JPH07114871B2 - Empty ring holding device for overlock sewing machine - Google Patents

Description

Description: [Industrial application] This invention relates to an overlock sewing machine in which an empty ring formed on a needle plate is sewn from a needle drop position in order to sew the empty ring into a stitch. The present invention relates to an empty ring holding device for a sewing machine, which is automatically held backward in the direction.

[Prior Art] Generally, in an overlock sewing machine, since it is necessary to sew an empty ring into a stitch formed on the back surface of the cloth, the empty ring previously wound around the needle plate is stretched before sewing is started, The work of holding it in an appropriate position by a clamp device is performed.

Conventionally, this empty ring setting work has been carried out manually by the worker, but this is because the productivity is low and unevenness in the quality of the sewn product occurs, and so on. A device as shown in FIG. 9 was proposed.

In this device, the cloth W set on the cloth base 2 is used as the needle plate 5
Edge trimming knives 7 provided on the sides of the edges of the fabric are used to trim edges of the cloth while aligning the edges.

Then, when the sewing operation is completed, the empty ring a is cut by the thread trimming knife 17, and the sewing machine is operated while sucking the cut end portion by the suction pipe 9 connected to the intake source (not shown), and the suction pipe 9 An empty ring of a predetermined length is formed inside. After this, the suction port 10a formed at one end of the empty ring suction pipe 10 is shown in FIG. 9 (a).
The needle plate claw 6 as shown in FIG.
To a position (second position) P2 in the vicinity of the suction pipe 9
The empty ring a formed therein is sucked into the empty ring suction pipe 10. Next, the empty ring suction pipe 10 is moved to a position (third position) P3 before the initial position P1 by the pipe rotating mechanism,
The empty ring a is sucked into the suction hole 12 of the empty ring holder 11 as shown in FIG. 9 (c). Then, the empty ring suction pipe 10 returns to the initial position (see FIG. 9 (d)).

After this, the rod 14a of the air cylinder 14 is shown in FIG. 9 (e).
As shown in (4), it moves to the left, enters between the empty ring clamp screw 15 fixed to the rod 14a and the empty ring pushing collar 16, and is held.

Here, when the cloth W is set and the sewing machine is driven, the ninth
As shown in FIG. (F), the empty ring a held by the empty ring holding base 11 and the empty ring clamp screw 15 is a hollow ring extrusion collar.
It is pushed to the right by 16 and cut by the thread trimming knife 7 and sewn under the cloth W.

In addition, the tip of the empty ring a that has not been sewn in is the empty ring holding table 11
The air is sucked from the empty ring suction port 12 and discharged to the outside, and then the suction operation is stopped.

[Problems to be Solved by the Invention] As described above, in the conventional device, by moving the empty ring suction pipe between the initial position P1 and the second position P2, the empty ring is automatically moved to the proper position. However, there are the following problems.

That is, in the above-mentioned conventional device, since the empty ring suction pipe 10 must be arranged between the needle plate 5 and the presser foot 3,
The raised position of the work clamp 3 must be set higher than usual, or the hollow ring suction pipe must be formed to have a considerably small diameter. To realize the former, a large space above the needle plate 5 is required. In addition, when the latter is carried out, when the empty ring is formed of thick thread, or when the empty ring is not sufficiently extended, the empty ring suction pipe 10 Inadequate suction of the air ring a is likely to occur, or even if it is sucked, it tends to be clogged inside, and stable operation cannot be obtained.

In addition, there is a problem that the air suction pipe 10 may rotate and come into contact with a worker's hand during the work, resulting in a reduction in work efficiency.

[Means for Solving the Problem] The present invention is directed to an intake / exhaust pipe having an intake / exhaust port for exhausting and sucking air along the sewing direction, and an empty space formed behind the needle drop position of the needle plate in the sewing direction. A ring suction port, an air jet nozzle located on the side of the intake / exhaust pipe for jetting air from a predetermined exhaust source toward the air ring suction port, the intake / exhaust pipe for the intake source and the exhaust source, an air ring And a control means for controlling the connection state between the suction port and the air jet nozzle.

