JPH03289993A - Sewing machine having a plurality of needlebars - Google Patents

Abstract

PURPOSE:To confirm the position of a balance after the stop of sewing machine by detecting whether the position of a balance is located in a balance stop position by means of a balance position detector when a sewing machine is stopped, operating a needlebar switching mechanism by means of a control device when it is situated in the balance stop position, and racing a sewing machine one time through operation of a jump stitch mechanism when it is not situated in the balance stop position. CONSTITUTION:When it is conformed by a balance position detector 32 that a balance 5 is located in a balance stop position, sewing operation is effected. When a sewing machine motor 44 is stopped or thread breakage occurs, it is discriminated by a control circuit 41 whether switching operation of a needlebar 4 is effected, and when switching of the needlebar is not effected, transfer to next sewing operation is effected. Mean while, when the balance is not situated in the balance stop position, an operation signal is outputted to a solenoid 30 from the control circuit 41, and a moving rod 31 enters the moving locus of a slope 16a of an engaging member 16. Simultaneously, a control signal by means of which a main spindle 9 is raced one time is outputted to a motor 44 for sewing machine, and the main spindle 9 is raced one time togetherwith a balance drive cam 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a sewing machine equipped with a plurality of needle bars.

[Conventional technology]

Conventionally, in a sewing machine that has a plurality of needle bars and is equipped with a jump stitch mechanism that can disable the vertical movement of the needle bar when the sewing machine main shaft is operated, when the needle bar is switched for color change after the sewing machine motor is stopped, If the take-up lever is not accurately stopped at the predetermined take-up stop position, the needle bar switching mechanism and the take-up lever drive mechanism will interfere with each other and will not operate properly. The detector outputs a signal indicating that the stop position of the balance is defective and stops the operation of the needle bar switching mechanism.

[Problem to be solved by the invention]

However, when the needle bar switching mechanism is stopped, the operator rotates the pulley fixed to the main shaft in order to move on to the next operation.
It is necessary to move the take-up lever to a predetermined take-up stop position and restart the needle bar switching mechanism, resulting in a decrease in work efficiency.

The purpose of the present invention was to solve the above-mentioned problems, and the purpose of the present invention is to automatically move and stop the take-up lever at the take-up stop position when the take-up lever is not locked at the take-up stop position when changing the needle bar. An object of the present invention is to provide a sewing machine equipped with a plurality of needle bars that can perform needle bar switching operations and improve work efficiency.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a sewing machine equipped with a plurality of needle bars, which includes: a thread take-up sensor for detecting a stop position of a thread take-up; and a determining means for judging whether a signal from the thread take-up sensor indicates a stop position of the thread take-up. , when the signal from the discriminating means indicates that the thread take-up is at the stop position, an operating signal is output to the needle bar selection operating means; on the other hand, when the thread take-up is not at the stop position, the jump stitch mechanism is operated to move the needle bar to the stop position. The control device is configured to move and stop the balance at a balance stop position by idling the main shaft once with the lifting mechanism disabled.

[For production]

When the sewing machine is stopped, the take-up lever position detector detects whether or not the take-up lever is at the take-up stop position, and if it is at the take-up stop position, the control device operates the needle bar switching mechanism.
If there is no take-up lever at the take-up stop position, the jump stitch mechanism is activated and the sewing machine idles once at low speed. After the sewing machine stops, the take-up lever position is checked again. If the take-up lever is stopped at the take-up take-up position, The needle bar switching mechanism is driven.

〔Example〕

An embodiment embodying the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a sewing machine head 3 is installed on the upper surface of a sewing machine table 2 above the machine base 1.

At the tip of the sewing machine head 3, a support case 6 equipped with a plurality of needle bars 4 and a plurality of thread take-up levers 5 provided corresponding to each needle bar 4 is capable of reciprocating in the left-right direction (arrow P in FIG. 2). (A plurality of yarn feeders 7 are supported on the upper surface of the sewing machine head 3, and threads 8 are supplied from the yarn feeders 7 to each of the thread take-up levers 5.

