connecting bar can be used to support the thread hitting bar so as to be sandwiched from both the left and right sides, and the thread hitting bar can be rotatably held at a position eccentric from the rotation center of the connecting bar. Then, by rotating the thread application bar in contact with the upper thread, the frictional force generated between the upper thread and the thread application bar can be absorbed, and extra tension is applied to the upper thread by the rotating body. Can be suppressed.

As described above, according to the first aspect of the present invention, the yarn breakage detecting means provided in the head portion located between each sewing needle and each balance, and the respective balances from the upper thread storage means. A rotating body that extends across a plurality of upper threads supplied to the respective sewing needles and rotates and displaces according to the thread tension applied to the upper thread by the balance, and the displacement of the rotating body is detected by detecting the displacement Since the rotation detecting means for detecting thread breakage is included, when one balance selected by a color changing mechanism or the like among a plurality of balances swings up and down, the upper thread is accompanied by the sewing machine. The rotating body can be rotated and displaced using the fact that it behaves so as to be pulled backward and forward with the needle, and the thread breakage is detected by detecting the displacement of the rotating body with the rotation detecting means. Occurrence can be detected early. Accordingly, it is possible to stably detect the yarn breakage of the upper thread or the lower thread selected by the color change mechanism or the like without being influenced by other non-selected upper threads.
In this case, since the rotating body is constituted by a thread pad, a connecting tool, a rotating plate and an urging means, the thread pad of the rotating body is arranged at a position eccentric from the center of rotation of the connecting tool, The rotational force in the direction in which the contact bar comes into contact with the upper thread can be generated using the weight of the thread contact bar, and the force for rotating the thread contact bar in the direction in which the thread contact bar comes into contact with the upper thread by the urging means It can be adjusted in relation to the weight of the thread stopper, and the movement of the entire rotating body can be prevented from becoming unbalanced. Then, the fact that the upper thread behaves forward and backward with the sewing needle as the balance swings is transmitted to the connecting member of the rotating body and the rotating plate via the thread pad. The entire rotating body can be stably rotated and displaced, and the operating characteristics of the rotating body can be improved corresponding to the high speed operation of the sewing machine.
In addition, the head portion is provided with a protective cover that covers the plurality of balances so that they can be opened and closed from the outside, and the rotating body and the rotation detecting means are attached to the protective cover. At the same time, the rotating body, the rotation detecting means and the like can be protected from dust such as surrounding lint or other obstacles, and the detection accuracy at the time of thread breakage can be improved. When the protective cover is opened, the yarn breakage detecting operation can be automatically canceled, and the maintainability during maintenance and inspection can be improved.

  According to the second aspect of the present invention, since the rotation detecting means is constituted by a non-contact sensor that detects the displacement of the rotating body in a non-contact state, the non-contact sensor detects the displacement of the rotating plate. The occurrence of yarn breakage can be detected with high accuracy by a signal from a non-contact sensor.

According to the third aspect of the present invention, the connecting device of the rotating body is provided on the connecting bar and on each support portion side of the connecting bar, and the connecting bar can be rotated together with the thread hitting bar toward the head portion side. The threaded bar can be supported by using the connecting bar so that it can be sandwiched from both the left and right sides, and the threaded bar can be offset from the center of rotation of the connecting bar. It can be held so that it can rotate. Then, by rotating the thread stopper in contact with the upper thread, the frictional force generated between the upper thread and the thread stopper can be kept low and absorbed, and extra tension is applied to the upper thread by the rotating body. And the life of the apparatus can be extended.

