JP2003000976A - Embroidery sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent needle breakages at the time of inserting and drawing out a sewing needle even in the case when the matter to be embroidered is a thick material, and also permit the formation of long stitches. SOLUTION: An embroidery sewing machine has such a type that a shuttle 50 synchronizes with the vertical drive of a needlebar 42 in a sewing machine head 16 to be rotated and driven, and that an embroidering frame is controlled to move by synchronizing with them so as to perform the embroidery sewing of the matter to be embroidered. A needlebar jump control in which the sewing machine head 16 shuts off the transmission of the vertical drive to the needle bar 42 is permitted. Moreover, in the shift control of the embroidering frame, it is possible to delay the shift-starting timing at one stitch at the time when the matter to be embroidered is a thick material, and advance the shift-finishing timing. At least one needlebar jump is performed at a stitch, and the embroidering frame is continuously shifted during jump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embroidery sewing machine capable of performing embroidery sewing on an embroidered object held in the embroidery frame by controlling the movement of the embroidery frame in synchronization with vertical movement of a needle bar.

[0002]

2. Description of the Related Art In an embroidery sewing machine of this kind, a needle bar and a balance of a sewing machine head are driven together with other auxiliary members based on rotational driving of a single sewing machine spindle, and a sewing machine table corresponding to the sewing machine head is also driven. The shuttle arranged at the lower part of is driven to rotate. On the other hand, the embroidery frame holding the embroidered object such as cloth is controlled to move along the upper surface of the sewing table by the drive mechanism thereof. The movement of the embroidery frame is controlled in synchronization with the vertical movement of the needle bar, and the embroidery sewing is performed on the embroidered object. The timing at which the embroidery frame can be moved is when the sewing needle attached to the lower end of the needle bar is completely removed from the embroidered object.

FIG. 6 is an explanatory view showing the motion when the vertical movement of the needle bar (sewing needle) is continuously developed, in relation to the rotation angle of the sewing machine main shaft. The horizontal axis of this drawing shows the rotation angle of the sewing machine main axis, and the vertical axis shows the height.
The motion of the needle bar is shown by the locus 100 of the needle tip. The embroidery frame can be moved in the section 110 in which the tip of the sewing needle comes out of the needle plate (the object to be embroidered) and is located above the needle plate. In order to form a stitch as long as possible with one stroke of the needle bar (one rotation of the sewing machine main shaft), the section 110 described above is used.
The movement of the embroidery frame is controlled by making maximum use of. That is, the movement of the embroidery frame is started immediately after the sewing needle comes out of the needle plate, and the movement is stopped immediately before the sewing needle is inserted again.

When the number of revolutions of the sewing machine spindle is increased, the time in the section 110 is naturally shortened, and the stitch length which can be formed in the section 110 is shortened. In that case, a long stitch is formed by using a jump control that cuts off the transmission of the vertical drive to the needle bar and holds the needle bar at its top dead center. Techniques relating to these are disclosed in, for example, Japanese Patent Laid-Open Nos. 58-149363 and 58-18706.

[0005]

When the object to be embroidered is a thick cloth, a thick material such as a urethane material having a thickness of 3 to 8 mm is placed on the cloth and embroidered from above. Then, the time until the sewing needle is completely inserted into the embroidered object or the time when the sewing needle completely comes out of the embroidered object becomes longer than that in normal embroidery. As a result, the timing of inserting or removing the sewing needle with respect to the embroidered object does not match the timing of starting or stopping the movement of the embroidery frame, and excessive force may be applied to the sewing needle to cause needle breakage. . The present invention is intended to solve the above-mentioned problems, and an object thereof is to prevent needle breakage at the time of needle insertion and needle removal of a sewing needle even when the object to be embroidered is thick, and to have a long stitch. It is also possible to form.

