JPH0344548B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a seam allowance control device that moves the fabric to be sewn in a direction intersecting the feeding direction of the fabric to form a desired seam allowance while sewing. .

[Conventional technology]

Conventionally, as a seam allowance control device for maintaining the distance from the edge of the fabric to the needle drop position along the cloth feeding direction, that is, the seam allowance width, at an appropriate position, for example, a sixth seam allowance control device has been used.
There are those shown in Fig. and Fig. 7.

In the figure, 1 is the sewing machine body, 2 is the needle, 3, 3
are two upper and lower pieces of fabric to be sewn placed on the sewing machine bed (hereinafter simply referred to as fabrics) 4, 4 are moving rollers, 5, 5 are bevel gears, 6, 6 are drive shafts, 6a,
Reference numeral 6a denotes a motor 7 as a driving source, and 7 is a fabric edge sensor that detects whether or not the fabric edge is at a reference position.

In addition, the moving roller 4, the bevel gear 5, the drive shaft 6
A cloth moving means is constituted by the motor 6a, and the moving roller 4 having knurls formed at the outer peripheral end thereof is rotationally driven by the motor 6a via the bevel gear 5 and the drive shaft.

Further, 8 is a presser foot, and 9 is a separation plate interposed between the upper fabric and the lower fabric.

Next, the operation will be explained based on FIG.

The moving roller 4 located on the cloth feed line NL of the cloth 3 is moved to a motor 6a via a bevel gear 5 and a drive shaft 6 based on the cloth edge detection information of the cloth edge sensor 7.
rotate clockwise or counterclockwise to move the fabric 3 forward and backward in the direction that intersects the direction of fabric movement by the feed dog of the sewing machine, that is, in the direction of the arrow Y (raking in and scraping out the fabric), so that the edge 3a of the fabric and the needle The purpose is to always maintain the distance to the falling point 2a at a predetermined value to perform proper sewing, and to hold one of the stacked pieces of fabric to be sewn and move it in a direction that intersects with the fabric feeding direction. The separating plate, the moving roller, and the motor that drives the moving roller constitute a dough moving means.

That is, if the fabric edge has not reached the reference point 7a on the fabric edge sensor 7, the moving roller 4 rotates counterclockwise to position the fabric edge at the reference point 7a, moving the fabric 3 upward in the figure. move it.

Further, when the edge of the fabric exceeds the reference point 7a of the fabric edge sensor 7, contrary to the above, the movable roller 4 rotates clockwise until the edge of the fabric reaches the reference point 7a, and moves the fabric 3 as shown in the figure. Move it downward.

[Problem that the invention seeks to solve]

However, in the conventional seam allowance control device described above, the fabric edge sensor detects the presence or absence of the fabric edge at the reference point, and the rotation of the moving roller 4 is controlled based on the detected information, so the seam allowance width is changed. In this case, the reference point 7a must be moved. That is, it is necessary to move the fabric edge sensor 7 in a direction intersecting the seam forming direction, resulting in a decrease in work efficiency. Therefore, it was considered to automate the movement of the fabric edge sensor 7, but
In order to realize this, an actuator to move the fabric edge sensor 7 and a positioning sensor to detect the movement position of the fabric edge sensor 7 are required, which only increases manufacturing costs compared to conventional ones. However, since various mechanisms are concentrated around the throat plate where the fabric edge sensor is attached, various problems arise in terms of space when attaching the actuator and the like described above.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a seam allowance control device that does not require a special mechanism and can change the seam allowance width extremely easily by input operation.

[Means for solving problems]

The present invention provides a fabric moving unit that moves the fabric to be sewn in a direction intersecting the fabric feeding direction based on seam allowance width information inputted by an input unit and fabric edge position detection information detected by a fabric edge detection unit. The drive of the motor is controlled.

[Effect]

In this invention, if the operator inputs the required seam allowance in advance, the control means calculates the error between the fabric edge position detected in the vicinity of the needle drop point and the position suitable for forming the seam allowance width. Since the determination is made and the moving means is controlled to eliminate the error, it is possible to obtain a good seam allowance width as input.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.
This will be explained based on the diagram. In each figure, the same or corresponding parts as in the conventional example are given the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is a plan view of the same as shown in FIG.

In each figure, numeral 10 denotes a solar cell as a fabric edge detection means that is placed near the front of the needle drop point 2a and detects the fabric edge at multiple points to enable the position detection of the moving fabric edge, and its upper and lower surfaces receive light. Surfaces 10a, 10
b. Further, this solar cell 10 has a rectangular shape extending in a direction intersecting the fabric conveying direction A on a feed dog (not shown), etc., and has both light receiving surfaces 1
Upper and lower fabrics 3, 3 cover a portion of 0a, 10b. 11a and 11b are light emitters that irradiate a constant amount of light onto the light receiving surfaces 10a and 10b. In addition, the fabric edge detection means is a television camera,
Any device that can detect the edge of the fabric at multiple positions, such as a CCD, will suffice.

Furthermore, FIG. 3 is a block diagram showing the configuration of the control system circuit in this embodiment.

