JPH0461887A - Thread feed device for sewing machine - Google Patents

Abstract

PURPOSE:To introduce the leading end of a remaining thread to a needle or a looper, and immediately enable the start of the next sewing by performing the control of a thread feed roller for stopping the rotation thereof, upon inputting signals detected with the first and second thread sensors, and detecting a thread cut with either of the aforesaid sensors. CONSTITUTION:If a thread cut occurs between the first thread sensors 31 to 33, and thread feed rollers 34 to 36, a thread at the supply side becomes stationary, and the first thread sensors 31 to 33 at the stationary thread immediately detects the thread cut. Furthermore, if a thread cut occurs between a thread feed roller 12 and the second thread sensors 34 to 36, a thread forward of the cut position passes the second thread sensors 34 to 36, and these sensors 34 to 36 detect the thread cut. According to the aforesaid construction, even if a thread is entrapped with the thread feed roller 12 and cut, the thread cut is immediately detected with the first thread sensors 31 to 33, or the second thread sensors 34 to 36, thereby stopping the thread feed roller 12 and minimizing the entrapped amount of the thread.

Description

[Detailed description of the invention] As a main business ■ Sarasato! The present invention relates to a thread feeding device for a sewing machine that uses a thread feeding roller or the like to feed thread to a sewing section of the sewing machine.

An example of the above-mentioned sewing machine thread supply device is one previously proposed by the applicant of the present application in Japanese Patent Application No. 1-287181. This device includes a yarn feeding roller with rollers that rotate on both sides sandwiching the yarn, and a yarn gripping solenoid provided upstream of the yarn feeding roller, and the yarn feeding roller forcibly feeds the yarn. The gripping solenoid is controlled on and off to repeatedly grip and release the thread, and the necessary amount of thread is intermittently sent to the sewing section. Note that the thread feeding roller will not operate until sewing is interrupted and the main shaft of the sewing machine, which is linked to the pedal, is stopped, until the power to the sewing machine is turned off while fishing on a boat.
Although the rollers may be spaced apart, they are always rotating.

However, in the case of the conventional device described above, there is no means for detecting yarn breakage that occurs in the middle of the yarn, so it is fine when there is a worker present, but for example when it is operated automatically. etc., the yarn feeding roller cannot be stopped even if a yarn breakage occurs, and in some cases, for example, if the gripping solenoid is off and is not gripping the yarn, the yarn that caused the yarn breakage may be stopped. There was a problem in that the yarn was wound around the yarn feeding roller and a large amount of yarn was let out from the yarn supply source side.

Note that the above-mentioned yarn breakage may occur due to the force of the yarn being wound around the yarn feeding roller at first.

Furthermore, when the thread is wound as described above, it takes time to unwind the wrapped thread, and there is also the problem that it takes time to start the next sewing.

The present invention has been made to solve such problems,
A thread supply system for sewing machines that can stop the thread feed roller immediately when a thread breakage occurs, prevent the cut thread from wrapping around the thread feed roller, and even if a thread breakage occurs, preparations for the next sewing can be quickly made. The purpose is to provide equipment.

The thread feeding device for a sewing machine according to the present invention is designed to pass thread between rollers of a thread feeding roller whose drive source is different from that of the main shaft of the sewing machine, and to turn on a thread gripping means provided upstream of the thread feeding roller. - In a thread feeding device of a sewing machine configured to feed thread by off control, a first thread sensor is provided upstream of the thread feeding roller and detects thread breakage based on the presence or absence of thread movement. , a second yarn sensor that is provided downstream of the yarn feeding roller and detects yarn breakage based on the presence or absence of movement of the yarn;
A control means for controlling the rotation of the yarn feeding roller to be stopped when the detection signals of the first and second yarn sensors are input and one of the yarn sensors detects yarn breakage. shall be.

In the present invention, when the sewing machine is operating and no thread breakage occurs, the entire thread fed out from the thread supply source is moving, so the first and second threads are Neither sensor detects yarn breakage, and the yarn feeding roller continues to rotate.

By the way, the detection situation by the thread sensor differs depending on the location where the thread breakage occurs. For example, if a yarn breakage occurs upstream of the first yarn sensor, the yarn closer to the supply source than the cutting section will remain stationary, and although the yarn on the tip side of the cutting section will be fed out by the yarn feeding roller, After a while, the trailing end passes the first yarn sensor, the first yarn sensor detects yarn breakage, and the control means stops the yarn feeding roller.

