JPH0382497A - Automatic sewing machine - Google Patents

Abstract

PURPOSE:To form perfect stitches with a simple movement of a cloth to be sewn in a specified direction by forming a slack on the lower thread by the movements of a cloth pressing plate and a cloth feed table, then controlling the cloth feed amounts in X- and Y-directions per specified one stitch. CONSTITUTION:When a cloth 8 is to be moved from a needle hole 12 to a needle hole 13 along the dotted line A, the cloth is first moved from the needle hole 12 to the left as shown with the solid line B, to the front of a needle 7 as shown with the solid line C, and to the target needle hole 13 as shown with the solid line D. By moving the cloth 8 to be sewn in this way, a leading end 9' of the upper thread 9 is engaged from the left to front side of the needle 7, and a perfect stitch is formed. By moving the cloth to be sewn in the specified direction in this way and causing the lower thread to slack so that the lower thread is located on the left of the movement direction of the cloth to be sewn of the needle hole guide, a hitch stitch formed by the feed direction of the cloth to be sewn relative to the needle is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic sewing machine that sews a series of seams with perfect stitches using a simple mechanism.

[Prior Art] As shown in Fig. 6, a conventional automatic sewing machine is
A presser foot 3 is fixed to a feed base 4 on the sewing machine table 2 of the sewing machine body 1, and the base end of the feed base 4 is controlled in the X and Y directions by pulse motors in the X and Y directions mounted on the sewing machine base 2'. It is attached to be movable in the direction, and a frame-shaped cloth holding plate 3 capable of holding cloth is fixed to the tip thereof. The presser plate 3 is mounted so as to be slidable in the vertical direction, and the fabric to be sewn is held between the presser plate 3 and a lower plate (not shown). Further, a needle 6 is fixed to a needle bar 5 mounted on the sewing machine body 1 so as to be movable up and down.

[Problems to be Solved by the Invention] In this type of sewing machine, when the fabric to be sewn held between the presser foot plate 3 and the presser foot lower plate is moved in the X and Y directions, the needle 6 is threaded in the direction of movement. Either a hit stitch or a perfect stitch is formed depending on where the upper thread exits or the bobbin thread exits from the bobbin is located relative to the needle 6, and the hit stitch has a better appearance than the perfect stitch. Moreover, there was a problem in that the knot points of the seams were likely to come loose.

So, to prevent this hitsuchi stitch.

A sewing machine has been proposed in which the entire sewing machine is rotated around the needle drop point so that the fabric to be sewn, which is being moved in the
(see publication).

However, since this sewing machine is large in size and weight, the rotating device that rotates the entire sewing machine is also very large, making the entire sewing machine large and expensive.

In order to solve this problem, a sewing machine has been proposed in which the needle bar and thread catcher are rotated synchronously to remove hitch stitches (see Japanese Patent Publication No. 60-21751). There was a problem in that the configuration for synchronizing the device with the transportation device became complicated.

Therefore, the present inventor has proposed a sewing method for forming perfect stitches based on a simple principle.The principle will be explained below. In FIG. 7, when the fabric to be sewn 8 is moved in the radial directions a' to h'' with respect to the needle 7, that is, when the fabric to be sewn 8 is moved in the direction of area B and area C, the hit stitch is This does not occur, and a perfect stitch is formed.However, when the sewing material 8 is moved in the radial direction a=h with respect to the needle 7 in FIG.
In other words, when the fabric 8 is moved in the direction of area A and area D, hit stitches occur.

Here, front, rear, left, and right refer to the positional relationship seen from the direction of the arrow in FIG.
has passed through the needle hole 10 of the needle 7 from the front to the rear, so when the sewing material moves in the direction of arrow a = h, the lead-out thread limb 9' of the needle thread 9 passes through the sewing material as shown in FIG. When pulled out from cloth 8.

In relation to the bobbin thread, it is on the front side of the needle 7, and when the needle 7 pierces the fabric to be sewn 8, the lead-out thread limb 9' of the upper thread 9 is on the rear side of the needle 7, so the stitch 11 is inclined. It becomes hitsuchi stitch.