[0006]

SUMMARY OF THE INVENTION The present invention is to achieve the above object. The invention according to claim 1 corresponds to a sewing machine head arranged above a sewing machine table and the sewing machine head. The sewing machine is provided with a shuttle arranged under the sewing machine table and an embroidery frame capable of holding an embroidered object and controlled to move along the upper surface of the sewing machine table, in synchronization with the vertical drive of the needle bar of the sewing machine head. An embroidery sewing machine of the type in which the hook is rotatably driven, and the embroidery frame is moved and controlled in synchronization with these to embroider on the embroidered object. It is possible to perform needle bar jump control that blocks the transmission of vertical drive to the bar. Further, the movement control of the embroidery frame can delay the movement start timing and advance the movement end timing for one stitch when the object to be embroidered is thick. Moreover, the needle bar jump is performed at least once in one stitch, and the embroidery frame is continuously moved during the jump. According to this structure, when the object to be embroidered is thick, the movement start timing of the embroidery frame is delayed and the end timing is advanced as described above, so that the force applied to the sewing needle during needle insertion or needle removal is too great. Can be avoided. Also, by controlling the needle bar jump, long stitches can be easily formed.

According to a second aspect of the present invention, there is provided the embroidery sewing machine according to the first aspect, wherein the needle bar reaches a position near the top dead center of the embroidery frame and the hook is moved to the upper hook. It is set so that it can be delayed after the needle thread caught in is pulled out from the hook with almost no resistance. As a result, the embroidery frame is moved at a timing at which the upper thread can be pulled out from the shuttle without resistance, and it is possible to eliminate an excessive force applied to the upper thread.

A third aspect of the present invention is the embroidery sewing machine according to the first aspect, wherein the normal sewing mode and the thick material sewing mode can be switched according to the thickness of the embroidered object. In the sewing mode, the movement start timing of the embroidery frame is delayed and the movement end timing is advanced in comparison with the normal sewing mode, and the needle bar jump is set. By enabling switching between the thick material sewing mode and the normal sewing mode in this way, it is possible to quickly switch operating conditions according to the thickness and properties of the embroidered object.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
5 will be described. FIG. 1 is an external perspective view showing a multi-head / multi-needle type embroidery sewing machine. A sewing machine frame 12 is arranged above the sewing machine table 10 in the embroidery sewing machine, and a plurality of (four) sewing machine heads 16 are provided on the sewing machine frame 12. An embroidery frame 14 for holding an embroidered object such as cloth is located on the upper surface of the sewing machine table 10. The embroidery frame 14 is controlled to move in the X and Y directions along the upper surface of the sewing machine table 10 by a frame driving device (not shown) based on the embroidery data.

2 and 3 are vertical sectional views showing the outline of the internal structure of one sewing machine head. The outer shell member of the sewing machine head 16 is separated into a sewing machine arm 18 mounted on the sewing machine frame 12 and a needle bar case 40 assembled so as to be slidable in the left-right direction with respect to the front surface portion of the sewing machine arm 18. There is. Sewing machine arm 1
A guide rod 2 is provided at a position near the front inside of 8.
0 is provided vertically, and the upper and lower ends of the guide rod 20 are supported by the sewing machine arm 18. Further, the base 22 and the needle bar drive member 24 are provided on the shaft of the guide bar 20.
It is attached so as to be able to reciprocate up and down along 0.

The needle bar drive member 24 is rotatable about the axis of the guide bar 20 with respect to the base 22, but is normally held in the state shown in the drawing by the force of a spring (not shown). The sewing machine arm 18 is equipped with a jump mechanism 32 shown in phantom in FIGS.
The jump mechanism 32 operates so that the roller 34 pushes the surface 24 a of the needle bar drive member 24 based on the needle bar jump signal. This causes the needle bar drive member 24 to rotate about the axis of the guide bar 20 against the base 22 against the spring force.

Inside the sewing machine arm 18, a sewing machine main shaft 26 penetrating over the respective sewing machine heads 16 is located. The sewing machine main shaft 26 rotates in one direction by a driving force of a motor (not shown) which is a drive source of the embroidery sewing machine.
The drive cam 2 fixed on the shaft of the sewing machine main shaft 26.
The rotation of 8 is transmitted to the base 22 (needle bar driving member 24) through the drive transmission link 30 as a driving force for vertically reciprocating the same. Further, inside the sewing machine arm 18, there is provided a balance driving lever 38 for repeatedly rotating (balance operation) a balance 36 described below based on the rotation of the sewing machine main shaft 26.