In addition, if yarn breakage occurs between the first yarn sensor and the yarn feeding roller, in this case as well, the tip side of the cut portion is fed out by the yarn feeding roller as before, but the yarn on the supply source side is fed out by the yarn feeding roller. The first yarn sensor present at the portion where the yarn is stopped immediately detects the yarn breakage, and the control means stops the yarn feeding roller.

Then, when a yarn breakage occurs between the yarn feeding roller and the second yarn sensor, the leading end side of the cutting part passes the second yarn sensor, the second yarn sensor detects the yarn breakage, and controls the The child stage stops the yarn feeding roller. Therefore, the yarn closer to the supply source than the cutting section does not wrap around the stopped yarn feeding roller.

Furthermore, when thread breakage occurs on the sewing side of the second thread sensor, the thread closer to the thread supply source than the cutting section is fed out by the thread feeding roller, but the thread portion that has passed through the thread feeding roller is Second
The yarn part that accumulates between the yarn sensor and the yarn sensor and is detected by the second yarn sensor does not generally move, and the second yarn sensor detects yarn breakage, and the control means stops the yarn feeding roller. let

Therefore, yarn sensors are provided upstream and downstream of the yarn feeding roller.

By the way, when sewing is interrupted and the main shaft of the sewing machine is stopped, there is no need to feed the thread, but as explained in the prior art section, even if the main shaft of the sewing machine is stopped, the thread feeding roller continues to rotate. There may be cases. In this state, even if the yarn wraps around the yarn feeding roller and breaks, the yarn breakage is immediately detected, so the amount of wrapping is small. Furthermore, even if only winding occurs without yarn breakage, when the yarn on the second yarn sensor side returns in the reverse feeding direction and passes the second yarn sensor, the control means stops the yarn feeding roller. .

Furthermore, when winding does not occur, there is no movement of the thread, so
1st. The second thread sensor erroneously detects that thread breakage has occurred even though it has not occurred, but the control means does not stop the thread feeding roller and immediately starts the next sewing after the interruption. can.

Back - Shi Ichigo Hereinafter, the present invention will be specifically explained based on the drawings.

FIG. 1 shows an embodiment of a sewing machine equipped with a thread supply device according to the present invention. In the figure, reference numeral 1 denotes, for example, an overedge sewing machine, which includes a conveying section 2 on which a material to be sewn, such as cloth, is placed and conveyed at a predetermined pitch, a cloth table 3 on which the material to be sewn is placed, and a cloth table. A pressing part 4 that presses the cloth placed on the cloth stand 3 with a predetermined force, an arm 6 to which a needle 5 for sewing is attached, and an arm 6 provided inside the sewing machine below the needle 5. Upper looper 7 and lower looper 8, needle 5 and upper and lower loopers
Needle thread T1 and looper thread T2゜T3 applied to 7 and 8
and a thread feeding amount adjustment device 10 for adjusting the supply amount per stitch of each group, and a cloth stand 3. which is each component described above. The sewing machine includes a sewing machine frame 9 in which the arm 6 and the yarn feed amount adjusting device 10 are arranged at optimal positions and accommodates each mechanism, and a yarn feeding roller control section 40 (see FIG. 3).

The three threads Tl to T3 are sent to the sewing machine from above the sewing machine L, and after the thread feed amount of these three threads Tl to T3 is adjusted by the thread feed amount adjustment device 10, a plurality of threads are sent to the sewing machine side. Through the threading member, the needle 5, upper and lower loopers 7,
Leads to 8.

As shown in FIG. 2, the yarn feeding amount adjusting device 10 includes a yarn feeding roller 12 driven by a motor 11 equipped with a rotary encoder provided inside the sewing machine frame 9, and three rollers provided near the yarn feeding roller 12. A first yarn sensor 31 is provided on the upstream side of the yarn feed amount adjusting device 10 and detects information regarding yarn movement for each yarn.
, 32° 33, and a similar second
Yarn sensors 34, 35, and 36 are provided. In addition,
The first yarn sensor 31, 32, 33 is located upstream of the yarn feeding roller 12 and is connected to the gripping solenoid 15, 16, 17.
It may also be provided on the downstream side.

