JP2017221644A - Covering chain stitch sewing machine - Google Patents

Abstract

An object of the present invention is to perform feeding so that there is no difference between an upper part and a lower part without damaging a sewing product. In a flat stitch sewing machine 10 in which a plurality of stitches along a feeding direction of a workpiece C are formed by a plurality of sewing needles 11 and a flat stitch is formed by sewing a decorative thread across a plurality of stitches. And an upper belt mechanism 50 including a plurality of feed belts that contact the workpiece on the needle plate 12 from above and feed the workpiece in the feed direction, and a feed motor 52 that is a drive source of the feed operation. The plurality of feed belts of the upper belt mechanism include a central belt 511 that is in contact with the sewing product on the downstream side in the feed direction with respect to the needle drop position, and side belts 512 and 513 that are in contact with the sewing product next to the central belt. have. [Selection] Figure 2

Description

  The present invention relates to a flat stitch sewing machine.

A conventional flat-sewn sewing machine performs feeding while holding the fabric up and down by a feed dog that appears and disappears from the lower side of the needle plate on the needle plate and a cloth presser that presses the workpiece on the needle plate from above. I was sewing.
However, the upper cloth on which the workpieces are stacked is pressed by the cloth presser, and the lower cloth is fed directly in contact with the feed dog, resulting in a difference in the feed amount between the upper and lower cloths, There is a possibility that the sewing quality may be deteriorated due to looseness in the sewing product.

In order to solve the above problems, it has been studied to divert the feed mechanism of the vertical feed sewing machine to a flat stitch sewing machine.
In the vertical feed sewing machine, on the upper side of the throat plate, the feed foot that reciprocally swings along the feed direction and the presser foot that does not swing move alternately up and down, and feeds at the timing when the feed foot is lowered. The feed leg has a structure that swings toward the downstream side in the direction and swings toward the upstream side in the feed direction at the timing when the presser foot descends and the feed leg rises (see, for example, Patent Document 1).
And since a feed dog and a feed leg synchronize and send a to-be-sewn product, it was possible to reduce the difference in the amount of feed that occurs between the upper and lower fabrics of the to-be-sewn item.

JP 2010-057906 A

  However, since the vertical feed mechanism using the feed leg of Patent Document 1 has a structure in which the workpiece is sandwiched and fed between the feed dog and the feed leg from above and below, the thickness of the workpiece to be sewn and the workpiece to be sewn with a level difference can be obtained. In such a case, there is a possibility that the clamping pressure is increased and the workpiece is damaged.

  An object of the present invention is to provide a flat stitch sewing machine that performs good feeding.

The invention according to claim 1 is a flat stitch sewing machine,
In a flat stitch sewing machine that forms a plurality of stitches along the feed direction of the sewing product by a plurality of sewing needles and performs a flat stitch that sews a decorative thread across the plurality of stitches.
An upper belt mechanism including a plurality of feed belts that contact the sewing product on the needle plate from above and send the sewing product in the feeding direction, and a feed motor that is a driving source of the feeding operation;
The plurality of feed belts of the upper belt mechanism include a central belt that contacts the sewing product on the downstream side in the feeding direction with respect to the needle drop position, and a side belt that contacts the sewing product next to the central belt. It is characterized by.

The invention according to claim 2 is the flat stitch sewing machine according to claim 1,
The central belt is disposed such that a position in contact with the sewing product and the needle drop position are aligned along the feed direction, and is in contact with the sewing product on the downstream side in the feed direction with respect to the needle drop position. It is arranged so that it may be arranged.

The invention according to claim 3 is the flat stitch sewing machine according to claim 1 or 2,
The bottom portion of the central belt is disposed at a lower position than the bottom portion of the side belt.

According to a fourth aspect of the present invention, in the flat stitch sewing machine according to any one of the first to third aspects,
The two side belts are disposed on both sides of the central belt.

According to a fifth aspect of the present invention, in the flat stitch sewing machine according to any one of the first to fourth aspects,
A control device for controlling the feed rate by the feed motor;
The control device includes an adjustment dial for setting and inputting a feed speed of the feed motor by a rotation operation.

The invention according to claim 6 is the flat stitch sewing machine according to any one of claims 1 to 5,
The upper belt mechanism includes two feed motors,
One side belt of the plurality of feed belts and the remaining other feed belt are individually driven by the two feed motors.

The invention according to claim 7 is the flat stitch sewing machine according to any one of claims 1 to 6,
The plurality of feed belts are supported so as to be transportable by a pressing plate that presses a sewing product from above,
The holding plate is supported so that the upstream end in the feed direction can be moved up and down with the downstream end in the feed direction as a fulcrum, and the upstream end in the feed direction is elastically moved downward by the elastic member. It is characterized by being granted.

The invention according to claim 8 is the flat stitching sewing machine according to any one of claims 1 to 7,
The plurality of feed belts are supported so as to be transported by a pressing plate that presses a workpiece to be sewn from above, and are arranged to be inclined upward on the downstream side in the feeding direction of the pressing plate,
A convex member is provided on the downstream side in the feed direction from the pressing plate, and is convex toward the downstream side in the feed direction with respect to the plurality of feed belts.

The invention according to claim 9 is the flat stitch sewing machine according to claim 8,
The lower end of the convex member has a shape in which the downstream side in the feeding direction is inclined upward.

The invention according to claim 10 is the flat stitch sewing machine according to any one of claims 1 to 9,
A lower belt mechanism including a plurality of feed belts that contact the sewing product on the needle plate from below and send the sewing product in the feeding direction, and a feed motor that is a driving source of the feeding operation;
The plurality of feed belts of the lower belt mechanism include a central belt that contacts the sewing product on the downstream side in the feeding direction with respect to the needle drop position, and a side belt that contacts the sewing product next to the central belt. It is characterized by.

  According to the present invention, since the feed motor is provided by the above-described configuration, the feed amount can be individually adjusted between the upper portion and the lower portion of the sewing product, and the workpiece having a step is formed because the feed belt is in contact with the sewing product. The occurrence of scratches can be reduced even with a sewn product or a thick sewn product.

