JPH03234291A - Sewing machine - Google Patents

Abstract

PURPOSE:To prevent rotary position relation between an upper shaft and a lower shaft unmatched even when the rotation of either shaft is performed manually by providing a detecting means to detect the rotational amount of the shaft on one side, and an interlocking control means to drive the motor of the shaft on the other side by the rotational amount corresponding to the detected rotational amount of the detecting means. CONSTITUTION:A rotary encoder 27 as the detecting means is provided at the upper shaft 20 to detect the rotational amount of the upper shaft 20 by the operation of a handle 26. When the upper shaft 20 is rotated by operating the handle 26 manually, a controller 28 drives rotatably a motor 10 for lower shaft which rotates the lower shaft 9 at every rotation by a small angle thetaby a micro angle alpha via a driving circuit 30. Therefore, when the upper shaft 20 is rotated manually, the lower shaft 9 is rotated with the motor 10 for lower shaft by the angle corresponding to the angle of rotation of the upper shaft 20, therefore, the unmatching of rotary position relation between the lower shaft 9 and the upper shaft 20 can be prevented from occurring.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is characterized in that a shaft for vertically moving a needle bar and a lower shaft for rotating a hook are each driven by dedicated motors. Regarding a sewing machine configured to.

(Prior Art) Conventional electric sewing machines employ a shared motor type in which a single motor drives an upper shaft for vertically moving a needle bar and a lower shaft for rotating a hook. In this device, the upper shaft is rotationally driven by a motor, and the rotation of the upper shaft is transmitted to the lower shaft via a transmission mechanism.

However, this shared motor type sewing machine requires a transmission mechanism to connect the upper shaft and the lower shaft, so the basic shape of the entire sewing machine must be U-shaped, which lacks flexibility in design. In addition, the transmission mechanism is installed so that the rotational position of the upper shaft and the F-axis is in a constant relationship.
This requires adjustment and is time consuming.

1Z like this! In order to deal with this problem, it has been considered to use a dedicated motor type in which the upper shaft and the lower shaft are each driven by dedicated motors.

With 10 and 4 threads, it is necessary to move the sewing needle up and down to pull the bobbin thread onto the throat plate before starting the lockstitch, and to pull the sewing needle up from the fabric after the lockstitch is finished. Raising and lowering the sewing needle manually makes it easier to stop the sewing needle at the desired device, so in conventional shared motor sewing machines, a handle is directly connected to the upper shaft. could be rotated.

(Problem to be solved by the invention) However, in a dedicated motor-type device in which both the upper and lower axes are driven by dedicated motors, if the upper shaft can also be operated manually, the rotation caused by the manual operation is is only on the upper axis.

As a result, the rotational positional relationship between the upper shaft and the lower shaft becomes incorrect, and when a loop is formed in the upper thread due to the lowering of the sewing needle, the hook catches the loop and threads the lower thread through it. It becomes impossible to rotate the upper shaft and the lower shaft.

Therefore, an object of the present invention is to provide a device in which the upper shaft and the lower shaft are rotated by dedicated motors, so that even if one of the shafts is rotated manually, the rotational positional relationship between the upper shaft and the lower shaft will be distorted. The purpose of the present invention is to provide a sewing machine that is free from the risk of causing.

[Structure of the Invention] (Means for Solving the Problems) The sewing machine of the present invention includes an upper shaft for vertically moving a needle bar to which a sewing needle is attached, and a loop formed in the upper thread by lowering the sewing needle. A lower shaft for capturing the lower shaft and a hook for threading the thread are rotated by dedicated motors, respectively, and an operating means for manually rotating one of the upper and lower shafts is provided. and detecting means for detecting the amount of rotation of the one shaft rotated by the operating means, and when the operating means is operated, the motor of the other shaft is driven by an amount of rotation corresponding to the amount of rotation detected by the detecting means. The present invention is characterized in that it is provided with an interlock control means.