That is, when the fabric to be sewn 8 moves to the right with respect to the needle 7,
If the lead-out thread limb 9' of the thread 9 is on the right side of the needle 7, a hit stitch is created. Therefore, as shown in FIG. 10, when the lead-out thread limb 9' of the upper thread 9 is passed from the left side to the front of the needle 7, the hit stitch is removed.

Therefore, as shown in FIG. 11(a), generally, the needle bar rises and the tip of the needle 7 passes through the top surface of the fabric 8 to be sewn, and then the tip of the needle 7 reaches the top surface of the fabric 8 to be sewn. The fabric 8 to be sewn is transferred from the stitch 12 to the target stitch by the shortest distance as shown by the dotted line A.

The needle 7 is transferred to the next stitch 13. However, in this proposal, in the direction of the arrow in Figure 8, first,
As shown in FIG. 11(a), move the workpiece 8 to the left as shown by the solid line arrow, and then move it to the target stitch 13 as shown by the solid line c. Ru. As a result, the lead-out thread limb 9'h of the needle thread 9h in FIG.
The stitch will be on the left side and will be a perfect stitch.

In addition, as shown in FIG. 11(b), in the case of arrow f in FIG. 8, in which the needle is transferred from the stitch 12 to the stitch 13 in the direction of the dotted line A, the workpiece 8 is indicated by the solid arrow opening from the stitch 12. like,
Move to the left, and then move the sewing material 8 to the front of the needle 7 as shown by the solid line C.
Move to the target stitch 13.

Furthermore, as shown in FIG. 11(c), in the case of arrow d in FIG. 8, in which the needle is transferred from the stitch 12 to the stitch 13 in the direction of the dotted line A, the workpiece 8 is indicated by the solid arrow opening from the stitch 12. , the sewing material 8 is moved to the left, as shown by the solid line C, and then moved to the front of the needle 7, first, and then moved to the target stitch 13, as shown by the solid line 2.

In addition, as shown in FIG. 11(d), in the case of the arrow in FIG. 8 in which the needle is transferred from the stitch 12 to the stitch 13 in the direction of the dotted line A, the solid line arrow indicates the sewing material 8 from the stitch 12. like,
Move leftward and further.

As shown by the solid line C, move the material 8 to be sewn in front of the needle 7,
Next, as shown by solid line 2, it is moved to the target stitch 13.

By transferring the fabric 8 to be sewn in this manner.

As shown in FIG. 10, each lead-out thread limb 9' of the upper thread 9
is hung from the left side of needle 7 toward the front, thus.

It becomes a perfect stitch.

However, at a = d in Fig. 10, the lead-out thread limb 9' of the upper thread 9 wraps tightly around the needle 7 in the sewing direction, so there is a problem that the probability of forming a perfect stitch is low. .

The present invention moves the fabric to be sewn in a predetermined direction to loosen the bobbin thread, so that the bobbin thread is positioned on the left side of the needle hole guide in the direction of movement of the fabric to be sewn. It is an object of the present invention to provide an automatic sewing machine capable of removing hit stitches formed depending on the feeding direction.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a cloth presser plate and a cloth feed table that are movable in XY force directions while holding the cloth to be sewn,
In an automatic sewing machine that reads a predetermined cloth feed amount in the XY force directions for each stitch from a control device and controls the movement of the cloth presser plate and cloth feed base according to the cloth feed amount, after the start switch is turned on. , cloth feeding direction determining means for determining whether the cloth feeding direction is perfect stitch or hit stitch, and when the cloth feeding direction determining means determines the cloth feeding direction of hit stitch, the lower thread is in the cloth feeding direction of the needle hole guide. After loosening the bobbin thread by moving the fabric to be sewn using the fabric presser plate and double feed table so that it is on the left side,
A cloth feed control means is provided for controlling the cloth feed amount in the XY force directions for each stitch.

