JPH04132591A - Thread winding device of sewing machine - Google Patents

Abstract

PURPOSE:To detect whether or not it is in thread winding state according only to the results of processing of electric signals without providing a new switch and control the speed of a sewing machine by a method wherein a control circuit judges whether or not it is in thread winding state according to counted values of both counters, and the judgment results are output by a thread winding state judging device. CONSTITUTION:At start of thread winding judging process, a thread winding judgment completion flag 30a, a thread winding state flag 30b, and counted values of first and second pulse counters 30c and 30d are reset. The thread winding judgment completion flag 30a shows whether or not thread winding judgment is completed, and is at 0 during thread winding judgment and at 1 when thread winding judgment is completed. The thread winding state flag 30b shows whether or not thread winding state is judged as 'thread winding'. When it is judged as 'no thread winding', the thread winding judgment completion flag 30a is at 1 and the thread winding state flag 30b is at 0, and when it is judged as 'thread winding', the thread winding judgment completion flag 30a is at 1 and the thread winding state flag 30 is at 1. During thread winding judgment, both thread winding judgment completion flag 30a and thread winding judgment completion flag 30b are at 0.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thread winding device for a sewing machine that is operated by the sewing machine in a thread winding state in which the driving connection between the sewing machine motor and the main shaft of the sewing machine is disengaged.

[Prior Art] Conventionally, in a sewing machine equipped with a bobbin winding device that is operated by the sewing machine motor in a bobbin winding state in which the driving connection between the sewing machine motor and the main shaft of the sewing machine is disengaged, the bobbin winding device is operated while the thread motor is operating, and the sewing machine Those equipped with a safety device that stops the sewing machine motor when the driving connection between the motor and the main shaft of the sewing machine is disconnected or connected, or when the stop switch is pressed, the needle will stop in the normal sewing state, but in the bobbin winding state. There are known methods in which the sewing machine motor stops immediately, or in which the sewing machine motor is controlled by setting a rotational speed different from that in the normal sewing state in the bobbin winding state.

By the way, in order to perform the above-described operation, it is necessary to provide some kind of bobbin winding state detection means.

For this reason, a conventional thread winding device for a sewing machine has been proposed in which a switch is provided that operates in conjunction with a device that disconnects the driving connection between the sewing machine motor and the main shaft of the sewing machine, and the state of the thread winding is detected in accordance with the operation of this switch.

“Problems to be Solved by the Invention” However, in such conventional bobbin winding devices, an extra switch must be provided, which increases the number of parts and increases costs.In addition, installing the switch is a labor-intensive task. There was a problem in that the workability of assembly deteriorated because of the need for

The present invention has been made to solve the above-mentioned problems, and is a sewing machine bobbin winder that detects whether or not the bobbin is winding by simply processing electrical signals and controls the speed of the sewing machine motor without installing a new switch. Its purpose is to provide equipment.

[Means for Solving the Problems] A thread winding device for a sewing machine according to the present invention includes a sewing machine motor operatively connected to a main shaft of the sewing machine, and a first pulse generating means that generates a pulse proportional to the speed of the sewing machine motor. a bobbin winding device operated by the sewing machine motor in a bobbin winding state in which the driving connection between the sewing machine motor and the sewing machine main shaft is disengaged; a second pulse generating means for generating pulses in relation to rotation of the sewing machine main shaft; and a control circuit connected to the second pulse generating means and controlling the speed of the sewing machine motor, the sewing machine comprising: a first counting means for counting pulses generated by the first pulse generating means; and second counting means for counting pulses generated by the second pulse generating means, and the control circuit judges whether or not the pincushion state is present based on the counts of both counting means, and the control circuit determines whether or not the pincushion state is present. The configuration includes a bobbin winding state determining means that outputs the result.

[Operation] According to the above configuration, the bobbin winding state determining means provided in the control circuit judges whether or not the bobbin winding state is in the bobbin winding state based on the counted value of the first counting means and the counted value of the second counting means, and based on the result, the sewing machine Control the speed of the motor.

[Example 1] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, a sewing machine frame 1 is formed by integrally standing a sewing machine arm 3 on a sewing machine head 2. As shown in FIGS. A needle bar 4 is provided at the tip of the sewing machine arm 3, and the needle bar 4 moves vertically and reciprocally in conjunction with the rotation of the sewing machine main shaft 15, and also swings laterally as necessary. is installed. Further, an automatic return type start/stop switch 6 for starting and stopping the stitch forming operation of the sewing machine is disposed near the needle bar 4 at the tip of the sewing machine arm 3.