(Function) When one shaft is manually rotated, the amount of rotation is detected by the detection means. Then, the motor of the other axis is
The interlocking control means drives the rotation amount according to the rotation amount detected by the detection means. Therefore, there is no possibility that the rotational positional relationship between the upper shaft and the lower shaft will be out of order.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, in Figure 2, the sewing machine body is placed on the base.
An arm portion 3 having a head portion 2 is provided via a pedestal 4. A throat plate 5 shown in FIG. 1 is provided on the upper surface of the base 1 so as to be openable and closable, and a cloth presser foot 6 for sandwiching the cloth to be sewn between it and the throat plate 5 is provided on the head 2 at the top and bottom. It is movable.

As shown in FIG. 1, inside the base 1, there is a feed dog 7 for feeding the cloth on the presser foot 6, and a hook 8 housing a bobbin (not shown) around which a bobbin thread is wound, arranged in a vertical positional relationship. It is arranged. Of these, the hook 8 is rotated by a lower shaft 9 disposed vertically within the base 1. And, this lower shaft 9 is equipped with a lower shaft seven-piece consisting of a direct current motor capable of forward and reverse rotation.
ri101. - Therefore, the rotating shaft 10a of the lower shaft 9 and the lower shaft motor 10 is driven.
l: The toothed pulleys 11 and 12 are installed, respectively.
Both pulleys 1] and 12 are connected by a toothed belt 13.

On the other hand, within the head 2, a thread take-up 14 is supported so as to be swingable up and down, and a needle bar 15 is supported so as to be movable up and down. Needle bar 1 protruding from the lower end of head 2
A sewing needle 16 is attached to the lower end of the second needle 5.
As shown in the figure, the thread tension mechanism 1 is pulled out from the thread spool 17.
An upper thread 19 is passed through the tip of the thread take-up 4 protruding from the front surface of the head 2 and the lower end of the sewing needle 16.

The balance 14 and the needle bar 15 are connected to a link mechanism 21 by an upper shaft 20 disposed horizontally in the arm portion 3.
and is driven via the crank mechanism 22. This upper shaft 2
0 is driven by an upper shaft motor 23 consisting of a direct current motor capable of forward and reverse rotation, and therefore a pair of bevel gears 24 and 25 that mesh with each other are connected to the upper shaft 21.
and is attached to the rotating shaft 23a of the upper shaft motor 23.

It takes 1! i) One end of the shaft 20 projects outward from the side surface of the pillar 4, and a handle 26 as an operating means is attached to the projecting end, and the upper shaft 20 can also be rotated by the handle 26. That's what I do. In order to detect the amount of rotation of the upper shaft 20 due to the operation of the handle 26, the upper shaft 20 is provided with a rotary encoder 27 as a detection means that can also detect the direction of rotation.

The sewing machine configured as described above is controlled by a control device 28 which is a control means mainly composed of a microcomputer shown in FIG. This control device 28 receives a signal from the rotary encoder 27 manually and is provided on the pedestal 4. Signals from two switches for starting and stopping 41' sewing are input. Part 1. The control device 28 controls the motors 10 and 23 based on the signals and the program stored in the third memory.
is controlled via the drive circuit 30.

Next, the contents of control by the control device 28 will be explained, focusing on the manual operation of the upper shaft 20, which is directly related to the present invention.

In the state where the lockstitch is stopped, the lower axis interlocking program shown in the flowchart of FIG. 4 is executed. That is, when the main program starts executing the lower shaft interlocking program, the control device 28 first determines whether or not the upper shaft 20 has rotated by a predetermined minute angle Δθ.
Cutoff stage step S1.

This ↑ cutting is performed based on the output signal of the rotary encoder 27. If the upper shaft 20 is not rotated by the handle 26, the control device 28 goes to rNOJ in step S1, ends the lower shaft interlocking program, returns to the main program, and starts executing the lower shaft interlocking program again. Repeat the movement.