Further, an empty ring locking member that moves forward and backward with respect to the empty ring suction port by a predetermined moving means may be provided.

[Operation] In the present invention, the intake / exhaust pipe is connected to the predetermined intake source during the air-ring forming operation, and the intake operation sucks the air-ring into the intake / exhaust pipe. When the empty ring forming operation is completed, the empty ring sucked inside by the exhaust operation of the intake and exhaust pipes is discharged to the outside, and is further blown toward the empty ring suction port by the air blown from the air jet nozzle. Then, one end of the empty ring is sucked and held by the empty ring suction port.

Further, an air ring locking member that advances and retracts with respect to the air ring suction port is provided, and the air ring moved by the air from the air ejection nozzle is locked by the air ring suction member to the air ring suction port. Then, the air suction operation at the air suction port can be executed more reliably.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. It should be noted that the same or corresponding parts as those of the above-mentioned conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is an external perspective view of the same embodiment.

In both figures, 9 is an intake / exhaust pipe provided on the cloth base 2, and an intake / exhaust port 9a is formed at one end thereof.
It is located in front of the claw portion 6 in the sewing direction. From this intake / exhaust port 9a, air is discharged obliquely rearward with respect to the sewing direction by the action of the intake source described later, and the intake operation is performed from the intake port 9a by the action of the intake source described later. Is supposed to do.

Reference numeral 21 is an intake / exhaust nozzle provided on the cloth table 2. The intake / exhaust nozzle 21 is connected to an exhaust source, which will be described later, and is configured to eject air toward the empty ring suction port 12 formed in the empty ring holder 11. The empty ring suction port 12 is located rearward of the claw portion 6 of the needle plate 5 in the sewing direction.

22 is an air cylinder (moving means) for raising and lowering the pin, which is provided on the side surface of the sewing machine main body M, and has a cylinder rod 22a
The locking pin 23 (air ring locking member) is fixed to the
The locking pin 23 is adapted to move up and down with respect to the empty ring suction port 12 when the cylinder rod 22a is moved up and down.

In addition, in FIG. 1 and FIG. 2, other configurations are the same as those of the above-mentioned conventional example.

Further, FIGS. 3 and 4 are views showing the connection state of each part to the intake source and the exhaust source in this embodiment.

First, referring to FIG. 3, reference numeral 24 is an air regulator as an intake source and an exhaust source, and its intake port 24a is connected to a compressor (not shown). and again,
The intake port 24b of the air regulator 24 is connected to solenoid valves 26, 27, 28 via a pipe 25, and the solenoid valve 28 is connected to an intake port 30a of a joint 30 via a pipe 29. The joint 30 has exhaust ports 30b and 30c in addition to the intake port 30a, and the exhaust port 30b is connected to the empty ring suction port 12 via a pipe 31. When air is supplied to the intake port 30a, the air is sucked from the air suction port 12, and the air is discharged from the exhaust port 30c to the outside through the pipe 32.

Reference numeral 33 is a joint connected to the solenoid valves 26 and 27. This fitting 3
3, intake ports 33a, 33b and intake / exhaust ports 33c, 33d are provided, and solenoid valves 26, 27 are connected to the intake ports 33a, 33b via pipes 34, 35, respectively. 8 pipes on 33c
Is connected to the intake / exhaust pipe 9. When the air is supplied from the intake port 33a, the air is supplied to the fourth
As shown in FIG. 4 (b), when air is exhausted from the intake / exhaust port 33c through the pipe 8 through the intake / exhaust port 9a, and air is supplied from the intake port 33b, intake / exhaust is performed as shown in FIG. 4 (a). Mouth 33
A flow of air from c to the exhaust port 33d is formed, and accordingly, air is sucked from the intake / exhaust port 9a of the intake / exhaust pipe 9. The solenoid valves 26 and 27 and the joint 3
3 constitutes a switching means.

