JPH0531283A - Sewing machine - Google Patents

Abstract

PURPOSE:To prevent a sewing failure by stopping each motor when a reciprocating motion position of a needle thread take-up is varied. CONSTITUTION:In the course of sewing, a needle thread take-up photointerrupter outputs a signal to a CPU in the lowest position and the uppermost position of a reciprocating motion of a needle thread take-up (S4), and a CPU discriminates whether its signal is outputted by an excitation phase of a needle thread take-up driving motor designated by a program of a ROM or not (S5). As a result, when a result of discrimination is abnormal (S5, NO), each motor is stopped after moving each member of the CPU to a prescribed position (S6) and the excitation of each motor is released (S7).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance which is reciprocally supported between a yarn pick-up position and a yarn loosening position, a balance driving means for driving the balance, and a vertically movable support. The present invention relates to a sewing machine having a needle bar and a needle bar drive unit that drives the needle bar in association with the reciprocating movement of the balance by the balance drive unit.

[0002]

2. Description of the Related Art Conventionally, the present applicant has developed a sewing machine which operates a needle bar, a balance, and a hook by separate drive sources, and is currently applying for a patent application No. 3-32034. The developing device will be described below with reference to FIG.

On the machine frame 5 of the sewing machine head 7, a needle bar base 9 functioning as a swing support frame is attached by a support shaft 11 in a vertical plane.
It is swingably pivoted at one end thereof. A needle bar 13 is inserted into and supported by the needle bar base 9 so as to be vertically movable. A projecting pin 15 is fixed to a substantially middle portion of the needle bar 13, and the projecting pin 15 slidably faces a slit 17 formed in the needle bar base 9 in a vertical direction. Also needle bar 13
A sewing needle 1 is attached to the lower end of the.

A rack 19a is attached to the machine frame 5 of the head 7.
An operating rod 19 formed on one side in the vertical direction is supported so as to be vertically reciprocable by a required stroke.
Engages with the pinion 23 fixed to the motor shaft of the needle drive motor 21 fixed in the machine frame 5. An arm 19b extending rightward in FIG. 5 is provided in the middle of the operating rod 19.
And the slot 1 provided in the arm 19b
The pin 15 of the needle bar 13 faces 9c. Therefore, when the needle drive motor 21 is driven, the needle bar 13 having the sewing needle 1 at the lower end reciprocates up and down. Further, the operating rod 19
A needle bar detection shutter 19d for setting the initial position of the needle bar 13 is formed on the upper part of the.

Further, the needle bar photo interrupter 22 for detecting the needle bar detecting shutter 19d is designed so that the needle bar detecting shutter 19d blocks the detection light path between the light emitting and receiving elements when the needle bar 13 reaches the uppermost position. It is arranged in the machine frame 5. At the uppermost position of the needle bar 13, the needle bar detection shutter 19d crosses between the light projecting and receiving elements of the needle bar photo interrupter 22, so that the needle bar photo interrupter 2
2 outputs a needle bar origin position signal.

The lower part of the needle bar base 9 is connected to a needle swing control motor (not shown) via a connecting rod 25, and is perpendicular to the needle bar base 9 and the sewing needle 1 about the support shaft 11. The required oscillating motion is imparted in the plane.

On a fixed shaft 29 provided on the machine frame 5 of the sewing machine head 7, a balance 31 for supplying and tightening the upper thread is provided at its base end between the thread pick-up position and the thread loosening position. It is pivotally supported so that it can reciprocate. Fan-shaped teeth 33 are integrally formed with the balance 31 on one side of the balance 31 on the base end side, and the tooth surface thereof is formed in a fan shape around the rotation axis of the balance 31. A balance detection shutter 33a for detecting the vertical position of the balance 31 is formed on one side of the fan-shaped tooth 33.

Further, the balance photointerrupter 39 for detecting the balance detecting shutter 33a has a machine frame 5 so that when the balance 31 reaches the lowest position, the balance detecting shutter 33a blocks the detection light path between the light emitting and receiving elements. It is located inside. At the lowest position of the balance 31, the balance detection shutter 33a crosses between the light emitting / receiving elements of the photo interrupter 39 for balance (only the projections 39a in which the light emitting elements are incorporated are shown in the figure), so that the balance photo The interrupter 39 outputs a balance origin position signal. The fan-shaped teeth 33 are the balance drive motor 35 fixed in the machine frame 5.
Since the pinion 37 fixed to the motor shaft of No. 3 meshes with the tooth number ratio greater than 1.0, the fan-shaped teeth 33 are
It is decelerated with respect to 7.

In the bed 41 of the sewing machine, a shuttle shaft 44 for supporting the outer shuttle 3 for catching the needle thread of the upper thread formed by the vertical movement of the needle 1 is mounted via a bearing 42 fixed to the machine frame 5. And is rotatably supported. Further, a driven gear 43 is fitted on the shuttle shaft 44, and the driven gear 43 is attached to the bed 41.
It engages with a drive gear 47 fixed to the motor shaft of a shuttle drive motor 45 fixed to the inner machine frame 5 to give the outer shuttle 3 a constant speed rotation. Further, the outer hook 3 is formed with a sword tip detection shutter 3b for setting the initial position of the sword tip 3a of the outer hook 3.

Further, in the sword tip photo interrupter 48 for detecting the sword tip detection shutter 3b, the sword tip 3a has the needle 1
The machine frame inside the bed 41 so that the detection light passage between the light emitting and receiving elements is blocked by the sword tip detection shutter 3b when the outer hook 3 comes to a position on the counter rotation side (origin position) by a predetermined angle from the position where the light is received. It is located at 5. At the origin position of the sword tip 3a, the sword tip detection shutter 3b crosses between the light emitting and receiving elements of the sword tip photo interrupter 48, so that the sword tip photo interrupter 48 outputs a sword tip origin position signal. Although not shown, an inner hook is rotatably supported in the outer hook 3, and a bobbin around which a lower thread is wound is accommodated in the inner hook.

