JPH0345292A - Seam margin controller - Google Patents

Abstract

PURPOSE:To improve the seam quality, holding a prescribed seam line position by correcting the deflection quantity of the clothe edge which is detected by a cloth edge detecting mechanism, according to the variation of the extension/ contraction characteristic, etc., of a cloth. CONSTITUTION:Each number of seams of the parts n1, n2, n3,... which is calculated by a CPU 25 on the basis of the extension length and cloth feed pitch which are inputted by a keyboard input means 21 is memorized into a memory 24. The output of a linear sensor 12 is inputted into the CPU 25 through an amplifier 22 and an A/D converter 23, and the revolution pulses of the main shaft of a sewing machine is counted by a counter 26 and ourputted as the needle operation data into the CPU 25. When the sewing machine is driven, and the seam formation onto a cloth 10 is started, the extension length data corresponding to the seam quantity data is read out from the memory 24 on the basis of the needle operation data supplied from the counter 26. Each cloth drawing-in quantity of the cloth press-contact rotary bodies 3u and 3d is corrected on the basis of the extension length data, and the revolution quantity of a motor 7 is controlled. In other words, as the extension length is larger, the prescribed correction quantity with the less draw-in quantity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a seam allowance control device, and particularly to a control device for keeping a seam allowance (stitch line) constant.

[Conventional technology]

Conventionally, a sewing machine has a detector that detects the position of the edge of the fabric near the front of the needle drop point in the sewing direction, and a feed mechanism installed in the sewing machine that presses against the fabric to move the fabric in a direction perpendicular to the direction of the bottom of the seam shape. An apparatus has been developed in which a roller-like rotating body provided with a roller is provided facing two upper and lower pieces of fabric, respectively, and a fixed seam line can be obtained by scraping and unrolling the fabric.

(In BL and FIG. 6, 1 is a wood stitch sewing machine, 2 is a sewing needle, and 3u and 3d are upper parts for moving the fabric in a direction perpendicular to the seam force direction of the fabric.

4u-1 and 4d-1 are light emitters added to detect the side edges of the fabric; 5 is the fabric pressing rotating body 3u and 3d; 6 is the transmission shaft, 7 is the motor, 8 is the upper and lower fabric separation plate to allow the upper and lower fabrics to operate independently and avoid interference with each other, and 9 is the presser foot of the sewing machine. , ], Ou, 10d are upper and lower fabrics, 11 is a fabric feed dog, 12 is a linear sensor that is operated from a solar cell to read the distance M14 from the seam line 15, and 13 is a side edge of the fabric.

In such a conventional seam allowance control device, when the fabric 10 whose side edge 13 is curved as shown in the arrow direction in FIG. 6 is fed by the fabric feed dog 11, the seam line I5 and the side edge 13 of the fabric are The distance 14 from 1 to 1 changes along the curve. The linear sensor 12 reads this change, controls the motor 7 so that the distance 14 is always constant, and moves the fabric 10 in the vertical direction in FIG. I try to keep it constant.

[Problem to be solved by the invention]

However, in such a conventional device, when the sewing progresses in Figure 6 and the seam moves from area A to area B in the figure, the weave of the fabric changes from the vertical or horizontal grain as shown in Figure 7. Change to subject. At this time, the fabric 10 is in a state where it is easy to stretch, and a tension is exerted between the force of the fabric feeding dog 11 pulling the fabric in the direction of the arrow in FIG. Therefore, elongation occurs in the feed direction, while contraction occurs in the direction perpendicular to the feed direction.

For this reason, the linear sensor I2 reads a small value, apparently upward X2, and the cloth pressing rotary bodies 3u, 3d are controlled in the direction of scraping the cloth (move the cloth upward in the figure) accordingly. As a result, if the stretched fabric returns to its original shape after sewing, the seam allowance width will become larger than the set value, resulting in unsatisfactory sewing quality.

The present invention seeks to eliminate the above-mentioned drawbacks.

[Means to solve the problem]

The seam allowance control device of the present invention has a mechanism that detects the distance between the fabric edge position and the seam line, and a fabric control mechanism that performs raking and raking operations of the fabric according to the output of this distance detection mechanism. The device includes a memory for storing the characteristics of the fabric at the sewing position of the fabric to be sewn, a means for detecting the actual sewing position, and a memory for storing the characteristics of the fabric at the sewing position detected by the position detecting means. It is characterized by being more powerful as a means for correcting the operation amount of the cloth control mechanism according to the characteristics.

[For production]

In the seam allowance control device of the present invention, the amount of deviation of the fabric edge detected by the fabric edge detection mechanism is corrected in accordance with changes in the stretch characteristics of the fabric.

〔Example〕

The present invention will be explained in detail below with reference to the drawings.

For example, when forming a seam along the edge of a fabric IO having an edge shape as shown in FIG.
+n2. n3+..., and each part is divided into nl+ n2+ by the technique described in the specification and drawings of Japanese Patent Application No. 1983-1985, filed by the applicant, for example.
For n, l+..., the elongation length in the seam line direction is measured.