Next, description will be given with reference to FIG. In the figure, 37, 38 and 39 are solenoid valves, which are connected to the air regulator 24 via a pipe 40.
Is connected to the outlet 24c. Of these solenoid valves,
The solenoid valve 37 is provided with the air jet nozzle 21 through the pipe 41.
The solenoid valve 38 is connected to the pin lifting air cylinder 22 via the pipe 42 and the solenoid valve 39 is connected to the air cylinder 22 via the pipe 43.
14 are connected to each.

As shown in FIG. 6, each solenoid valve described above is connected to a CPU 50 as control means, and its opening / closing is controlled by a control signal from the CPU 50.

Further, the CPU 50 is supplied with various detection data such as the detection signal sent from the cloth detection sensor S, the stitch number setting data set by the input device 53, and a start command from the start pedal 54. It has become. In FIG. 6, 51 is a ROM storing operation programs and the like, 52
Is a RAM that stores control data and the like, MO is a sewing machine motor, and 56 is an encoder that sends a predetermined pulse signal in synchronization with the rotation of the sewing machine main shaft.

Next, the operation will be described based on the above configuration.

FIG. 7 (e) shows the state at the start of the sewing operation. In this state, the empty ring a formed after the sewing operation one cycle before is linearly stretched from the claw portion 6 of the needle plate 5 to the empty ring suction port 12 by the operation described later. .

When the power switch is turned on to operate the sewing machine motor MO, the cloth W is further placed on the needle plate 5 and the starter pedal 54 is depressed, the cloth pressing member 3 descends and presses the cloth W (No. (See Figure 8). As a result, the cloth W is
The needles are conveyed in the sewing direction and the edges are cut and aligned by the knife 7.

At the same time when the cloth W reaches the stitch cloth detection sensor S and overcast stitches start to be formed on the cloth, the CPU 50 responds to the cloth detection signal of the sensor S based on the pulse signal sent from the encoder 56, Starts counting operation. At this time, the empty ring a is rolled up in the overlock seam to be formed. Then, when the count value reaches the preset number of needles involved in the air ring, the solenoid valve 39 is opened, and the cylinder rod 14a of the air cylinder 14 causes the air ring extrusion collar 16 and the clamp screw 15 to move to the position shown in FIG. ) Move to the right as shown in. As a result, the empty ring a is moved to the right by the empty ring pushing collar 16, and the empty ring a other than the portion caught in the seam is cut by the knife 7 together with the cloth W during this time. Further, the empty ring a separated here is the empty ring suction port 12
It is excluded to the outside by the intake action of.

When the sewing operation is completed and the cloth W is separated from the cloth detection sensor S, the solenoid valve 39 is closed and the cylinder rod 14a of the air ring holding cylinder 14 is returned to the initial position (left position).
The solenoid valve 27 is opened, and the intake operation is performed from the opening 8a of the intake / exhaust pipe 8 (see FIG. 8). At this time, the start pedal 54
Even after the depression of the button is released, the sewing machine motor MO continues to operate for the predetermined number of stitches and performs the empty ring forming operation. Then, the air ring a formed here is sucked into the inside as shown in FIG. 7A while being expanded by the intake operation in the intake / exhaust pipe 9.

After that, when the sewing machine motor MO stops and a predetermined delay time elapses, as shown in FIG. 8, the cloth pressing member 3 rises and the solenoid valve 27 closes to stop the intake operation in the intake and exhaust pipes. After a certain time has elapsed, the solenoid valve 28 is opened and air is exhausted from the intake / exhaust pipe 8. The air ring a that has been sucked into the intake / exhaust pipe 8 by this exhaust action is discharged from the intake / exhaust port 8a onto the needle plate 5 as shown in FIG. 7 (b).

After the exhaust operation of the intake / exhaust pipe 8 is completed, the electromagnetic valve 37 is opened for a certain period of time, and the air is ejected from the air ejection nozzle 21 toward the air ring suction port 12. The air ring a discharged onto the needle plate 5 by this air moves to the air ring suction port 12 (see FIG. 7 (c)), is sucked into the pipe 31 from here, and is linear along the sewing direction. (See FIG. 7 (d)). Also, in this embodiment, the air jet nozzle
Simultaneously with the air ejection operation of 21, the solenoid valve 38 is opened to operate the pin elevating cylinder 22 to lower the locking pin 23, so that the air ring a blown away toward the air ring suction port 12 is The locking pin 23 is adapted to lock on the empty ring suction port 12. Therefore, the air suction operation at the air suction port 12 can be performed more reliably. In addition,
Since the air ring pushing collar 16 and the clamp screw 15 are moved to the right by the cylinder 14 while the intake / exhaust pipe 8 is being exhausted (see FIGS. 7 (b) and 8), The inconvenience that the air ring a blown off toward the air ring suction port 12 is caught by the collar 16 or the screw 15 does not occur.