[Function] According to the present invention, when sewing with an automatic sewing machine, when the fabric to be sewn is fed forward to the right by the fabric presser plate and the fabric feed table, the lead-out thread limb of the needle thread does not get tangled with the needle. A perfect stitch is formed when the bobbin thread is on the left side of the needle hole with respect to the direction of movement of the fabric, so first feed the fabric to the right hand a distance longer than the specified feed. After that, the cloth is further moved back to the predetermined cloth feeding position.

Leave the bobbin thread slack and control it so that it is positioned on the left side of the needle hole guide.

[Example] First, the present invention will be explained in detail. As mentioned above, the 9th
In the figure, when the lead-out thread limb 9' of the needle thread 9 is pulled out from the fabric to be sewn 8, it is on the near side of the needle 7 in relation to the bobbin thread.
When the needle 7 pierces the fabric 8, the lead-out thread limb 9'' of the upper thread 9 is on the rear side of the needle 7, so the stitch 11 is inclined and becomes a hit stitch, but in this case, the lower thread 14 and Looking at the relationship between the needle hole 15 and the needle 7, as shown in FIG. When this bobbin thread 14 is placed on the left side of the needle hole 15 as shown in Fig. 2, in Fig. 9,
Since the lead-out thread limb 9' of the needle thread 9 is above the needle 7, a perfect stitch is obtained.

In order to do this, when the fabric 8 to be sewn is transferred in the direction b in FIG.
In order to move the fabric 8 to be sewn as shown by the dotted line A from the stitch 17, first move the fabric 8 to the lower right for a length longer than the predetermined stitch length as shown by the solid line opening, and then thread the bobbin thread 14. After creating slack in the upper left stitch 17, as shown by the solid line,
The fabric to be sewn 8 is moved in the direction returning to .

By doing this, when the bobbin thread 14 with slack is transferred to the upper left direction, the bobbin thread 14 is moved to the upper left direction of the needle hole 15 due to the friction between the workpiece fabric 8 and the bobbin thread 14, and It will look like Figure 2 b.

Furthermore, when the fabric 8 to be sewn is transferred in the direction d in FIG.
As shown in FIG. 3(b), in order to move the fabric 8 to the seam indicated by the dotted line A from the stitch 16 to the stitch 17, first,
After moving the fabric 8 to the lower right as shown by the solid line for a length longer than the predetermined stitch length to create slack in the bobbin thread 14, move it back to the upper left stitch 17 as shown by the solid line. The cloth to be sewn 8 is moved.

By doing this, when the bobbin thread 14 with slack is transferred to the upper left direction, the bobbin thread 14 is brought to the upper left direction of the needle hole 15 due to the friction between the sewing material 19 and the bobbin thread 14.
It will look like d in Figure 2.

Note that the same applies to directions a and c in FIG.

Referring to FIG. 4, in the automatic sewing machine control device according to the embodiment of the present invention, a central processing unit (hereinafter referred to as CPU) 1
8, a read-only memory (hereinafter referred to as ROM) 19 that stores control programs, and a read/write memory (hereinafter referred to as RA) that temporarily stores data from input devices and floppy disks.
M) 20 is connected, and the microcomputer 21
It consists of Further, a floppy disk device 22 is connected to the CPU 18 for storing the XY force direction and cloth feed amount for each stitch as data for each sewing pattern. Further, on the input side of the CPU 18, there is an input device 23 such as a keyboard for inputting sewing data regarding the cloth feed direction and cloth feed amount necessary for forming a sewing pattern onto a floppy disk. A pulse generating means 24 that outputs the period from immediately after it comes out to before it enters the fabric as a pulse, and a switch that is provided with a sewing machine start switch and a switch for starting the stitching of the sewing pattern from the origin position for sewing the sewing machine. Devices 25 and the like are connected. Further, a sewing machine motor 27 is connected to the output side of the CPU 18 via a motor driver 26, and
A pulse motor 29 for feeding in the X direction is connected via a motor driver 28, and a pulse motor 31 for feeding in the Y direction is further connected via a motor driver 30. 31
The feed table 32 is driven by.

