JPH07313756A - Sewing machine for working buttonhole - Google Patents

Abstract

PURPOSE:To easily execute overlapped sewing without exchanging a main cam by driving a knife to be passed through a position, where the formation of a buttonhole is planned, after working sewing is repeated when the overlapped sewing is set before the rotation of the main cam at a prescribed angle is detected. CONSTITUTION:A working sewing means M1 executes the working sewing around the position, where the formation of the buttonhole is planned, on fabric with one time rotation of the main cam rotated by an upper shaft. Besides, a knife driving means M2 passes the knife through the position where the formation of the buttonhole is planned. Further, a stopping means M3 detects one time rotation of the main cam and stops the rotation of the upper shaft. Thus, an angle detecting means M4 detects the rotation of the main cam at the prescribed angle. A setting means M5 sets the overlapped sewing of working sewing. When the overlapped sewing is set before the rotation of the main cam at the prescribed angle is detected, an overlapped sewing control means M6 drives the knife driving means M2 after the working sewing is repeated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buttonhole sewing machine for sewing a buttonhole at a predetermined portion and forming a buttonhole by penetrating a knife.

[0002]

2. Description of the Related Art Conventionally, buttonhole sewing machines have been
The main cam is rotated in synchronization with the rotation of the upper shaft, and the fabric is fed and the buttonhole is formed in response to one rotation of the main cam. For example, when feeding cloth, one end of an arm having a cloth pressing plate is fitted into a groove formed in the main cam,
It is performed by reciprocating the arm in the buttonhole forming direction by the rotation of the main cam. In addition, the button hole is formed by a part of the knife drive mechanism abutting on the convex cam part provided on the main cam when the cloth reciprocates and the well-known overlock stitching is completed. The knife drive mechanism moves the knife.

By the way, in the case of performing buttonhole stitching, so-called lapped stitching in which buttonhole stitching is once performed is performed again in order to enhance the reinforcing effect of the buttonhole. In this case, if the main cam used for single overedging is used, the knife driving mechanism is activated at the end of the first overedging, and a button hole is formed before performing overstitching. Therefore, there is a problem that the cloth with button holes flutters and the stitches of lapped stitches are not formed.Therefore, when performing lapped stitches, the button holes are not formed at the end of the first overstitching and at the end of lapped stitches. Sewing was performed by replacing the main cam for lap stitching formed so that the knife drive mechanism operates.

[0004]

However, in such a conventional one, there is a problem that replacement of the main cam requires skill, is extremely complicated and difficult, and two kinds of main cams must be prepared. There was also the problem of having to do so.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a buttonhole sewing machine which can easily perform lapped stitches without performing a complicated work such as replacement of a main cam. is there.

[0006]

In order to achieve such an object, the present invention has the following constitution as means for solving the problem. That is, as illustrated in FIG. 1, overlock stitching means M1 for performing overlock stitching around the buttonhole formation planned portion of the cloth by one rotation of the main cam rotated by the upper shaft, and a knife for the buttonhole formation planned portion. Knife driving means M2 to penetrate
And an angle detecting means M4 for detecting that the main cam has rotated a predetermined angle in a buttonhole sewing machine including a stop means M3 for detecting one rotation of the main cam and stopping the rotation of the upper shaft. When the overlapped stitch is set by the setting means M5 for setting the overlapped stitch of the overedging and by the angle detecting means M4, when the overlapped stitch is set, one rotation by the stopping means M3 is performed. Regardless of the detection, the structure of the buttonhole sewing machine is characterized in that the buttonhole sewing machine is provided with lapped stitching control means M6 for driving the knife driving means M2 after repeating overedging by the overedging means M1 again. is there.

Further, the setting means M5 is provided with a lap stitch switch for detecting the depression of the start pedal which is larger than the depression of the start switch for detecting the depression of the start pedal, and the lap stitch is set by the operation of the lap stitch switch. Alternatively, the setting means M5 may be configured to detect that the start switch for detecting the depression of the start pedal is repeatedly depressed and set the overlapped stitch when the depression is repeatedly depressed.

