JP3158641B2 - Buttonhole sewing device for zigzag sewing machine - Google Patents

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 a buttonhole sewing start position.

[0002]

2. Description of the Related Art Conventionally, there is a buttonhole sewing apparatus of this kind as disclosed in Japanese Patent Publication No. 62-40035. According to this, as shown in FIG. 7A, a needle plate 12 is provided on a bed portion 11 of the sewing machine. And
As shown in FIG. 7B, the needle plate 12 has a needle hole 14 and a feed dog slot 15 formed therein.
5, the feed dog 16 projects upward, and feeds the work cloth in the directions of the arrows A and B. Further, a presser fitting 25 is mounted on a presser rod 24 mounted on the sewing machine main body.

The holding frame 33 for the buttonhole is slidably provided on the holding member 27, and the holding member 25 is mounted on the holding member 27, so that the holding frame 33 can slide in the A direction and the B direction. It is. Further, a button base 50 is provided at the front end of the pressing frame 33 in the B direction, and the button base 50 is, as shown in FIG.
And a button engaging portion 60. Fixing unit 40
Is fixed to a fixed position at the front end in the direction B of the holding frame 33 as shown in FIG. Further, in order to sandwich a button of an arbitrary size between the fixing unit 40 and the button engaging unit 60, the engaging unit 60 is slidable in the directions of arrows A and B. A coil spring 53 is provided between the presser 27 and the fixing unit 40, and the pressing frame 27 and the fixing unit 40 are in close contact with the presser frame 27 and the fixing unit 40 by the urging force of the coil spring 53. It is maintained at the buttonhole formation start position.

Next, the operation of the buttonhole sewing apparatus having the above-described configuration will be described.

First, when the presser frame 33 is mounted on the presser fitting 25 and the buttonhole sewing is started, when the presser frame 33 mounted on the presser 27 is lowered or after the presser frame 33 is lowered, the presser frame 33 is attached to the work cloth. The presser 27 and the fixing unit 40 are not in close contact with each other, and a displacement of 3 mm is generated between the presser 27 and the fixing unit 40. Suppose that When the start / stop switch is operated from this state to start buttonhole formation, first, the presser foot 33 is fed by two stitches in the direction of arrow A together with the work cloth, and the correction sewing is performed. Here, in this buttonhole sewing apparatus, one stitch of the correction sewing at the start of the buttonhole sewing is 2.3 mm.

The operation of the correction sewing will be described in detail.
First, the presser frame 33 is one stitch, that is, 2.3 m, together with the work cloth.
The sheet is sent in the direction of the arrow A, and the jump stitching is performed. At this time, the needle is jumped from the starting points a to b shown in FIG. 9, that is, 2.3 mm. Thereafter, jump stitching for another stitch is performed in the same manner. However, in this case, since the gap between the presser 27 and the fixing unit 40 is 3 mm, the presser frame 33 is further moved in the direction A by one stitch together with the work cloth, and the presser 27 contacts the fixing unit 40 during jump sewing. Touch Therefore, the feed dog 16 slides on the work cloth, and the presser frame 33 and the work cloth are not further fed, and the second stitch of the jump stitch is c, and the distance between bc is less than 2.3 mm.

[0007] As described above, the holding frame 33 is put together with the work cloth into the A
By performing the feed correction sewing by two stitches in the direction, the start position of the buttonhole sewing can be corrected.

[0008]

However, in the buttonhole sewing apparatus as described above, the presser frame 33 and the work cloth are fed in the direction A only for two stitches. If the displacement is two stitches or more, that is, 4.6 mm or more, there is a problem that the start position of the buttonhole sewing is not correctly corrected. When the work cloth is a thin cloth or a two-ply cloth, since the cloth feed amount is as large as 2.3 mm, two stitches are performed at the start of buttonhole sewing, and the feed dog 16 slides on the work cloth. At that time, there was a problem that the work cloth was displaced or wrinkled, and a buttonhole was not formed cleanly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. At the time of starting buttonhole sewing, the presser frame can be surely corrected by the shift amount, and the size of the button can be adjusted. An object of the present invention is to provide a buttonhole sewing device capable of forming a buttonhole.