It is a perspective view of the flat stitch sewing machine which is the first embodiment. It is a perspective view around the needle drop position of a flat stitch sewing machine. It is a side view of a cloth pressing mechanism and an upper belt mechanism. It is a perspective view of the lower end part of a cloth presser mechanism and an upper belt mechanism. It is a perspective view of a cloth presser. It is a front view of the pressing plate of a cloth presser. It is an expansion perspective view of a cloth presser. It is a side view of a cloth presser. It is a side view of the other example of the upper belt mechanism provided with two feed motors. It is a perspective view of the needle plate periphery of the flat stitch sewing machine which is 2nd embodiment. It is a perspective view of the lower belt mechanism mounted in the flat stitching sewing machine. It is a side view of a lower belt mechanism.

[Schematic configuration of the first embodiment]
The flat stitch sewing machine 10 which is 1st embodiment is demonstrated based on FIGS.
FIG. 1 is a perspective view of the flat stitch sewing machine 10, and FIG. 2 is a perspective view of the vicinity of the needle drop position of the flat stitch sewing machine 10.
In the following description, a horizontal direction is defined as an X-axis direction, a horizontal direction perpendicular to the X-axis direction is defined as a Y-axis direction, and a vertical direction is defined as a Z-axis direction. Further, as shown in FIG. 1, the following description will be made assuming that one side in the X-axis direction is “front”, the other is “rear”, one “left” in the Y-axis direction, and the other is “right”.

  The flat stitch sewing machine 10 includes a sewing machine frame 20, a needle vertical movement mechanism (not shown) that moves the two sewing needles 11 up and down using the sewing machine motor as a driving source, and a lower looper that uses the sewing machine motor as a driving source below the needle plate 12. And a lower looper mechanism (not shown) for inserting the lower looper thread into the loop of the upper thread of the two sewing needles, and the upper decorative thread for the two stitches formed by the two sewing needles 11. A spreader mechanism (not shown) that guides the upper decoration thread so as to be sewn in the Y-axis direction, and a feed dog from the lower side of the throat plate 12 to move the workpiece to the downstream in the feed direction along the X-axis direction A lower feed mechanism (not shown) that feeds to the sewing machine, a cloth presser mechanism 30 that presses the sewing product from above with the cloth presser 31, and a feed belt that is in contact with the sewing product on the needle plate 12 from above and downstream in the feed direction An upper belt mechanism 50 that is fed forward), a cloth cutting mechanism 80 that cuts off the end of the folded workpiece, a thread tension mechanism 13, a balance mechanism 14, and a control device 90 that controls each of the above components. It has.

[Sewing frame]
The sewing machine frame 20 includes a sewing machine bed portion 21 extending along the Y-axis direction at a lower portion of the flat stitch sewing machine 10, a standing body portion 22 erected from one end portion of the sewing bed portion 21, and the standing body portion 22. A sewing machine arm portion 23 extending from the upper end portion in the same direction as the sewing bed portion 21 is provided.
A needle plate 12 is provided on the upper surface of the end of the sewing machine bed portion 21 opposite to the standing body portion 22, and needle dropping by the two sewing needles 11 is performed in a needle hole formed in the needle plate 12.

[Needle vertical movement mechanism]
The needle up-and-down movement mechanism includes a needle bar 15 (see FIG. 3) supported so as to be movable up and down along the Z-axis direction at the tip of the sewing machine arm 23, and two needles held at the lower end of the needle bar 15. Sewing needle 11 and a crank mechanism for applying a vertical movement to the needle bar 15 from the sewing machine motor.
The needle bar 15 holds two sewing needles 11 arranged in the Y-axis direction at the lower end thereof.
In the flat stitch machine 10, the workpiece is conveyed forward in the X-axis direction, and two stitches arranged in the Y-axis direction are formed along the X-axis direction by the two sewing needles 11.

[Thread tension mechanism and balance mechanism]
The flat stitch sewing machine 10 performs sewing with two upper threads, a lower looper thread, and an upper decoration thread, and the thread tension mechanism 13 includes a plurality of thread tension devices that apply thread tension to these threads. .

  The balance mechanism 14 includes an oscillating balance through which the two upper threads to which the thread tension is applied in the thread tension mechanism 13 are inserted. This balance obtains swinging power from the sewing machine motor, and swings in synchronism with the vertical movement of the sewing needle 11, thereby pulling up each upper thread at an appropriate timing.

[Lower looper mechanism]
The lower looper mechanism is disposed inside the sewing machine bed portion 21 and includes a lower looper that performs a reciprocating advance / retreat operation along the Y-axis direction, and a transmission mechanism that imparts an advance / retreat operation from the sewing machine motor to the lower looper.
The lower looper is a sharp member extending toward the left side in the Y-axis direction, and a threading hole through which the lower looper thread is inserted is formed at the tip of the lower looper. Yes. Then, when moving forward to the left, it is possible to enter the upper thread loop passed through the lowered two sewing needles 11 and to insert the lower looper thread into the two upper thread loops. Yes.
Further, the two sewing needles 11 descending into the loop of the lower looper thread formed when the lower looper retreats to the right enter, and the two upper threads are inserted. By repeating these alternately, two seams are formed along the X-axis direction.

[Spreader mechanism]
The spreader mechanism includes a spreader that is disposed above the needle plate and guides the upper decoration thread at the tip, and a turning mechanism that imparts a turning action so that the tip of the spreader reciprocates along the Y-axis direction. ing.
The rotation mechanism uses the sewing machine motor as a drive source to apply a reciprocating rotation operation of the spreader in synchronization with the vertical movement of the sewing needle 11.
The upper decorative yarn guided by the spreader is swung to the left and right in synchronization with the needle drop of the two sewing needles 11, and can be alternately sewn into the two stitches formed on the sewing product. .