Further, the angle detecting means M4 may be constructed so as to detect that the rotation of the upper shaft has been rotated to a low speed switching angle for switching from high speed to low speed.

[0009]

In the buttonhole overlock sewing machine having the above-mentioned structure, the overlock stitching means M1 performs overlock stitching around the buttonhole formation planned portion of the cloth by one rotation of the main cam rotated by the upper shaft. When the angle detection means M4 detects the rotation of the main cam by a predetermined angle, the overlapped stitching control means M6, when the overlapped stitching is set by the setting means M5, regardless of the detection of one rotation by the stopping means M3. After repeating the overedging by the overedging means M1 again, the knife driving means M2 is driven to form the button hole.

If the setting means M5 is provided with a lap stitch switch, the lap stitch is set when the lap stitch switch is actuated, and the setting means M5 detects that the start pedal is repeatedly depressed. What you do
Set the overlapped stitch when the start pedal is repeatedly depressed.

Further, in the case where the angle detecting means M4 detects a low speed switching angle, when the low speed switching angle is reached, overlapped stitching is performed without slowing the rotation of the upper shaft.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 2, an upper shaft 2 is rotatably supported in the sewing machine arm 1, and a pulley 4 fixed to the upper shaft 2 and a pulley 10 fixed to an output shaft 8 of a drive motor 6 are provided. The belt 12 is stretched. A synchronizer 14 is attached to one end of the upper shaft 2 and is configured to detect the rotation angle of the upper shaft 2.

A worm gear 16 mounted on the upper shaft 2.
A wheel gear 18 rotatably supported by the sewing machine arm 1 is meshed with this. A gear (not shown) that rotates integrally with the wheel gear 18 is meshed with a gear 22 attached to a main cam 20 that is rotatably supported by the sewing machine arm 1.

A cam portion 24 is formed on the main cam 20. According to the cam contour of the cam portion 24, the sewing machine bed 26 is rotated by one rotation of the main cam 20 via the cloth pressing arm 25 which is in contact with the cam contour. The upper presser foot 28 is configured to reciprocate. On the other hand, when the upper shaft 2 rotates once, the sewing needle 29 is moved up and down using a cam mechanism (not shown) to form a stitch.

A presser bar 30 corresponding to the cloth presser 28 is supported on the sewing machine arm 1 so as to be vertically movable.
A roller 32 is rotatably supported at its tip.
The presser bar 30 is urged downward by a spring (not shown), is engaged with one end of an oscillating arm 34 oscillatably supported by the sewing machine arm 1, and is oscillated by the oscillating arm 34. It is configured to be lowered by the force and to be able to press the cloth 36 by the cloth presser 28 via the roller 32.

One end of a connecting rod 38 is rotatably connected to the other end of the swing arm 34, and a rod 40 is connected to the other end of the connecting rod 38 to connect the cylinder 4 for lifting the cloth.
By driving 2, the swing arm 34 can be swung via the rod 40 and the connecting rod 38.

Further, a knife shaft 44 is supported on the sewing machine arm 1 so as to be vertically movable, and a knife 46 is attached to the lower end of the knife shaft 44. The upper end of the knife shaft 44 has a knife driving cylinder 48 attached to the sewing machine arm 1.
Are linked to. On the other hand, the main cam 20 is provided with a stop drive cam portion 50 and a low speed drive cam portion 52, and a detection arm 54 that is swingably supported by the sewing machine arm 1.
However, it is arranged so as to come into contact with the stop drive cam portion 50 and the low speed drive cam portion 52 and swing as the main cam 20 rotates.

The stop drive cam portion 50 is provided on the outer peripheral side of the main cam 20 and corresponding to the original position of the main cam 20, and when the main cam 20 makes one revolution and returns to the original position. Is arranged so as to contact the detection arm 54 and swing the detection arm 54 largely. A stop sensor 56 that detects the swing of the detection arm 54 at this time and issues a stop signal is provided.

