JP2751553B2 - Sewing machine with multiple needle bars - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sewing machine provided with a plurality of needle bars.

[Conventional technology]

Conventionally, in a sewing machine having a plurality of needle bars equipped with a jump stitch mechanism that can invalidate the vertical movement of the needle bar during operation of the sewing machine spindle, after stopping the sewing machine motor, when performing a needle bar switching operation for color change, If the balance is not accurately stopped at the predetermined balance stop position, the needle bar switching mechanism and the balance drive mechanism interfere with each other and do not operate properly, so the balance position for confirming that the balance is at the balance stop position. The detector stops the operation of the needle bar switching mechanism by outputting a stop position failure signal of the balance.

[Problems to be solved by the invention]

However, when the needle bar switching mechanism is stopped, it is necessary for the operator to rotate the pulley fixed to the main shaft to move to a subsequent operation, move the balance to a predetermined balance stop position, and restart the needle bar switching mechanism. There was a drop in work efficiency.

An object of the present invention is to solve the above-described problem, and automatically stops moving the balance to the balance stop position when the balance is not locked at the balance stop position at the time of needle bar switching. Another object of the present invention is to provide a sewing machine provided with a plurality of needle bars capable of performing a needle bar switching operation and improving work efficiency.

[Means for solving the problem]

In order to achieve the above object, the present invention provides, in a sewing machine having a plurality of needle bars, a balance position detector for detecting a balance stop position, and determining whether a signal from the balance position detector is a balance stop position. Determining means for performing the operation, the operation signal is output to the needle bar selecting operation means when the signal from the determination means is at the balance stop position, and when the signal is not at the balance stop position, the jump stitch mechanism is operated. And a control device for rotating the spindle once to stop the balance at the balance stop position with the needle bar lifting mechanism disabled.

(Operation)

When the sewing machine is stopped, the balance position detector detects whether or not the balance is at the balance stop position. If the balance is at the balance stop position, the needle bar selecting operation means is operated by the control device, and the balance is moved to the balance stop position. If not, the jump stitch mechanism is operated, the sewing machine is idled once at a low speed, the position of the balance is confirmed again after the sewing machine stops, and if the balance is stopped at the balance stop position, the needle bar selecting operation means Is driven.

〔Example〕

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

As shown in FIG. 2, a sewing head 3 is mounted on the upper surface of the sewing machine table 2 above the machine base 1. A support case 6 having a plurality of needle bars 4 and a plurality of balances 5 provided corresponding to the respective needle bars 4 is reciprocally movable in the left-right direction (arrow P in FIG. 2) at the tip of the sewing machine head 3. A plurality of thread supply bodies 7 are supported on the upper surface of the sewing machine head 3, and the thread 8 is supplied from the thread supply body 7 to each of the balances 5.

As shown in FIG. 3, a main shaft 9 rotated by a sewing machine motor 44, which will be described later, is rotatably supported at a predetermined position inside the sewing head 3, and a balance driving cam 10 is fitted to a tip end of the main shaft 9. It is fixed. The balance driving cam
A crank 11 is connected to a front end face of the 10 by a connecting pin 12. A guide rod 13 is fixed to the sewing machine head 3 in the up-down direction, and an elevating body 14 fitted to the guide rod 13 so as to be able to reciprocate in the up-down direction and a tip end of the crank 11 are connected by a connecting pin. Connected by 15.

An engaging member 16 is inserted into the elevating body 14 so as to be able to move up and down in synchronization with the elevating body 14 and to be rotatable about a guide rod 13. An engagement recess 17 for engaging the engagement projection 19 of the fixed lifting member 18 is formed. The engaging member 16 is always urged and held at the operating position by a spring (not shown). The needle bar 4 is vertically reciprocable with respect to fixed support frames 20 and 21 attached and fixed to the support case 6, and is urged by coil springs 22 and 23 in a direction always located at a predetermined needle bar stop position. Have been.

