JPH0492695A - Correcting method for feeding pitch - Google Patents

Abstract

PURPOSE:To obtain an exact pitch without the read error of an actual pitch by correctively calculating the pitch by idly sewing a length decided in advance according to various feeding pitch data. CONSTITUTION:When the operator side edge of cloth to be sewn is matched to a reference point and the starting pedal of a sewing machine is pre-stepped, the sewing machine is rotated and the cloth is fed. In this case, when the operator side edge of the cloth is detected by a cloth edge detection sensor, the sewing machine is stopped. At such a time, the voltage of a potentiometer, the number of sewing stitches and the rate of feeding completion when detecting the cloth edge are read in. Next, the feeding pitch is automatically set to the second pitch data. When the cloth is matched to the reference point again and the starting pedal of the sewing machine is pre-stepped, the cloth is fed. When the operator side edge of the cloth is detected by the cloth edge detection sensor, the sewing machine is stopped. At such a time, the voltage of the potentiometer, the number of sewing stitches and the rate of feeding completion when detecting the cloth edge are read in and according to these data, the pitch is correctively calculated. Thus, the feeding pitch can be exactly detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a sewing machine having a feed pitch detecting means and a material edge detecting means, and the pitch data stored in advance can be accurately read by simply running the sewing machine twice. The present invention relates to a feed pitch correction method for correcting the actual feed pitch.

[Prior Art] Conventionally, a part of a feeding device is equipped with a feeding pitch detection means.
A sewing machine equipped with a potentiometer has been proposed as shown in FIGS. 5 and 6. 5 and 6, a feed adjuster 2 is connected to the main shaft 1 of the sewing machine via a crank rod, and a cloth feed means 3 is connected to the feed adjuster 2 via a horizontal feed shaft. The means 3 is provided to cause the feed dog to move in and out of the throat plate to make four movements. Further, a swing shaft 5 is connected to the feed adjuster 2 via a rod 4, and this swing shaft 5 is fixed to the rear end of an adjustment cam 6, and the tip of an adjustment screw 7 is attached to the cam surface of the adjustment cam 6. engaged. This adjustment screw 7 can be rotated from the outside of the sewing machine, and this rotation changes the engagement position of the adjustment cam 6 depending on the forward/backward position of its tip. By varying the horizontal movement component in the feed regulator 2 as a function of position, the amount of the feed dog of the cloth feed means 3 can be varied.

The base of the L-shaped feed lever 8, one end of which protrudes outside the sewing machine, is loosely supported by an adjustment shaft 9, and the base end of the adjustment shaft 9 is connected to the swing shaft 5 via a connecting arm 10. ,
By rotating the adjustment shaft 9, the feed amount can be reduced or the feed direction can be reversed. The other end of the feed lever 8 is biased clockwise in the figure by a spring 11 whose one end is fixed to the machine frame, and a pin 8a projecting horizontally is provided in the middle of the feed lever 8. . The bin 8a is engaged with a swinging arm 12 that projects horizontally, and when one end of the feed lever 8 that projects outside is rotated downward, the swinging arm 12 is pressed downward.

Rotate the adjustment shaft 9 downward. Further, the free end of the swinging arm 12 is connected to a potentiometer 14 via a link 13, which converts the amount of rotation of the swinging arm 12 into an electrical amount.

Further, a bent portion of an L-shaped operating lever 15 is supported by a loose fit on the adjustment shaft 9, and an operating pin 15a projecting from the swing arm 12 is fixed to one free end of the operating lever 15.

Further, a connecting arm 16 is connected to the other end of the operating lever 15, one end of an L-shaped operating rod 17 is connected to the other end of the connecting arm 16, and the other end of the operating rod 17 is supported by an actuator 18a of a solenoid 18. As the actuator 18a moves up and down, the joint between the first operating rod 17 and the connecting arm 16 moves left and right. Further, when the engaging portion 16a of the connecting arm 16 moves to the right in the figure, it faces the cam body 19 so as to come into contact with the cam surface 19a of the cam body 19, and this cam body 19 is connected to the stepping motor 2°. is fixed to the shaft. This cam surface 19a changes to the engaging portion 16a depending on the rotation angle of the cam body 19.
Since the timing of contact with the actuator changes, the amount of movement differs, and this amount of movement causes the swinging arm 12 to rotate downward via the action pin 15a of the action lever 15, thereby reducing the amount of feed.