Further, the low speed drive cam portion 52 is provided closer to the center of the main cam 20 than the stop drive cam portion 50, and rotates the drive motor 6 before the main cam 20 makes one rotation and returns to the original position. It is provided so that the stop accuracy of the upper shaft 2 can be secured by switching from high speed to low speed. The detection arm 54 comes into contact with the low-speed drive cam portion 52 and
A low-speed drive detection sensor 58 is provided which detects the rocking and outputs a low-speed signal when the rocking is performed.

Further, in this embodiment, when the starting pedal 60 is stepped on slightly by the depression operation of the starting pedal 60,
A start switch 62 for issuing a start signal and a start pedal 60
And a lap stitching switch 64 that emits a lap stitching signal when the key is greatly depressed. Further, the sewing machine arm 1 is provided with a cloth presser switch 66.

The drive motor 6 and the synchronizer 1
4, stop sensor 56, low speed drive detection sensor 58, start switch 62, overlapped stitching switch 64, presser foot switch 6
6 and the like are connected to an electronic control circuit 70, and the electronic control circuit 70 is a well-known CPU 72, ROM 74, RAM 76.
An input / output circuit 78 configured to perform input / output with the outside is connected to each other via a common bus 80.

The CPU 72 inputs the input signals from the synchronizer 14, the stop sensor 56, the low speed drive detection sensor 58, the start switch 62, the overlap stitching switch 64, and the work clamp switch 66 via the input / output circuit 78, and outputs these signals. The CPU 72 outputs drive signals for the drive motor 6, the presser foot lifting cylinder 42, and the knife driving cylinder 48 via the input / output circuit 78 based on the signals and the data stored in the ROM 74 and the RAM 76 and the control program stored in advance. .

In this embodiment, the drive motor 6, the upper shaft 2, the worm gear 16, the wheel gear 18, the gear 22,
Main cam 20, presser foot arm 25, presser foot 28, sewing needle 29
And the like constitute overedging means M1. Also, the female shaft 4
4, knife 46, knife driving cylinder 48 constitutes knife driving means M2, low speed driving cam portion 52, detection arm 54,
The low speed drive detection sensor 58 constitutes the angle detection means M4,
The starting pedal 60 and the overlapped stitching switch 64 are the setting means M5.
Make up.

Next, the overlapped stitching control process performed in the electronic control circuit 70 will be described with reference to the flowchart of FIG. First, it is determined whether the work clamp switch 66 has been operated (step 100, hereinafter S100).
Say. The same applies below. ), When the work clamp switch 66 is not operated, it waits until it is operated, and when it is operated, the work clamp lifting cylinder 42 is driven, and the rod 40,
The pressing rod 30 is lowered by the action of the spring via the connecting rod 38 and the swing arm 34 (S110). As a result, the cloth 36 is pressed through the cloth presser 28.

Next, it is determined whether or not the start pedal 60 is depressed by the operator, the start switch 62 is turned on, and the start signal is input (S120). Starting pedal 6
When 0 is not operated, it waits until the start switch 62 is turned on, and when the start signal is input (S12
0), the drive motor 6 is driven at high speed (S130).

As a result, the upper shaft 2 is rotated at a high speed, the sewing needle 29 is moved up and down, the main cam 20 is rotated through the worm gear 16, the wheel gear 18, and the gear 22, and the cloth presser 28 is reciprocated. Then, overlock stitching is performed around the button hole formation planned portion.

With the rotation of the main cam 20, the low speed drive cam portion 52 is rotated, the detection arm 54 is swung by the low speed drive cam portion 52, and it is determined whether or not a low speed signal is input from the low speed drive detection sensor 58. (S140). When the low speed signal is not input, the start pedal 60 is deeply depressed and the overlapped stitching switch 64 is turned on.
It is determined whether or not the overlapped stitching signal is input (S15).
0).

In this embodiment, the overlapped stitching switch 64
Is used to determine whether or not lap stitching has been set.
It is also possible to implement a structure in which the overlap stitching is set when the start switch 62 is repeatedly turned on within a predetermined time without providing the overlap stitching switch 64.

When the overlapped stitching switch 64 is turned on (S150), the rotation of the upper shaft 2 is maintained at the high speed rotation, and the low speed signal is inputted twice until S130,
The process of S140 is repeated. That is, even if the first low speed signal is input, the high speed rotation is continued without slowing down the rotation of the upper shaft 2.