, °〉, before starting the lockstitch, set the upper thread]9 on the scale]4
, the thread tension mechanism 18 and the sewing needle 16 (two threads), and the handle 26 is manually operated to pull out the F thread onto the throat plate 5 from the bobbin (not shown) housed in the shuttle 3.
Rotate the shaft 20. Then, the control device 28 controls the upper shaft 2
0 rotates by a minute angle Δθ to 6 degrees, and in step S1 r
The answer is YESJ and the process moves to the next step S2, where the lower shaft 9 is rotated by a minute angle corresponding to the minute rotation angle Δθ of the upper shaft 20.
In order to avoid rotation, the lower shaft motor 10 is connected to the drive circuit 30.
The operation of rotationally driving by a minute angle Δα through the rotation is repeated. Therefore, the hook rotates in conjunction with the operation in which the sewing needle 16 descends by manual operation of the upper shaft 20, and then rises when it reaches the bottom dead center. Then, by the operation of the C5 sewing needle 16, a single upper thread is formed, and a loop is caught by the tip of the hook 8, and a C thread (not shown) is passed through the loop, and the lower thread is raised by the sewing needle 16. The loop formed in the needle thread 19 is pulled up and pulled onto the needle vi5. Then, the upper shaft 2 ``] by the handle 26
When the four-turn operation is stopped, the control device 28 goes to rNOJ in step S1 and returns to the main program.

After that, place the cloth to be sewn on the throat plate 5, lower the presser foot 6 to press the cloth against the throat plate 5, and in this state, press the switch 29.
Turn on to start lockstitching.

Then, the control device 28 drives the electric motors 10 and 23 via the drive circuit 30. During this lockstitching, both motors 10
and 23 are rotated so as to maintain the timing such that, for example, by so-called feedback control, the tip L2 of the hook 8 catches the loop of the upper thread 19 formed as described above and passes the bobbin thread through the loop. controlled.

Now, when the switch 29 is turned off to start lockstitching, both the stitches 10 and 23 are stopped.

Then, the sewing needle 16 stopped for 1° with it stuck in the cloth.
At n 1%, the handle 26 is operated to pull up the sewing needle 16 from the cloth. In this case as well, the lower shaft interlocking program as described above is executed, and the lower shaft 9 is rotated by the lower shaft motor ]-0 by the amount of rotation corresponding to the amount of rotational operation of the upper shaft 20.

According to this embodiment, when the upper shaft 2 C1 is manually rotated, the lower shaft 9 is rotated by the lower shaft motor 10 by an angle corresponding to the rotation angle of the upper shaft 20. There is no possibility that the rotational positional relationship between the shaft 9 and the upper shaft 20 will be distorted. Therefore, by the operation of the sewing sword 16, the upper thread 1
The lockstitch operation in which the bobbin thread is threaded through the loop formed in the hook 9 by the operation of the hook 8 is performed normally.

In the above embodiment, the amount of rotation of the upper shaft 20 is directly detected by the row encoder 27;
By detecting the amount of vertical movement of the upper shaft 2,
It may be configured to detect a rotation amount of 0.

Further, in the above embodiment, the upper shaft 20 is manually rotated, but the lower shaft 9 may also be manually rotated. In this case, the rotary encoder 27 is used to rotate the lower shaft 9 by It is configured to detect the amount of rotation and drive the motor 23 for the upper shaft according to the detected rotation position.

[Effects of the Invention] As explained above, according to the present invention, even if one of the upper shaft and the lower shaft is manually rotated, the amount of rotation of the other shaft corresponds to the amount of rotation of the other shaft. Since the shaft is rotated by a motor, there is no risk of the rotational positional relationship between the upper and lower shafts being out of order, and the lockstitching operation can always be performed normally, which is an excellent practical effect.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional front view of the main part, Fig. 2 is a front view showing the overall outline, Fig. 3 is a control circuit configuration diagram, and Fig. 4 is a control circuit diagram. FIG. In the figure, 8 is a hook, 9 is a lower shaft, 10 is a lower shaft motor, 15 is a needle bar, 6 is a sewing needle, 20 is an upper shaft, 23 is an upper shaft motor, 26 is a handle (operating means), Reference numeral 27 is a low-resolution encoder (detection means), and reference numeral 28 is a control device (interlock control means).

Claims (1)

[Claims] 1. An upper shaft for vertically moving a needle bar to which a sewing needle is attached, and a lower shaft for rotating a hook that captures a loop formed in the upper thread by lowering the sewing needle and threads the bobbin thread. , each of which is rotated by a dedicated motor, an operating means for manually rotating one of the upper and lower axes, and a detection unit for detecting the amount of rotation of the one shaft rotated by the operating means. and interlock control means for driving the motor of the other shaft by a rotation amount corresponding to the rotation amount detected by the detection means when the operation means is operated.