The needle bar case 40 has a plurality of needle bars 42.
Are supported so as to be able to reciprocate up and down, and each needle bar 42 is provided with a pin 44 protruding toward the sewing machine arm 18 at a substantially middle portion between the upper and lower sides. One of the needle bars 42 is selected by slidingly controlling the needle bar case 40 with respect to the sewing machine arm 18, and a pin 44 of the needle bar 42 is selected.
Engages with the needle bar drive member 24 in a state in which power can be transmitted in the vertical direction (FIG. 2). Therefore, the selected needle bar 42 is vertically driven together with the sewing needle 46 and the cloth presser 48 in conjunction with the vertical movement of the needle bar drive member 24.

On the axis of each needle bar 42, a coil spring 45 is provided which exerts an elastic force between the upper end of each needle bar 42 and the needle bar case 40. Due to the elastic force of the coil spring 45, the needle bar 42 in a state where the needle bar drive member 24 and the pin 44 are not engaged is held at the top dead center (FIG. 3). With respect to the needle bar 42 selected as described above, when the needle bar drive member 24 is rotated around the axis of the guide bar 20 by the operation of the jump mechanism 32 based on the needle bar jump signal, the needle bar drive member 24 and the pin are rotated. 44 is disengaged. As a result, the needle bar 42 is held at the top dead center as shown in FIG.

The needle bar case 40 is provided with as many balances 36 as the number of the needle bars 42 so that they can be repeatedly rotated around the axis of the balance shaft 37. Then, the balance 3 corresponding to the needle bar 42 selected by the slide control of the needle bar case 40
Only 6 receives the driving force by the balance driving lever 38. By selecting the needle bar 42 and the balance 36 by sliding the needle bar case 40, the balance 36 and the sewing needle 4 are selected.
The color and properties of the thread passed through 6 will be selected.

The needle plate 5 shown in FIGS. 2 and 3 is provided on the upper surface of the sewing machine table 10 and at a position corresponding to each sewing machine head 16.
2 and the shuttle 50 (vertical shuttle) is located below the needle plate 52. The shuttle shaft 51 of the shuttle 50 is driven to rotate together with the outer shuttle 50a in synchronization with the sewing machine main shaft 26. The hook 50 in the embroidery sewing machine is of a type generally called a "two-turn hook", and the outer hook 50a makes two revolutions per revolution of the sewing machine main shaft 26. The needle plate 52 has a needle hole 54 through which the sewing needle 46 is inserted.

FIG. 4 is an explanatory view showing the respective motions when the vertical movement of the needle bar and the repetitive rotation of the balance are continuously developed in relation to the rotation angle of the sewing machine main shaft.
FIG. 4 is an explanatory diagram showing a motion when the vertical movement of the needle bar is continuously expanded when the needle bar jump is controlled in relation to the rotation angle of the sewing machine main shaft. In these figures, the horizontal axis shows the rotation angle of the sewing machine main shaft 26, and the vertical axis shows the height. The position of "0" on the vertical axis is the upper surface of the needle plate 52, and the motion M1 of the needle bar 42 is shown by the locus drawn by the lower end of the sewing needle 46. Further, the motion M2 of the balance 36, which is shown by a virtual line in FIG. 4, is shown by a locus drawn by the leading end of the balance through which the needle thread is passed. However, the motion M2 of the balance 36 represents the timing with respect to the motion M1 of the needle bar 42, and is unrelated to the numerical value of the height shown on the vertical axis.

Further, FIG. 4 shows the outer pot 50 in the pot 50.
The rotation of a is shown in association with the rotation angle (horizontal axis) of the sewing machine main shaft 26. As described above, the shuttle 50 is of a type in which the outer shuttle 50a makes two revolutions per revolution of the sewing machine main shaft 26. The rotation angle of the sewing machine main shaft 26 when the blade tip 50b of the outer hook 50a reaches the uppermost position is 197 °,
At this timing, the needle thread passed through the sewing needle 46 is captured by the sword tip 50b. Outer pot 50a from here
The needle thread is pulled out most from the supply side by the shuttle 50 around a rotation angle of 287 ° of the sewing machine spindle 26 rotated by about 180 ° (rotation angle of the sewing machine spindle = 90 °). Therefore, the tip end portion of the balance 36 is in the lowered position as shown by the motion M2 in FIG. 4, and the upper thread is pulled into the shuttle 50 without difficulty.