As shown in FIG. 3, inside the sewing machine head 3, a main shaft 9 rotated by a sewing machine motor 44, which will be described later, is rotatably supported at a predetermined position. Fixed. A crank 11 is connected to the front end surface of the balance drive cam 10 by a connecting pin 12. Also, the sewing machine head 3 has a guide rod 1.
3 is erected and fixed in the vertical direction, and the elevating body 14 is fitted to the guide rod 13 so as to be able to reciprocate in the vertical direction, and the tip of the crank 11 is connected by a connecting pin 15.

An engaging member 16 is fitted into the elevating body 14 so as to be movable up and down in synchronization with the elevating body 14 and rotatable about the guide rod 13. An engagement recess 17 is formed for engaging the engagement protrusion 19 of the fixed lifting member 18. Further, the engaging member 16 is always biased and held in the operating position by a spring (not shown).

The needle bar 4 is attached to a fixed support frame 2 that is attached and fixed to a support case 6.
0 and 21, and is always biased by coil springs 22 and 23 in the direction of positioning the needle bar at a predetermined stop position.

A tilting lever 26 is provided in the sewing machine head 3 by a fixed support shaft 25 so as to be located near the upper side of the thread take-up cam 10.
A cam follower 27 is rotatably supported at the lower end of the tilting lever 26 and is engaged with the cam groove 10a of the balance drive cam 10. When the IO is rotated, the tilting lever 26 is reciprocated in the direction of arrow Q in FIG. 3 about the support shaft 25. An engaging portion 28 is supported at the upper end of the tilting lever 26, and the engaging portion 28 is engaged with an engaging recess 5a provided below the base end of the balance 5 when the tilting lever 26 is moved. When the balance 5 is rotated back and forth, the balance 5 is rotated back and forth about the support shaft 29 in the direction of the arrow R in FIG. 3.

On the other hand, a solenoid 30 constituting a jump stitch mechanism is arranged on the side of the engagement member 16 as shown in FIG. When the retaining member 16 is moved upward along the guide rod 13 together with the elevating body 14 by entering the vertical movement trajectory, the engaging member 1
6 is rotated around the guide rod 13 to engage the engagement recess 17.
The engaging protrusion 19 is disengaged from the spring 2, so that the needle bar 4 is
2.23, the movement is stopped at the needle bar stop position.

A balance position detector 32 is attached to the outer end of the main shaft 9 to detect whether the tilting lever 26 and the balance 5 have been moved to the balance stop position or not.

Next, the control device will be explained based on FIG.

A control circuit 41 having memories such as a program memory and a working memory is connected to the balance position detector 32 as well as a spindle rotation detector 43 for detecting the amount of rotation of the spindle 9.

Further, a sewing machine motor 44 for rotating the main shaft 9 is connected to the control circuit 41, and a needle bar selection motor 45 for operating the support case 9 to switch needle bars is also connected. Furthermore, the solenoid 30 is connected to the control circuit 41.

Next, the operation of the sewing machine constructed as described above will be explained with reference to the flowchart shown in FIG. The following flowchart proceeds under the control of the control circuit.

Now, when it is confirmed by the thread take-up position detector 32 that the thread take-up 5 is located at the thread take-up stop position, the sewing operation is performed. Then, when the sewing machine motor 44 is stopped or thread breakage occurs, the control circuit 41 determines whether or not the needle bar 4 switching operation is to be performed, and if the needle bar switching is not performed, the next Shift to sewing operation.

On the other hand, when the needle bar is switched, the control circuit 41 determines whether or not the take-up lever 5 is at the take-up stop position using the take-up position detector 32, and if it is at the take-up stop position, the needle bar is selected. The motor 45 is driven to switch the needle bar 4.

On the other hand, if the balance is not at the balance stop position, the control circuit 41
An operating signal is output to the solenoid 30 to move the movable rod 31 into the movement locus of the slope 16a of the engaging member 16, and a control signal is output to the sewing machine motor 44 to idle the main shaft 9 once, causing the main shaft to rotate. 9 is the balance drive cam 1
It is idled once with 0. At this time, the engaging member 16 is moved forward by the movable rod 31 to disengage the engaging protrusion 19 and the engaging recess 17 and turn on the jump stitch mechanism, so that the needle bar 4 is moved to the needle bar stopping position. Since the tilting lever 26 is tilted by the rotation of the balance drive cam 10, the balance 5 is reciprocated once in the empty state. When the main shaft rotation detector 43 detects one idle rotation, a stop signal is output to the sewing machine motor 44, and the main shaft 9 and the thread take-up 5 are
etc. will be stopped.

