KR20120077868A

KR20120077868A - Method for controlling rotating speed of upper axis of pattern sewing machine

Info

Publication number: KR20120077868A
Application number: KR1020100139982A
Authority: KR
Inventors: 이창영
Original assignee: 주식회사 썬스타
Priority date: 2010-12-31
Filing date: 2010-12-31
Publication date: 2012-07-10
Also published as: CN102535048B; CN102535048A; DE102011057145A1

Abstract

In the pattern sewing machine, a method of controlling the upper shaft rotation speed according to the amount of head rotation is disclosed.
The upper shaft rotation speed control method may include: capturing a deceleration starting time point before N stitches from a head rotation command generation time by referring to a pattern program controlling a sewing operation of the pattern sewing machine; Stepwise decelerating the rotational speed of the upper shaft from the deceleration start time until the head rotation command is performed; Rotating the head by the head rotating command; And when the head rotation is completed, accelerating the rotational speed of the upper shaft in stages.
According to the present invention, by lowering the rotational speed of the upper shaft to a speed suitable for head rotation it is possible to perform the sewing without deterioration of the sewing quality due to the rotation angle change by performing the head rotation.

Description

Method for controlling rotating speed of upper axis of pattern sewing machine}

The present invention relates to a sewing machine having a rotatable head, and more particularly, to a method for controlling the upper shaft rotational speed according to the amount of head rotation.

A sewing machine having a rotatable head is used to fix the sewing material on a table using a clamp, and then sewing while moving the clamp in the X-Y direction.

FIG. 1 shows the appearance of a conventional sewing head lifting type sewing machine, and FIG. 2 shows a state of forming a stitch according to a pattern in the apparatus shown in FIG. The left side of Fig. 2 shows a rhombic pattern and the right side shows a rectangular pattern.

Arrows indicate the direction in which pattern formation proceeds, and P (Perfect) and H (Half perfect) indicate the quality of the stitches.

P represents a flawless stitch, H represents a few defective stitches, and Hitch Stich represents a defective stitch.

FIG. 3 shows a distribution diagram of H-P stitches for each section in the apparatus shown in FIG. 1. Referring to Figure 3, it can be seen that the quality of the stitch is determined according to the area from the center inside the pattern. That is, it can be seen that when the center point inside the pattern is divided into four quadrants, the stitch quality in the third and fourth quadrants, in particular the fourth quadrant, is reduced.

A sewing machine having a rotatable head capable of rotating the head has been developed to solve this problem in the sewing head lifting type sewing machine as shown in FIG. 1.

A sewing machine having such a rotatable head is, for example, when sewing is to be made in three or four quadrants as shown in FIG. 2, such that sewing is performed in one to two quadrants by rotating the head in the radial direction. By increasing the quality of the sewing.

4 shows a head turning configuration in a sewing machine having a rotatable head. Referring to FIG. 4, a head rotating motor 101 and a bed rotating motor 102 are installed on the upper and lower sides of the “100” -shaped frame 100, respectively. The bed rotating motor 102 rotates in rotation of the head rotating motor 101 and rotates in a radial direction about a vertical axis in the drawing. A sewing head 107 is installed below the head rotating motor 101, and a bed 108 is installed above the bed rotating motor 102. Although not shown, a clamp as shown in FIG. 1 is installed between the sewing head 107 and the bed portion 108.

The upper shaft drive motor 105 rotates the upper shaft for driving the needle bar. The rotation of the upper shaft drive motor 105 is transmitted to the upper shaft (not shown) through a power transmission means such as a timing belt. On the other hand, the lower shaft drive motor 106 is rotated in synchronization with the rotation of the upper shaft drive motor 105.

Here, since the operation of the sewing machine occurs in the rotation of the upper shaft and the lower shaft, the rotational motion of the sewing head 107 and the bed 108 by the head rotating motor 101 and the bed rotating motor 102 is also the upper shaft driving motor ( 105) and the lower shaft drive motor 106 should be synchronized with the rotation of the upper and lower shafts.

In FIG. 4, the rotation of the head rotating motor 101 and the bed rotating motor 102 are rotated separately with respect to the rotation of the upper shaft so that they do not appear to be related to each other. Since it operates with the moment of inertia according to the rotation of the shaft, the amount of rotation possible by the head rotating motor 101 is substantially limited according to the rotational speed of the upper shaft.

Accordingly, it is necessary to control the rotational speed of the upper shaft in accordance with the amount of head rotation.

An object of the present invention is to provide a method for controlling the rotational speed of the upper shaft in accordance with the head rotational amount in a sewing machine having a rotatable head.

Upper shaft rotation control method of the sewing machine according to the present invention to achieve the above object

In the method of controlling the rotational speed of the upper shaft of the sewing machine having a rotatable head in accordance with the amount of rotation of the head,

Capturing a start point of deceleration before N stitches from a point rotation time of a head rotation command with reference to a pattern program controlling a sewing operation of the machine;

Stepwise decelerating the rotational speed of the upper shaft from the deceleration start time until the head rotation command is performed;

Rotating the head by the head rotating command;

Ending the head rotation is characterized in that it comprises a step of accelerating the rotational speed of the upper shaft in stages.