1 is a front view showing a multicolor embroidery sewing machine provided with a thread breakage detecting device according to an embodiment of the present invention. FIG. 2 is a right side view of FIG. 1 showing a part of a multicolor embroidery sewing machine. It is a front view which expands and shows the head part in FIG. FIG. 4 is a partially broken side view showing the head portion from the direction of arrows IV-IV in FIG. 3. It is sectional drawing which shows a protective cover, a thread breakage detector, etc. from the arrow VV direction in FIG. It is a perspective view which shows the rotation body of a thread break detector. It is an enlarged view which shows the slit board of a thread break detector. It is operation | movement explanatory drawing which shows a motion of the embroidery thread | yarn, a slit board, etc. in a scale bottom dead center. It is operation | movement explanatory drawing which shows a motion of the embroidery thread | yarn, a slit board, etc. in the balance middle point. It is operation | movement explanatory drawing which shows a motion of the embroidery thread | yarn, a slit board, etc. in the balance top dead center.

  Hereinafter, a thread breakage detecting device for a multicolor embroidery sewing machine according to an embodiment of the present invention will be described in detail with reference to FIGS.

  In the figure, reference numeral 1 denotes a base of a multicolor embroidery sewing machine. On the base 1, side frames 2 and 3 are erected apart from each other on the left and right sides, and between the left and right side frames 2 and 3 The head support 4 is arranged so as to hang over.

  Reference numeral 5 denotes a head portion of a sewing machine provided on the front side of the head support 4. The head portion 5 is provided on the front side of the head main body 6 and the head main body 6 as shown in FIG. Needle bar case 7 that can be moved left and right (in the directions of arrows a and b in FIG. 1), and needle bar case 7 provided on needle bar case 7 by color change mechanism 8. It is composed of a thread tension base 9 that is moved in the left and right directions.

  The head body 6 is provided with a balance drive unit and a needle bar drive unit (both not shown) driven by the spindle motor 10 shown in FIG. The balance 17 and the needle bar 18 are driven up and down, respectively. The color changing mechanism 8 performs the color changing operation described later by moving the needle bar case 7 and the thread tension base 9 together to the left and right.

  Reference numeral 12 denotes a cheese stand as upper thread storage means disposed on the rear side of the head support 4, and the cheese stand 12 includes a plurality of upper thread bobbins 12A, 12B, 12C,. These upper thread bobbins 12A, 12B, 12C,... Are wound with, for example, a plurality of upper thread threads (hereinafter referred to as embroidery thread S) such as red, blue, yellow, white, and black. Yes. During the embroidery work, the embroidery thread S is selectively drawn from the upper thread bobbins 12A, 12B, 12C,... By the balance 17, and embroidery is performed on an embroidery object (not shown) such as an embroidery cloth. It is.

  13, 13,... Are thread tensioners provided on the thread tension base 9 of the head unit 5, and these thread tensioners 13 are spaced apart from each other on the upper side of the thread tension base 9 as shown in FIG. A total of nine are arranged. 14, 14,... Indicate, for example, nine thread tensions provided on the thread tension stand 9 at the lower side of each thread tensioner 13.

  Then, the embroidery thread S drawn from the upper thread bobbins 12A, 12B, 12C, etc. of the cheese stand 12 is guided to each thread tension 14 via the thread tensioner 13, and the thread tension 14 moves toward the balance 17 side. The yarn is fed with low friction. In this case, the thread tension 14 applies a tension of, for example, about 10 to 50 g to the embroidery thread S, and when the embroidery thread S is pulled beyond the tension by a sewing needle 19 or the like described later, the thread tension 14 is directed toward the balance 17 side. The embroidery thread S is allowed to be fed.

  Reference numeral 15 denotes a thread guide provided on the thread tension base 9 below the thread tension 14. The thread guide 15 is a plate-shaped metal fitting extending left and right along the lower end side of the thread tension base 9. For example, a total of nine thread insertion holes (not shown) are arranged at intervals on the left and right. One embroidery thread S is inserted between the thread tension 14 and the balance 17 in each thread insertion hole of the thread guide 15.

  Reference numeral 16 denotes another thread guide provided on the front side of the needle bar case 7 and positioned below the balance 17, and the thread guide 16 extends in the width direction (left and right directions) of the needle bar case 7. For example, a total of nine thread insertion portions 16A (only one is shown in FIG. 8) are arranged in the same manner as the thread insertion holes of the thread guide 15.

