JP2589381B2 - Buttonhole sewing machine cloth cutting timing detection adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a buttonhole overlock sewing machine which forms a buttonhole overlock stitch by performing a cycle drive of a predetermined number of stitches and pierces between the stitches. Button drilling machine that punches by operating a cloth cutting knife with an air drive cylinder, and related to the automatic technology of the cloth cutting mechanism of the sewing machine, which can cut a predetermined position accurately regardless of the operation speed of the sewing machine. The present invention relates to a cloth cutting timing detection adjustment device.

[Conventional technology]

Conventionally, a cutting mechanism that automatically cuts a buttonhole of a cloth immediately before completion of a buttonhole stitch formation cycle in conjunction with an upper shaft of a sewing machine or the like has a driving device including a blocking frame as shown in FIG. This driving device is disclosed in Japanese Patent Publication No. 53-37779, etc., and will be briefly described. When the chain 50 is pulled downward by a foot pedal (not shown), the pressing portion of the activation lever 51 is pressed.
52 is pushed rightward to rotate the blocking frame 53 counterclockwise about the shaft 54, and the rotation causes the stop piece 55 of the blocking frame 53 to slip out of the cam groove of the stop cam, thereby driving the sewing machine. It rotates at high speed. Then, the sewing machine is driven at a low speed several stitches before the completion of the stitch forming cycle.

Next, when the stitch forming cycle is completed, the cut-off frame
The rotation of the spring 53 is restored by the action of the spring 56. The stop piece 55 comes into contact with the stop cam and protrudes into the cam groove to stop rotation to the main shaft and stop the sewing machine at a fixed position. Reference numeral 57 denotes a support fixed to the sewing machine arm 58, 59 denotes a rotating shaft of the latch lever 60, and 61 denotes a high-speed surface, a low-speed surface, and a stop surface which engage with the latch piece 62 at the left end of the latch lever 60. The speed switching cam 63 is a driving device.

Therefore, when the sewing machine starts, the start connection rod 64 having one end connected to the shut-off frame 53 moves in the direction of the arrow A, so that the switch 65 is turned from ON to OFF. Then, since the other end of the activation connecting rod 64 pulls the arm 66a of the activation arm 66 in the direction of the arrow A, the activation arm 66 rotates clockwise about the axis 66b, and contacts with the pin 67a of the female drive hook 67. The engagement is released. Then, the projection 67b of the female drive hook 67 is engaged with the operating claws 68, 69 (the upper end of the operating claw 69 is always bent by the spring force of the spring 70a inserted into the shaft 70). (It is in contact with the upper end). Buttonhole sewing proceeds in this state. On the other hand, the lower end of a rod 73 is in sliding contact with the upper surface of a main cam 72 which rotates in conjunction with the upper shaft 71, and slightly before the end of the buttonhole sewing, the rod 73 rides on the cam piece 74 and the operating claw 68 , 69 are rotated clockwise about the shaft 70. As a result, the protrusion 67b of the female drive hook 67 is disengaged from the upper end of the operating claw 69 that has been in contact therewith, and comes into contact with the upper end of the operating claw 68 by the elastic force of the spring 76. When the main cam 72 further rotates from this state and the rod 73 falls off the cam piece 74, the operating claw 68 rotates counterclockwise against the spring 70a by the elastic force of the spring 75.

At this time, the operating claw 69 does not rotate because it is in contact with the side of the projection 67b, and the upper ends of both the operating claws 68 and 69 are separated from each other, and the projection 67b is inserted into the gap by the elastic force of the spring 76. When the female drive hook 67 enters, the female drive hook 67 rotates counterclockwise. Thereby, the periphery of the concave portion 67c of the female drive hook 67 comes into contact with the engagement plate 77. The engaging plate 77 and the rocking plate 78 are rocked up and down with the rotation of the upper shaft 71.
Then, the rocking plate 78 is fitted when it descends.

 Thereafter, the engaging plate 77 also moves up with the raising of the swing plate 78.