The rotation of the outer hook 50a thereafter causes slack in the upper thread. However, since the tip end portion of the balance 36 turns upward, the upper thread absorbs the slack and the hook 5
It is pulled up from the 0 side. However, the upper thread remains restricted by the shuttle 50 until the rotation angle of the sewing machine main shaft 26 reaches 330 °. Therefore, even if an attempt is made to pull out the upper thread from the hook 50 before that, the upper thread cannot be pulled out from the hook 50, and if an excessive force is applied, the upper thread is pulled out from the upstream side (supply side) of the sewing needle 46. Will be done.

In the conventional embroidery sewing machine, the movement of the embroidery frame is started before the rotation angle of 330 ° of the main shaft of the sewing machine in order to control the movement of the embroidery frame by making maximum use of the section 110 shown in FIG. Is set to. The movement of the embroidery frame causes the upper thread to be pulled, and as a result, an unreasonable force is applied to the upper thread while being held in the shuttle, but this is due to the tension of the thread (upper thread / lower thread). I managed to deal with it by adjusting.

The embroidery sewing machine according to this embodiment can switch between the normal sewing mode and the thick material sewing mode according to the thickness of the embroidered object. In the thick material sewing mode, the movement start timing α of the embroidery frame 14 is sufficiently delayed from the rotation angle A of the sewing machine main shaft 26, and the movement end timing β of the embroidery frame 14 is changed from the rotation angle B as shown in FIG. Is early enough. The rotation angle A is the timing when the lower end of the sewing needle 46 comes out of the needle hole 54 of the needle plate 52, and the rotation angle B is when the lower end of the sewing needle 46 is the needle plate 52.
It is the timing to be inserted into the needle hole 54 of. Further, in the thick material sewing mode, the needle bar jump is set by the control of the jump mechanism 32 as is apparent from the motion M1 of the needle bar 42 shown in FIG. The movement control of the embroidery frame 14 is performed in the section 70 shown in FIG.

The longer the movement start timing α of the embroidery frame 14 is delayed from the rotation angle A of the sewing machine spindle 26, the thicker the embroidery object can be handled, and the movement end timing β is the sewing machine spindle 26.
The faster the rotation angle B is, the thicker the embroidery object can be handled. The movement start timing α in the thick material sewing mode is set to 330 ° or later as the rotation angle of the sewing machine main shaft 26. The height of the lower end of the sewing needle 46 from the needle plate 52 at this rotation angle of 330 ° is the height at the top dead center (about 30 mm).
It has reached close to it and can handle most thick objects. Moreover, after the rotation angle of the sewing machine main shaft 26 of 330 °,
As described above, it is a timing at which the upper thread can be pulled out from the shuttle 50 without resistance, and the upper thread is not unduly applied by the movement of the embroidery frame 14. The movement end timing β in the thick material sewing mode is set to the rotation angle of the sewing machine main shaft 26 of about 70 °.

The above-mentioned needle bar jump is under automatic jump control. In the automatic jump control, by setting the reference stitch length by the needle bar jump, if the stitch data prefetched at the time of embroidery sewing has an execution stitch length that is longer than the reference stitch length, the number of jumps and Calculate and execute the remaining stitch length. That is, when the reference stitch length is set to, for example, 5 mm, and the execution stitch length is 7 mm, the stitch is formed by one needle bar jump and the remaining 2 mm of stitches. Also, if there is a running stitch length of 13 mm, that stitch is formed by two consecutive jumps and the remaining 3 mm of stitch.