In this embodiment, the needle bar elevating mechanism for reciprocating the needle bar 4 in the up-down direction includes the main shaft 9, the balance driving cam 10,
11, guide rod 13, lifting body 14, engagement member 16, engagement recess 1
7. It is composed of the elevating member 18, the engaging projection 19 and the like.
In this embodiment, the holding means for holding the plurality of needle bars 4 at the needle bar stop positions is constituted by the fixed support frames 20, 21 and the coil springs 22, 23 and the like.

A tilting lever 26 is reciprocally rotatably supported by a fixed support shaft 25 in the sewing machine head 3 so as to be located near the upper side of the balance driving cam 10, and a cam follower rotatably supported at the lower end of the tilting lever 26. 27 is the balance driving cam 10
When the balance driving cam 10 is rotated by the rotation of the main shaft 9, the tilting lever 26 is reciprocated in the direction of arrow Q in FIG. 3 around the support shaft 25. It has become. An engaging portion 28 is supported on the upper end of the tilting lever 26. The engaging portion 28 is engaged with an engaging recess 5a provided below the base end of the balance 5, and the tilting lever 26 is
Is reciprocated, the balance 5 is moved to the third position
It is designed to be reciprocated in the direction of the arrow R in the figure.

In this embodiment, the holding means for holding the plurality of balances 5 at the balance stop position is constituted by the balance driving cam 10, the fixed support shaft 25, the tilting lever 26, the cam follower 27, the engaging portion 28, and the like. Further, in this embodiment, the balance driving mechanism for reciprocatingly rotating the balance 5 in the vertical direction is provided with the main shaft 9, the balance driving cam
10, the tilt lever 26, the engaging portion 28, and the like.

On the other hand, a solenoid 30 constituting a jump stitch mechanism is disposed on the side of the engaging member 16 as shown in FIG. 4, and the movable rod 31 of the solenoid 30
When the engaging member 16 is moved upward along the guide rod 13 together with the elevating body 14 by entering the vertical movement locus of the inclined surface 16a, the engaging member 16 Rotated in the direction of the arrow, the engagement concave portion 17
19 is disengaged, so that the needle bar 4 is stopped by the springs 22 and 23 to move to the needle bar stop position.

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

 Next, the control device will be described with reference to FIG.

The balance position detector 32 is connected to a control circuit 41 having a function as a discriminating means having a memory such as a program memory and a working memory and a control device, and a spindle rotation detector for detecting a rotation amount of the spindle 9. 43 is connected. A sewing machine motor 44 constituting a driving mechanism for rotating the main shaft 9 is connected to the control circuit 41, and a needle bar selecting operation for switching the needle bar by operating the support case 6 in the left-right direction. The needle bar selecting motor 45 constituting the means is connected. Further, the solenoid 30 is connected to the control circuit 41.

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

Now, when the balance position detector 32 confirms that the balance 5 is located at the balance stop position, the sewing operation is performed. Then, when the sewing machine motor 44 is stopped or the thread breaks, the control circuit 41 determines whether or not the switching operation of the needle bar 4 is performed. Shift to sewing operation of.

Conversely, when the needle bar switching is performed, the balance position detector 32 determines whether the position of the balance 5 is at the balance stop position or not by the control circuit 41. When the balance bar is at the balance stop position, the needle bar is selected. The driving motor 45 is driven, and the needle bar 4 is switched.

On the other hand, when the balance is not at the balance stop position, the control circuit 41
The operation signal is output to the solenoid 30 from the
Is entered into the movement locus of the slope 16a of the engaging member 16, a control signal for causing the main shaft 9 to idle once is output to the sewing machine motor 44, and the main shaft 9 is idled once together with the balance driving cam 10. . At this time, since the engagement member 16 is reciprocated by the movable rod 31 and the engagement between the engagement projection 19 and the engagement recess 17 is released and the jump stitch mechanism is turned on, the needle bar 4 is moved to the needle bar stop position. The movement is stopped and the balance drive cam
Since the tilting lever 26 is tilted by the rotation of 10, the balance 5 is reciprocated once empty. When one idle rotation is detected by the spindle rotation detector 43, a stop signal is output to the sewing machine motor 44, and the spindle 9 and the balance 5 are stopped.