As a result, one end is rotatably connected to the female drive hook 67, and the other end is biased by the spring 79, and the position is regulated by the adjusting bolt 81 screwed to the protrusion 80 of the arm 58 of the sewing machine. Since the drive lever 82 rotates clockwise about the axis 82a, the switch 83 is turned off.

Therefore, the solenoid valve 84 is opened for a predetermined time by an AND circuit of two signals (OFF signals) of the switch 65 and the switch 83 for detecting the operating state of the knife, and the air drive cylinder 85 is driven from an air source (not shown), and the knife rod 86 is moved. It is configured to push down and form a cloth cut on a cloth 89 sewn in a buttonhole sewn shape with a cloth cutting knife 87.

The number of stitches is changed by changing the length of the button hole or the like by changing the rotation speed of the main cam 72 by changing gears connected to the upper shaft of the sewing machine.

[Problems to be solved by the invention]

Accordingly, when the sewing machine is driven at high speed, the swing of the knife drive arm (engaging plate 77 and swing plate 78) interlocking with the upper shaft is also in a high speed state, and in this state, the knife drive hook 67 and the knife drive arm try to engage. Then, in order to prevent the occurrence of abnormal sound or breakage accident due to overload on the related members, and to prevent the knife drive lever 82 from being inoperative due to the phenomenon that the knife drive arm flips the knife drive hook 67, In order to make the knife drive lever 82 operate more slowly and change the low-speed rotation section of the sewing machine drive device 63 and adjust the position of the cam piece 74 to adjust the knife operation timing, etc. It took a lot of time to change the length of the hole.

Further, as the cloth cutting knife device, in order to operate the timing switch 83 for detecting the knife operating state, despite the fact that the sewing machine is driven separately from the rotation of the sewing machine by using the air drive cylinder, the sewing machine is not provided with the above structure. The low-speed operation section cannot be eliminated, and the cycle time of the sewing machine cannot be reduced.

[Means for solving the problem]

The cloth cutting timing detection and adjustment device for a buttonhole holing machine according to the present invention is a cam for mechanically connecting an operation timing of a cloth cutting knife by an air drive cylinder to an upper shaft of the sewing machine in a cloth cutting knife device for a buttonhole holing machine. A cloth cutting basic timing setting section that detects the cloth cutting knife operation timing from the cam projection of the panel and inputs it to the central processing unit, and electrically sets the operation timing arbitrarily according to the number of rotations of the upper shaft etc. of the sewing machine and can change it The gist of the present invention is that it is determined by a signal from an operation timing adjustment unit to be controlled.

That is, in the cloth cutting knife device of the buttonhole overlock sewing machine,
A cloth cutting knife driven forward and backward by an air drive cylinder driven through a drive cylinder control valve that is opened and closed by a central processing unit is provided, and the cloth is cut directly from a cam projection of a cam disk mechanically connected to the upper shaft of the sewing machine. The cloth cutting basic timing setting section that detects the cutting knife operation timing and inputs it to the central processing unit, and electrically sets the operation timing from the cloth cutting knife operation timing arbitrarily according to the number of rotations of the upper shaft of the sewing machine, etc. The drive cylinder control valve is driven and controlled by a central processing unit in response to a signal from an operation timing adjustment unit that performs variable control.

[Action]

Therefore, in the above configuration, the rotation of the upper shaft is directly detected, the cloth cutting knife operation timing mechanically obtained from the upper shaft of the sewing machine is detected, and the number of rotations of the upper shaft is obtained to determine the cloth cutting knife operation timing. The operation timing is set arbitrarily electrically and variably controlled by a setting input mechanism such as a dip switch.
It can be set.

Further, since the structure is such that the cloth cutting knife operation timing and the operation timing based on the cloth cutting knife operation timing are electrically controlled, there is no conventional detection mechanism by the operation of the drive lever that requires low-speed rotation, and the sewing machine can operate at high speed. Can be used as is.

〔Example〕

Hereinafter, an embodiment of a cloth cutting timing detection and adjustment device for a buttonhole holing machine according to the present invention will be described with reference to FIGS.

