JPS603809Y2 - Double needle sewing control device for electronic sewing machine - Google Patents

Description

[Detailed description of the invention] The present invention uses an electronic device that can generate sewing patterns by controlling the amount of needle lateral runout and/or the amount of fabric feed using an electromechanical drive in place of the conventional mechanical pattern generation device. Regarding the stitch control drive device of a sewing machine, its purpose is to switch between normal sewing and double-needle sewing using a simple switching device, and to proportionally reduce the amount of needle lateral runout on the double-needle line for each stitch. The aim is to control the needle plate so that it is safe for the needle hole in the throat plate and the thread loop catching device even at the maximum lateral vibration.

As an electromechanical drive device, pulse motors are used for stitch control drives in electronic sewing machines because their positioning is highly reliable and their control can be easily performed digitally, but on the other hand, their positioning resolution is limited. Therefore, it is economical and necessary that the number of steps of the pulse motor, that is, the number of divisions of control, which specifies the maximum lateral runout control range of the needle necessary for normal sewing, is 3 degrees.

In a double-needle line, neither needle is allowed to protrude outside the maximum lateral run-out position formed by a single needle line with respect to the throat plate needle hole or the thread ring catcher, so this is more important than in a single-needle line. This results in the formation of a pattern due to a small horizontal runout of the needle.

Due to this restriction, the computer can calculate the width control data to be reduced and allocate it to each stitch, but the problem arises that the pattern becomes coarse at the same resolution as that for the wooden nail line.

In the present invention, the stored stitch control signals are shared with those for single-needle sewing when pattern sewing is performed using a double-needle line, and the control unit for double-needle sewing is determined by the proportion that the needle lateral vibration control amount is reduced. By reducing the amount, the number of control divisions for the maximum control amount is ultimately the same, so that the pattern does not become coarse even in the case of double-needle lines.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a mounting body, which is attached to a sewing machine body (not shown).

Reference numeral 2 denotes a pulse motor for controlling needle lateral runout, which is attached to the mounting body, and a base plate 4 is fixed to its shaft 3.

This plywood has two protrusions 4at4b as shown in the overall front view of Fig. 2 which shows the same members as Fig. 1.
The rotation range is limited by a restriction portion 5 formed by the main body 1.

Reference numeral 6 denotes a light shielding plate fixed to the base plate 4, which generates a rotational position signal for the pulse motor 2 by shielding the photointerrupter 7 fixed to the main body 1 at the position shown in FIG. 1 or 2. .

Reference numeral 8 denotes a needle lateral runout control cam, which is fixed to the base plate 4, and its details are shown in FIG.
and a control section B which has a relatively small lead and has the same control rotation angle as the control section A, mainly for use with double needle wires.

A needle lateral runout control driven pin 10 embedded in an L-shaped lever 9 is engaged with the control cam, and the L-shaped lever 9 is pivotally supported by a stepped screw 11 and is connected to a second swinging width rod 12. It is designed to transmit rocking motion in the left-right direction in the figure.

The spring 13 biases the L-shaped lever 9 counterclockwise to engage the driven pin 10 with the surface of the cam 8.

The swinging width rod 12 swings to the left maximum when the driven pin 10 is on the cam surface A1 in FIG. Maximum sideways vibration.

The intermediate position between the cam surfaces A□ and A2 makes the amount of needle lateral runout zero.

Then, when it is on cam surface a, if a wooden nail is used, the horizontal runout will be less than the maximum left on cam surface A1, but if a double needle is used, the needle on the left side will be one needle on cam surface A1. These cam surface heights are set so that the needle located on the right side of the two needles coincides with the position of the single needle on the cam surface A2 when the two needles are at the cam surface height.

The rotation of the cam surface 8 in the respective control ranges of the cam surfaces A and B is controlled by the pulse motor 2 rotating under the control of a microcomputer to be described later.

To switch from the normal one-needle line to the two-needle line, switch the driven pin 10 from the normal one-needle line to the two-needle line by operating a two-needle line selection operation section (not shown) provided outside the sewing machine main body. This is done by shifting from the cam surface A by the rotation angle α formed by the wooden nail cam surface A1 and the bi-folding cam surface B□ to correspond to the cam surface B.