In the sewing machine configured in this way, when the solenoid 18 is not energized, the feed amount set by the adjusting screw 7 is detected by the potentiometer 14, and when the solenoid 18 is energized, the feed amount is set by the stepping motor 20. (See Japanese Patent Publication No. 63-22838).

By the way, the sewing machine configured in this manner has a built-in control device including a CPU (not shown), and feed pitch data is set in advance in this control device. The feed pitch is detected by comparing the voltage value of the potentiometer 14 with the pitch data value.

[Problem to be solved by the invention] However, in this method of detecting the feed pitch,
Since there are always variations in the precision of parts and adjustment values for each sewing machine head, there will be a discrepancy between the pitch data held in advance and the actual feed pitch, making it impossible to accurately detect the feed pitch. There wasn't.

In order to solve this problem, it is possible to detect the pitch more accurately by testing the garment twice and inputting the difference between the actual pitch and the data using a dip switch, but it is possible to detect the pitch more accurately by sewing the garment twice. There was a problem in that it took time and effort to measure the pitch and then input it to the dip switch.6 The present invention has been developed by performing blank stitching on a predetermined length using different feed pitch data. To provide a feed pitch correction method that calculates feed pitch correction from the potentiometer voltage, number of sewing stitches, and feed completion rate at each feed pitch, and obtains an accurate actual feed pitch from this correction calculation. This is the purpose.

[l! Means for Solving the Problems] In order to achieve the above object, the present invention provides a rotation detector for detecting the rotational position of a main shaft of a sewing machine, a feed pitch detection means connected to a cloth feed means of the sewing machine, and a feed pitch detecting means connected to a cloth feed means of the sewing machine. A sewing machine having an automatic feed pitch adjustment means connected to a pitch detection means and capable of changing the feed pitch, and a material edge detection means provided at a predetermined position before the needle drop point on the throat plate and outputting a material edge detection signal. , a first feed pitch is set by the pitch automatic adjustment means, and the cloth edge detection means detects the first feed pitch from a reference point provided on the needle plate before the cloth edge detection means in the sewing direction. a first sewing stage in which the output value of the feed pitch detection means, the number of sewing stitches, and the feed completion rate at the time of cloth edge detection are read in the first sewing stage; and a stage in which the pitch is automatically adjusted. A second feed pitch is set by a means, and a period from a reference point provided on the needle plate before the cloth edge detection means in the sewing direction to detection by the cloth edge detection means at the second feed pitch is determined. a second sewing step in which sewing is performed; a step in which the output value of the feed pitch detection means, the number of sewing stitches, and the feed completion rate at the time of cloth edge detection are read; Temporary pitch PAL is determined from the number of sewing stitches and the length from the reference point to the cloth edge detection point at each sewing stage.

PA2 is calculated, and the actual pitch P1. This step consists of a step of calculating P2 and a step of calculating corrected pitch data from this actual pitch and the output value of the feed pitch detecting means.

[Operation] According to the present invention, first, when a test program is selected, the feed pitch is automatically set to the first pitch data stored in advance. next.

Align the front edge of the fabric to be sewn with the reference point and press the start pedal of the sewing machine, the sewing machine will rotate and the fabric will be fed. Here, when the front edge of the fabric is detected by the fabric edge detection sensor, the sewing machine stops. At this time, the voltage of the potentiometer, the number of sewing stitches, and the feed completion rate when detecting the edge of the fabric are read. Next, the feed pitch is automatically set to the second pitch data. Then, once again align the fabric with the reference point and press the sewing machine's start pedal forward, the sewing machine will start rotating.