[Bottom feed mechanism]
The lower feed mechanism includes a feed dog that causes the tooth tip to protrude from the opening of the throat plate 12 and a turning mechanism that turns around an ellipse locus along the X-axis direction with respect to the feed dog.
The orbiting mechanism includes a horizontal feed shaft and a vertical feed shaft that reciprocally rotate using a sewing machine motor as a drive source, and feeds the feed base that supports the feed dog by applying a reciprocating motion in the X-axis direction. The circular motion of the ellipse is given to the teeth.
When the feed dog passes through the upper part of the elliptical locus, the tooth tip projects upward from the opening of the needle plate, and at that time, the feed dog moves forward. As a result, the tooth tip comes into contact with the workpiece on the needle plate from below, and the workpiece can be intermittently fed forward at a constant feed pitch.

[Cloth cutting mechanism]
The sewing product C is a fabric with the right edge folded back downward, and the cloth cutting mechanism 80 has a width in the Y-axis direction of the folded portion of the sewing product C on the upstream side in the cloth feeding direction from the needle drop position. In order to align them uniformly, the front end of the folded portion is excised.

  As shown in FIG. 2, the cloth cutting mechanism 80 includes a positioning ruler 81 against which a right edge that is a fold of the folded portion C1 (see FIG. 5) of the sewing product C at the time of sewing and a bottom of the sewing product C A fixed knife 82 and a moving knife 83 that cut off the left edge that is folded back are provided, and a knife vertical movement mechanism that moves the moving knife 83 up and down.

The positioning ruler 81 is a flat plate member along the XZ plane, and a fold portion (right edge) of the sewing product C is abutted against the left plane. The positioning ruler 81 can be adjusted in position along the Y-axis direction, whereby the Y-direction width of the folded portion of the sewing product C can be adjusted.
The fixed knife 82 is disposed with the tooth tip thereof facing upward, and the moving knife 83 descends toward the tooth tip of the fixed knife, and passes through the space between the fixed knife 82 and the moving knife 83. The folded left side edge can be excised.
The knife vertical movement mechanism includes a drive shaft that performs reciprocating rotation using a sewing machine motor as a drive source, and supports the moving knife 83 at the tip of the drive shaft. Then, the moving knife 83 is given a reciprocating rotation operation, whereby the tip of the moving knife 83 can be moved up and down to cut out the sewing product C.

[Cloth holding mechanism]
3 is a side view of the cloth presser mechanism 30 and the upper belt mechanism 50, FIG. 4 is a perspective view of the lower ends of the cloth presser mechanism 30 and the upper belt mechanism 50, and FIG.
As shown in FIGS. 2 to 5, the cloth presser mechanism 30 includes a cloth presser 31, a presser bar 32 that supports the cloth presser 31 at the lower end, an air cylinder 33 that applies a pressurizing pressure to the cloth presser 31, and a manual operation. The pressing pressure release mechanism 34 is provided.

  The presser bar 32 is supported at the front end of the sewing machine arm 23 so as to be movable up and down, and the upper end of the presser bar 32 is connected to the plunger of the air cylinder 33. Then, by the operation of the air cylinder 33, it is possible to switch between applying a pressing pressure to the sewing product C by the cloth presser 31 and releasing the pressing pressure by raising the cloth presser 31.

In addition, the air cylinder 33 is provided with two valves 331 and 332 to which pneumatic air is supplied from an external pneumatic pressure source. One of the valves 331 has a pressure reducing valve (not shown) from the external pneumatic pressure source. low pressure through (e.g., 2 kgf / cm ²⁾ air is supplied, air is supplied in a high pressure (e.g., 4 kgf / cm ²⁾ without passing through the pressure reducing valve from the outside of the air pressure source to the other of the valve 332 .
Each of the valves 331 and 332 has manual push buttons 333 and 334 for switching between supply and stop of air, and the pressing pressure of the cloth presser 31 is changed by switching these push buttons 333 and 334. You can switch between strong and weak.

As shown in FIG. 3, the presser pressure release mechanism 34 is fixedly mounted on the rod holder 341 fixedly mounted on the presser bar 32, the input shaft 342 connected to a manual presser lifting lever (not shown), and the input shaft 342. The pivot arm 343, and a link member 344 that couples the pivot end of the pivot arm 343 and the rod holder 341.
With this configuration, when the press-up lever is manually rotated counterclockwise, the rotation end of the rotation arm 343 is rotated upward via the input shaft 342, and the pressure bar 32 is rotated via the link member 344. And the cloth presser 31 can be pulled up.

As shown in FIGS. 3 to 8, the cloth presser 31 includes a presser plate 311 and a standing portion 312 provided at the front center of the presser plate 311. In addition, illustration of the standing part 312 is abbreviate | omitted in FIG.
The upper end portion of the standing portion 312 is provided with a connection hole into which the lower end portion of the presser bar 32 can be inserted, and the presser bar 32 can be held by a headless screw.

  The pressing plate 311 has a function of applying the pressing pressure from the air cylinder 33 described above to the sewing product C. In the center portion of the pressing plate 311, two needle insertion portions 313 that penetrate vertically are provided. 314 is formed. Through the needle insertion portions 313 and 314, the needle drop by the two sewing needles 11 and 11 is performed on the workpiece C under the presser plate 311.

Further, the pressing plate 311 passes through the bottom surface from the upper surface via the rear end portion or a position slightly ahead of the rear end portion, and a central belt 511 that is three feeding belts of the upper belt mechanism 50 described later. , The left belt 512 and the right belt 513 are also guided so as to be transportable in the feed direction.
Therefore, a first left roller 351 and a second left roller 352 for conveying the left belt 512 are rotatably disposed on the left rear end portion and the left front end upper portion of the pressing plate 311.
Further, a first right roller 353 and a second right roller 354 for conveying the right belt 513 are rotatably disposed on the right rear end portion and the right front end upper portion of the pressing plate 311.