  Further, the yarn guide 16 is provided with a total of nine yarn hooking portions 16B corresponding to the respective yarn insertion portions 16A as shown in FIG. Each embroidery thread S guided from the upper thread guide 15 is inserted into a thread hooking portion 16B of the thread guide 16, and then drawn toward a thread insertion hole 17B of a balance 17, which will be described later, from the thread insertion hole 17B. The guide 16 is guided to the sewing needle 19 side shown in FIG. 4 through the thread insertion portion 16A.

  17, 17,... Are scales provided to protrude from the needle bar case 7 of the head portion 5 to the front side, and these balances 17 are arranged on the left and right sides in the needle bar case 7 as shown in FIG. As shown in FIG. 4, a balance gear 17A is provided on the base end side. A balance gear 17A of the balance 17 meshes with a drive gear (not shown) of the balance drive unit provided in the head body 6, and the balance 17 is moved upward as shown in FIGS. It swings down.

  In this case, for example, when any one of the nine balances 17 in total is selected by the color change mechanism 8, only the selected balance 17 is swung up and down. The remaining balance 17 which is not selected remains at the top dead center position indicated by a solid line in FIG. 4 and is held at this top dead center position until it is selected by the color changing mechanism 8 thereafter. is there.

  A thread insertion hole 17B is formed on the tip (protruding end) side of the balance 17, and the embroidery thread S is inserted into the thread insertion hole 17B. In this state, when the balance 17 is driven downward from the top dead center to the bottom dead center, the balance 17 gives a slight slack to the embroidery thread S between the sewing needle 19 and the embroidery thread S. Feed the yarn to the side.

  Further, when the balance 17 is driven upward, the embroidery thread S is pulled up between the seam (not shown) formed on the embroidery cloth or the like by the sewing needle 19 and the thread tension 14 and the like. Tension is applied to the thread S, and the seam is tightened and the embroidery thread S is fed out.

  .. Are, for example, nine needle bars provided in the needle bar case 7 at the lower side of the balance 17, and a sewing needle 19 can be attached to and detached from the lower end side of each needle bar 18. It is installed. The needle bar 18 and the sewing needle 19 are driven up and down in accordance with the rotation of the main shaft 11 by a needle bar drive unit (not shown) provided in the head body 6.

  The needle bar 18 and the sewing needle 19 are also selected by the color changing mechanism 8 in the same manner as the balance 17, and only the selected needle bar 18 is reciprocated up and down together with the sewing needle 19. . The remaining non-selected needle bar 18 stays at the top dead center position as shown in FIG. 3 together with the sewing needle 19 and is held at the top dead center position until selected by the color changing mechanism 8. It is.

  As shown in FIGS. 1 and 2, 20 is a moving frame such as an embroidery frame that is located on the base 1 of the sewing machine and is located below the head portion 5, and the moving frame 20 is an embroidery cloth (not shown). Etc.) are held in a stretched state, and the frame is moved in the horizontal direction from the front, back, left and right on the base 1 together with the embroidery cloth.

  When the moving frame 20 is moved in this manner, the sewing needle 19 on the head portion 5 side is moved up and down almost in conjunction with this movement, so that the embroidery cloth or the like corresponds to the embroidery data. An embroidery pattern is realized. As shown in FIG. 1, a lower thread rotary hook 21 and the like are provided below the moving frame 20 between the lower frame and the lower thread bobbin (see FIG. 1). Etc.) are arranged.

  Further, as shown in FIG. 1, a sewing machine control device 22 called, for example, an automat is provided on the head support 4, and this control device 22 displays information necessary for embroidery work. And an input key (not shown) such as a keyboard, a jog key, and a switch.