[0010]

In order to achieve this object, a buttonhole sewing apparatus according to the present invention comprises a presser fitting mounted on a presser bar as shown in FIG. 1 and a cloth feeding direction mounted on the presser fitting. And a presser frame movable in the anti-cloth feeding direction,
A detecting device that generates a variable output signal in accordance with the movement of the presser frame, and at the start of buttonhole formation, the presser frame is moved in its spring biasing direction until the level value of the variable output signal detected by the detector does not change. Send and start buttonhole sewing
Buttonhole forming control means for controlling the position of the button frame to be formed in accordance with the size of the button by correcting the position, and then feeding the presser frame in the direction opposite to the spring urging direction and in the spring urging direction. Have.

[0011]

In the buttonhole sewing apparatus according to the present invention having the above-described structure, at the start of the buttonhole formation, the variable output generated by the movement of the presser frame detected by the detection device.
Until the level value of the force signal no longer changes, the buttonhole forming control means sends the presser frame in the
Correct the start position of the buttonhole sewing, and then send the presser frame in the direction opposite to the spring bias direction and in the spring bias direction to correct the buttonhole start position and form the buttonhole according to the button size. I do.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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 the present embodiment includes a presser fitting 10 mounted on a presser bar mounted on the sewing machine main body,
The presser fitting 10 is provided with a presser frame 12 slidably provided in a work cloth feed direction and a counter cloth feed direction. A spiral spring 13 is mounted inside a hollow stopper 12a fixed to the upper surface of the end of the presser frame 12 in the direction of arrow A. The presser frame 12 is constantly urged by the elastic force of the spiral spring 13 so that the presser fitting 10 and the stopper 12a come into contact with each other as shown in FIG. 3, that is, the buttonhole sewing start position. Have been.

Further, the button base 1 extends over the inside and outside of the holding portion 12b, which is the end of the holding frame 12 in the direction of arrow B shown in FIG.
4 is provided so as to be slidable, 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.

A potentiometer 18 corresponding to a detecting device is mounted on the holding metal fitting 10 so as to extend outside the holding frame 12 and be parallel to the holding frame 12.
b. Detecting unit 2 connected to the tip extending from button base 14 in b.
0 is provided. A variable resistor is provided in the potentiometer 18, and the detecting unit 20 is configured to vary the resistance value by sliding in the potentiometer 18.

Here, when the detecting section 20 is located closest to the presser fitting 10, the resistance value is 0. On the other hand, as the detecting section 20 moves away from the presser fitting 10 in the B direction, the resistance value increases. growing. A lead wire 22 is connected to the potentiometer 18 so that the potentiometer 18
Is connected to the CPU of the sewing machine main body.

Next, FIG. 2 shows the electrical configuration of this embodiment.
This will be described with reference to FIG.

First, the main body of the sewing machine is provided with a CPU 24 mainly composed of a microcomputer.
4 is configured to operate in accordance with a flowchart 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 each connected to a CPU 24.
And is configured to supply each signal to the CPU 24. Further, a memory 31 is connected to the CPU 24, and is configured to read and write data in accordance with 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. The pulse motor driver 32 is connected to a needle swing pulse motor 36 and a cloth feed pulse motor 38, respectively. 34 is a sewing machine motor 40
Is connected. In accordance with a 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 apparatus according to the present embodiment will be described with reference to FIGS.

First, in the buttonhole sewing apparatus according to the present embodiment, the holding member 10 is urged by the elastic force of the spiral spring 13 and the holding member 10 is in contact with the stopper 12a. Then, the button base 14 is pulled in the direction of arrow B from this state, 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 stand is slid in the direction of arrow A until the button 16 comes into contact with the button 16 so that the button 16 is moved to the end portion 14a and the holding portion 1
2b. Then, the presser fitting 10 of the buttonhole sewing device is attached to the cloth 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 attached to the sewing machine main body is lowered and the work cloth is pressed, the operator forcibly shifts the position of the work cloth, and as shown in FIG. It is assumed that it has been shifted and attached.