In addition, the presser plate 311 is notched widely from the front end portion to the central portion, and the first central roller 355 and the second central roller 356 for conveying the central belt 511 are rotated inside the front and rear sides. Arranged to be possible. And the 3rd center roller 357 is rotatably arrange | positioned at the center front-end upper part of the pressing board 311. As shown in FIG.
Note that the second left roller 352, the second right roller 354, and the third center roller 357 are supported not by the press plate 311 but by the standing portion 312.

  By these rollers 351 to 357, the central belt 511, the left belt 512, and the right belt 513 can be smoothly conveyed forward in the state of being aligned in the Y-axis direction and the bottom surface of the pressing plate 311. The upper surface of the sewing product C can be fed forward while contacting the upper surface of the sewing product C with the pressing pressure of the pressing plate 311.

The first central roller 355 is arranged side by side with the needle insertion portions 313 and 314 that are the needle drop positions along the X-axis direction (feed direction), and forward of the needle insertion portions 313 and 314 ( It is arranged on the downstream side in the feed direction.
On the other hand, the first left roller 351 and the first right roller 353 are located on the left side and the right side of the needle insertion portions 313 and 314, and rearward (upstream in the feed direction) of the needle insertion portions 313 and 314. Is arranged.
As a result, the central belt 511 is in contact with the workpiece on the downstream side in the feed direction from the needle drop position, and the left belt 512 and the right belt 513 are to be sewn on the upstream side in the feed direction from the needle drop position. Sends in contact with.

As shown in FIG. 6, the center belt 511, the left belt 512, and the right belt 513 are supported at different heights at the bottoms that come into contact with the sewing product C. That is, the center belt 511 is supported such that its bottom is at its lowest position, the bottom of the left belt 512 is at its lowest position, and the bottom of the right belt 513 is at its highest position.
In addition, the height of the bottom part of the center belt 511 is adjusted by the installation height of the 1st center roller 355 and the 2nd center roller 356, and the height of the bottom part of the left belt 512 and the right belt 513 is the press plate 311. The depth of the grooves 311a and 311b for guiding the respective belts formed on the bottom surface side of the belt is adjusted.

For this reason, since the center belt 511 is in the state where the center belt 511 is most in pressure contact with the sewing product C with respect to the center portion where resistance to feed is easily generated due to the needle drop, the delay with respect to the left and right is suppressed. Thus, it becomes possible to send the sewing product stably.
Further, when sewing is performed by folding the right edge of the sewing product C, the folded portion C1 does not exist on the left side of the needle drop position, and the sewing product is substantially thinner on the left side than the right side of the needle drop position. Therefore, by placing the bottom of the left belt 512 at a lower position than the bottom of the right belt 513, the left belt 512 and the right belt 513 can be pressed against the sewing product in a balanced manner on the left and right sides. The sewing product C can be sent stably without being biased.

Further, as shown in FIG. 7, the front end portion (end portion on the downstream side in the feed direction) of the pressing plate 311 is pivotally supported by a fulcrum shaft (not shown) so as to be swingable about the Y-axis with respect to the standing portion 312. . As a result, the rear end portion (upstream end portion in the feed direction) of the press plate 311 swings around a fulcrum shaft (not shown) provided at the downstream end portion in the feed direction of the press plate 311 and can be moved up and down. It has become.
Further, a torsion coil spring 316 as an elastic member is provided on the left side surface of the pressing plate 311 by a step screw 315, and one end portion of the torsion coil spring 316 is locked to the standing portion 312 side, and the other end portion is The presser plate 311 is in pressure contact with the upper surface of the rear end portion. Thereby, the presser plate 311 is in a state in which an elastic force downward is applied to the rear end portion thereof.
In FIG. 7, the belts 511 to 513 and the rollers 351 to 357 are not shown.

Since the presser plate 311 is pressed downward by the air cylinder 33 via the presser bar 32, the bottom surface of the presser plate 311 maintains the horizontal state and presses the workpiece C during normal sewing. .
However, since the pressing plate 311 can swing with respect to the standing portion 312 as described above, the sewing product C has a stepped portion, and the stepped portion is fed from the rear toward the front. And the rear end portion of the presser plate 311 swings upward against the torsion coil spring 316 to easily get over the stepped portion, and smoothly and satisfactorily feed the workpiece C with the stepped portion. Can be done.

Further, as shown in FIG. 8, the center belt 511, the left belt 512, and the right belt 513 are all in a front obliquely upward direction from the front end portion (downstream end portion in the feed direction) of the press plate 311 of the cloth presser 31. It extends with substantially the same inclination angle.
A convex member 317 is formed at a front end portion (downstream side end portion in the feed direction) of the standing portion 312 of the cloth presser 31 and ahead of the front end portion of the presser plate 311. The convex member 317 extends obliquely upward as viewed from the side, and is convex forward of the central belt 511, the left belt 512, and the right belt 513.
The convex member 317 has a downwardly inclined surface 317 a that faces obliquely upward in the front direction from substantially the same position as the front end portion of the bottom surface of the pressing plate 311 when viewed from the side. Further, the convex member 317 is arranged so as not to overlap the belts 511 to 513 when viewed from the X-axis direction.
The inclined surface 317a is inclined upward at a gentler angle than the belts 511, 512, and 513. For this reason, the convex member 317 is in a state of projecting forward and downward from the belts 511, 512 and 513 when viewed from the side.

When it is assumed that the convex member 317 does not exist, the sewing product C fed forward by the belts 511, 512, and 513 is projected upward in front of the bottom front end portion of the pressing plate 311. Looseness is likely to occur. When such looseness occurs, the good feeding operation of the sewing product C is hindered, and therefore the operator of the sewing machine needs to perform sewing while pulling the sewing product C forward so that no loosening occurs. .
However, by providing the convex member 317 at the front end portion of the cloth presser 31, there is no space for the sewing product C to be loosened in front of the bottom front end portion of the presser plate 311, and the occurrence of looseness can be suppressed. It becomes.
Furthermore, since the lower part of the convex member 317 has a shape having an inclined surface 317a, the sewing product C can be satisfactorily fed forward while eliminating slack. This eliminates the need for the operator of the sewing machine to pull the workpiece C forward and improves workability during sewing.