  Next, reference numeral 24 denotes a protective cover provided on the front side of the head portion 5. The protective cover 24 is provided on the front side of the needle bar case 7 using left and right hinge shafts 25 and 25 as shown in FIG. It is provided so that it can be opened and closed, and is configured to cover each balance 17, the thread guide 16 and the like from the outside. Accordingly, the protective cover 24 protects the balance 17 and the like from external dust, obstacles, and the like on the front side of the needle bar case 7.

  Here, the protective cover 24 is formed with a large rectangular window portion 24A as shown in FIG. 5, and a transparent plate 26 is attached to the window portion 24A. The protective cover 24 is provided with left and right bearing portions 27 and 27 at positions spaced downward from the hinge shaft 25, and a rotating body 32 of a thread breakage detector 31 described later is provided on each bearing portion 27. It is pivotally supported so that it can rotate.

  Further, as shown in FIG. 3, the protective cover 24 is provided with a stopper 28 positioned below the hinge shaft 25, and the stopper 28 has a closed position indicated by a solid line in FIG. It is selectively positioned at the door opening position indicated by a two-dot chain line.

  31 is a yarn breakage detector provided as a detecting means provided on the protective cover 22, and the yarn breakage detector 31 extends left and right in the protective cover 24 as shown in FIG. , 27 is rotatably supported by a rotating body 32 and an optical sensor 39 which will be described later.

  Here, as shown in FIGS. 5 and 6, the rotating body 32 is formed using a rigid and long metal plate or the like, and becomes support portions 33 </ b> A and 33 </ b> A whose both ends are bent in an L shape. The connecting bar 33 and each support portion 33A located on the left and right ends of the connecting bar 33 are fixed by bolts or the like, and the support portions 33A of the connecting bar 33 are rotated to the bearing portions 27 and 27 of the protective cover 24. The rotation shafts 34 and 35 are connected to each other, and a thread contact rod 36, a slit plate 37, a spring 38, and the like which will be described later.

  Reference numeral 36 denotes a thread contact bar that is rotatably provided between the support portions 33A of the connecting bar 33. The thread contact bar 36 is formed of a hollow elongated tube using a light material such as aluminum, for example. It is attached to the connecting bar 33 with being sandwiched between 33A. The thread hitting bar 36 extends in the left and right directions in parallel with the connecting bar 33, and both end sides thereof are rotatably connected to the support portions 33 </ b> A of the connecting bar 33.

  Here, the thread hitting bar 36 is supported by each support part 33A of the connecting bar 33 at a position eccentric from the rotary shafts 34, 35. A connecting tool connected to the protective cover 24 on the side is configured.

  Then, as shown in FIG. 3, the rotating body 32 including the connecting bar 33 and the thread hitting bar 36 traverses a plurality of embroidery threads S between the balances 17 and the sewing needles 19 in the left and right directions. The embroidery thread S is in contact with the outer peripheral surface of the thread striking bar 36 as shown in FIGS. At this time, the thread contact bar 36 is rotationally displaced in the directions indicated by arrows A and B shown in FIGS. 8 to 10 together with the connecting bar 33 and the like by the tension of the embroidery thread S and the biasing force of the spring 38.

  Further, the connecting bar 33 holds the thread hitting bar 36 in an eccentric position away from the rotation center of the rotary shafts 34 and 35 so that the thread hitting bar 36 can rotate, so that the thread hitting bar 36 freely rotates by contact with the embroidery thread S. (Rotation) is compensated for, whereby the frictional force generated between the embroidery thread S and the thread pad 36 can be absorbed, and extra tension is applied to the embroidery thread S by the rotating body 32. Can be suppressed.

  Reference numeral 37 denotes a slit plate as a rotating plate provided between one support portion 33A of the connecting bar 33 and the rotating shaft 35. The slit plate 37 is made of a thin metal plate or the like as shown in FIG. A mounting hole 37A of the rotating shaft 35 is formed at the center thereof. Further, the slit plate 37 is provided with a mounting hole 37B for the thread hitting bar 36 at a position eccentric from the central mounting hole 37A, and spaced apart from each other on the circumference centering on the mounting hole 37A. A plurality of slits 37C, 37C,... And a plurality of retaining holes 37D, 37D,.