Here, the deceleration process is preferably decelerated to a rotation speed corresponding to the head rotation amount by the head rotation command.

According to the present invention, by lowering the rotational speed of the upper shaft to a speed suitable for head rotation it is possible to perform the sewing without deterioration of the sewing quality due to the rotation angle change by performing the head rotation.

Figure 1 shows the appearance of a conventional sewing head lifting type sewing machine.
FIG. 2 shows a state of formation of stitches according to patterns in the apparatus shown in FIG. 1.
FIG. 3 shows a distribution diagram of HP stitches per section in the apparatus shown in FIG. 1.
4 shows a head turning configuration in a sewing machine having a rotatable head.
5 is a view illustrating an upper shaft rotation control method according to the head rotation amount according to the present invention.

The operation of a conventional sewing head lifting type sewing machine occurs in synchronization with the rotation of the upper shaft. That is, a timing pulse is generated in synchronization with the rotation of the upper axis, and necessary operations are performed based on the phase of the timing pulse.

In a sewing machine having a rotatable head, the rotation of the head should also be synchronized with the rotation of the upper shaft. By the way, the amount of rotation by the head rotating motor 101 is different depending on the rotational speed of the upper shaft. That is, the number of head rotation pulses suitable for each rotation speed of the upper shaft is different. For example, when the upper shaft rotates at 2,000 rpm, the appropriate number of head turning pulses for one rotation of the upper shaft is 10, and when the upper shaft rotates at 1,500 rpm, the appropriate number of head turning pulses is 15. This means that the rotational speed of the upper shaft should be changed in accordance with the required amount of head rotation.

In general, the lower the rotational speed of the upper shaft, the larger the number of corresponding head rotation pulses. That is, the lower the rotational speed of the upper shaft, the larger the amount of rotation by one driving pulse in the head rotating motor 101.

Accordingly, the rotation speed of the upper shaft should be controlled to reduce the rotation speed of the upper shaft according to the head rotation. However, in this method, when the rotational speed of the upper shaft is changed in synchronism with the rotation of the head, there may be a problem in that an impact is applied to the reduction gear transmitted to the upper shaft by decelerating the rotation of the upper shaft driving motor 105. That is, when instantaneous deceleration torque is applied to lower the rotational speed of the upper shaft in accordance with the start of the head rotation, an impact may be applied to the reduction gear, which may cause undesirable effects such as breakage of the reduction gear and deterioration of impact resistance. Accordingly, it can be seen that it is preferable to gradually reduce the rotational speed of the upper shaft so as to change the rotational speed of the upper shaft according to the head rotation, but not to impact the reduction gear.

5 is a view illustrating an upper shaft rotation control method according to an amount of head rotation according to the present invention. Referring to Figure 5, the upper shaft rotation control method according to the present invention detects whether the head rotation before the head rotation occurs in advance, the speed corresponding to the head rotation amount from the normal speed to the rotation speed of the upper shaft until the head rotation occurs After gradually decelerating until the head is rotated, after the rotation of the head is finished, the rotational speed of the upper shaft is gradually accelerated to the normal speed again.

A sewing machine having a rotatable head performs sewing in accordance with a given pattern program. Accordingly, it is possible to detect whether the head is rotated in advance by referring to the position of the head rotation command in the pattern program. In the pattern sewing program, the period from the time of detection until the head rotation occurs can be expressed by the number of stitches (number of stitches), and one stitch corresponds to one rotation of the upper axis.

First, the rotational time of the head is detected in synchronization with the rotation of the upper shaft. Where N is a positive integer.

In addition, "before N stitches from the time of generation of the head rotation command" corresponds to the time of starting deceleration in the summary of the present invention.

If it is before the N-stitch from the time of the head rotation command (s504), the rotation speed corresponding to the rotation amount of the head, that is, the target rotation speed suitable for the rotation amount of the head, is calculated (s506). Obtained by reference.

The rotational speed of the upper shaft is gradually reduced to the target rotational speed until the head rotation time (s508).

Rotate the head. (S510)

When the head rotation is finished, the rotation speed of the upper shaft is accelerated during the N stitches (s512). In the embodiment of the present invention, the acceleration speed is a speed before deceleration, but this speed may be set differently as necessary.

In addition, by gradually accelerating and decelerating the rotational speed of the upper shaft, it is possible to achieve the head return without straining the reduction gear.

100 ... frame
101.Head rotating motor 102 ... Bed rotating motor
105 ... Upper Shaft Drive Motor 106 ... Lower Shaft Drive Motor
107 sewing head 108 bed

Claims

In the method of controlling the rotational speed of the upper shaft of the sewing machine having a rotatable head in accordance with the amount of rotation of the head,
Capturing a start point of deceleration before N stitches from a point rotation time of a head rotation command with reference to a pattern program controlling a sewing operation of the machine;
Stepwise decelerating the rotational speed of the upper shaft from the deceleration start time until the head rotation command is performed;
Rotating the head by the head rotating command;
When the head rotation is finished, the upper shaft rotational speed control method of the sewing machine comprising the step of accelerating the rotational speed of the upper shaft.

The method of claim 1,
The deceleration process is the upper shaft rotation speed control method of the sewing machine, characterized in that for decelerating to a rotation speed corresponding to the head rotation amount by the head rotation command.