In the figure, 12 is an amplifier for amplifying the output from the solar cell 10, 13 is a sample-and-hold circuit connected to the output side of this amplifier 12, and 14 is the sampled output from the solar cell 10 by this sample-and-hold circuit 14. An A/D converter that digitizes the output, and the output is controlled by the CPU15 as a control means.
is input. A keyboard 16 serves as an input means for inputting target seam allowance width data to the CPU 15. The seam allowance width input using the keyboard 16 is input according to the feed amount of the fabric, the number of stitches, etc. For example, as shown in FIG. 4, when trying to form seam allowances of different widths on the fabric 3,
Input the seam allowance width up to the nth stitch as _a2 , and the seam allowance width after that as _a1, and so on. Also, 17
is a pulse generator that generates a pulse P in synchronization with the vertical movement of the needle 2, and outputs one pulse for each needle as shown in FIG. 5a, which is input to the CPU 15. 18 is a drive circuit for the motor 6a that rotates the moving roller 4, and is controlled by the CPU 15.

Based on the above configuration, the operation will be explained next.

When the cloth is not set, light is irradiated onto the entire light receiving surfaces 10a and 10b of the solar cell 10, and a constant output value is output. Here, when the fabrics 3, 3 are set, a portion of the light-receiving surfaces 10a, 10b are covered by the fabrics 3, 3, the light-receiving area is reduced, and an output corresponding to the light-receiving area is transmitted. In other words, outputs are sent out according to the positions of the fabric edges 3a, 3a. The output signal from the solar cell 10 is amplified by an amplifier 12, sampled by a sample hold circuit 13, and then sent to an A/D converter 14.
The signal is converted into a digital signal and input to the CPU 15.

Here, when the sewing operation is started, the fabric 3 is sent in the direction of arrow A shown in FIG. changes. In addition, at the same time as the sewing operation starts, the CPU 15 starts counting the pulses P sent from the pulse generator 17, determines the current number of stitches, and calculates the seam allowance width input corresponding to the number of stitches and the solar battery. The difference from the current distance to the edge of the fabric represented by the output value of 10 is calculated, and the drive circuit 18 is operated based on the difference, and the fabric 3 is raked in so that the seam is formed according to the target seam allowance width. , perform scraping.

For example, if the seam allowance width data input to the CPU 15 is to sew fabric 3 with the seam allowance width up to the nth stitch as a ₂ and the subsequent seam allowance width as a ₁ , then up to the nth stitch In the sewing operation, if the current fabric edge position detected by the solar cell 10 is larger than the target seam allowance width input in advance, the fabric edge is moved toward the needle drop point 2a ( If the current fabric edge position is smaller than the target seam allowance width, the drive circuit 18 is driven to move the fabric edge away from the needle drop point 2a (to scrape it out). In Fig. 5b, S ₁ is the output value (target output value) of the solar cell 10 when the fabric edge position matches the target seam allowance width up to the n-th stitch, and S ₂ is the output value (target output value) when the fabric edge position matches the target seam allowance width. S3 indicates the output value of the solar cell 10 when the width is larger than the target seam allowance width, and _S3 indicates the output value when the fabric edge position is smaller than the target seam allowance width.

Further, signals S _{' 2} and S _{' 3 shown} in FIG.
is output by

When the n-th stitch sewing operation is completed as described above, the CPU 15 changes the target seam allowance width data to a ₁ , compares this with the detected fabric edge position as described above, calculates the difference, and calculates the difference. Accordingly, the drive circuit 18 is activated and the sewing operation is performed while maintaining the seam allowance width at _a1 . In addition, in FIG. 5b, S ₄ indicates the target output value from the solar cell 10 after the nth stitch.

In the above embodiment, the solar cell 10 is arranged between the upper and lower two pieces of fabric 3, 3, but it may also be placed on the bottom surface of the two pieces of fabric. Applicable sewing machines are not limited to lockstitch sewing machines, but can also be applied to overlock sewing machines and the like.

Furthermore, it is also possible to use a sensor other than a solar cell, such as a magnetic sensor, as the detection means.

〔Effect of the invention〕

As explained above, according to the present invention, there is an effect that the seam allowance width can be changed extremely easily just by input operation without using any special mechanism.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is an enlarged plan view of the main part shown in Fig. 1, Fig. 3 is a block diagram of the control system circuit in this embodiment, and Fig. 4. is a plan view showing an example of the sewing state of the fabric, FIG. 5 is a diagram showing output waveforms at each part of FIG. 3, FIG. 6 is a diagram showing a conventional seam allowance control device,
FIG. 7 is an enlarged plan view of the main part shown in FIG. 6. 3...Dough, {4...Movement roller, 5...Bevel gear, 6a...Drive shaft, 6a...Motor}Dough moving means, 15...CPU (control means), 16...Keyboard (input means) .

Claims (1)

[Claims] 1. One of the stacked fabrics to be sewn is held between a separating plate and a moving roller, and this moving roller is driven by a motor to move the fabric to be sewn in a direction that intersects with the fabric feeding direction. fabric moving means; fabric edge detection means arranged near the fabric edge of said one of the fabrics to be sewn in front of the needle drop point and detecting the fabric edge at a plurality of points so as to be able to detect the position of the moving fabric edge; an input means for inputting target seam allowance width data of the cloth; and controlling the cloth moving means based on the cloth edge position information detected by the cloth edge detection means and the target seam allowance width data inputted by the input means. A seam allowance control device comprising a control means.