Thereafter, buttonhole sewing is selected by the pattern selection dial 26 provided on the sewing machine main body, and a start signal for starting buttonhole sewing is transmitted to the CPU 24 by the start / stop switch 30 (S1).
U24 reads the resistance value R1 of the potentiometer 18 and stores it in the memory 31 (S2). Here, since the button 16 is sandwiched as shown in FIG.
Is separated from the holding section 12b, the detection section 20 also moves in the direction B in the potentiometer 18 in accordance therewith, 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 by one in the half cloth feed direction, that is, in the direction of arrow B shown in FIG.
The stitches are fed by, for example, 0.4 mm, and the jump stitching is performed (S4). After the jump sewing, the resistance value R2 detected by the potentiometer 18 is read into the CPU 24 again (S6), and it is determined whether or not 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), the process returns to S2, and S2
To S8 are repeated. Then, as shown in FIG. 3, the work cloth is fed in the anti-feed direction, and
2a, when 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 a button hole bar tack 70a shown in FIG. 6 (S12). Further, the needle swing amount is changed, and the cloth feed pulse motor 38 is also driven to feed the work cloth in the direction of arrow A (S14), the sewing of the L side 70b is performed, 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 end of the potentiometer 18 in the A direction (S18). If the resistance value Rn is not 0 (S
18: NO), returning to S14 and repeating 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 a signal from the CPU 24, and the work cloth is fed in the B direction.
The sewing of the side 70d is performed (S22). Then, the resistance value Rn of the potentiometer 18 is read again (S24), and the read resistance value Rn is referred to as S1.
At 0, it is determined whether or not the resistance value is the same as the resistance value R stored in the memory 31 (S26). Two resistance values Rn,
If it is determined that R is not the same (S26: NO),
Returning to S22, 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, and the stop sewing is performed.
The sewing machine motor 40 is stopped (S28).

As described above, the buttonhole sewing device according to the present embodiment measures the size of the button as the resistance value R using only one device, that is, the potentiometer 18, and positions the presser frame 12 during the buttonhole sewing. Is detected as the resistance value Rn, and a buttonhole having a desired size can be formed.

Further, at the start of buttonhole formation, the position of the presser frame 12 is detected as a resistance value Rn, and the position of the presser frame 12 is detected in the reverse cloth feed direction until the resistance value no longer changes, that is, until the presser fitting 10 and the stopper 12a come into close contact. The presser frame 12 is sent together with the work cloth. Therefore, it is possible to reliably correct the amount by which the holding metal 10 and the stopper 12a are displaced. Also,
Since the feed amount is as small as 0.4 mm, it is not corrected much more than the actual shift, so that the work cloth does not shift or wrinkle, and a buttonhole of a desired size is accurately formed. be able to.

Furthermore, the configuration of the buttonhole sewing device is simplified, and the variation in component accuracy caused by the product is reduced at a low cost. In addition, the number of components can be reduced, the device can be manufactured at a low cost 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 apparatus of the present invention, when the buttonhole sewing is started, the presser frame is held until the level value of the variable output signal detected by the detecting apparatus does not change. By feeding in the spring biasing direction and correcting the start position of the buttonhole sewing, a buttonhole having a desired size can be accurately formed.

[Brief description of the 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 one embodiment of the present invention.

FIG. 3 is a top view of the buttonhole press according to the present embodiment before being mounted on a sewing machine main body.

FIG. 4 is a top view of the buttonhole presser attached to the sewing machine body in a shifted state.

FIG. 5 is a flowchart illustrating an operation of a CPU according to the present embodiment.

FIG. 6 is an explanatory view showing an example of a buttonhole to be formed.

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

 DESCRIPTION OF REFERENCE NUMERALS 10 holding bracket 12 holding frame 14 button base 18 potentiometer 20 detection

Claims (1)

(57) [Claims] 1. A presser fitting mounted on a presser bar, and a presser frame mounted on the presser fitting and movable in a cloth feed direction and a counter cloth feed direction, and one end of the presser frame at the start of buttonhole formation. With the biasing force of the spring provided between the presser fitting and the one end of the presser frame, the sewing needle is swung laterally from a state in which it comes into contact with the presser fitting, and in a direction orthogonal to the swing direction of the sewing needle. In a buttonhole sewing device for forming a buttonhole of a desired size on a work cloth by starting a buttonhole formation by feeding a work cloth, detecting that a variable output signal is generated with movement of the presser frame. When the buttonhole formation is started, the presser frame is sent in the spring biasing direction until the level value of the variable output signal detected by the detection device no longer changes, and the buttonhole sewing is started.
Position correcting, then the pressing bias frame and with the spring and reverse directions as well as Ba
A buttonhole stitching apparatus for a zigzag sewing machine, comprising: a buttonhole formation control unit that controls the buttonhole according to the size of the button by sending the buttonhole in the urging direction .