JPS61131793A - Cloth end position detector of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] This invention provides a fixed position stop device for sewing machines that continuously detects the position of cloth fed by four-moving feed dogs or rotating feed rollers. This invention relates to generating signals for controlling devices.

[Conventional technology]

As a fixed position stop device for the sewing machine mentioned above, for example,
-46989 is known. This device was constructed by combining two cloth edge sensors, a needle bottom detection section, a pulley rotation angle detection section, and an electronic calculation control section.

In other words, based on the distance between the two fabric edge centers arranged in the sewing machine feed direction, the feed required for the last needle to accurately stop at a predetermined stop position can be determined by detecting how many stitches have been made between the two fabric edge centers arranged in the sewing machine feed direction. It seeks quantity. According to these conventional detection means, since detection is performed at a specific point on the cloth feeding path, the current position of the moving cloth cannot be detected at all times, and when the cloth is transferred in the feeding direction due to the cloth feeding movement. As the cloth moves on the table, it is subjected to frictional resistance with the table surface and the action of various sewing machine operating means, and depending on the type of cloth, the cloth may expand and contract, which causes the length of the cloth to change. The detection timing could become inaccurate due to changes. Then, since the pinch is calculated based on the time including this error and the device is controlled, the purpose of the device cannot be fully achieved and there is a problem in the quality of the sewing product.

The present invention has been made to solve these problems, and an object of the present invention is to constantly detect the moving position of the cloth edge by using a sensor that continuously detects the moving position of the cloth.

〔Example〕

An embodiment of the present invention will be described based on the drawings.

In this embodiment, sewing of the sewn product (・defect B (second
This invention relates to a fixed position stop control device for a sewing machine in which the needle automatically drops to the position shown in the figure.

In Fig. 3, reference numeral 1 indicates a well-known fabric feeding means disposed on the underside of the sewing machine so that the feed dog can move forward and backward on the throat plate, and 2 indicates the main shaft of the sewing machine, and 3 indicates the main shaft via a crank rod. A well-known feed adjuster 4 is connected to 2 and transmits the horizontal motion component to the cloth feeding means as a horizontal feed amount, and 4 is rotatable from outside the sewing machine and is adjusted to move the tip forward or backward in the axial direction depending on the rotation angle. The screw, 5, has a cam surface that engages with the tip of the adjustment screw 4, and the position of engagement with the cam surface changes depending on the forward/backward position of the screw, and 6 is a well-known adjustment cam that is rotated around the intermediate portion. A swing shaft 7 fixed to the rear end of the cam 5 is connected to the swing shaft 6, and adjusts the feed amount of the feed dog by changing the horizontal movement component in the feed adjuster 3 in relation to the rotation position of the adjusting cam 50. These are rods connected to change the

Further, in FIGS. 3 and 4, 9 is a feed lever, the base end of which is rotatable up and down relative to the machine frame, and is biased upward by a spring 9b with one end fixed to the machine frame. 9C, and a part of the lever 9 has a pin 9 that protrudes in the horizontal direction.
a is fixed.

Reference numeral 10 denotes an adjustment shaft whose support part is loosely fitted and supported concentrically with the base end of the lever 9, and which is rotatable relative to the machine frame.
A rocking arm 11 is provided on a part of the lever 9 so as to protrude so as to be opposed to the lower pin 9a of the lever 9, and the base end of the adjustment shaft 100 is connected to the rocking arm 6 via a connecting arm 12. are doing. 8
is a spring provided at the base end of the swinging arm 6 between it and the machine frame, and always urges the cam surface of the °C adjustment cam 5 upward. When the lever 9 is rotated downward, the pin 9a presses the swing arm 11 downward and the adjustment shaft 10 is rotated downward. This adjustment shaft 10
The rotation causes the swing shaft 6 to rotate via the connecting arm 12,
The feed adjuster is operated to adjust the amount of feed of the cloth feed teeth 10 in the cloth feed means 1.

Reference numeral 13 denotes an L-shaped operating lever whose bent portion is supported loosely on an adjustment shaft, and an operating pin 13a extending onto the swing arm 11 is fixed to one free end of the operating lever 13. 14 is a connecting arm that rotatably supports the other end of the operating lever, and 15 is an L-shaped actuator that rotatably connects one end to the other end of the connecting arm 14 and rotatably supports the intermediate part on the machine frame. The other end is supported by the actuator 16a of the solenoid 16, and as the actuator 16a moves up and down, the operating rod 15
The connecting portion with the connecting arm 14 moves left and right.

