JPH05309185A - Button hole sewing device in zigzag sewing machine - Google Patents

Abstract

PURPOSE:To compensate a position where the formation of a button hole is started for a shift between a retainer frame and a retainer fixture by reversing the feed of cloth web, and by detecting a position of the retainer frame in accordance with a resistance value of a potentiometer upon a start of the forma tion of a button hole. CONSTITUTION:The feed of cloth web is reversed (S4) and a position of a retainer frame is detected in accordance wit a resistance value of a potentiometer (S6). The fabricated cloth web is fed in a direction reverse to the feeding direction of the cloth web until resistance value does not vary (S8) to adjust the starting position of forming a button hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buttonhole sewing device capable of correcting the start position of buttonhole sewing.

[0002]

2. Description of the Related Art Conventionally, a buttonhole sewing device of this type is disclosed in Japanese Patent Publication No. 62-40035. According to this, as shown in FIG. 7A, the needle plate 12 is provided on the bed portion 11 of the sewing machine. And
As shown in FIG. 7B, the needle plate 12 is formed with a needle hole 14 and a feed dog groove hole 15.
The feed dog 16 projects upward through 5 to feed the work cloth in the arrow A direction and the arrow B direction. Further, a holding metal fitting 25 is attached to the holding rod 24 attached to the sewing machine main body.

Further, since the press frame 33 for the buttonhole is slidably provided on the presser 27 and the press fitting 25 is mounted on the presser 27, the press frame 33 can slide in the A direction and the B direction. Is. Further, a button stand 50 is provided at the front end of the pressing frame 33 in the B direction, and the button stand 50 is, as shown in FIG.
And button engaging portion 60. Fixing unit 40
Is fixed to a fixed position at the tip of the holding frame 33 in the B direction as shown in FIG. Further, in order to hold a button of an arbitrary size between the fixing section 40 and the button engaging section 60, the engaging section 60 is slidable in the arrow A and B directions. A coil spring 53 is provided between the presser foot 27 and the fixing section 40, and the pressing frame 27 and the fixing section 40 are in close contact with each other by the biasing force of the coil spring 53. It is maintained at the buttonhole formation start position.

Next, the operation of the buttonhole sewing device having the above structure will be described.

First, when the presser frame 33 is attached to the presser fitting 25 to start buttonhole sewing, when the presser frame 33 attached to the presser 27 is lowered or lowered, the presser frame 33 is changed to a work cloth. When the operator presses the work cloth forcibly, the presser foot 27 and the fixing section 40 are not in close contact with each other, and a 3 mm deviation occurs between the presser foot 27 and the fixing section 40. Suppose that When the start / stop switch is operated from that state to start forming the buttonhole, first, the presser foot 33 is fed together with the work cloth by two stitches in the direction of arrow A, and correction sewing is performed. Here, in this buttonhole sewing device, one stitch of correction sewing at the start of buttonhole sewing is 2.3 mm.

The operation of the correction sewing will be described in detail below.
First, the presser frame 33 together with the work cloth is for one stitch, that is, 2.3 m.
m It is sent in the direction of arrow A, and jump stitching is performed. At this time, the needle is sewn from the starting point a to b shown in FIG. After that, jump stitching for another stitch is performed in the same manner. However, in this case, since the gap between the presser foot 27 and the fixing portion 40 is 3 mm, the presser foot frame 33 moves with the work cloth by one stitch in the direction A, and the presser foot 27 contacts the fixing portion 40 while the jump stitch is performed. Contact. Therefore, the feed dog 16 slides on the work cloth, and the presser frame 33 and the work cloth are not fed further, the second stitch of the jump stitch is c, and the distance between b and c is less than 2.3 mm.

In this way, the pressing frame 33 together with the work cloth A
The start position of buttonhole sewing can be corrected by performing feed correction sewing for two stitches in the same direction.