In addition, although the lower part of the convex member 317 illustrated the inclined surface 317a which goes straight ahead diagonally upward, a shape is not restricted to this. For example, the lower part of the convex member 317 may have a curved surface that gradually curves upward from the same horizontal state as the bottom surface of the pressing plate 311.
Moreover, although the convex member 317 may be formed integrally with the standing portion 312 of the cloth presser 31, it may be formed by a separate member.

[Upper belt mechanism]
The upper belt mechanism 50 includes an endless annular central belt 511, a left belt 512, and a right belt 513 as a plurality of feed belts, a feed motor 52 serving as a belt feed driving source, and each belt from the feed motor 52 to the cloth presser 31. And a guide mechanism 53 for guiding 511 to 513.

As the feed motor 52, a motor whose rotation speed can be controlled, for example, a DC motor, an AC motor, a stepping motor, or the like is used.
The feed motor 52 is fixedly mounted on the front side of the tip end portion of the sewing machine arm portion 23 via the motor bracket 521 with the output shaft directed leftward.
The output shaft of the feed motor 52 is equipped with a motor pulley 522 around which one end of each belt 511 to 513 is wound.

  The guide mechanism 53 is mainly composed of a plurality of guides rotatably provided at each part of the belt path from the motor pulley 522 to the cloth presser 31 and the guide arm 533 including the first and second link members 531 and 532. And a roller 534.

One end of the first link member 531 of the guide arm 533 is connected to the lower portion of the motor bracket 521 so as to be rotatable about the Y axis, and the other end is connected to one end of the second link member 532 around the Y axis. It is connected to the pivotable.
The other end of the second link member 532 is connected to a fastening member 535 that is hung on the lower end of the presser bar 32 just above the cloth presser 31 so as to be rotatable about the Y axis.

  Each of the first link member 531 and the second link member 532 includes a pair of left and right flat plate side walls along the XZ plane, and the side walls are opposed to each other. And the guide roller 534 is arrange | positioned in each position on the opposing surface of the mutually opposing side wall part of each link member 531,532, Thereby, the belt path | route of each belt 511-513 is each link member of the guide arm 533. 531 and 532 are formed.

The guide roller 534 is disposed at each position of the motor bracket 521 in addition to the link members 531 and 532.
Each guide roller 534 is a tension roller arranged in a pressure contact state so that the belts 511 to 513 do not loosen in addition to those arranged at the corners of the path to form a predetermined belt path. Something that functions as is also included.

One end of each belt 511 to 513 is wound around a motor pulley 522, and the other end is wound around each roller 351 to 357 provided on the cloth presser 31 via each guide roller 534.
Thereby, when the feed motor 52 is driven, the belts 511 to 513 are conveyed forward on the bottom surface side of the cloth presser 31 by the torque.

In principle, the rotation speed of the feed motor 52 is such that the conveyance speed of the belts 511 to 513 on the bottom surface of the cloth presser 31 averages the intermittent feed speed by the lower feed mechanism to a continuous feed speed. Control is performed so as to match the converted virtual feed rate.
However, when there is a difference in feed speed between the upper part and the lower part of the sewing product C, adjustment control for increasing or decreasing the rotation speed of the feed motor 52 is performed.

  Further, when releasing the pressing pressure, the cloth presser 31 moves up to the upper retracted position via the presser bar 32, so that the other end portion of the second link member 532 of the guide arm 533 is not pressed. Although it moves upward together with the rod 32, both ends of the guide arm 533 are connected so as to be rotatable around the Y axis, and the first link member 531 and the second link member 532 are also rotatable around the Y axis. Since they are connected, the bending angle is changed between the first link member 531 and the second link member 532, so that it is possible to cope with the rise of the cloth presser 31.

[Control device]
The control device 90 is a control circuit including a CPU, a RAM, a data memory, and the like, and is connected to a sewing machine motor, a feed motor 52, and the like via a driver circuit, and controls the start and stop of these drives, the drive speed, and the like. be able to.
Further, an operation panel 91 and an adjustment dial 92 shown in FIG. 1 are connected to the control device 90 via an interface (not shown).

The operation panel 91 includes an input unit such as buttons and keys for inputting various settings relating to sewing, and a display unit for performing display for assisting the setting operation.
From the operation panel 91, for example, the number of rotations of the sewing machine motor, the feed speed of the sewing product by the upper belt mechanism 50, the start of sewing, and the like are input.
The feed speed of the sewing product by the upper belt mechanism 50 is not limited to a direct speed, and may be, for example, an input of a speed difference or a speed ratio with respect to the feed speed of the lower feed mechanism.
When the various numerical values are set, for example, the increase / decrease of the set value displayed on the display unit is input using the increase / decrease key, and the set value is determined by the enter key.

The adjustment dial 92 can be rotated and input, and an input amount is detected by a rotation amount detection sensor such as a built-in encoder and is input to the control device 90.
The adjustment dial 92 is an input means for inputting the adjustment of the feed speed of the upper belt mechanism 50 exclusively. The adjustment dial 92 inputs an increase in the set value of the feed speed of the upper belt mechanism 50 in the forward rotation and the feed speed in the reverse rotation. Enter the set value reduction.
Further, the increase or decrease in the feed speed set value input from the adjustment dial 92 may be reflected in the speed control of the feed motor 52 in real time during the rotation operation, or may be set by rotating the adjustment dial 92. After inputting the value, the input operation for determination may be performed with the determination key or the like and then reflected in the speed control of the feed motor 52. In addition, when a determination input operation is performed using a determination key or the like, the determination key on the operation panel 91 may be used, or the dial of the adjustment dial 92 can be pushed in and clicked. It may be determined.