The fabric will be sent. Here, when the front edge of the fabric is detected by the fabric edge detection sensor, the sewing machine stops. At this time, the voltage of the potentiometer, the number of sewing stitches, and the feed completion rate when detecting the edge of the material are read. Next, pitch correction calculations are performed from each of these detected data, and a table of corrected feed pitch data is created. and exit.

[Embodiment 1] In FIG. 1, in a configuration for implementing the feed pitch correction method according to an embodiment of the present invention, a RAM 22 and a ROM 23 are connected to the CPU 21 as storage devices;
A cloth edge detection sensor 24, a pedal 25, and a potentiometer 26 serving as a feed pitch detection means are connected to the input side of the paper feeder 1. 27 is a rotation detector of the sewing machine, which outputs a needle up signal, a needle down signal, and a timing pulse in response to the rotation of the main shaft. Further, a solenoid 28 of automatic feed pitch adjustment means, a stepping motor 29, and a sewing machine motor 3o are connected to the output side of the CPU 21.

Further, referring to FIG. 2, a cloth edge detection sensor 24 is provided in front of the needle drop point 32 of the throat plate 31 in the sewing direction, and a reference point C is provided in front of the cloth edge detection sensor 24 in the sewing direction. The lengths of the end detection sensor 24 and the needle drop point 32 are set to A, and the lengths of the reference point C and the needle drop point 32 are set to B.

Next, the operation of this embodiment will be explained using the aWj-th flowchart. First, when a test program is selected (step 1), the pitch data stored in the ROM 23 in advance is read out, and the solenoid 27 and stepping motor 29 of the feed pitch automatic adjustment means are driven, and the feed pitch is automatically set to 21. (Step 2).

Next, place the front edge of the fabric to be actually sewn at reference point C in Figure 2.
When the start pedal 25 is stepped forward at the same time, the sewing machine motor 30 rotates and the fabric is fed and sewing is performed (step 3). At this point, the CPU 21 determines whether the fabric edge detection sensor 24 has detected the front edge of the fabric. Step 4)
, when the front edge of the fabric is detected by the fabric edge detection sensor 24,
The sewing machine motor 30 is stopped with the needle up (step 5). At this time, the CPU 21 reads the voltage V 2 mm from the potentiometer (feeding pitch detection means) 26, and reads the voltage V 2 mm from the rotation detector 27.
The number of sewing stitches N2 is read by counting the needle up signal, and the output of the rotation detector 27 and the cloth edge detection sensor 24
From the output, count the timing pulses from one fall just before the cloth edge detection to the time of detection, and read the feed completion rate α2mm for the feed to form one stitch (step 6).

Next, the pitch data stored in the ROM 23 in advance is read out, and the solenoid 27 of the feed pitch automatic adjustment means
Then, the stepping motor 29 is driven, and the feed pitch is automatically set to the pinch data of 3 mm (step 7). Next, when the front end of the fabric to be actually sewn is aligned with the reference point C in Fig. 2 and the starting pedal 25 is depressed forward, the sewing machine motor 30 rotates and the fabric is fed and sewing is performed (
Step 8). Here, the CPU 21 detects the cloth edge detection sensor 2.
Step 9) When the front edge of the fabric is detected by the fabric edge detection sensor 24, the sewing machine motor 30 is stopped at the top of the needle (Step 10).
). At this time, the CPU 21 reads the voltage V 3am of the potentiometer 26 and counts the needle up signal of the rotation detector 27 to read the number of sewing stitches N3■. Timing pulses from one drop immediately before the cloth edge detection to the time of detection are counted, and the feed completion rate α31 for the feed for forming one stitch is read (step 11). Then, the next feed pitch correction calculation is performed.

First, the number of sewing stitches N2+a when 2+am, 3m1m1
From a+, N3■, the temporary pitch PA2+e is calculated by the following formula.
m and PA3mm are determined (step 12).