[0008]

However, in the buttonhole sewing device as described above, since the presser frame 33 and the work cloth are fed in the direction A only for two stitches, for example, the presser foot 27 and the fixing section 40 are When the deviation of 2 stitches or more, that is, 4.6 mm or more, there is a problem that the start position of buttonhole sewing is not corrected correctly. Further, when the work cloth is a thin cloth or a cloth of two layers, the cloth feed amount is as large as 2.3 mm, so that two stitches are sewn when the buttonhole sewing is started and the feed dog 16 slides on the work cloth. At that time, there was a problem that the buttonhole was not formed properly because the work cloth was misaligned or wrinkled.

The present invention has been made in order to solve the above-mentioned problems, and at the start of buttonhole sewing, it is possible to surely correct the amount by which the presser frame is displaced, and it is possible to adjust according to the size of the button. An object is to provide a buttonhole sewing device capable of forming a buttonhole.

[0010]

In order to achieve this object, a buttonhole sewing device of the present invention is provided with a press fitting attached to a presser bar as shown in FIG. 1 and a cloth feed direction attached to the press fitting. And a holding frame movable in the opposite cloth feed direction,
A detection device that generates a variable analog signal with the movement of the presser frame, and at the start of buttonhole formation, move the presser frame in the direction of spring bias until the level value of the variable analog signal detected by the detection device does not change. It is provided with a buttonhole formation control means for controlling so as to form a buttonhole according to the size of the button by feeding and then feeding the presser frame in the direction opposite to the spring biasing direction.

[0011]

In the buttonhole sewing apparatus of the present invention having the above-mentioned structure, when the buttonhole formation is started, the level value of the variable analog signal generated by the movement of the presser frame detected by the detection device does not change. The buttonhole formation control means sends the presser frame in its spring urging direction,
After that, the pressing frame is fed in the direction opposite to the spring urging direction to correct the buttonhole start position and form a buttonhole corresponding to the size of the button.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the configuration of the buttonhole device of this embodiment will be described with reference to FIG.

The buttonhole device of this embodiment includes a holding metal fitting 10 attached to a holding rod attached to a sewing machine main body,
The holding metal fitting 10 is provided with a holding frame 12 slidable in the feed direction of the work cloth and the opposite feed direction of the work cloth. A spiral spring 13 is mounted inside a hollow stopper 12a fixed to the uppermost end surface of the holding frame 12 in the direction of arrow A. The holding frame 12 is constantly urged by the elastic force of the spiral spring 13 so that the holding metal fitting 10 and the stopper 12a are in contact with each other as shown in FIG. 3, that is, the buttonhole sewing start position is reached. Has been done.

Further, the button base 1 is provided inside and outside the holding portion 12b which is the end portion of the holding frame 12 in the direction of arrow B shown in FIG.
4 is slidably provided, and the button 16 can be held between the end portion 14a of the button base 14 outside the holding portion 12b and the holding portion 12b.

The holding metal fitting 10 is provided with a potentiometer 18 which extends outside the holding frame 12 and which is parallel to the holding frame 12 and corresponds to a detection device.
The detection unit 2 connected to the tip extending from the button base 14 in b.
0 is provided. A variable resistor is provided in the potentiometer 18, and the resistance value is varied by sliding the detection unit 20 in the potentiometer 18.

Here, when the detecting portion 20 is located closest to the holding metal fitting 10, the resistance value is 0. On the other hand, as the detecting portion 20 moves away from the holding metal fitting 10 in the B direction, the resistance value becomes smaller. growing. Further, a lead wire 22 is connected to the potentiometer 18 and the potentiometer 18
Is connected to the CPU of the sewing machine body.

Next, FIG. 2 shows the electrical construction of this embodiment.
Will be described.

First, the sewing machine main body is provided with a CPU 24 mainly composed of a microcomputer.
4 is configured to operate according to a flow chart described later, and a pattern selection dial 26 for selecting a desired pattern, a potentiometer 18, and a sewing machine motor start / stop switch 30 are respectively provided in the CPU 24.
And is configured to supply respective signals to the CPU 24. A memory 31 is connected to the CPU 24, and is configured to read and write data according to a signal from the CPU 24.