The yarn feeding roller 12 consists of a drive roller 13 that is attached to the shaft of a motor 11 equipped with a rotary encoder and driven to rotate at a constant speed, and two driven rollers 14a and 14b whose rotation is transmitted through a gear mechanism. Become. The driven rollers 14a, 14b are rotatably supported by two bearing members 24a, 24a, which are respectively supported rotatably in an angular range formed by two shafts 24 (only one of which is shown). ing. A shaft 24.2 is attached to a support piece 21.22 attached to one end side of a roller support member 20 fixed to the sewing machine frame 9.
4 are supported in the direction of arrow X by spring mechanisms 25 (only one of which is shown) respectively attached to both sides of the hanging portion 20a at the other end of the roller support member 20. 24a is resiliently biased about axis 24.24.

Further, on the other end side of the roller support member 20, the bifurcated intermediate portions of the bifurcated opening member 23 are rotatably supported, respectively.
Its two free ends act on bearing members 24a, 24a, respectively. Therefore, the driven rollers 14a and 14b contact the drive roller 13 in a pressed state.

A needle thread T is provided between the driving roller 13 and the driven roller 14b.
1 is passed through, and a looper thread T2. T3 passed, and each faction T1-T3
is fed by the rotation of the yarn feeding roller 12.

If thread feeding is not necessary, actuate the latch solenoid 26 provided on the sewing machine frame 9 via a support (not shown) to push the middle part of the opening member 23 in the direction of arrow Y.
The pressed state between the driven rollers 14a, 14b and the drive roller 13 is released.

Three gripping solenoids 15, 16, 17 provided on the upstream side in the yarn supply direction with respect to the drive roller 13 have respective groups Tl, T2. Holding T3, each group moves the drive roller 12
This is to forcefully stop the yarn being fed to the side and adjust the amount of yarn supplied.

Each of the above-mentioned gripping solenoids 15 to 17 is a solenoid main body 15.
a to 17a and the press plate 15 attached to the tip of the solenoid shaft.
b to 17b, and press plates 15b to 17b when energized.
approaches the solenoid bodies 15a to 17a, grips each group between the two, and releases the grip on each group when de-energized. Note that the gripping force of each gripping solenoid 15 and the like is sufficiently stronger than the yarn conveying force of the yarn feeding roller 12.

The yarn sensors 31 to 36 each have a rotary encoder 3.
1a to 36a, rollers 31c to 36c attached to their rotating shafts 31b to 36b, and rotary encoders 31a to 36a.
Built-in encoder 36a and low reencoder 31a-3
An output unit (not shown) is provided which binarizes the signal detected at 6a and outputs a yarn breakage signal or non-yarn breakage signal to the yarn feeding roller control unit 40, which will be described later. Rollers 31c to 36
When each section T1 to T3 is hooked to C, the rollers 31c to 36c rotate due to the movement of the thread, and in response to this rotation, the rotary encoders 31a to 36a rotate, and as a result,
The output section outputs a Fri level non-thread breakage signal.

Also, if the thread breaks, the rotary encoders 31a to 36a
stops, and the output section outputs the LO level thread breakage signal. In addition, the way the thread gets caught on the rollers 31c to 36c is as follows.
The rollers 31c to 36c displace the yarn, which becomes straight when it is not hooked on the rollers 31c to 36c, in the lateral direction so that the movement of the yarn is surely transmitted to the rollers 31c to 36c. For example, as shown in the figure, to explain the roller 31c related to the needle thread T1 as an example, the sides on which the thread is applied to the roller 31c and the gripping solenoid 15 are reversed left and right, and the thread is connected to the thread S.
Make it look like a letter (.

The threads T1 to T3 that have passed through the second thread sensors 34 to 36 pass through the thread threads provided at a plurality of locations, and then pass through the needle 5. It is led to upper and lower loopers 7 and 8.

FIG. 3 is a block diagram showing the yarn feeding roller control section 4o. This control unit 40 includes AND circuits 42 to 44 and 46 to 4 for giving a signal to stop the yarn feeding roller.
8.50-52.

AND circuits 42, 46.50 respectively connect the first yarn sensor 3
1, 32. Output signal AI from 33, A2゜A3 is NO
Via the T-elements 42a, 46a, 50a, the output signals Bl, B2 . B3 and the rotation signal C of the sewing machine main shaft are input as they are, and when all the input signals are at Hi level, the stop signal E is sent to the power supply circuit 1.
Output to 8. AND circuits 43, 47.51
l.

B2. B3 is connected to the AI, A2 . A3 and C are input as is,
When all input signals are Hi level, a stop signal F is output to the power supply circuit 18.