  Then, the slit plate 37 selectively latches a later-described spring 38 in any one of the latching holes 37D, whereby the spring 38 causes the rotating body 32 to be indicated by an arrow in FIG. The biasing force when biasing in the A direction is adjusted. When the rotating body 32 including the slit plate 37 is rotationally displaced in the directions indicated by arrows A and B shown in FIGS. 8 to 10, each slit 37C intermittently transmits or blocks light from the optical sensor 39 described later. By doing so, the displacement of the rotating body 32 is detected by the optical sensor 39.

  Reference numeral 38 denotes a spring as an urging means provided between the protective cover 24 and the rotating body 32. The spring 38 is constituted by a torsion coil spring, a helical spring, etc. as shown in FIG. Is hooked to the protective cover 24. The spring 38 is inserted from the outside into the rotating shaft 35 side of the rotating body 32, and the other end side 38B is attached to the retaining hole 37D of the slit plate 37 as described above.

  The spring 38 applies an urging force in the direction indicated by the arrow A to the rotating body 32. For example, thread breakage or the like occurs in the embroidery thread S, and the thread tension of the embroidery thread S is applied to the thread hitting bar 36 of the rotating body 32. In a state where it does not substantially act, the rotating body 32 is held in a stopped state at the position shown in FIG.

  39 is an optical sensor which is provided on the protective cover 24 at a position close to the slit plate 37 and constitutes a non-contact type sensor as a rotation detecting means. The optical sensor 39 is composed of, for example, a photo interrupter, etc. The rotation of the slit plate 37 is detected by receiving the light at a light receiving part (both not shown).

  That is, the rotating body 32 including the connecting bar 33, the thread hitting bar 36, the slit plate 37, and the like resists the spring 38 by the thread tension of the embroidery thread S by the balance 17, and moves in the direction indicated by the arrow B shown in FIGS. When the optical sensor 39 is rotated, light from the light emitting unit is intermittently transmitted or blocked to the light receiving unit side through the slits 37 </ b> C of the slit plate 37.

  For this reason, the light-receiving part of the optical sensor 39 receives light in pulses and outputs a detection signal composed of a pulse signal. On the other hand, when the thread breakage occurs and the rotating body 32 is stopped by the biasing force of the spring 38, for example, at the position shown in FIG. 10, the slit plate 37 is also stopped at the position shown in FIG. The output of the pulse signal (detection signal) from the optical sensor 39 is also stopped, whereby the occurrence of yarn breakage can be detected.

  The multi-color embroidery sewing machine thread breakage detecting device according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, when the spindle 11 is rotated by the spindle motor 10 and the balance driving unit and the needle bar driving unit of the head unit 5 are reciprocated, the needle bar 18 selected by the color changing mechanism 8 is moved to the sewing needle 19 by the needle bar driving unit. At the same time, it is driven up and down to move the sewing needle 19 relative to the embroidery cloth.

  Further, the balance 17 selected by the color changing mechanism 8 is also swung in the directions indicated by arrows C and D shown in FIGS. 8 to 10 by the balance driving unit, and the balance 17 becomes the bottom dead center at the position shown in FIG. Thereafter, it passes through the intermediate position shown in FIG. 9 and is repeatedly moved up and down to the top dead center position shown in FIG.

  The desired embroidery thread S selected by the color changing mechanism 8 is one of the upper thread bobbins 12A, 12B, 12C,... On the cheese stand 12 shown in FIG. Is supplied to the sewing needle 19 side through the yarn tensioner 13, the thread tension 14 and the like. During this time, the embroidery thread S is sewn on the embroidery cloth on the moving frame 20 side as the sewing needle 19 moves, and each time the sewing needle 19 forms a seam on the embroidery cloth, the embroidery thread S moves to the sewing needle 19 side. And a desired embroidery pattern is created.