Further, a pulse motor driver 32 and a sewing machine motor driver 34 are connected to the CPU 24, and a needle swing pulse motor 36 and a cloth feed pulse motor 38 are connected to the pulse motor driver 32, respectively. 34 is a sewing machine motor 40
Are connected. Then, according to the signal from the CPU 24, the pulse motor driver 32 issues a command to the needle swing pulse motor 36 and the cloth feed pulse motor 38, and the sewing machine motor driver 34 issues a command to the sewing machine motor 40.

Next, the operation of the buttonhole sewing machine of this embodiment will be described with reference to FIGS.

First, in the buttonhole sewing apparatus of this embodiment, the holding metal fitting 10 is in a state of being urged by the elastic force of the spiral spring 13 so that the holding metal fitting 10 is in contact with the stopper 12a. Then, from that state, the button base 14 is pulled in the direction of the arrow B, and the button 16 is inserted between the end portion 14a and the holding portion 12b as shown in FIG. Then, the end portion 14a of the button base is slid in the direction of arrow A until it abuts on the button 16, so that the button 16 and the holding portion 1 are held.
It is clamped by 2b. Then, the presser foot 10 of the buttonhole sewing device is attached to the presser foot attached to the tip of the needle bar of the sewing machine main body, and the lead wire 22 is connected to the sewing machine main body. Here, when the presser foot attached to the sewing machine main body is lowered to press the work cloth, the operator forcibly shifts the position of the work cloth, and as shown in FIG. Suppose that it has been installed in the wrong position.

Thereafter, when the buttonhole sewing is selected by the pattern selection dial 26 provided on the sewing machine main body, and the start / stop switch 30 sends a start signal for starting the buttonhole sewing to the CPU 24 (S1), CP
U24 reads the resistance value R1 of the potentiometer 18 and stores it in the memory 31 (S2). Here, since the button 16 is clamped as shown in FIG.
Is separated from the sandwiching part 12b, the detecting part 20 is also moving in the direction B in the potentiometer 18 accordingly, and the potentiometer 18 detects a certain resistance value R1.

After the resistance value R1 detected by the potentiometer 18 is stored in the memory 31 (S2), the work cloth is moved in the half cloth feed direction, that is, in the direction of arrow B shown in FIG.
The stitches, for example 0.4 mm, are fed, and jump stitching is performed (S4). After the jump stitching is performed, the resistance value R2 detected by the potentiometer 18 is read into the CPU 24 again (S6), and it is determined whether the resistance values R1 and R2 are the same (S8). In this embodiment, the resistance values R1 and R2
Are not the same (S8: NO), return to S2 and S2
~ S8 is repeated. Then, as shown in FIG. 3, the work cloth is fed in the opposite cloth feed direction, and the pressing metal fitting 10 is moved to the stopper 1
2a and it is determined that the resistance values R1 and R2 are the same (S8: YES), the resistance value R is stored in the memory 31.
(S10).

Thereafter, the needle swing pulse motor 36 and the sewing machine motor 40 are driven to form the buttonhole bartack 70a shown in FIG. 6 (S12). Further, the needle swing amount is changed, the cloth feed pulse motor 38 is also driven to feed the work cloth in the direction of arrow A (S14), the L side 70b is sewn, and the resistance value Rn of the potentiometer 18 is read ( S16). Then, it is determined whether or not the read resistance value Rn is 0, that is, whether or not the detection unit 20 has reached the extreme end of the potentiometer 18 in the A direction (S18). When the resistance value Rn is not 0 (S
18: NO), and returns to S14 and repeats S14 to S18. On the other hand, when the resistance value Rn becomes 0 (S18: YES) and the L side 70b of the buttonhole is formed, the bar tack 70c is subsequently formed (S20), and the process proceeds to S22.