As a result, the main cam 20 does not stop after one rotation and continues to rotate, and therefore, the overlock stitch is repeatedly overlapped with the overlock stitch of the button hole formation planned portion formed in the first one rotation. When the second low speed signal is input (S140), the rotation of the drive motor 6 is switched from high speed to low speed, and the rotation of the upper shaft 2 is reduced (S170).

On the other hand, when the overlapped stitching switch 64 is not turned on (S150), the low speed drive detection sensor 58 is used.
It is determined whether a low speed signal is input from (S16
0) Until a low speed signal is input, that is, until the first low speed signal is input, S130 to S160 are repeatedly executed to rotate the upper shaft 2 at high speed and perform overlock stitching. When the low speed signal is input, the drive motor 6 is switched to the low speed to rotate the upper shaft 2 at a low speed (S170).

After lowering the rotation of the upper shaft 2 (S17)
0), it is determined whether or not a predetermined time set in advance has elapsed by a timer that starts timing after the low speed switching (S
180). When the predetermined time has not elapsed (S17
0), the stop drive cam portion 50 of the main cam 20 driven by the low-speed rotation of the upper shaft 2 comes into contact with the detection arm 54 and swings it, and the stop sensor 56 detects this swing and reaches the stop position. It is determined whether or not (S200).

When not rotating to the stop position, S
When it is determined that the predetermined time has elapsed during the repetition of the processing of 180 or less (S180), the drive signal of the knife driving cylinder 48 is output to drive the knife driving cylinder 48, and the knife shaft is driven. 44 is lowered and the female 46
Is pierced at the place where the button hole is to be formed (S190).

As a result, a button hole is formed and S20
When it is determined that the rotation has reached the stop position by executing the processing of 0, the drive of the drive motor 6 is stopped and the rotation of the upper shaft 2 is stopped (S210). Next, the cloth presser lifting cylinder 42 is driven to raise the presser bar 30 via the rod 40, the connecting rod 38, and the swing arm 34 (S22).
0). As a result, the cloth presser 28 is raised against the biasing force of the spring, and the cloth 36 is released.

In this embodiment, when a low speed signal is input,
When the stop signal is input while the upper shaft 2 is rotating at a low speed and the upper shaft 2 is rotating at a low speed, the rotation of the upper shaft 2 is stopped according to the rotation signal from the synchronizer 14. As a result, since the sewing machine is stopped at a low speed, the stopping accuracy is improved, and the sewing needle 29 can be stopped every time in a fixed state.

Further, the timing at which the knife 46 penetrates the button hole formation planned portion needs to be after stopping because the cloth 36 is still moving before the upper shaft 2 is stopped. From the time relation, it is preferable to penetrate the upper shaft 2 when the rotation of the upper shaft 2 is stopped. However, based on the input of the stop signal of the upper shaft 2, the knife driving cylinder 48
When driving, the time elapses until it descends and penetrates, and the tact time becomes longer accordingly.

Therefore, in this embodiment, a low speed signal is input so that the knife driving cylinder 48 is driven before the rotation of the upper shaft 2 is stopped and the knife 46 penetrates when the rotation is stopped. The predetermined time of the timer of S180 is set so that the knife 46 starts to descend when a predetermined time has passed from then and the knife 46 penetrates the cloth 36 when the upper shaft 2 stops.

In this embodiment, when the overlapped stitching is set by the operation of the overlapped stitching switch 64, the upper shaft 2 is rotated at a high speed until the low speed signal is inputted twice, and then the overlapped stitching is performed. The knife 46 is lowered to form a button hole. Therefore, it is possible to easily switch between the single overlock stitching and the overlapped stitching without performing a complicated work such as replacement of the main cam 20.

Further, when the start pedal 60 is greatly depressed, the overlapped stitching switch 64 is operated so that the operator can hold the cloth 36 with both hands, even if both hands are closed. The overlapped stitching switch 64 can be easily operated.