In the block diagram of FIG. 2, 21 is a keyboard manual means for manually inputting the elongation length and cloth feed pinch as data, and 24 is a calculation in the CPU 25 based on the input elongation length and input cloth feed pitch. The number of stitches for each part n I+ n 2+ ”:l+...
This is a memory that stores the length of each part divided by the specified double feed pinch. The elongation length is readably stored in correspondence with the count. The output of the linear sensor 12 is connected to the amplifier 22 and the A/D
It is input to the CPU 25 via the converter 23. The sewing machine has a well-known pulse generator (
(not shown) is provided, and the counter 26 counts this one rotation pulse and outputs it to the CPU 25 as hand movement data. Reference numeral 27 represents a driver that controls each of the two motors 7 separately.

In the above configuration, the sewing machine is driven and the fabric 10 is
When the seam formation starts, elongation length data corresponding to the count data is read from the memory 24 based on the hand movement data from the counter 26, and based on this elongation length data, the fabric pressing rotating body 3u, The cloth scraping amount of 3d is corrected, and the rotation amount of the motor 7 is controlled. That is, a predetermined correction amount is given such that the greater the elongation length, the smaller the scraping amount. This predetermined correction amount can be obtained by calculation or by storing it on a table in memory.

Furthermore, the elongation rate may be used as data instead of the elongation length.

Next, a second embodiment will be explained. In the first embodiment, the elongation length is measured in advance, stored in the memory, and read out in accordance with the movement of the hands, but in the second embodiment shown in FIGS. The elongation length measuring members 28a and 28b detailed in the specification and drawings of the above-mentioned Japanese Patent Application No. 63-285699 are installed in front of the body 3u in the cloth feeding direction, and elongation length measuring members 28a and 28b are installed on each seam-shaped boshin in synchronization with the driving of the sewing machine. Measure the elongated length. The CPU 25, which receives this elongation length detection output as input, controls the rotation of the motor 7 so as to correct the scraping amount of the cloth press-contacting rotating body 3u in the same manner as described above.

The counting data and elongation length data in the first embodiment are based on the position of the sewing needle 2 in the cloth feeding direction and the linear sensor 12.
The elongation length corresponding to the fabric portion located on the linear sensor 12 is read out in consideration of the distance between the measuring members 28a, 28b and the linear sensor 12. The measuring members 28a, 2
Timing is set so that when the fabric on 8b moves onto the linear sensor 12, the fabric pressing rotary bodies 3u and 3d are controlled.

In each of the above embodiments, the amount of rotation of the cloth pressing rotating bodies 3u, 3d is corrected, but the output of the linear sensor 12 may be corrected.

〔Effect of the invention〕

As described above, in the seam allowance control device of the present invention, the apparent amount of fabric edge deviation can be corrected based on the elongation rate of the fabric, the relationship between the seam direction and the weave, etc., so that the seam line position can be maintained as specified. It is possible to improve the sewing quality.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the fabric applied to the seam allowance control device of the present invention, FIG. 2 is a block diagram of the seam allowance control device of the present invention, and FIG.
FIG. 4 is a block diagram of the second embodiment; FIG. 5 is a front view and a side view of a conventional seam allowance control device also used in the present invention; Figure 6,
FIG. 7 is an explanatory diagram of the operation showing the elongation of the dough. 1... Lockstitch sewing machine, 2... Sewing needle, 3u3d---
Fabric pressure contact rotating body, 4u-1, 4d-1... light emitting body, 5
... Bevel gear, 6... Transmission shaft, 7... Motor, 8... Upper and lower dough separation plate, 9... Presser foot, 10...
・Dough, 10u. 10d... Upper and lower fabric, 11... Fabric feed dog, 12.
...Linear sensor, 13...Side edge of fabric, 14...
distance, 15... seam line, 21... keyboard input means, 22... amplifier, 23... A/D converter, 2
4...Memory, 25...CPU. 26 ・ ・ Counter, 27 ・ Dora 4 Zutakudanrame u

Claims (3)

[Claims] (1) A seam allowance control device that has a mechanism that detects the distance between the fabric edge position and the seam line, and a fabric control mechanism that performs raking and raking operations of the fabric in accordance with the output of this distance detection mechanism. A fabric control mechanism based on the memory storing the characteristics of the fabric at the sewing position of the fabric to be sewn, a means for detecting the actual sewing position, and the characteristics of the fabric stored in the memory at the sewing position detected by the position detecting means. A seam allowance control device comprising: means for correcting the amount of movement of the seam allowance control device. (2) The seam allowance control device according to claim 1, wherein the characteristic of the fabric is elongation of the fabric at each sewing position. (3) In a seam allowance control device having a mechanism for detecting the distance between a fabric edge position and a seam line, and a fabric control mechanism for performing raking and raking operations of the fabric according to the output of the distance detection mechanism, A seam allowance control device comprising: means for detecting a characteristic of the fabric before the detecting mechanism in the cloth feeding direction; and means for correcting the amount of operation of the cloth control mechanism based on the output of the characteristic detecting means.