A cam body 17 is fixed to the shaft of the stepping motor 18 and has one end surface formed in a cam shape. The cam surface 17a has a wall thickness that differs from the other end surface depending on the circumferential direction, and the retaining portion 14a at one longitudinal end of the connecting arm 14 and the cam surface 17
a are arranged facing each other, and the distance from the retaining portion 14a is varied depending on the rotation angle of this cam surface 17a. Therefore, the connecting arm 14 comes into contact with the cam surface 17a by moving rightward in the figure, but since the distance it travels until it comes into contact changes depending on the rotation angle of the cam surface 17a, the change in the amount of movement causes the action lever 13 to come into contact with the connecting arm 14. Working pin 13
The swing arm 11 is rotated downward via a to change the feed amount. In other words, the connecting arm 14 is rotated by the rotation angle of the cam body 170 set by the stepping motor 18.
Since the backward movement distance of the solenoid 16 is determined, the energization of the solenoid 16 results in a decrease in the feed amount corresponding to this movement distance.

Next, FIG. 1 shows an embodiment of the fabric edge position detection device for a sewing machine according to the present invention, in which reference numeral 22 is placed below the sewing machine throat plate 33 and is provided opposite to a projector 30 placed above the throat plate. A plurality of photosensitive cells 81 are spatially and electrically independent from each other over a length b along the cloth feeding direction.
By arranging ~Sn on a semiconductor substrate and sequentially applying a pulse voltage to each photosensitive cell, each photosensitive cell 81~
It is detected whether Sn is irradiated with light of a certain level or higher.

In addition, solid-state line sensors include CC-DC charge-coupled semiconductor optical sensors) and MOS (metal oxide semiconductor optical sensors).
), CID (charge injection semiconductor optical sensor), and the like are known, and any one of them may be used in this embodiment.

Reference numeral 21 denotes a needle down detector provided on the main shaft, and a slit disk 21a provided on the main shaft rotates according to changes in the angle of the main shaft.
It is constructed so that a needle down signal is generated when the needle bar descends to the bottom dead center.

FIG. 5 is a control block diagram of the fixed-position stop nipple of the sewing machine, in which 20 is a microcomputer that executes predetermined arithmetic control of this device, 21 is a needle-lower detector that inputs a needle-lower signal to the microcomputer 20, and 23 is a cloth position detection circuit that determines the cloth position from the needle hole to the cloth edge based on the detection pulse from the line sensor 22, and inputs a cloth position signal to the microcomputer 20. Reference numeral 24 indicates a stitching setting device inputted to the microcomputer 20, and 25 indicates an STM driver for driving the stinning motor 18, which generates drive pulses based on drive signals output from the microcomputer 20.

26 is an SQL driver that drives the solenoid 16, and causes a drive current to flow based on a drive signal output from the microcomputer 20.

[For production]

The operation of this device which operates the above mechanism to accurately and automatically stop the sewing material at a preset seam allowance will be described.

First, an example of actual sewing is shown in Fig. 6. Let's assume that we want to form a straight seam from an arbitrary point . This setting will be explained with reference to the flowchart shown in FIG.

The circuit is turned on, the cloth is placed on the sewing machine table, the sewing start point is placed in the needle hole, and the line sensor 22 is covered with cloth A. Therefore, the line sensor 22 is equipped with the projector 3.
Detection light from 0 is not irradiated, and no detection pulse is output.

The sewing machine is driven and the cloth A is sequentially transferred in the feed direction by the feed dog. A needle down signal is emitted from the needle down detector 21 for each stitch, but a loop is formed between determinations 100 and 101 until the edge of the fabric is transferred onto the line sensor. Needle hole 32
and the length e of the line sensor. If the length e to the cloth edge is smaller, the e value is returned to el and stored in the next process 102.

Next, in judgment 103, the rise of the needle down signal is checked again, and if it rises, in process 104, the length e value at that time is stored as e2. Next, in step 105, e2 is subtracted from el to obtain the feed pitch P for one stitch. For example, e,=2Qmm
If e2==18mm, P220-18:2fl
・・・・・・・・・・・・・・・ U). In process 106, the number of stitches n' until the sewing machine stops is set to O, and in process 107, the seam allowance a is subtracted from e2 to find the length from the needle hole 32 to the seam allowance. In the above example, the seam allowance is 1-
and v:y%', ・rokara, e2=18 1=17m
・・・・・・・・・・・・(2) Judgment 108
Check if the distance e2 between the needle hole 32 and the fabric edge becomes smaller than the feed pitch P, and if it does not become smaller, proceed to step 10.
After subtracting the pinch P from e2 at step 9 and adding one stitch to the number of stitches n' using the counter at step 110, e2 minus P is checked again at step 108. In this way, 108 → 1
Repeat the loop of 09→110→108 (as e2 becomes smaller than the pinch P, find the number of stitches n' until the final needle pinch and the final needle pitch P2. In the above example, the initial value of e2 is The value is 17m, so n' = 8 stitches, P2 = = = 0, and after sewing 8 more stitches, if the feed amount of the 9th stitch is 11, then the sewing (・It is calculated that the last needle will fall due to a defect.) reactor.