PA2+u+= (B −A) ÷ (N2i+m+0.5
)PA3mm=(B-A)÷(N3mm+0.5)(
However, 0.5 is a correction coefficient from the start of sewing to 1 drop, and the feed amount Px from the beginning to the time of detection is determined from data table 1 on the previous page and data table 2 on the next page (step 13).

Then, calculate each actual pitch P from the following formula (
Step 14).

(B-A) - (Po2+a++Px2++m) This temporary pitch PA2-m, PA3mm and completion rate α2■, α
, 1111, the feed amount P0 from the top stop at the beginning of sewing to the first 1 drop point and the 1 drop just before the fabric edge detection (B -
A) - (P, 3mm + Px3mm) Actual pitch P 2mm, P 2mm calculated using the above formula and potentiometer voltage v determined in step 6.11 of Figure 3.
Create a table of potentiometer voltage vs. actual feed pitch shown in Figure 4 based on the 2nd and 3rd layer shoes (Step 15)
In FIG. 4, curve A is pitch data corrected in the test mode, and curve B is pitch data that has been stored in advance.

This table allows accurate actual feed pitch to be determined from potentiometer voltage.6 In this embodiment, the accuracy of the parts of the sewing machine head and assembly can be improved by simply performing two blank stitches to correct the pitch data and actual feed pitch. Accurate actual feed pitches can be obtained without measuring actual feed pitches without reading errors caused by variations in attachment adjustment.

[Effects of the Invention] Since the present invention is configured as described above, the pitch data stored in the storage device and the actual feed can be corrected by two empty stitches.

There is no need to measure the pitch or input dip switches, and the effect is that it is possible to obtain an accurate actual feed pitch without reading errors in the actual feed pitch that occur due to variations in the accuracy of parts in the sewing machine head or assembly adjustments. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration for implementing the method of the present invention, FIG. 2 is a plan view of the throat plate portion for implementing the method of the present invention, and FIG.
The figure is a flowchart for explaining the present invention in detail, FIG. 4 is a diagram showing pre-stored pitch data and corrected pitch data, and FIG. A schematic configuration diagram of the amount adjusting device, FIG.
FIG. 3 is a side view of a portion of the figure; 2l---CPU, 22---RAM, 23---RO
M, 24... Cloth edge detection sensor, 25... Pedal, 2
6... Potentiometer, 27... Rotation detector, 2
8... Solenoid, 29... Stepping motor,
30... Motor, 31... Throat plate, 32... Needle drop point, C... Reference point. Patent applicant Juki Co., Ltd. Figure 1 Figure 3 Figure Potentiometer voltage diagram

Claims (1)

[Claims] 1: a rotation detector for detecting the rotational position of the sewing machine main shaft; a feed pitch detection means connected to the cloth feed means of the sewing machine;
A feed pitch automatic adjustment means connected to the feed pitch detection means and capable of changing the feed pitch, and a cloth edge detection means provided at a predetermined position in front of the needle drop point of the needle plate and outputting a cloth edge detection signal. In the sewing machine, a first feed pitch is set by an automatic pitch adjustment means, and the cloth edge detection means detects the first feed pitch from a reference point provided before the cloth edge detection means of the throat plate in the sewing direction. a first sewing stage in which sewing is performed until the pitch A second feed pitch is set by the automatic adjustment means, and the distance from a reference point provided on the throat plate before the cloth edge detection means in the sewing direction until detected by the cloth edge detection means at the second feed pitch is set. a second sewing step of sewing the gap; a step of reading the output value of the feed pitch detection means, the number of sewing stitches, and the feed completion rate when detecting the cloth edge in the second sewing step; Temporary pitches PA1 and PA2 are calculated from the number of sewing stitches and the length from the reference point to the cloth edge detection point in each sewing stage of step 2,
A feed pitch correction method comprising the steps of calculating actual pitches P1 and P2 from this provisional pitch and the feed completion rate, and calculating corrected pitch data from this actual pitch and the output value of the feed pitch detection means.