  Here, the embroidery cloth S selected by the color changing mechanism 8 is pulled between the sewing needle 19 (seam) following the movement of the balance 17, and as shown in FIGS. It behaves like overhanging. 9 moves so that the embroidery thread S protrudes to the front most, and at this time, the rotating body 32 opposes the spring 38 due to the tension of the embroidery thread S. Is rotated.

  Further, since the embroidery thread S moves backward at the top dead center position of the balance 17 shown in FIG. 10, the rotating body 32 is rotated in the direction indicated by the arrow A by the spring 38 at this time. While the balance 17 selected by the color changing mechanism 8 swings up and down, the embroidery thread S behaves so as to protrude forward and backward, and this behavior is used. The rotating body 32 can be repeatedly rotated and displaced in the directions indicated by arrows A and B with a rotation range of about 20 to 40 degrees, for example.

  On the other hand, when the embroidery thread S is cut off during the embroidery operation, the thread tension by the balance 17 is lost, and the behavior of the embroidery thread S as described above stops. For example, the rotating body 32 is stopped at the position shown in FIG. In this case, the rotating body 32 is held in a stopped state, for example, at the position shown in FIG. 10 by the weight balance of the connecting bar 33 and the thread hitting bar 36 around the rotating shafts 34 and 35 and the biasing force of the spring 38. Is.

  In this case, the spring 38 is selectively latched in any one of the latching holes 37D on the slit plate 37 of the rotating body 32 in a preparation stage before starting the embroidery work. Thus, the urging force when the spring 38 urges the rotating body 32 in the direction indicated by the arrow A in FIG. 8 is adjusted, and the stop position of the rotating body 32 can be adjusted accordingly.

  Further, the balance 17 is at the top dead center at the position shown in FIG. 10, and the top dead center position is also used for each unselected balance 17 not selected by the color changing mechanism 8 by using a balance holding mechanism (not shown). Therefore, even if the moving frame 20 is moved in this state, the non-selected embroidery thread S is not pressed against the thread hitting bar 36 side of the rotating body 32 due to the frame movement. .

  For this reason, when a thread breakage occurs while one embroidery thread S is selected from a plurality of embroidery threads S and the embroidery operation is being performed, the other non-selected embroidery threads S are moved to the frame of the moving frame 20. Even if it vibrates with movement, the rotating body 32 is not displaced in the direction of arrow B in FIG. 10 against the spring 38, and the rotating body 32 is held in a substantially stopped state. Can do.

  Thus, according to the present embodiment, the yarn breakage detector 31 including the rotating body 32 and the optical sensor 39 is provided on the protective cover 24, and the entire rotating body 32 is placed in the balance 17 when the protective cover 24 is closed. And the sewing needle 19 are arranged so as to cross the embroidery threads S, and the thread striking bar 36 of the rotating body 32 comes into contact with the embroidery thread S selected by the color changing mechanism 8, and the balance 17. Thus, the rotary body 32 is rotationally displaced according to the thread tension applied to the embroidery thread S.

  While the rotating body 32 is rotationally displaced in the directions indicated by arrows A and B shown in FIGS. 8 to 10, the optical sensor 39 detects the rotation of the slit plate 37 and outputs a pulse signal. Since the output of the pulse signal is interrupted when the rotation is stopped, the movement of the rotating body 32 can be detected by the optical sensor 39, and the occurrence of yarn breakage can be detected at an early stage.

  Further, when the thread breakage occurs at a portion below the needle tip of the sewing needle 19 due to the thread breakage of the lower thread or the consumption of the lower thread, the embroidery thread is not supplied to the sewing needle 19 side. Since the supply of the embroidery thread S and the movement of the embroidery thread S by 17 are interrupted, the rotating body 32 is not rotationally displaced by the embroidery thread S in this case as well, and the thread breakage of the lower thread can be detected at an early stage. .

