JPS61279293A - Stitch performance controller of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention supplies the needle thread consumed for stitch formation by a needle thread feeding device using an auxiliary thread take-up without relying on a thread take-up action.
The balance relates to a sewing machine that performs only a cloth tightening action.

BACKGROUND ART Conventionally, when the upper thread required for stitch formation is supplied to the thread take-up side by a forced upper thread feeder, a measuring device is installed on the upper thread running path to measure the upper thread supply amount. It was necessary to detect the amount. For this reason, when an encoder for measuring the needle thread is provided on the roller, high-speed control becomes difficult due to its inertia. In addition, if a step motor is used as the needle thread payout device, after the needle thread amount required for one stitch has been paid out.

Since the needle thread must be stopped while gripping the upper thread, a large capacity is required and the inertia is large, so the response speed cannot be made very fast.

Problems to be Solved by the Invention The present invention solves the problem of inertia when using a roller equipped with an encoder for detecting the amount of traveling needle thread as described above, and the problem of inertia when using a roller equipped with an encoder for detecting the amount of traveling upper thread. The purpose of this invention is to solve the problem of inertia of the feeding device when feeding the required amount of needle thread, and to obtain a sewing machine capable of high-speed operation.

Means for Solving the Problems The present invention provides an auxiliary thread take-up, which is determined by the rotation angle of the main shaft, to hold the needle thread between two electromagnetic needle thread grippers that are turned on and off at almost opposite times by an encoder provided on the main shaft. The amount of needle thread required for one stitch is supplied to the thread take-up side by controlling the encoder.

Function: As mentioned above, the needle thread is fed out by pushing the needle thread stretched between the two electromagnetic needle thread grippers, which are controlled to turn on and off at almost opposite times by the encoder installed on the main shaft. With the auxiliary take-up lever configured in this way, the amount of needle thread required for one stitch is controlled by reading the rotation angle of the main shaft of the sewing machine, thereby providing a sewing machine that can operate at high speed without increasing inertia with a simple configuration. .

Embodiment FIG. 1 is a side view showing the configuration of a sewing machine equipped with a needle control device according to the present invention, FIG. 2 is a perspective view showing the configuration of an auxiliary balance, and FIGS. Fig. 4 shows the configuration, (a) is a side sectional view, (b) is a front view of the slit disk, Fig. 4 is a sectional view showing an example of an electromagnetic needle thread gripper, and Fig. 5 is a balance holder. A diagram showing the relationship between the upper characteristic curve, the upper thread supply curve by the auxiliary thread take-up, and the operating state of the electromagnetic upper thread gripper,
It is.

In Figure 1, ■ is a sewing needle, 2 is a thread take-up, 3 is a thread bottom spring,
4 and 5 are thread guides, 6 is an electromagnetic needle thread gripper on the thread take-up side, 7 is a guide pin, 8 is an auxiliary thread thread driven by the main shaft, 9 is a guide pin, and 10 is an electromagnetic needle thread gripper on the needle thread supply side. , 11 is a paste tension plate, 12 is an upper thread bobbin, and 13 is an upper thread.

The needle thread 13 from the needle thread bobbin 12 is given tension to the extent that the thread is not disturbed by the pace tension plate 11, and the needle thread supply side electromagnetic needle thread gripper 10 and the needle thread take-up side electromagnetic needle thread gripper 6 are applied.
The needle thread delivered to the guide pin 7.9 between the needle thread and the needle thread is let out by being pushed down by an auxiliary thread take-up 8, which is a lever with a link motion suitable for high-speed vertical movement. That is, when the auxiliary thread take-up 8 is operated with the electromagnetic needle thread gripper 6 on the lever side closed and the electromagnetic needle thread gripper 10 on the needle thread supply side opened, the needle thread 13 is gripped on the thread take-up side.
Since the supply side is open, the auxiliary thread take-up will act to pull out the upper thread from the bobbin 12. ■When the auxiliary thread take-up 8 has drawn out the amount of needle thread required for the stitch, close the electromagnetic needle thread gripper 10 on the needle thread supply side and open the electromagnetic needle thread gripper 6 on the take-up side. It acts to pull back a corresponding amount of the needle thread that is not let out from the bobbin 12 side but is loosened toward the thread take-up. This means that the amount of needle thread required for one stitch has been supplied to the second side. Therefore, if the suture thread is tightened using the thread take-up 2 in this state, a good seam will be formed. The electromagnetic needle thread gripper 6 on the take-up side is as shown in FIG.

Even if the needle thread supply side electromagnetic needle thread gripper 10 is closed a little before it is released, if the auxiliary thread take-up lever 8 is in the inoperative position above the line connecting the guide pins 7 and 9 at this time, the needle thread will be paid out. There is no effect on

By the way, the amount of needle thread pulled out by the auxiliary thread take-up 8 is as follows.

As shown in FIG. 5, since it is determined by the operating time of the auxiliary thread take-up 8 with respect to the upper thread, the signal from the encoder 16 provided on the main shaft 15 equipped with the sewing machine pulley 14 determines the
It is only necessary to control the operations of the electromagnetic needle thread gripper lO on the needle thread supply side and the electromagnetic needle thread gripper 6 on the take-up side.