Now switching to the thick material sewing mode, the embroidery frame 1
4 is the rotation start timing α of the sewing machine main shaft 26 rotation angle
It is assumed that thick embroidery is performed by setting the movement end timing β at a rotation angle of 70 ° at 330 °. In this case, if the rotation speed of the sewing machine main shaft 26 is about 800 rpm, the stitch length that can be formed by one vertical movement of the needle bar 42 is at most about 1 mm. Therefore, it is necessary to set the reference stitch length of the needle bar jump in the above automatic jump control to 1 mm. In this case, since most of the execution stitch lengths are 1 mm or more, in actual embroidery, the control is such that at least one needle bar jump is performed in one stitch. Although this substantially increases the total number of stitches, embroidering with good thread tightness is performed on a thick embroidered object without applying an unreasonable force to the sewing needle 46 at the time of needle insertion or needle removal. be able to.

In the normal sewing mode, the movement start timing α of the embroidery frame 14 is set to 23 by the rotation angle of the sewing machine main shaft 26.
It is set to 0 ° or later, and the movement end timing β is fixed to the rotation angle of the sewing machine main shaft 26 of 100 °. It is of course possible to embroider an embroidered object that is not thick in the thick material sewing mode. When it is desired to perform embroidery with a good finish even at the cost of embroidering, the thick material sewing mode is selected.

In both the normal sewing mode and the thick material sewing mode, the movement start timing α of the embroidery frame 14 can be adjusted within a predetermined range, and the movement end timing β of the embroidery frame 14 can be adjusted in the thick material sewing mode. Can be adjusted within a predetermined range. An example of these adjustment widths will be given below. Movement start timing α for normal sewing mode: 230 ° to 300 ° (adjustment in 10 ° units) Movement end timing β; 100 ° (no adjustment) Movement start timing α for thick material sewing mode: 330 ° to 370 ° (10 °) (Adjustment in units) Movement end timing β; 30 ° to 80 ° (adjustment in units of 10 °) In the present embodiment, the multi-head / multi-needle type embroidery sewing machine has been described, but the sewing machine head 16 has only one unit. Naturally, it is also possible to target a head type embroidery sewing machine.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a multi-head, multi-needle type embroidery sewing machine.

FIG. 2 is a vertical cross-sectional view showing the outline of the internal structure of the sewing machine head.

FIG. 3 is a vertical cross-sectional view showing the outline of the internal structure of the sewing machine head when jumping the needle bar.

FIG. 4 is an explanatory diagram showing the motion of the needle bar and the balance in relation to the rotation angle of the sewing machine main shaft.

FIG. 5 is an explanatory view showing the motion of the needle bar with jump control in relation to the rotation angle of the sewing machine main shaft.

FIG. 6 is an explanatory diagram showing the motion of the needle bar up to now in relation to the rotation angle of the sewing machine main shaft.

[Explanation of symbols]

10 sewing table 14 Embroidery frame 16 sewing head 32 jump mechanism 42 needle bar 50 kettles

Claims (3)

[Claims] 1. A sewing machine head arranged above the sewing machine table, a shuttle arranged below the sewing machine table corresponding to the sewing machine head, and an object to be embroidered can be held.
And an embroidery frame whose movement is controlled along the upper surface of the sewing machine table. The shuttle is driven to rotate in synchronization with the vertical movement of the needle bar in the sewing machine head, and the embroidery frame moves in synchronization with these. An embroidery sewing machine of the type in which movement is controlled and embroidery sewing is performed on the embroidered object, wherein the sewing machine head can perform needle bar jump control for interrupting transmission of vertical drive to the needle bar. It is possible to control the movement of the embroidery frame by delaying the movement start timing and advancing the movement end timing in one stitch when the object to be embroidered is thick, and performing at least one needle bar jump in one stitch. An embroidery sewing machine that continuously moves the embroidery frame during a jump. 2. The embroidery sewing machine according to claim 1, wherein the needle bar reaches a position near the top dead center of the embroidery frame at the movement start timing and is caught by the shuttle. Is an embroidery sewing machine that can be delayed after being pulled out of the hook with almost no resistance. 3. The embroidery sewing machine according to claim 1, wherein the normal sewing mode and the heavy-weight sewing mode can be switched according to the thickness of the embroidered object, and the normal sewing mode is used in the heavy-weight sewing mode. The embroidery sewing machine is configured such that the movement start timing of the embroidery frame is delayed, the movement end timing is advanced, and the needle bar jump is set as compared with the above.