Thereafter, the solenoid 30 is demagnetized and the movable rod 3
1 is separated from the slope 16a of the engagement member 16, the engagement recess 17 and the engagement protrusion 19 are engaged again, and the balance 5 is stopped moving to the balance stop position. In this state, the take-up lever position detector 32 again detects whether or not the take-up lever is at the take-up stop position. If it is at the take-up stop position, the needle bar is replaced and the next sewing operation is started. do.

In this way, in the embodiment, when the take-up lever 5 is not at the take-up stop position, the take-up stitch mechanism is turned on, and the take-up lever drive cam IO is rotated once along with the main shaft 9 to move the take-up lever 5 to the take-up stop position. This eliminates the need for the operator to manually adjust the position of the take-up lever to the take-up stop position, allowing the needle bar to be quickly switched during sewing and improving work efficiency. In addition, since the position of the take-up lever is automatically corrected and the machine moves on to the next operation, sewing will not be interrupted even if the operator is not in front of the sewing machine.
This prevents the sewing work from being interrupted for a long period of time, which would occur in the past when an abnormality occurs while the worker is absent.

〔Effect of the invention〕

As described in detail above, even if the take-up lever is not stopped at the take-up stop position when the needle bar is changed, the main shaft is rotated once and the take-up stop position is adjusted so that the sewing machine can be stopped when the needle bar is changed. The sewing operation can be automatically continued without interruption, which has the effect of improving work efficiency.

[Brief explanation of the drawing]

Fig. 1 is a flowchart for explaining the needle bar switching operation of a sewing machine equipped with a plurality of needle bars according to the present invention, Fig. 2 is a perspective view showing the entire sewing machine, and Fig. 3 shows the drive mechanism of the needle bar and thread take-up. 4 is a perspective view showing the jump stitch mechanism, and FIG. 5 is a block diagram showing the control device. 4... Needle bar, 5... Take-up lever, 5a... Engagement recess, 6
...Support case, 9...Main shaft, 10...Take-up lever drive cam, 10a...Cam groove, 11...Crank, 13
...Guide rod, 16...Engagement member, 17...Engagement recess, 18...Elevating member, 19...Engagement protrusion, 2
2.23...Spring, 26...Tilt lever 2
7...Cam follower 228...Engagement part, 29.
... Support shaft, 30 ... Solenoid constituting the jump stitch mechanism, 31 ... Movable rod, 41 ... Control circuit, 42 ... Balance position detector, 43 ... Main shaft rotation detector, 44 ...Sewing machine motor, 45...Needle bar selection motor.

Claims (1)

[Claims] 1. A main shaft built into the sewing machine head and rotated by a drive mechanism; a support case mounted so as to be able to reciprocate in the lateral direction relative to the sewing machine head; and a main shaft capable of reciprocating up and down with respect to the support case. A plurality of needle bars are attached and held at a needle bar stop position by a holding means when not in use, and a plurality of needle bars are also supported to be capable of reciprocating up and down relative to the support case in correspondence with each of the needle bars, and are fixed. A plurality of thread take-up levers are held at a take-up stop position by a holding means in the use state; a needle bar selection operation means for moving the support case left and right to selectively arrange a specific needle bar at the use position; a needle bar lifting mechanism that reciprocates the needle bar up and down, which is interlocked and held in a use position; and a needle bar lift mechanism that is engaged with the thread take-up, which is moved and held in a use position in conjunction with the main shaft, and moves the take-up up and down. In a sewing machine equipped with a plurality of needle bars including a thread take-up mechanism that rotates back and forth in the direction of the thread take-up, and a jump stitch mechanism that can disable the operation of the needle bar lifting mechanism, the sewing machine includes a thread take-up sensor that detects a stop position of the thread take-up; , a determining means for determining whether or not the signal from the balance sensor indicates that the balance is at a stop; if the signal from the determining means indicates that the balance is at a stop position, outputting an operation signal to the needle bar selection operation means; and a control device for operating the jump stitch mechanism to disable the needle bar lifting mechanism and idling the main shaft once to move and stop the take-up lever at the take-up stop position when the take-up lever is not at the take-up stop position. A sewing machine equipped with a plurality of needle bars.