The sewing machine bed 2 is provided with a throat plate 7 corresponding to the needle 5, and is also provided with a feed dog 8 for imparting a feed motion to the work cloth.
, forms a stitch forming mechanism 9 together with the sewing machine main shaft 15 and the like. Pattern number display 10a on the front upper part of the sewing machine arm 3
A pattern selection device 10 of a well-known configuration including a pattern selection switch 10b and a speed selection switch 11 for setting the sewing speed to two levels, "high" and "low" are provided.

A flywheel 12 connected to the sewing machine main shaft 15 is provided on the upper right side of the sewing machine arm 3, and the sewing machine main shaft 15 can be rotated manually. sewing machine arm 3
On the upper right side of the bobbin, there are provided a thread winding shaft 13 for rotating the bobbin in order to wind the bobbin thread on the bobbin, and a bobbin presser 14 for appropriately winding the thread. This bobbin holder 14 has an eccentric disk horizontally attached to the tip of a vertical rotating shaft attached to the sewing machine frame 1, and by changing the rotating position of the eccentric disk, the thread is wound around the bobbin. The amount can be adjusted, and when a predetermined amount of thread is wound, the thread winding shaft 1
A known mechanism is provided for disengaging the operative connection between the thread winding shaft 13 and the sewing machine motor 17 to stop the rotation of the thread winding shaft 13.

The main parts of the power transmission mechanism of the sewing machine are constructed as shown in FIG. The driving force generated in the sewing machine motor 17 controlled by the control circuit 24 is transmitted to the intermediate shaft 18 through the belt 26, and further transmitted to the main shaft gear 25 by a gear provided on the intermediate shaft. - The driving force transmitted to the main shaft gear 25 is transmitted to the main shaft gear 25 by a known connection control mechanism 16.
It is further transmitted by a bevel gear to the vertical shaft 21 which controls the movement of the feed dog 8 at a rotation ratio of 1:1. At this time, the connection control mechanism 16 has a structure in which no driving force is transmitted to the bobbin winding shaft 13. Here, when the bobbin winding shaft 13 is manually moved in the input direction, the connection control mechanism 16 transmits the driving force only to the bobbin winding shaft 3 and not to the main shaft 15. A first slit 19 as shown in FIG. 3(b) is provided in the intermediate shaft 18 in the first photointerrupter 20, and a fourth
As shown in the figure, the first pulse generating circuit 20a outputs a number of first pulses proportional to the speed of the sewing machine motor 17 to the control circuit 24. A second photo-interrupter 23 is provided with a second slit 22 as shown in FIG. A second pulse for this purpose is output to the control circuit 24.

Next, the electrical configuration will be described according to FIG. Control circuit 24
are microcomputer 24a1 motor drive circuit 24b
, a needle swing drive circuit 24c, and a feed drive circuit 24d. When the start/stop switch 6 is pressed, the microcomputer 24a sends a motor drive signal to the motor drive circuit 24b to drive the sewing machine motor 17 if the sewing machine motor is stopped, and sends a motor drive signal if the sewing machine motor is being driven. , and the sewing machine motor 17 is stopped. Internal memory of the microcomputer 24a (
The RAM) 30 includes a thread winding determination end flag 30a, a thread winding state flag 30b, a first pulse counter 30c, and a second pulse counter 30d. and,
The pulses output by the first pulse generating circuit 20a are counted by a first pulse counting counter 30c. Also,
The pulse output by the second pulse generating circuit 23a is
It is counted by the pulse counting counter 30d.

The rotation speed of the sewing machine motor 17 is set to either "high" or "low" by the speed selection switch 11, and the processing in the microcomputer 24a is performed by the first pulse output from the first pulse generation circuit 20a. Feedback controlled. The data corresponding to the stitch pattern selected by the pattern selection switch 10b is sent to the microcomputer 2.
4B outputs to the needle swing drive circuit 24c and the feed drive circuit 24d at the rising or falling timing of the second pulse outputted by the second pulse generating circuit 23a, and the needle swing drive circuit 24c The needle swing actuator 27 is connected to the feed drive circuit 24d, and the feed drive circuit 24d is connected to the feed actuator 28.
are operated respectively to form a seam.

The above is the configuration of a conventionally known sewing machine, and the manner in which the thread winding state is determined within the microcomputer 24a in this configuration will be described with reference to the flowchart shown in FIG. 5. When the start/stop switch 6 is pressed (YES branch in step S2) while the motor is stopped (No branch in step S1), the motor is started and the thread winding determination process is started (step 33). In step S3, when starting the thread winding judgment process, the thread winding judgment end flag 30 is
a. Reset the count values of the thread winding state flag 30b, the first and second pulse counters 30c, and 3Qd. The thread winding determination completion flag 30a is a flag indicating whether or not the thread winding determination has been completed, and is set to 0 when the winding determination is in progress, and is set to 1 when the winding determination has been completed. The thread winding state flag 30b is a flag indicating whether or not the thread winding is determined to be thread winding.If it is determined that the thread winding is not winding, the thread winding determination end flag 30a is 1 and the thread winding state flag 30b
is O and it is determined that the thread is wound, the thread winding determination end flag 30a is 1 and the thread winding state flag 30b is 1. During the thread winding judgment, both the thread winding judgment end flag 30a and the thread winding state flag 30b are set to 0.