The AND circuits 44, 48.52 are connected to the above Bl, B2, B3.
are NOT elements 44a, 48a, and 52a.

C is input through the NOT elements 44b, 48b, 52b, and the Al, A2 . When A3 is input as is and all input signals are at Hi level, a stop signal G is output to the power supply circuit 18.

Then, the power supply circuit 18 receives an output signal E from the control section 40.
-G, the electric power constantly supplied to the motor 11 is stopped.

Table 1 is a table showing the contents controlled by the yarn feeding roller control section 4o based on the input signals AI, B1, and C regarding the needle thread T1. Although not shown in the table, the yarn feeding roller control section 4o controls the other two looper yarns T2. T3
The same control is performed for

Table 1 Next, yarn supply control of the apparatus of the present invention configured as described above will be explained.

When the sewing machine is operating, that is, the main shaft of the sewing machine is rotated, and threads are being supplied to each section T1 to T3 without any breakage, the entire thread fed out from the thread supply source is moving.
First thread sensors 31-33, second thread sensors 34-36
Both do not detect thread breakage. In this case, No. 4 in Table 1
As shown in <A.

B and C are all at Hi level, the yarn feeding roller control section 40 does not output any output, and the power supply circuit 18 continues to rotate the yarn feeding roller 12.

By the way, the detection situation by the thread sensor differs depending on the location where the thread breakage occurs, but if the thread breakage occurs upstream of the first thread sensors 31 to 33, the thread closer to the supply source than the cutting part remains stopped. Although the leading end side of the cutting part is sent out by the yarn feeding roller, the trailing end passes the first yarn sensors 31 to 33 after a while, and is fed out by the yarn feeding roller.
3 detects thread breakage. That is, the state shown in No. 1 in Table 1 is reached. In this case, the AND of the yarn feeding roller control section 40
The circuit 42 (or 46.50) sends the stop signal E to the power supply circuit 1.
8, the motor 11 equipped with a rotary encoder is stopped, and the yarn feeding roller 12 is stopped.

Also, first yarn sensors 31 to 33 and yarn feeding rollers 34 to 3
If a thread breakage occurs between the thread 6 and the thread 6, in this case as well, the tip end side of the cut part is fed out by the thread feeding roller as before, but
The yarn on the supply source side remains stationary, and the first yarn sensors 31 to 33 present at the portion where the yarn is stationary immediately detect yarn breakage.

That is, the state shown in No. 1 in Table 1 is reached. In this case too,
AND circuit 42 (or 46.5
0) gives a stop signal E to the power supply circuit 18, and the yarn feeding roller 1
Stop 2.

Further, when yarn breakage occurs between the yarn feeding roller 12 and the second yarn sensors 34 to 36, the tip end side of the cut portion passes through the second yarn sensors 34 to 36, and the second yarn sensor 34 ~3
6 detects thread breakage. That is, the state becomes No. 2. In this case, the AND circuit 43 (
or 47.51) gives a stop signal F to the power supply circuit 18,
The yarn feeding roller 12 is stopped. Therefore, the yarn closer to the supply source than the cutting section does not wrap around the stopped yarn feeding roller.

Further, when thread breakage occurs on the sewing side of the second thread sensors 34 to 36, the thread closer to the thread supply source than the cut section is fed out by the thread feeding roller 12, but the thread feeding roller The yarn portion that has passed through the yarn sensor 12 accumulates between the second yarn sensors 34 to 36, and the yarn portion detected by the second yarn sensors 34 to 36 does not generally move and is detected by the second yarn sensor 34 to 36. 34~
36 detects thread breakage. That is, the state shown in No. 2 of Table 1 is reached. In this case as well, A of the yarn feeding roller control section 40
The ND circuit 43 (or 47.51) applies a stop signal F to the power supply circuit 18 to stop the yarn feeding roller 12.

By the way, when sewing is interrupted and the main shaft of the sewing machine is stopped, there is no need to supply thread, but as mentioned above,
Even if the main shaft of the sewing machine is stopped, the yarn feeding roller 12 may continue to rotate. In this state, the yarn is fed to the yarn feeding roller 1.
Even if yarn breakage occurs due to winding around the thread 2, the first yarn sensors 31 to 33 and the second yarn sensors 34 to 36 immediately detect the yarn breakage and stop the yarn feeding roller 12. few. Further, even if the yarn is only wrapped without breaking, the yarn of the second yarn sensors 34 to 36 returns in the reverse feeding direction and passes through the second yarn sensors 34 to 36, and then the second The yarn sensors 34 to 36 detect an abnormality.