The reverse switching is performed by continuing to perform normal pattern selection, and these controls are also based on microcomputer control.

The mounting position of the light shielding plate 6 to the base plate 4 is such that the reset position of the pulse motor when the control power for controlling the pulse motor 2 is turned on is set so that the driven pin 10 is connected to the cam surfaces A□ and A.
This is to set the value to be between 2 and 2, and the reset is done by, for example, the patent application filed in 1973 by the same applicant as the present application.
The method detailed in No. 3-27951 is used.

FIG. 4 is a control block diagram, in which solid line arrows indicate the relationship and direction of electrical signals, and chain line arrows indicate mechanical relationships.

The ROM is a read-only electronic storage device that stores a plurality of stitch pattern control signals including straight stitch and each program control signal.

The CPU is a central processing unit that controls each program.

The RAM is a temporary storage device that temporarily stores the processes and results of each program execution.

Ilo is an input/output port.

These ROM, CPU, RAM. Ilo constitutes a microcomputer.

ps is a pattern selection section, and when a desired pattern is selected by a pattern selection switch (not shown) provided on the sewing machine head, the result is stored in the temporary storage RAM. It includes a double needle line selection operation section (not shown) that is operated in conjunction with the switch.

PG is an upper shaft pulse generator, which generates pulses for each fixed position phase in synchronization with the rotation of the upper shaft of the sewing machine, and provides the pulse signals to the arithmetic processing unit CPU in order to read out the stitch control signal from the storage device ROM. .

DV is an electric drive device for controlling the needle lateral runout, and drives the pulse motor 2 for controlling the needle lateral runout based on a signal from the arithmetic processing unit CPU.

Reference numeral 7 denotes a photointerrupter, which generates a pulse signal by means of a light shielding plate 6 that rotates together with the pulse motor 2, and the signal is sent to the arithmetic processing unit CPU as a signal for resetting the pulse motor 2.

FIG. 6 is a block diagram showing the means for realizing the functions of the control system centered on the arithmetic processing unit CPU, where solid line arrows indicate electrical control and chain line arrows indicate mechanical control.

The storage means ME stores signals related to the designation of the pattern by the pattern selection part name and the designation of the single needle sewing pattern or the double needle sewing pattern for the pattern at the beginning after the control power is turned on. Every time a new pattern is selected by PS or the designation is changed between a wooden nail sewing pattern and a double needle sewing pattern, the discriminating means DP selects the previously stored designation and the new designation in the storage means ME. After the comparison is made, the contents are stored in the new designation.

When the pattern selection section ps specifies a new designation of a single-needle sewing pattern and a double-needle sewing pattern that are different from each other, the discriminating means DP stores the contents of the storage means ME to the new designation as described above. At the same time, a determination signal indicating the new designation is given to the electric drive device.

The needle top position confirmation means DN confirms that the needle is near the top dead center based on the signal from the upper shaft pulse generator PG.

When the needle is near the top dead center, the electric drive device DV drives the pulse motor 2 to rotate the driven member 10 in each of the first and second rotations of the needle lateral runout control cam 8 based on the discrimination signal. It is made to engage with the section of control sections A and B that corresponds to the new designation.

The operation of the above configuration will be explained with reference to the flowchart of FIG. 5. When the control power is turned on, the control circuit of FIG. 4 becomes operational and the program starts.

When the light shielding plate 6 is not in a position facing the photointerrupter 7, the pulse motor 2 is rotated and reset to the position facing the photointerrupter 7 as shown in FIG.

This rotation is controlled by the arithmetic processing unit CPU by the upper shaft pulse generator P.
This is done after confirming that the needle is near the top dead center by the G signal.

Next, each selection switch (key) of the pattern selection section including the double needle line selection is read.

If a normal pattern is selected and a double needle line is not selected, the pattern selection is the first operation after turning on the control power, or the double needle is not registered in a later process. If a single needle is registered, the cam 8 moves from the state in which the driven pin 10 is engaged between the cam surface A1 and the cam surface A1 to a specific position within the range A that specifies the first stitch position of the pattern. Rotate to match.