In step s4, it is determined whether the second pulse is input or not.

The second pulse causes the main shaft 15 to rotate, and along with this, the vertical shaft 21
It enters only when rotates. When the main shaft 15 rotates, it means that it is on the side where the thread is not wound.

In other words, the fact that the second pulse is applied means that there is no pincushion state.

If the second pulse is input during the thread winding judgment, the process goes from S4 to step S5 to step S8, and since the thread winding state is not present, the thread winding judgment ends.

If the second pulse is input when it has been determined that the thread is not wound, the process moves from step S4 to step S9 via steps S5 and S6. If the second pulse is input when it has been determined that the bobbin winding state is complete, it means that the bobbin winding shaft 13 was tilted in the direction opposite to the arrow A from the bobbin winding side while the motor was being driven, so steps S4 to S5 and S6 are performed.
The process then proceeds to step S7, where the motor is stopped for safety. In step SIO, it is determined whether the first pulse has been counted a predetermined number of times. When the pin is wound, the second
Since the pulse does not enter, the count value of the first pulse is not reset in step S9. If the predetermined number of pulses is n+1 or more, assuming that the number of second pulses is 1 for every 0 times of the first pulse when not in the thread-winding state, the process proceeds to step Sll only in the thread-winding state. When the first pulse is counted a predetermined number of times during the bobbin winding determination, the process goes from step S10 to step S14 to step S14, where the bobbin winding state is determined, the bobbin winding determination is completed, and the motor speed is set to the speed for bobbin winding. . When the first pulse is counted a predetermined number of times when it has been determined that the bobbin is not in the bobbin winding state, the bobbin winding shaft 13 moves from the non-bobbin winding side to arrow A while the motor is being driven.
Since the motor is tilted to the bobbin winding side, the process goes from step S10 to step S13 via steps S11 and S12, and the motor is stopped for safety. When the first pulse is counted a predetermined number of times when the determination that the thread is wound has been completed, the process goes from step S10 to step S15 via steps S11 and S12.

If the start/stop switch 6 is pressed while the motor is being driven in step S15, the process proceeds to step S16, and depending on whether the thread winding state flag is 0 or 1, it is determined whether the motor is stopped above the needle or stopped immediately.

The present invention is not limited to the embodiments detailed above,
Various changes can be made without departing from the spirit of the invention.

For example, in this embodiment, the speed for winding the thread is set in step S14 in FIG. 5, but this may be omitted, or step S16.
If 5 is YES, the process may directly proceed to step S17 and the process may be stopped immediately regardless of the thread winding state flag 30b.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, the bobbin winding state can be determined only by processing electrical signals by the existing circuit without providing a new switch for detecting the bobbin winding state. This has the excellent effect of solving problems such as an increase in cost due to an increase in the number of parts and a deterioration in assembly workability due to the necessity of mounting the switch.

[Brief explanation of the drawing]

1 to 5 show embodiments embodying the present invention; FIG. 1 is a front view showing the external appearance of the sewing machine, FIG. 2 is a configuration diagram of the main parts of the power transmission mechanism, and FIG. FIG. 4 is a detailed diagram of the slit, FIG. 4 is a block diagram of the electrical configuration, and FIG. 5 is a flow chart showing how the thread winding is determined inside the microcomputer.

Claims (1)

[Claims] 1. A sewing machine motor operatively connected to the main shaft of the sewing machine, and a first sewing machine motor that generates pulses proportional to the speed of the sewing machine motor.
a spool generating device that is operated by the sewing machine motor in a spooled state in which the driving connection between the sewing machine motor and the sewing machine main shaft is disengaged, and a second pulse generator that generates pulses in relation to the rotation of the sewing machine main shaft. and a control circuit connected to the first and second pulse generating means to control the speed of the sewing machine motor, the first pulse generating means counting the pulses generated by the first pulse generating means. comprising a counting means and a second counting means for counting pulses generated by the second pulse generating means,
A spool winding device for a sewing machine, wherein the control circuit includes a spool state determining means for determining whether or not the spool is in a spool state based on the counts of both counting means and outputting the determination result to the control circuit.