In this way, when the empty ring a is held in the empty ring suction port 12,
The empty ring pushing collar 16 and the clamp screw 15 that had been retracted to the right move to the left again by the action of the cylinder 14,
The state shown in FIG. 7 (e) is restored to prepare for the next sewing operation.

As described above, in the above-described embodiment, the empty ring a can be automatically and reliably held in the empty ring suction port 12 by the air.

[Effects of the Invention] As described above, in the present invention, the air ring formed in the intake / exhaust pipe is moved to the air ring suction port by the air flow from the intake / exhaust pipe and the air jet nozzle. As in the past, there is no unstable element such as passing the empty ring between the members, the empty ring can be reliably moved to the empty ring suction port, and the reliability of the device can be greatly improved. it can. Further, since the member (air ring suction pipe) that moves on the needle plate is eliminated, the work is facilitated, and the raised position of the cloth pressing member can be kept to the minimum necessary for attaching and detaching the cloth.

Further, if the empty ring moved by the air of the air jet nozzle is locked at the empty ring suction port by the empty ring locking member, the suction and holding operation of the empty ring at the empty ring suction port can be performed more reliably. Can be run.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of the present invention, FIG. 2 is an external perspective view of the embodiment, and FIG. 3 is an explanatory view showing a connection state of a solenoid valve and a joint in the embodiment. 4 (a) and 4 (b) are longitudinal side views showing the flow of air in the joint shown in FIG. 3, and FIG. 5 is an explanatory view showing a connected state of the solenoid valve and the cylinder in the same embodiment. FIG. 6 is a block diagram showing the configuration of the control system circuit in the same embodiment, FIGS. 7 (a) to (f) are plan views showing the empty ring holding operation according to the same embodiment, and FIG. 8 is the same embodiment. 9 is a timing chart showing the operation timing of each part in FIG. 9, and FIGS. 9 (a) to 9 (f) are plan views showing the operation state of the conventional empty ring holding device. In the figure, 5 ... Needle plate 12 ... Air ring suction port 9 ... Intake / exhaust pipe 9a ... Intake / exhaust port 22 ... Air cylinder (moving means) 23 ... Locking pin (locking member) 24 ... Air regulator (Intake source, exhaust source) 50 …… CPU (control means) 26,27 …… Solenoid valve (switching means) 33 …… Coupling (switching means)

Claims (1)

[Claims] 1. An intake / exhaust pipe which is selectively connected to a predetermined intake source and an exhaust source via a switching means and has an intake / exhaust port for exhausting and sucking air along a direction intersecting a sewing direction, An empty ring suction port that is connected to a predetermined intake source and that is formed rearward of the needle drop position of the needle plate in the sewing direction, and an empty ring locking member that moves up and down with respect to the empty ring suction port. An air ejection nozzle located on the side of the intake / exhaust pipe for ejecting air from a predetermined exhaust source toward the empty ring suction port, and the intake / exhaust pipe, the empty ring suction port and air for the intake source and the exhaust source A control means for controlling the connection state with the ejection nozzle is provided, and the empty ring formed by the needle plate is sucked inside by the intake operation of the intake and exhaust pipes during the empty ring forming operation period after the sewing operation is completed. After the forming operation is completed, The empty ring is discharged by moving the empty ring to the empty ring suction port by the air blown from the air jet nozzle, and the moved empty ring end is sucked and held by the empty ring suction port. An empty ring holding device for an overlock sewing machine, wherein the empty ring is locked at the empty ring suction port by moving the empty ring locking member to the empty ring suction port.