Thereafter, the solenoid 30 is demagnetized and the movable rod 31
Is separated from the slope 16a of the engagement member 16, the engagement recess 17
And the engaging projection 19 are engaged again, and the balance 5 is stopped at the balance stop position. Then, in this state, the balance position detector 32 detects again whether the position of the balance is at the balance stop position, and when the balance is at the balance stop position, the needle bar is replaced, and the next sewing operation is performed. Transition.

As described above, in the above embodiment, when the balance 5 is not at the balance stop position, the balance driving cam 10 together with the main shaft 9 is idled once with the jump stitch mechanism turned on, and the balance 5 is moved to the balance stop position. , It is not necessary for the operator to manually adjust the position of the balance to the balance stop position, so that the needle bar switching operation during sewing can be performed quickly, and the working efficiency can be improved. In addition, since the position of the balance is automatically corrected and the next operation is performed, sewing is not interrupted even if the operator is not in front of the sewing machine. The interruption of the sewing operation for a long time as in the case of occurrence is prevented.

〔The invention's effect〕

As described in detail above, even when the balance is not stopped at the balance stop position at the time of needle bar switching, the sewing machine can be rotated at the time of needle bar switching by adjusting the stop position of the balance by rotating the main spindle once. The sewing operation can be automatically and continuously performed without interruption, and the working efficiency can be improved.

[Brief description of the drawings]

1 is a flowchart for explaining a needle bar switching operation of a sewing machine having a plurality of needle bars according to the present invention, FIG. 2 is a perspective view showing the entire sewing machine, and FIG. 3 is a drive mechanism for a needle bar and a balance. FIG. 4 is a perspective view showing a jump stitch mechanism, and FIG. 5 is a block diagram showing a control device. 4 needle bar, 5 balance, 5a engagement recess, 6 support case, 9 spindle, 10 balance drive cam, 10a cam groove, 11 crank, 13 Guide rod, 16 engagement member, 17 engagement recess, 18 elevating member, 19 engagement projection, 22, 23 spring, 26 tilting lever, 27
Cam follower, 228 ... engaging part, 29 ... spindle, 30 ...
Solenoids constituting the jump stitch mechanism, 31: movable rod, 41: control circuit having functions as discriminating means and a control device, 32: balance position detector, 43: spindle rotation detector, 44: drive Sewing machine motor as a mechanism, 45…
... Needle bar selecting motor as needle bar selecting operation means.

Claims (1)

(57) [Claims] A main shaft built in the sewing machine head and rotated by a driving mechanism; a support case mounted on the sewing machine head so as to be capable of reciprocating in a lateral direction; And in a non-use state, a plurality of needle bars held at a needle bar stop position by holding means, and also supported by the support case in a vertically reciprocable manner corresponding to each of the needle bars, and in a non-use state. A plurality of balances held at a balance stop position by holding means, a needle bar selecting operation means for moving the support case left and right to selectively arrange a specific needle bar at a use position, and interlocking with the main shaft. A needle bar elevating mechanism that reciprocates the needle bar that is switched and held in the use position in the vertical direction, and is engaged with the balance that is switched and held in the use position in conjunction with the main shaft, and moves the balance vertically. In a sewing machine having a plurality of needle bars configured by a balance driving mechanism that rotates backward, and a jump stitch mechanism that can invalidate the operation of the needle bar elevating mechanism, a balance position detector that detects a stop position of the balance. Determining means for determining whether or not the signal from the balance position detector is a balance stop; and, when the signal from the determination means is the balance stop position, outputting an operation signal to the needle bar selecting operation means. Conversely, when the balance is not at the balance stop position, a control device for operating the jump step mechanism and disabling the needle bar elevating mechanism to spin the spindle once to stop moving the balance to the balance stop position. And a sewing machine provided with a plurality of needle bars.