[Technical effects of the first embodiment]
The flat-sewn sewing machine 10 includes a feed motor 52 that is a driving source for the feed operation of the sewing product C, a central belt 511 that contacts the sewing product C on the downstream side in the feed direction with respect to the needle drop position, and a central belt 511. Since the upper belt mechanism 50 is provided with the left belt 512 in contact with the sewing product C on the left side and the right belt 513 in contact with the sewing product C on the right side of the center belt 511, the speed of the feed motor 52 is increased. By controlling separately from the sewing machine motor, it becomes possible to reduce the difference in feed amount between the upper part and the lower part of the sewing product C.
Furthermore, since the belts 511, 512, and 513 are in contact with the upper side of the sewing product C and are fed, even in the case of the sewing product C having a step or a thickness, unlike the case of being fed by being held by the feed dog from above and below. It is possible to reduce the generation of scratches and indentations caused by the clamping pressure.

The central belt 511 is arranged so that the position in contact with the sewing product C and the needle drop position are aligned along the X-axis direction, and is sewn on the downstream side (front side) in the feed direction with respect to the needle drop position. It arrange | positions so that the thing C may be touched.
For this reason, in the state in which the sewing needle 11 is stuck in the sewing product, resistance is generated, and the feeding of the sewing product C is more likely to be delayed than the left and right, but the central belt 511 is downstream of the needle drop position in the feeding direction. By arranging so as to be in contact with each other, the sewing product C can be sent while being pulled. Therefore, the delay of the central portion can be reduced, and the sewing product C can be sent satisfactorily as a whole.

Further, since the bottom of the central belt 511 is disposed at a lower position than the bottoms of the left belt 512 and the right belt 513, the central belt 511 is the most against the central portion where resistance to feed is likely to occur due to needle drop. Since the sewing product C is in pressure contact with the sewing product C, a delay with respect to the left and right is suppressed, and the sewing product can be sent stably.
Further, since the left belt 512 and the right belt 513 are disposed on both sides of the central belt 511 with respect to the Y-axis direction, the three belts 511 to 513 can perform feeding with excellent straightness.

Further, since the flat stitch sewing machine 10 includes the control device 90 that controls the feed speed by the feed motor 52, the ratio of the feed amount by the upper belt mechanism 50 with respect to the lower feed mechanism can be arbitrarily adjusted. Proper feed can be performed with good balance between the upper and lower portions of the sewn product C, and the sewing quality can be improved.
Further, since the control device 90 includes the adjustment dial 92, the feed amount of the lower feed mechanism can be adjusted with high operability, and the adjustment work can be performed intuitively, so that it can be performed even during sewing. It can be freely adjusted.

The presser plate 311 of the cloth presser 31 of the cloth presser mechanism 30 is supported so that the upstream end in the feed direction can be moved up and down with the downstream end in the feed direction as a fulcrum, and the upstream end in the feed direction is An elastic force is applied in the downward direction by the torsion coil spring 316.
For this reason, even when the sewing product C has a stepped portion or a portion whose thickness changes, the upstream end in the feed direction of the presser plate 311 is moved up and down to maintain a state in close contact with the sewing product C. This makes it possible to suppress fluctuations in the feed amount and perform a stable feed operation.

Further, the cloth presser 31 of the cloth presser mechanism 30 is provided with a convex member 317 that protrudes downstream in the feed direction with respect to the plurality of belts 511 to 513 on the downstream side in the feed direction from the presser plate 311. .
Thereby, there is no space in which the sewing product C is loosened forward of the front end portion of the bottom surface of the presser plate 311, and the occurrence of loosening can be suppressed.
Moreover, since the lower part of the convex member 317 has the inclined surface 317a, the sewing product C can be fed forward well while eliminating the slack, and the operator of the sewing machine pulls the sewing product C forward. Work is unnecessary, and the workability during sewing can be improved.

[Other examples of upper belt mechanism]
FIG. 9 shows another example of the upper belt mechanism. The upper belt mechanism 50A is different from the above-described upper belt mechanism 50 in that two feed motors 52 are provided, and the other points are almost the same. Therefore, regarding the upper belt mechanism 50A, the same components as those of the upper belt mechanism 50 are denoted by the same reference numerals, and redundant description is omitted.

The upper belt mechanism 50A includes a motor bracket 521A that supports two feed motors 52 and 52 side by side. The motor bracket 521A is attached to the sewing machine arm portion 23 at the same position as the motor bracket 521 described above. Yes.
Each of the output shafts of the feed motors 52 is equipped with a motor pulley 522. Only the left belt 512 is wound around the motor pulley 522 of the upper feed motor 52, and the motor pulley of the lower feed motor 52 is wound. A central belt 511 and a right belt 513 are wound around 522.
Alternatively, the left belt 512 and the central belt 511 are wound around the motor pulley 522 of the upper feed motor 52, and only the right belt 513 is wound around the motor pulley 522 of the lower feed motor 52. good.

  As described above, the left belt 512 and the right belt 513 are transported by the separate feed motors 52, so that the feed speeds of the two feed motors 52 and 52 are controlled so as to provide a difference. The feeding direction of the object C can be controlled to turn right or turn left, and it becomes possible to easily and satisfactorily cope with sewing of a right turn or left turn. Further, by arbitrarily setting the feed speed difference between the two feed motors 52, 52, it becomes possible to control the curvature of the right turn or the left turn.

It should be noted that the setting of the feed speed difference between the two feed motors 52, 52 is desirably performed by the input operation of the operation panel 91 described above.
Further, another adjustment dial that is the same as the adjustment dial 92 described above may be provided so that the feed speed difference between the two feed motors 52 and 52 can be set and input by forward rotation or reverse rotation of the new adjustment dial.
Further, three feed motors may be provided, and the belt feed speed may be individually controlled by the central belt 511, the left belt 512, and the right belt 513.