In S22, the cloth feed is reversed by the signal from the CPU 24, the work cloth is fed in the B direction, and the R
The side 70d is sewn (S22). Then, the resistance value Rn of the potentiometer 18 is read again (S24), and the read resistance value Rn is the S1 value.
At 0, it is determined whether the resistance value R is the same as the resistance value R stored in the memory 31 (S26). Two resistance values Rn,
When it is determined that R is not the same (S26: NO),
The process returns to S22 and S22 to S26 are repeated. On the other hand, when it is determined that the two resistance values Rn and R are the same, that is, when the sewing of the R side 70d is completed (S26: YES), the process proceeds to S28, where the stop stitching is performed,
The sewing machine motor 40 is stopped (S28).

As described above, the buttonhole sewing device of this embodiment measures the button size as the resistance value R by only one device, that is, the potentiometer 18, and the position of the presser frame 12 during the buttonhole sewing. Can be detected as a resistance value Rn to form a buttonhole of a desired size.

Further, at the start of forming the buttonhole, the position of the holding frame 12 is detected as a resistance value Rn, and until the resistance value does not change, that is, until the pressing metal fitting 10 and the stopper 12a come into close contact with each other, the cloth is fed in the opposite direction. The press frame 12 is sent together with the work cloth. Therefore, it is possible to surely correct the amount by which the pressing fitting 10 and the stopper 12a are displaced. Also,
Since the feed amount is also as small as 0.4 mm, there is no need to make a correction larger than the actual deviation, so the work cloth will not be displaced or wrinkled, and a buttonhole of the desired size can be accurately formed. be able to.

Furthermore, the structure of the buttonhole sewing device is simplified, and the variation in the precision of parts caused by products can be suppressed at a low cost. In addition, the number of parts can be reduced, the cost can be reduced as a whole, and a complicated electronic circuit and arithmetic processing are not required, which leads to cost reduction.

[0030]

As is apparent from the above description, according to the buttonhole sewing device of the present invention, when the buttonhole sewing is started, the presser frame is held until the level value of the variable analog signal detected by the detection device does not change. By feeding the spring in the biasing direction and correcting the start position of buttonhole sewing, a buttonhole of a desired size can be accurately formed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of an embodiment of the present invention.

FIG. 3 is a top view of the buttonhole retainer of this embodiment before being attached to the sewing machine main body.

FIG. 4 is a top view of the buttonhole retainer mounted on the sewing machine main body in a shifted state.

FIG. 5 is a flowchart showing the operation of the CPU of this embodiment.

FIG. 6 is an explanatory diagram showing an example of a buttonhole formed.

FIG. 7 (a) is a perspective view when the conventional device is attached to the sewing machine main body. FIG. 7B is an explanatory view for explaining the needle plate of the sewing machine body in the conventional device.

FIG. 8 is a configuration diagram showing a configuration of a conventional device.

FIG. 9 is an explanatory diagram illustrating a buttonhole formed by a conventional device.

[Explanation of symbols]

 10 Presser fitting 12 Presser frame 14 Button stand 18 Potentiometer 20 Detector

Claims (1)

[Claims] 1. A presser fitting attached to a presser bar, and a presser frame attached to the presser fitting and movable in a cloth feed direction and a non-cloth feed direction. One end of the presser frame at the start of buttonhole formation. The sewing needle is oscillated laterally from the state where one end of the press frame is in contact with the press fitting by the urging force of the spring provided between the press fitting and the direction perpendicular to the swing direction of the sewing needle. In a buttonhole sewing device that starts buttonhole formation by sending a work cloth and forms a buttonhole of a desired size on the work cloth, a detection that generates a variable analog signal with the movement of the presser frame. At the start of forming the device and the buttonhole, the pressing frame is fed in its spring biasing direction until the level value of the variable analog signal detected by the detecting device does not change, and then the pressing frame is moved to its bar position. By sending in the direction opposite to the bias direction, buttonhole sewing device zigzag sewing machine, characterized in that a buttonhole forming control means for controlling to form a buttonhole in accordance with the size of the button.