That is, in this case, since the main shaft of the sewing machine is stopped, the signal C is at the Lo level, resulting in the state shown in No. 3 in Table 1. In this case, A of the yarn feeding roller control section 40
The ND circuit 44 (or 48.52) applies a stop signal G to the power supply circuit 18 to stop the yarn feeding roller 12. Note that even if only winding occurs in this way, the second yarn sensors 34 to 3
Since No. 6 detects an abnormality and the same condition as No. 2 occurs, the input of signal C is not necessarily necessary.

Furthermore, when winding does not occur, there is no movement of the thread, so
1st. The second yarn sensors 31 to 36 each erroneously detect that yarn breakage has occurred even though no yarn breakage has occurred, but since the circuit configuration of the control unit 40 is shown in FIG. The unit 40 inputs each input signal A, B, C to N in Table 1.
Even in the state shown in o5, no output is made, the yarn feeding roller 12 continues to rotate, and the next sewing can be started immediately after the interruption. Note that at this time, since the main shaft of the sewing machine is stopped, the yarn feeding roller may be rotated as in this control example, but may also be stopped.

Therefore, by controlling in this manner, when thread breakage occurs, the next sewing can be started immediately by guiding the tip of the remaining thread to the needle or louver. In addition, if the yarn is wrapped around the yarn feeding roller, the yarn feeding roller is immediately stopped, so the amount of yarn wrapped around the yarn feeding roller is small, and it can be easily removed. It is possible to start the next sewing immediately by guiding the sewing machine to the louver or to the louver.

In the above embodiment, the signal from the rotary encoder that monitors the rotation and stoppage of the main shaft of the sewing machine is transmitted to the first . Although the signal C from the rotary encoder is used together with the signal from the second yarn sensor for control, the signal C from the rotary encoder is not essential and may not be used. However, when using signal C for control, No.
It is possible to perform control by determining whether the state is No. 2 or No. 3.

Further, in the above embodiment, a thread sensor equipped with a rotary encoder is used, but the thread sensor used in the present invention is not limited to the above-mentioned one, and can detect thread breakage based on the amount of thread movement. Other sensors that can detect this may also be used. For example, it is possible to use a sensor whose charge level changes as the thread moves. It should be noted that the present invention can be practiced even if an optical sensor with a different thread breakage detection principle is used.

Furthermore, in this embodiment, the yarn feeding roller control section 40 shown in FIG.
is displayed using a logic circuit, but a microcomputer
It is also possible to control using program software using .

As described in detail above, in the case of the present invention, the yarn feeding roller is stopped immediately when a yarn breakage occurs, so that it is possible to prevent the yarn cut by 4° from wrapping around the yarn feeding roller, and thus the yarn can be prevented from wrapping around the yarn feeding roller. Even if a thread breakage occurs, the next sewing can be started quickly without any trouble, and the thread feed roller stops when a thread breakage is detected, so you can sew with confidence even when the sewing machine is running automatically. It has the effect of being able to.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of a sewing machine with a thread feeding device according to the present invention, Fig. 2 is a perspective view showing a thread feed amount adjustment device provided in the device, and Fig. 3 is a thread feeding roller control. FIG. TI...needle thread, T2. T3... Louver thread, 10.
... Yarn feed amount adjustment device, 11 ... Motor with rotary encoder, 13 ... Drive roller, 14a, 14
b...Followed roller, 15-17...Gripping solenoid, 31-33...First thread sensor, 34-36...
Second yarn sensor, 40... Yarn feeding roller control section, 42~
44°46~48.50~52...AND circuit.

Claims (1)

[Claims] (1) Thread is passed between rollers of a yarn feeding roller whose drive source is different from the main shaft of the sewing machine, and the thread is held in the A thread feeding device for a sewing machine in which thread is supplied by a thread feeding roller, comprising: a first thread sensor that is provided upstream of the thread feeding roller and detects thread breakage based on the presence or absence of movement of the thread; A second yarn sensor is provided on the downstream side of the yarn feeding roller and detects yarn breakage based on the presence or absence of yarn movement; the detection signals of the first and second yarn sensors are input; A thread supply device for a sewing machine, comprising: a control means for controlling rotation of the thread supply roller to be stopped when the thread supply roller detects thread breakage.