[Second Embodiment]
A flat stitch sewing machine 10B according to the second embodiment will be described with reference to FIGS.
10 is a perspective view of the periphery of the needle plate of the flat stitch sewing machine 10B, FIG. 11 is a perspective view of the lower belt mechanism 70B mounted on the flat stitch sewing machine 10B, and FIG. 12 is a side view of the lower belt mechanism 70B.
In the flat stitch sewing machine 10B as well, one horizontal direction is defined as an X-axis direction, a horizontal direction perpendicular to the X-axis direction is defined as a Y-axis direction, and a perpendicular direction is defined as a Z-axis direction. Further, as shown in FIG. 1, the following description will be made assuming that one side in the X-axis direction is “front”, the other is “rear”, one “left” in the Y-axis direction, and the other is “right”.

The flat stitch sewing machine 10B is different from the flat stitch sewing machine 10 in that a flat belt sewing machine 10B is provided with a lower belt mechanism 70B that feeds the workpiece C on the needle plate 12B from below, instead of the above-described lower feed mechanism.
Therefore, in the following description, the same components as those of the flat stitch sewing machine 10 will be denoted by the same reference numerals, and the description thereof will be omitted.

[Lower belt mechanism]
The lower belt mechanism 70B includes an endless annular central belt 711B, a left belt 712B, and a right belt 713B as a plurality of feed belts, a lower feed motor 72B as a feed motor serving as a belt feed drive source, and a lower feed motor 72B. And a guide mechanism 73B that guides the belts 711B to 713B through a path passing through the needle plate 12B.

As the lower feed motor 72B, a motor whose rotation speed can be controlled, for example, a DC motor, an AC motor, a stepping motor, or the like is used.
The lower feed motor 72B is fixedly mounted on the front side of the front end portion of the sewing machine bed portion 21 via the motor bracket 721B with the output shaft directed to the right.
Further, a motor pulley 722B around which a part of each of the belts 711B to 713B is wound is provided on the output shaft of the lower feed motor 72B.

  The guide mechanism 73B is provided on a guide frame 731B that guides the belts 711B to 713B, a plurality of guide rollers 732B that form a belt path of the central belt 711B from the motor pulley 722B to the needle plate 12B, and the guide frame 731B. A guide roller 733B that supports the left belt 712B and the right belt 713B so as to be transportable is provided so as to go around the outer periphery of the sewing machine bed portion 21.

The guide frame 731 </ b> B is a substantially rectangular frame when viewed from the Y-axis direction, and is mounted on the sewing machine bed portion 21 so as to surround the distal end portion of the sewing machine bed portion 21.
The upper part of the guide frame 731B is connected to the needle plate 12, and the belts 711B to 713B supported by the guide frame 731B can be guided to the upper surface of the needle plate 12B.

The guide roller 732B of the central belt 711B is provided at a position between the motor pulley 722B and the needle plate 12B and at a position near the needle hole 121B of the needle plate 12B and on the downstream side in the feed direction of the needle hole 121B. ing.
The needle plate 12B is cut out from the center of the front end to the front of the needle hole 121B, and one of the guide rollers 732B is disposed inside the cutout.
One end of the central belt 711B is stretched over the motor pulley 722B, and the other end is stretched over the guide roller 732B inside the notch of the needle plate 12B. Further, the two guide rollers 732B in the middle function as tension rollers so that the central belt 711B does not slack.

  The guide rollers 733B of the left belt 712B and the right belt 713B are provided at the four corners of the guide frame 731B, and form a substantially rectangular belt path surrounding the tip of the sewing machine bed portion 21. In addition, the guide roller 733B includes a roller that functions as a tension roller disposed so as to be in pressure contact with the motor pulley 722B in a state where the left belt 712B and the right belt 713B are not slackened.

Two guide grooves along the X-axis direction are formed on both sides in the Y-axis direction across the needle hole 121B on the upper surface of the needle plate 12B. Each belt 712B, 713B is guided by each guide roller 733B so as to pass through the two guide grooves of the needle plate 12B.
These guide grooves are formed so that the depth of the grooves is shallower than the thickness of each of the belts 712B and 713B so as to make good contact with the workpiece C placed on the upper surface of the needle plate 12B from below. Yes.

By means of the guide mechanism 73B and the needle plate 12B, the central belt 711B is in contact with the sewing product C on the needle plate 12B from below at the downstream side in the feed direction of the needle hole 121B that is the needle drop position. Feed.
Further, the left belt 712B and the right belt 713B are sewn articles C on the needle plate 12B in the range from the upstream side to the downstream side in the feed direction from the needle hole 121B on the left and right sides of the needle hole 121B which is the needle drop position. The material to be sewn C is fed in a state where it touches from below.

The rotation operation of the lower feed motor 72B is also controlled by the control device 90. In this case, in principle, the lower feed motor 72B is controlled so that the feed speeds of the feed motor 52 of the upper belt mechanism 50 and the workpiece C are equal.
However, adjustment control for increasing / decreasing the rotational speed of the lower feed motor 72B is performed separately from the feed motor 52 so as to cope with a difference in feed speed between the upper portion and the lower portion of the sewing product C. You may comprise so that it can do.
When the feed speed of the lower feed motor 72B is controlled independently, the feed speed of the lower feed motor 72B is input from the operation panel 91, or the speed difference or speed ratio with respect to the feed speed of the upper belt mechanism 50 is input. .
Further, as in the case of the feed motor 52 of the upper belt mechanism 50, the lower feed motor 72B may also be provided with an adjustment dial for inputting an increase / decrease in feed speed by a rotation operation.

[Technical effects of the second embodiment]
Since the flat stitch sewing machine 10B is provided with the lower belt mechanism 70B, the belt 711B to 713B is always used for the sewing product, unlike the lower feeding mechanism that feeds intermittently with the feed dog that contacts the sewing product C. Feeding can be performed in contact with the sewing product C. Therefore, the workpiece C can be fed from above and below in a state where it is always in contact with the belt, and the upper and lower portions of the workpiece C are less likely to be displaced, and sewing can be performed with high sewing quality.
Further, since the belts 711B, 712B, and 713B are in contact with the lower side of the sewing product C to perform feeding, unlike the case of feeding with the feed dog, even in the case of the sewing product C having a step or thickness, scratches caused by the feed dog And the generation of indentations can be reduced.