FIG. 1 is a schematic diagram showing the configuration of the entire apparatus, and FIG. 2 is a perspective view of the essential parts. Reference numeral 1 denotes an upper shaft which is rotated in the direction of arrow C by the sewing machine drive motor 2 via the belt 3 and the drive pulley 4, and a worm 5 mounted on the upper shaft 1.
A rotation transmission mechanism D meshed with a worm gear 6 and a rotation ratio setting mechanism formed by meshing a first stitch number setting gear 8 and a second stitch number setting gear 9 axially mounted on a rotation shaft 7 of the worm gear 6. E
A vertical axis 10 is provided so as to be driven (rotational direction F) at a predetermined rotation ratio via a cam plate 12. It becomes. Reference numeral 13 denotes a female operating cam projection that is provided on the lower surface of the cam disc 12 via a screw so as to be adjustable in mounting position. 15, the sliding contact projection 17 is always elastically biased in a direction in which the sliding contact projection 17 comes into sliding contact with the cam surface of the cam disc 12, and
And the switch protrusion of the cloth cutting timing setting switch 18
The cloth cutting timing setting switch 18 is provided with a female operating cam projection 13 through a switch pressing lever 16.
ON / OFF. Here, the female operation cam projection
13 is fastened to the cam disc 12 so that the mounting position in the circumferential direction can be adjusted by screws. With the rotation of the cam disc 12, the female operation cam projection 13 is displaced and engaged with the sliding contact projection 17 to engage The cloth cutting timing setting switch 18 is pressed via the switch pressing lever 16 and the state of the "cloth cutting female operation switch ON" via the input / output circuit 22 of the central processing unit 21 of the circuit board 20. Is applied as an input signal.

Reference numeral 23 denotes a sensor object such as a magnetic or slit plate fixedly formed on one side of the upper shaft 1, and rotation of the upper shaft 1 by a sensor 24 such as a Hall sensor (magnetic sensor) or an optical sensor. The structure for detecting the arrow C) is obtained.

The cloth cutting knife 25 is a female rod 27 that is slidably mounted in the vertical axis direction.
The cloth bar 40 is fixed to the lower end of the cloth cutting knife 25, and the cloth bar 40 is located at the lower end of the cloth cutting knife 25. Drive shaft 26a of air drive cylinder 26
It becomes connected with. The air drive cylinder 26 controls opening and closing of the drive cylinder control valve 30 by the central processing unit 21,
The cloth cutting knife 25 is cut down and retracted by the drive of the drive shaft.

Next, the operation of the cloth trimming timing detecting and adjusting device of the buttonhole holing machine having the above-mentioned configuration will be described with reference to the flowchart shown in FIG. 3 and the cloth cutting knife operation timing chart shown in FIG.

With the rotation of the upper shaft 1 accompanying the driving of the sewing machine, the cam disc 12 pivotally mounted on the vertical axis 10 rotates via the rotation transmission mechanism D and the rotation ratio setting mechanism E, and the female operation cam mounted at a predetermined position. When the projection 13 comes into contact with the sliding contact projection 17 of the switch pressing lever 16, the cloth cutting timing setting switch 18 is turned on and the cloth cutting knife is turned on.
Detect the timing to activate 25. After detecting this timing, the number of rotations of the upper shaft 1 is read by the sensor object 23 and the sensor 24 attached to the upper shaft 1, and the central treatment device is previously set by the DIP switch 31 in the circuit board 20.
When the number of rotations of the upper shaft 1 after detecting the cloth cutting knife operation timing set in 21 is reached, the central processing unit 21 outputs an operation command to the drive cylinder control valve 30.

When the operation command is output to the drive cylinder control valve 30, the air drive cylinder 26 pushes out the drive shaft 26a,
The female rod 27 connected to this is lowered. The female stick
Since the cloth cutting knife 25 is fixed to the lower end of the cloth 27, the cloth already formed with the buttonhole stitch is located, and the button hole of the cloth is cut.