  Therefore, according to the present embodiment, the yarn breakage detector 31 is constituted by the rotating body 32 and the optical sensor 39, so that the yarn breakage detector 31 can detect when the yarn breakage occurs at an early stage. Thread breakage can be detected stably without being affected by other non-selected embroidery threads S.

  Further, slits 37C are formed in the slit plate 37 of the rotating body 32 at intervals in the circumferential direction at positions away from the center of rotation, and the optical sensor 39 made of a photo interrupter or the like passes through the slits 37C. Since the displacement of 37 is optically detected, the occurrence of yarn breakage can be detected with high accuracy by a signal from the optical sensor 39.

  Then, the rotating body 32 is bent at the left and right end sides in an L shape to form support portions 33A and 33A, and the connection bar 33 provided on each support portion 33A side of the connection bar 33. The thread support rod 36 is composed of rotating shafts 34 and 35 rotatably connected to the protective cover 24 on the head unit 5 side. The thread support rod 36 extends in the left and right directions in parallel with the connection bar 33, and has both ends. The side is configured to be rotatably supported by each support portion 33 </ b> A of the connecting bar 33.

  For this reason, it is possible to support the thread hitting bar 36 so as to be sandwiched from both the left and right sides using the connecting bar 33, and to hold the thread hitting bar 36 so as to be rotatable at a position eccentric from the rotation center of the connecting bar 33. it can. Then, the thread pad 36 is formed of a hollow elongated tube to reduce the weight of the thread pad 36 and to rotate the thread pad 36 in contact with the embroidery thread S, thereby allowing the embroidery thread S and the thread pad 36 to be rotated. The frictional force generated between the embroidery threads S can be absorbed smoothly with low friction, and the extra tension applied to the embroidery thread S by the rotating body 32 can be suppressed, and the life of the apparatus can be extended. it can.

  Further, since the thread application bar 36 of the rotating body 32 is arranged at a position eccentric with respect to the rotation center of the connecting bar 33, the rotational force in the direction in which the thread application bar 36 contacts the embroidery thread S is applied. It can be generated using the weight of the rod 36. Further, by using the spring 38, a force for rotating the thread hitting bar 36 in the direction in which the thread hitting bar 36 is brought into contact with the embroidery thread S (the direction indicated by the arrow A in FIGS. 8 to 10) is applied. And the biasing force of the spring 38 can be adjusted, and the movement of the entire rotating body 32 can be prevented from becoming unbalanced.

  In this case, since the plurality of latching holes 37D, 37D,... Are formed in the slit plate 37 of the rotating body 32, the spring 38 is selected for any one of the latching holes 37D. Therefore, the biasing force when the spring 38 biases the rotating body 32 in the direction indicated by the arrow A can be easily adjusted, and the stop position of the rotating body 32 can be appropriately adjusted accordingly. it can.

  Then, as the balance 17 swings, the embroidery thread S behaves so as to protrude forward and backward from the sewing needle 19. By transmitting to the slit plate 37, the entire rotating body 32 can be stably rotated and displaced, and the operating characteristics of the rotating body 32 can be improved in response to high-speed operation of the sewing machine (main shaft motor 10).

  Further, the head portion 5 of the sewing machine is provided with a protective cover 24 that covers the plurality of balances 17, 17,... From the front side so that the balance can be opened and closed, and the rotating body 32 and the optical sensor 39 are attached to the protective cover 24. Therefore, it is possible to protect the rotating body 32 and the optical sensor 39 together with the respective balances 17 using the protective cover 24 from dust such as surrounding lint or other obstacles, etc., and the detection accuracy at the time of thread breakage is improved. Can be improved. Furthermore, when the protective cover 24 is opened, the detection operation of the yarn breakage detector 31 can be automatically canceled, and the maintainability during maintenance and inspection can be improved.