Further, the central belt 711B is arranged so that the position in contact with the sewing product C and the needle drop position (needle hole 121B) are aligned along the X-axis direction, and the downstream side in the feed direction with respect to the needle drop position ( It arrange | positions so that the to-be-sewn material C may be touched in the front side.
For this reason, it becomes possible to reduce the delay in feeding the sewing product C by the sewing needle 11 and to feed the sewing product C more satisfactorily.
Further, since the left belt 712B and the right belt 713B are disposed on both sides of the central belt 711B with respect to the Y-axis direction, the three belts 711B to 713B can perform feeding with further excellent straightness. .

In the case of the lower belt mechanism 70B, similarly to the upper belt mechanism shown in FIG. 9, two lower feed motors are provided, and the central belt 711B and the left belt 712B are fed by one lower feed motor, and the other lower feed mechanism is fed. The right belt 713B may be fed by a motor, and the lower belt feed speed may be individually controlled. Alternatively, the central belt 711B and the right belt 713B may be fed by one lower feed motor, the left belt 712B may be fed by the other lower feed motor, and the lower belt feed speed may be individually controlled.
Alternatively, three lower feed motors may be provided, and the lower belt feed speed may be individually controlled by the central belt 711B, the left belt 712B, and the right belt 713B.

[Others]
In the upper belt mechanism 50, 50A, the case where three feeding belts are used is illustrated, but two feeding belts may be used. In that case, the feed belt to be deleted is preferably the left belt 512 or the right belt 513.
As described above, even when the feed belt is composed of two belts, the difference in the feed amount between the upper part and the lower part of the workpiece C is reduced by controlling the speed of the feed motor 52 separately from the sewing machine motor. Is possible.
Similarly, the lower belt mechanism 70B may have two feeding belts (a central belt 711B and a left belt 712B, or a central belt 711B and a right belt 713B).

  Further, when the left belt 512 (or the left belt 712B) is deleted, it becomes easy to guide the sewing product C so as to bend to the right side, and when the right belt 513 (or the right belt 713B) is deleted, It becomes easy to guide the sewing product C so as to curve to the left side, and it is possible to easily form a curved seam by manual operation.

10, 10B Flat sewing machine 11 Sewing needle 12, 12B Needle plate 30 Cloth holding mechanism 50, 50A Upper belt mechanism 52 Feed motor 53 Guide mechanism 70B Lower belt mechanism 72B Lower feed motor (feed motor)
90 Control device 91 Operation panel 92 Adjustment dial 311 Holding plate 312 Standing portion 313, 314 Needle insertion portion 351 First left roller 352 Second left roller 353 First right roller 354 Second right roller 355 First central roller 356 Second Central roller 357 Third central roller 511 Central belt (feed belt)
512 Left belt (side belt, feed belt)
513 Right belt (side belt, feed belt)
711B Central belt (feed belt)
712B Left belt (side belt, feed belt)
713B Right belt (side belt, feed belt)
C Sewing product C1 Folded part

Claims (10)

In a flat stitch sewing machine that forms a plurality of stitches along the feed direction of the sewing product by a plurality of sewing needles and performs a flat stitch that sews a decorative thread across the plurality of stitches.
An upper belt mechanism including a plurality of feed belts that contact the sewing product on the needle plate from above and send the sewing product in the feeding direction, and a feed motor that is a driving source of the feeding operation;
The plurality of feed belts of the upper belt mechanism include a central belt that contacts the sewing product on the downstream side in the feeding direction with respect to the needle drop position, and a side belt that contacts the sewing product next to the central belt. Flat stitch sewing machine characterized by   The central belt is disposed such that a position in contact with the sewing product and the needle drop position are aligned along the feed direction, and is in contact with the sewing product on the downstream side in the feed direction with respect to the needle drop position. The flat-sewn sewing machine according to claim 1, wherein the sewing machines are arranged as described above.   The flat-sewn sewing machine according to claim 1 or 2, wherein a bottom portion of the central belt is disposed at a lower position than a bottom portion of the side belt.   The flat sewing machine according to any one of claims 1 to 3, wherein the two side belts are arranged on both sides of the central belt. A control device for controlling the feed rate by the feed motor;
The flat stitch sewing machine according to any one of claims 1 to 4, wherein the control device includes an adjustment dial for setting and inputting a feed speed of the feed motor by a rotation operation. The upper belt mechanism includes two feed motors,
The one side belt among the plurality of feed belts and the remaining other feed belt are individually driven by the two feed motors, respectively. A flat-sewn sewing machine as described in 1. The plurality of feed belts are supported so as to be transportable by a pressing plate that presses a sewing product from above,
The holding plate is supported so that the upstream end in the feed direction can be moved up and down with the downstream end in the feed direction as a fulcrum, and the upstream end in the feed direction is elastically moved downward by the elastic member. The flat-sewn sewing machine according to any one of claims 1 to 6, wherein the sewing machine is provided. The plurality of feed belts are supported so as to be transported by a pressing plate that presses a workpiece to be sewn from above, and are arranged to be inclined upward on the downstream side in the feeding direction of the pressing plate,
8. The convex member according to claim 1, further comprising a convex member that is convex toward the downstream side in the feeding direction with respect to the plurality of feeding belts, downstream of the pressing plate in the feeding direction. The flat stitch sewing machine described.   The flat-sewn sewing machine according to claim 8, wherein a lower end of the convex member has a shape in which a downstream side in the feeding direction is inclined upward. A lower belt mechanism including a plurality of feed belts that contact the sewing product on the needle plate from below and send the sewing product in the feeding direction, and a feed motor that is a driving source of the feeding operation;
The plurality of feed belts of the lower belt mechanism include a central belt that contacts the sewing product on the downstream side in the feeding direction with respect to the needle drop position, and a side belt that contacts the sewing product next to the central belt. The flat stitch sewing machine according to any one of claims 1 to 9, wherein:

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