Therefore, in the above configuration, the sensor 24 for detecting the number of rotations of the upper shaft 1 and the cloth cutting timing setting switch 18 for detecting the operation timing of the cloth cutting knife 25, and the air drive cylinder for driving the cloth cutting knife 25 by the air drive cylinder 26 The control valve 30 is provided, and after input of the operation signal of the cloth cutting knife 25, the number of rotations of the upper shaft 1 is read and the timing of actually operating the cloth cutting knife 25 (air drive cylinder 26) is determined by the number of rotations from the upper shaft 1. Can be arbitrarily changed and set by a DIP switch 31 as an operation timing adjustment unit, and the position adjustment of the female operation cam projection 13 by changing the number of stitches, which required more time than before, can be performed. Becomes unnecessary.

In addition, the device that detects the operation signal of the cloth cutting knife 25 by the operation of the conventional drive lever that requires low-speed rotation does not require any low-speed rotation, and the female operation cam protrusion 13 fixed to the cam disc 12 With the device that can directly detect the operation signal via the switch pressing lever 16,
The sewing machine does not require any low-speed rotation when the cloth cutting knife 25 is operated, so that the low-speed sewing process of the sewing machine can be eliminated or shortened, and the cycle time can be greatly reduced by 20% or more.

In the above embodiment, the sensor 24 for inputting the rotation of the upper shaft 1 is not limited to the one fixed to the upper shaft 1,
Apart from this, it goes without saying that it can be mounted on any of the turning parts of the sewing machine linked to the rotation of the upper shaft 1.

〔The invention's effect〕

As described above, the cloth cutting timing detection and adjustment device of the buttonhole overlocking sewing machine according to the present invention does not require most parts of the mechanism for mechanically dropping the cloth cutting knife, so that a significant cost reduction can be expected, and a small High reliability can be obtained by the number of parts and the movement of the drive unit which does not impose a large burden on the parts and which is slow and does not require a load. Also, when changing the number of stitches by changing the buttonhole length, the cloth cutting knife drop timing can be changed by inputting the setting of the dip switch, and it is not necessary to set the low-speed rotation. Changes. A tool such as a screwdriver for adjusting the cam projection on the cam board for setting the low-speed rotation is completely unnecessary. Further, since the air drive cylinder is configured to detect and rotate the rotation of the upper shaft, in any state, the upper shaft of the sewing machine is rotating, and except in a predetermined position of the button hole being sewn. It has features such as having a safety function of not driving, and the effect after implementation of the present invention is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of the entire apparatus for detecting and adjusting a cloth cutting timing of a buttonhole holing machine according to the present invention,
FIG. 2 is a perspective view of the essential parts, FIG. 3 is a flowchart showing the operation of the apparatus of the present invention, FIG. 4 is a timing chart showing the operation of the cloth cutting knife, and FIG. It is a principal part perspective view which shows a cutting device. 1 ... Upper shaft 2 ... Sewing machine drive motor 10 ... Vertical axis, 12 ... Cam disc 13 ... Female operation cam projection 16 ... Switch pressing lever 18 ... Basic cloth cutting timing setting switch 20 ... Circuit board , 21 ... Central processing unit 22 ... I / O circuit, 23 ... Sensor object 24 ... Sensor, 25 ... Cloth cutting knife 26 ... Air drive cylinder 27 ... Female rod 30 ... Drive cylinder control valve 31 ...... Dip switch, D ... Rotation transmission mechanism E ... Rotation ratio setting mechanism

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References Jiko 2-38699 (JP, Y2)

Claims (1)

(57) [Claims] 1. A cloth cutting knife apparatus for a buttonhole holing machine, comprising: a cloth cutting knife 25 driven forward and backward by a drive cylinder driven through a drive cylinder control valve that is opened and closed by a central processing unit; A cloth cutting timing setting switch 18 for detecting a cloth cutting knife operation timing from a cam protrusion of a cam board connected to the CPU and inputting the timing to a central processing unit; a sensor 24 for detecting a rotation speed of an upper shaft of the sewing machine; An operation timing adjusting unit that can electrically set an operation timing for operating the cloth cutting knife after the detection of the cloth cutting knife operation timing in response to the number of rotations of the upper shaft of the sewing machine; The drive cylinder control valve is driven and controlled by the central processing unit by a signal from the
25. A cloth trimming timing detecting and adjusting device for a buttonhole holing machine characterized by actuating 25.