  In the above-described embodiment, the thread stopper 36 is rotatably connected to the rotating shafts 34 and 35 so that the thread stopper 36 is sandwiched from both ends by using the long connecting bar 33. The present invention is not limited to this. For example, the long connecting bar 33 is eliminated, and both the left and right ends of the thread hitting bar 36 are respectively connected to the rotary shafts 34 and 35 by using one connecting bracket or the like. It is good also as a structure to connect.

  In the above-described embodiment, the case where the yarn breakage detector 31 including the rotating body 32 and the optical sensor 39 is attached to the protective cover 24 provided on the head unit 5 of the sewing machine has been described as an example. The present invention is not limited to this. For example, the protective cover 24 may be omitted. In this case, the thread breakage is detected on the front side of the head unit 5 between the balances 17 and the sewing needles 19. What is necessary is just to set it as the structure which provides detection means, such as the instrument 31. FIG.

  Further, in the above-described embodiment, the rotation detecting means for detecting the rotation of the rotating body 32 is described as being configured by the optical sensor 39. Instead of this, for example, a non-contact such as a magnetoresistive element, a Hall element, etc. The rotation detection means may be configured using a type sensor.

DESCRIPTION OF SYMBOLS 1 Base 2, 3 Side frame 4 Head support body 5 Head part 6 Head main body 7 Needle bar case 8 Color change mechanism 9 Thread tension stand 11 Spindle 12 Cheese stand (upper thread storage means)
14 Thread tension 17 Balance 18 Needle bar 19 Sewing needle 20 Moving frame 24 Protective cover 27 Bearing part 31 Thread breakage detector (detection means)
32 Rotating body 33 Connecting bar (connecting tool)
34, 35 Rotating shaft 36 Thread rest rod 37 Slit plate (rotating plate)
37C slit 38 spring (biasing means)
39 Optical sensor (non-contact sensor, rotation detection means)
S Embroidery thread (upper thread)

Claims (3)

A plurality of sewing needles and balances are provided for performing multicolor embroidery, and one of the sewing needles and the balance is selectively driven by one of the sewing needles and the balance, and each sewing machine of the head portion An upper thread storage means for storing a plurality of upper threads for supplying an upper thread to the needles via a balance, and a thread breakage provided between the sewing needles and the scales and provided in the head unit. In a thread breakage detecting device of a multicolor embroidery sewing machine comprising detecting means for detecting presence or absence,
The detecting means extends across the plurality of upper threads supplied from the upper thread storage means to the respective sewing needles via the respective balances, and is rotated and displaced according to the thread tension applied to the upper threads by the balance. A moving body and rotation detecting means for detecting the yarn breakage by detecting the displacement of the rotating body ;
The rotating body extends to the left and right of the head part so as to cross the plurality of upper threads, and a thread pad that is in contact with the upper thread on the outer peripheral surface, and the thread rest that is provided at both ends of the thread pad. A connecting tool for rotatably connecting the thread holding bar to the head part side at an eccentric position, and a connecting tool positioned on at least one end side of both ends of the thread holding bar. And a rotation plate that rotates integrally with the coupling tool, and a biasing means that is provided between the coupling tool and the head portion side and biases the thread striking bar in a direction to contact the upper thread. ,
Opened from the outside a plurality of balance to the head portion is provided with a protective cover closed can cover, the rotating body and multicolor embroidery machine characterized in that it is configured to attach to the protective cover and the rotation detection means Yarn breakage detection device.   2. The multi-color embroidery sewing machine thread breakage detecting device according to claim 1, wherein the rotation detecting means comprises a non-contact type sensor that detects a displacement of the rotating body in a non-contact state. The connecting member of the rotating body includes a connecting bar extending in the left and right directions in parallel with the thread hitting bar and having both ends serving as support parts for rotatably supporting the thread hitting bar, and each support part side of the connecting bar The thread breakage detecting device for a multicolor embroidery sewing machine according to claim 1 or 2 , comprising a connecting shaft and a rotating shaft that rotatably connects the connecting bar to the head portion side together with a thread hitting bar.

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