FIG. 3 (aHb) shows the configuration of the encoder, in which a light emitting element 18 and a light receiving element 9 are sandwiched between a slit disk 20 fixed to the main shaft 15 on the side wall of a casing 17 through which the main shaft 15 passes. As shown in Fig. 5, after the tension generation period A to C has elapsed during cloth cotton work using the thread take-up lever 2 (this position is determined by the rotational position of the spindle), the needle thread supply side electromagnetic Release the needle thread holding by the type needle thread gripper IO, close the electromagnetic type needle thread gripper 6 on the take-up side, and feed out the needle thread amount 2 required for one stitch according to the thread take-up ratio curve by the auxiliary thread take-up 8. At the second period when the pulse signal of the period is detected by the microcomputer built in the sewing machine, the upper thread supply side electromagnetic upper thread gripper 10 is closed again, and the electromagnetic upper thread gripper 6 on the take-up side is released. In addition, the code entry in the figure is the top dead center of the balance 2, 6
M is an upper thread gripping section by the electromagnetic upper thread gripper 6 on the take-up side; I
OM indicates the upper thread gripping section by the electromagnetic upper thread gripper 10 on the upper thread supply side. Furthermore, as can be understood from Fig. 5, before the tension increases due to the threading action of the thread take-up 2, there are phenomena of tension increase due to the needle thread passing through the hook, coming off the hook, and coming off the hook's catching claw. At this time, the upper thread is still being held by the electromagnetic upper thread gripper 10 on the upper thread supply side.
The effects of these changes in tension can be avoided.

Figure 4 shows an electromagnetic upper thread gripper 6.10 used in the present invention.
This is a sectional view showing the configuration of a coil pobbin 23 that slides onto a cylindrical yoke 22 with a magnet 21 provided on the inside of the outer wall. A friction plate 24 is provided on the upper surface of the coil pobbin 23, and a cap-shaped body is fixed to the upper part of the yoke across the needle thread passage space. Coil bobbin 2
3 is configured to be gripped by energizing. When such an electromagnetic upper thread gripper is used, the inertia is small and the response speed is fast, so that the sewing machine can be operated at high speed.

FIG. 2 shows a schematic configuration of the auxiliary take-up lever 8 that performs link motion. A link 27 is driven by a cam 26 provided on the main shaft 15, and the auxiliary take-up lever 8 is supported by a lever 28 fixed to the sewing machine head. can be moved up and down at high speed, allowing the upper thread stretched between the guide pins 7 and 8 to be fed out. In addition.

The needle thread payout curve by the auxiliary thread take-up 8 is as shown in FIG.
This is unique to the sewing machine, and the needle thread payout amount can be determined by detecting the rotation angle of the sewing machine main shaft.
The amount of needle thread required for one stitch can be paid out by operating the two electromagnetic needle thread grippers 6.10.

Effects of the Invention In the present invention, with the electromagnetic needle thread gripper on the take-up side closed and the electromagnetic needle thread gripper on the needle thread supply side opened, both electromagnetic needle thread grippers are moved by the auxiliary take-up driven by the main shaft. The needle thread payout characteristics of the auxiliary thread take-up when operated to push down the needle thread stretched between the two.

Utilizing the property that the spindle changes in a fixed manner according to the rotation angle of the spindle, the spindle rotation angle required to pay out the needle thread amount for the stitch is detected by pulses from a rotary encoder installed on the spindle. With this, I was able to configure the sewing machine to control the on/off of the two electromagnetic needle thread grippers using the built-in microcomputer.

There is no need to use components with large inertia such as an encoder with a roller that repeatedly rotates and stops to measure the amount of needle thread being fed out, and a sewing machine that can perform high-speed sewing with a simple configuration can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of a sewing machine equipped with a sewing needle control device according to the present invention, FIG. 2 is a perspective view showing the configuration of an auxiliary balance, and FIGS. (a) is a side sectional view, (b) is a front view of the slit disk, Fig. 4 is a sectional view showing an example of an electromagnetic needle thread gripper, and Fig. 5 is a characteristic for taking up the thread. FIG. 3 is a diagram showing the relationship among a curve, an upper thread supply curve by an auxiliary thread take-up, and an operating state of an electromagnetic upper thread gripper. 1... Sewing needle, 2... Balance, 3... Mitsutori spring, 4.5... Thread guide. 6...Take-up lever side electromagnetic needle thread gripper, 7.9...Guide bin, 8...Auxiliary thread take-up, 10.
...Needle thread supply side electromagnetic needle thread gripper, 11... Paste tension plate, 12... Needle thread bobbin. 13... Upper thread, 15... Sewing machine main shaft,
16... Encoder, 20... Slit disk, 21... Magnet, 22... Cylindrical yoke, 23... Coil bobbin, 26... Cam, 6M,
10M: Electromagnetic needle thread gripper operating range, Q: 1st stitch needle thread payout amount.

Claims (1)

[Claims] Two electromagnetic needle thread grippers configured to grip the needle thread at opposite times are installed between the thread take-up and the needle thread supply side, and a link type needle thread feeder driven by the main shaft is located between them. An auxiliary thread take-up is installed, and a signal from an encoder installed on the main shaft of the sewing machine closes the electromagnetic needle thread gripper on the take-up side and releases the electromagnetic needle thread gripper on the needle thread supply side after the end of the suture tightening period by the thread take-up. Then, the needle thread is pulled out by pushing the needle thread between the electromagnetic needle thread grippers using the auxiliary thread take-up, and after drawing out the required amount of needle thread for the first stitch from the supply side, the upper thread is pulled out on the thread take-up side by the signal from the encoder. A sewing tension control device for a sewing machine, characterized in that a thread gripper is released and an upper thread gripper on a needle thread supply side is closed.