Thereafter, the pattern program is executed by repeating key reading and return point RET signals, and each time the sewing machine rotates, the arithmetic processing unit CPU receives the signal from the upper axis pulse generator PG and controls the stitches in the storage device ROM for each stitch. The signal is read out and the drive device DV is operated to control the rotation of the pulse motor 2.

The needle maximum lateral runout signal in the storage device ROM at this time maximizes the needle lateral runout of the single needle of the sewing machine.

When the double-needle line has been registered before the pattern selection, the driven pin 10 has already engaged with the cam surface B, so the arithmetic processing unit CPU rotates the cam 8 at the rotation angle α from the engagement point.
Rotate counterclockwise in FIG. 2 to return it by the same amount.

Thereafter, single needle stitches are formed by executing the same program as above.

When the twin needle is attached to the sewing machine and the twin needle line is selected, the driven pin 10 advances by the rotation angle α from the state held on the cam surface A unless the twin needle registration described later is performed. Therefore, the cam 8 rotates clockwise in FIG.

And register the two needles. Thereafter, the rotation of the pulse motor 2 is controlled by the same stitch control signal as in the wooden nail.

When two needles are registered, the pattern program is executed without controlling the rotation angle α.

The total needle lateral runout formed by the two needles in the cam surface range B is reduced to match the maximum needle lateral runout formed by the single needle in the cam surface range A in the maximum lateral runout control.
At each point in the cam surface range B, the reduction ratio is reduced.

In addition, in the cam shape shown in Fig. 3, cam surface A and cam surface B correspond to each other with the same rotational force direction and the same rotation angle, but when selecting two needles, the pulse motor rotation in one needle If the arithmetic processing unit CPU performs data conversion to reverse the direction, the cam surface A and B2 will be interchanged, and the cam surface A
The step difference in switching between and B is reduced.

As described above, according to the present invention, the normal single-needle line and double-needle line are controlled using the same stitch control signal, and the switching is done electromechanically by changing the engagement position of the cam when selecting a pattern. It has many advantages, such as simple switching, simple control, and good operability.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a control mechanism showing an embodiment of the present invention;
Fig. 2 is a top view, Fig. 3 is a detailed view of the needle lateral runout control cam, Fig. 4 is a control circuit diagram, Fig. 5 is a control flow chart, and Fig. 6 is a detailed diagram of the needle lateral runout control cam.
The figure is a block diagram showing means for realizing the functions of the control system. In the figure, 2 is a pulse morse, 8 is a needle lateral runout control cam, 10 is a driven member, 12 is a needle lateral runout adjustment section, ps is a pattern selection section,
Usua is a storage means, DV is an electric drive device, and DP is a discrimination means.

Claims (1)

[Scope of utility model registration request] In a sewing machine that uses an electromechanical drive to control the amount of needle lateral runout to form sewing patterns, there is a pattern selection section that enables selection of multiple sewing patterns including a double needle line selection section, and a needle lateral runout control section. a rotary cam having a first rotation control section for single-needle sewing pattern control and a second rotation control section for double-needle sewing pattern control; have the same control angle and are rotationally controlled using a common stitch pattern control signal, and the second rotation control section is different from the first rotation control section. A needle lateral vibration control cam that reduces the needle lateral vibration control amount for a unit control angle, a driven member that follows the needle lateral vibration control cam, and a driven member that is connected to the driven member and that reduces the needle lateral vibration control amount. a needle lateral runout adjusting section that adjusts the amount of needle lateral runout based on the needle lateral runout; and a motor that rotates the needle lateral runout control cam, the motor rotating the needle lateral runout control cam;
and a pulse motor which selects the driven member to be driven in one of the second rotation control sections and operates in synchronization with the rotation of the sewing machine in the rotation control section, and designation of the pattern by the pattern selection section and the corresponding pattern. storage means for storing a signal relating to a designation of a single-needle sewing pattern or a double-needle sewing pattern; and a storage means for storing a signal relating to a designation of a single-needle sewing pattern or a double-needle sewing pattern; determining means for determining whether the sewing pattern and the double needle sewing pattern are new designations that are different from each other, and causing the storage means to memorize the new designation;
and an electric drive device that drives the pulse motor based on the determination by the determining means to engage the driven member in the section corresponding to the new designation among the first and second rotation control sections. Two-needle wire control device for electronic sewing machines.