In process 111, the final needle pitch P2 is input to the STM Drino<-25, thereby driving the stevening motor 18 to set the cam body 17 at a position corresponding to the pitch P2 (IWrIn described above). In process 112, one stitch is added to n' as the final stitch, and the process waits for the next needle down signal to be input.

When the next needle down signal is output from the needle down detector 21, one stitch is subtracted from the number of stitches n' in step 114, and the needle down signal is counted until the number of stitches n' becomes one. That is, in the above example, eight stitches are sewn. Then, when the number of stitches reaches n,=l, a drive signal is issued to the SQL driver 26, and the solenoid 16 is operated. The cam body 17 is already connected to the engaging portion 14a by a feed amount equivalent to the final needle (l in the above example).
Since the pitch is set to P2 of w ), the feed adjuster 3 changes the feed amount. Here, when the last stitch is sewn and the sewing machine travels over the sewing defect, a needle down detection signal is generated and the number of stitches reaches n'20, the current to the stitching/sewing stitch 6 is stopped by judgment 115. The solenoid slides downward due to the actuator's own weight and returns to its normal position, and at the same time, the feed adjuster 3 also returns to its initial feed amount. Then, in step 119, the main motor of the sewing machine is stopped.

[Other Embodiments] In the above embodiments, the detection light from the light emitter is radiated from the upper surface of the cloth and is received by the line sensor 22 arranged below the cloth facing each other. It is also possible to determine the position of the cloth edge by installing the sensor 22 on the upper or lower surface of the cloth and using a reflective type that detects the edge shape 30b created by the detection light 30a hitting the cloth edge (Figure 8).
.

Alternatively, the line sensor 22 may be replaced by a large number of photodiodes arranged continuously in the cloth feeding direction.

Furthermore, the cloth feeding means of the sewing machine has four feeding teeth,
This device can also be used to feed cloth using a rotating feed roller.

Further, the detection signal may be used to control operating means of a sewing machine different from that of this embodiment.

Furthermore, although it is placed in front of the head of the sewing machine in the cloth feeding direction, it may be placed anywhere on the cloth moving path.

In addition, when sewing two layers together, even if the upper fabric is a pocket fabric or other small item, the position of the upper fabric can be detected by detecting the transmitted light or by detecting the shape of the detected light and using the configuration described above. It is possible.

〔effect〕

The present invention consists of the above-mentioned configuration 1, and since the moving position of the cloth can be continuously detected, calculations are processed in conjunction with the cycle of periodic moving parts of the sewing machine, such as the up and down of the needle bar or the rotation angle of the main shaft. This makes it possible, for example, to construct a fixed position stop device for a sewing machine. Therefore, depending on the fabric, the shift in the feed due to the periodic expansion and contraction of the fabric that occurs during the feed movement can be detected within the needle feed time, so this shift is canceled out, making it possible to determine the accurate feed amount. It is possible to obtain a device with high sewing quality by removing the feed error (which is calculated from the conventional number of stitches per constant speed). In addition, when comparing the feed amount with other conventional devices that detect the feed amount from the movement of the feed dog or from the feed adjuster, the feed error due to the movement of the feed dog not being accurately transmitted to the cloth can also be reduced by the amount of cloth movement. In addition, since a large amount of information can be obtained through continuous movement detection, the number of components such as sensors can be reduced in applied equipment, and the configuration of the calculation control unit can be simplified. , it is possible to obtain a highly reliable device with reduced costs.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the mechanical configuration of the fabric edge position detection device of the sewing machine according to the present invention, Fig. 2 is a seam formation diagram when sewing a collar, and Fig. 3 is a diagram showing the sewing machine fixed position stop device. Fig. 4 is a front view showing the device for adjusting the cloth feed amount;
6 is a control block diagram of a fixed position stopping device of a sewing machine, FIG. 6 is a diagram showing an example of sewing using the same device, FIG. 7 is a flowchart of the same device, and FIG. 8 is a diagram showing another embodiment.

Claims (1)

[Scope of Claims] A sewing machine in which cloth is moved by a cloth feeding means has light emitting means disposed opposite to each other on a path in the cloth feeding direction, and light from the light emitting means can be received separately, and the position of the moving cloth edge is continuously adjusted. a detection means consisting of a plurality of light receiving means which are arranged continuously along the cloth feeding direction so as to detect the light, and each of which generates a detection signal in relation to light reception or light blocking; A fabric edge position detection device for a sewing machine, comprising: a detection circuit for detecting a moving position of an edge;