The operation of the control device of this embodiment configured as described above will be explained with reference to the flowchart shown in FIG. First, when starting, press the start button of the sewing machine to start the sewing machine (Step 1) Next, the pulse motor 29 for feeding in the X and Y directions
, 31 are respectively driven to send the feed table 32 to the origin position (step 2).

Next, move the feed base 32 to the sewing start point (step 3
), and then it is determined whether the start switch of the switch device 25 is on or not (step 4), and if it is off, the process continues to wait until on is input. Here, if the start switch is turned on, it is determined from the cloth feeding direction of the sewing pattern shown in FIG. 7 whether or not it is a hit stitch (step 5). ), the fabric to be sewn is fed in the direction explained in (b) (step 6), and when - stitches have been sewn (step 7), it is determined whether or not a predetermined number of n stitches have been sewn (step 8). ), if the predetermined number of stitches n is not completed,
Return to step 5. If the stitch is a perfect stitch, one normal stitch is sewn (step 9), and when the number of stitches reaches a predetermined number n, the sewing is finished.

As described above, in the present invention, the needle wound can be fixed as shown in FIG. can form perfect stitches.

[Effects of the Invention] Since the present invention is constructed as described above, a perfect stitch can be formed simply by moving the fabric to be sewn in a predetermined direction, and therefore the construction is simple.

This has the advantage of being easier to control.

[Brief explanation of drawings]

Figure 1 shows the direction of movement of the fabric to form hit stitches, the relationship between the bobbin thread and the needle hole, and Figure 2 shows the direction of movement of the fabric to form perfect stitches, and the relationship between the bobbin thread and needle. Figures 3(a) and 3(b) are diagrams showing the relationship between the holes, and Figures 3(a) and 3(b) are diagrams showing the moving direction of the fabric to be sewn in which a perfect stitch is formed to explain the present invention in detail. A block diagram of an automatic sewing machine control device according to an embodiment of the present invention that moves the sewing fabric in the directions shown in FIGS. 3(a) and (b), and FIG. 5 explains the operation of the control device shown in FIG. 4. Fig. 6 is a perspective view of the automatic sewing machine, Fig. 7 is a diagram showing the feeding direction of the fabric to be sewn in which perfect stitches or hit stitches are formed, and Fig. 8 is a diagram showing the needle direction in which hit stitches occur. Figure 9 shows the relationship between the needle and the needle where the hit stitch is formed, and Figure 10 shows the relationship between the needle and the needle where the perfect stitch is formed. FIG. 11 is a diagram for explaining the moving direction of the fabric to be sewn so that the needle and needle thread lead-out thread limbs become the perfect stitch shown in FIG. 9. 18...CPU, 19...ROM, 20...RA
M, 21... Microcomputer, 22... Floppy disk device, 23... Input device, 24...
Pulse generating means, 25... switch device, 26...
Motor driver, 27... Sewing machine motor, 28...
Motor driver, 29...Pulse motor for feeding in the X direction. 30... Motor driver, 31... Pulse motor for Y direction feeding, 32... Feeding base.

Claims (1)

[Claims] 1. A cloth presser plate and a cloth feed table are provided which are movable in the X and Y directions while holding the cloth to be sewn, and a predetermined cloth feed amount in the X and Y directions for each stitch is read out from a control device, and according to the cloth feed amount,
In the automatic sewing machine that controls movement of the cloth presser plate and the cloth feed table, the cloth feed direction determining means determines whether the cloth feed direction is a perfect stitch or a hitch stitch after a start switch is turned on; When the determination means determines the cloth feed direction for hitch stitching, the cloth is moved by the cloth presser plate and the cloth feed table so that the bobbin thread is on the left side of the needle hole guide in the cloth feed direction. An automatic sewing machine characterized by being provided with cloth feed control means for controlling the cloth feed amount in the X and Y directions for each stitch after slackening.