Further, the number of switches can be reduced by not providing the overlapped stitching switch 64 separately but by setting the overlapped stitching when the start switch 62 is repeatedly depressed. Further, in this embodiment, when the overlapped stitching switch 64 is operated before the main cam 20 is rotated to the low speed switching angle, the overlapped stitching is executed, but the low speed drive cam portion 52 and the low speed drive detection sensor 58 are operated. Alternatively, the detection cam portion may be provided at a predetermined rotation angle, and an angle detection sensor for detecting the detection cam portion may be separately provided.

As described above, by determining whether or not the overlapped stitching switch 64 is operated before the main cam 20 is rotated to the predetermined angle, the operator sees the state of the first overedging, After determining that the overlapped stitching is necessary, the starter pedal 60 can be depressed greatly to set the overlapped stitching. Also, by judging by the low speed signal,
Before switching the upper shaft 2 to the low speed rotation, it is possible to judge the execution of the overlapped stitch, perform the next second rotation while keeping the high speed rotation, and perform the overlapped stitch in a short takt time, and also to use the detection sensor in common. Therefore, the number of parts can be reduced.

In this embodiment, the stop drive cam section 50,
Detection arm 54, stop sensor 56 and S200, S21
Execution of the process of 0 works as the stop means M3, and S140-
The execution of the processing of S200 works as the overlapped stitching control means M6. The present invention is not limited to the embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

[0043]

As described above in detail, the buttonhole sewing machine of the present invention can easily switch between the single overedging and the overlapped sewing without performing a complicated work such as the replacement of the main cam. Has the effect. Further, by providing the overlapped stitching switch operated by the start pedal, the overlapped stitching can be easily set even when both hands of the operator are closed, or the starter switch is repeatedly depressed. The number of switches can be reduced by configuring the overlap stitching to be set at times. Further, by adopting a configuration in which it is determined that the rotation has been made at a predetermined angle by the low speed signal, the second rotation can be performed while the high speed rotation is performed, and overlapped sewing can be performed in a short tact time, and the detection sensor is shared. Therefore, the number of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of a buttonhole sewing machine of the present invention.

FIG. 2 is a schematic configuration diagram of a buttonhole sewing machine as one embodiment of the present invention.

FIG. 3 is a flowchart showing an example of overlapped stitching control processing performed in the electronic control circuit of the present embodiment.

[Explanation of symbols]

M1 ... Overlocking means M2 ... Knife driving means M
3 ... Stopping means M4 ... Angle detecting means M5 ... Setting means M
6 ... Overlock stitching control means 1 ... Sewing machine arm 2 ... Upper shaft 6
… Drive motor 20… Main cam 28… Presser foot 2
9 ... Sewing needle 46 ... Female 56 ... Stop sensor 5
8 ... Low speed drive detection sensor 62 ... Start switch 64 ... Overlap stitching switch

Claims (4)

[Claims] 1. Overlocking means for performing overlock stitching around a buttonhole formation scheduled portion of cloth by one rotation of a main cam rotated by an upper shaft, and knife driving means for penetrating a knife to the buttonhole formation scheduled location. A buttonhole sewing machine including: a stop means for stopping the rotation of the upper shaft by detecting one rotation of the main cam; an angle detecting means for detecting that the main cam has rotated a predetermined angle; Setting means for setting overlapped stitches of overlock stitches, and when the overlapped stitches are set before the angle detecting means detects that a predetermined angle has been rotated, regardless of detection of one rotation by the stopping means, The buttonhole overedging machine comprising: overlapped stitching control means for driving the knife driving means after repeating overedging by the overedging means again. N. 2. The setting means includes a lap stitch switch that detects a stepping-on of the start pedal that is larger than a step-down of a start switch that detects the stepping-on of a start pedal, and sets the lap stitch by operating the lap stitch switch. The buttonhole sewing machine according to claim 1, wherein: 3. The setting means detects that the start switch for detecting the depression of the start pedal is repeatedly depressed, and sets the overlapped stitch when the depression is repeatedly depressed. Buttonhole sewing machine. 4. The button according to claim 1, wherein the angle detecting means detects that the upper shaft has rotated to a low speed switching angle for switching the rotation of the upper shaft from high speed to low speed. Hollow sewing machine.