Further, a main switch 49 for controlling the start / stop of the sewing machine is provided on the side of the operator of the sewing machine head 7, and when the main switch 49 is pressed by the operator, the sewing machine is started, When the main switch 49 is pressed again, the sewing machine is stopped.

The bed 41 is provided with feed dogs that perform well-known four-motion feed for feeding the work cloth, and that are raised and lowered in the feed groove of the needle plate. The feed dogs and the sewing machine head 7 move up and down. The work cloth is clamped by a cloth presser foot which is provided so as to be constantly urged toward the feed dog, and the work cloth is intermittently fed. Further, inside the bed 41, a feed dog up-and-down drive motor and a feed tooth forward-backward drive motor are provided, and the up-and-down and forward-backward movement (four-motion feed) are given to the feed tooth. A feed dog detection shutter (not shown) for setting an initial position of vertical and forward / backward movement of the feed dog and a feed dog photo interrupter (not shown) are provided in the bed 41, and the needle bar is provided. 13, as well as the balance 31, the pot 3,
When the feed dog reaches the origin position, the feed dog photointerrupter detects the feed dog detection shutter and outputs a feed tooth origin position signal.

The above-mentioned sewing machine includes a control device based on a CPU (not shown). This CPU has a main switch 49, a photo interrupter 22,
39, 48, and a feed dog photo interrupter are respectively connected, and further, on the output side thereof, a drive circuit for driving the needle drive motor 21, a drive circuit for driving the balance drive motor 35, and a drive for driving the shuttle drive motor 45. A circuit, a drive circuit for driving the needle swing control motor 27, a drive circuit for driving the feed dog front / rear drive motor, and a drive circuit for driving the feed dog up / down drive motor are respectively connected.

This CPU drives the motors according to a ROM (not shown) that stores programs for driving the drive motors, and when the power is turned on, the origin position signals are sent from the photo interrupters 22, 39, 48 and the like. An initial setting mode in which each motor is output and moves each member to an initial position in response to an origin position signal, and then each motor is stopped, and the ROM is used when sewing by pressing the main switch 49.
And a stitch forming mode for forming a desired stitch by driving each motor in accordance with a driving program for each motor.

In the sewing machine thus constructed, when a power switch (not shown) is turned on, the CPU drives the balance drive motor 35 according to the program in the ROM to move the balance 31 downward. Then, when the balance photo interrupter 39 detects the balance detection shutter 33a and outputs a balance origin position signal to the CPU, the CPU reverses the balance drive motor 35 and moves the balance 31 to the uppermost position which is the initial position. After that, the balance drive motor 35 is stopped and the initial position of the balance 31 is set. Similarly, the CPU sets the outer hook 3, the needle bar 13, and the feed dog to the initial positions.

When the sewing machine is started by operating the main switch 49, the CPU controls each motor according to the drive program of each motor from the ROM, and the balance 31, the outer hook 3, the needle bar 13, and the feed dog. The respective operations are performed to form a desired stitch.

[0017]

However, during sewing of the sewing machine as described above, the CPU causes the balance drive motor 35 to operate in accordance with the drive program for each motor from the ROM.
Is driven to reciprocate the balance 31 between the yarn pick-up position and the yarn loosening position, so that when the thread is entangled or the like, the balance drive motor 35 causes a step out and the balance 31 moves. The reciprocating position may change, and the balance driving motor 35 may be driven while the reciprocating position of the balance 31 changes. Therefore, there is a drawback in that it is not possible to satisfactorily perform sewing after the reciprocating position of the balance 31 is changed and before the main switch 49 is pressed by the operator to stop each motor.

Further, even if the thread is entangled and the balance drive motor 35 is out of step, the balance drive motor 35 continues to be driven, so that needle breakage or thread breakage occurs, and the operator switches the main switch 49.
The drive of the sewing machine was stopped by pressing.

The present invention has been made to solve the above-mentioned problems, and when the reciprocating position of the balance changes, each motor can be stopped to prevent defective sewing, and needle breakage and thread breakage can be prevented. An object of the present invention is to provide a sewing machine capable of preventing the above.

[0020]

Means for Solving the Problems In the present invention for achieving this object, a balance supported reciprocally between a yarn pick-up position and a yarn loosening position, and a balance driving means for driving the balance. And a needle bar supported so that it can move up and down,
A sewing machine having needle bar driving means for driving the needle bar in conjunction with reciprocating movement of the balance by the balance driving means,
A balance position detecting means for detecting a predetermined position of reciprocating movement of the balance by the balance driving means, and a judgment as to whether or not the result of detection of the reciprocating position of the balance by the balance position detecting means is normal. And a control means for stopping the movement.

Here, the balance position detecting means can detect the predetermined position of reciprocating motion of the balance and the origin position of reciprocating motion.

[0022]

In the sewing machine of the present invention having the above structure, the balance driving means drives the balance supported so as to be capable of reciprocating between the yarn pick-up position and the yarn loosening position. Then, in conjunction with the reciprocating movement of the balance by the balance driving means, the needle bar driving means drives the needle bar movably supported up and down. The balance position detecting means detects a predetermined position of the reciprocating movement of the balance by the balance driving means, and the control means judges whether or not the detection result is normal, and when it is not normal, the reciprocating movement of the balance is stopped.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

However, regarding the same members as in the prior art,
The same reference numerals are given and the description thereof is omitted.

As shown in FIG. 1, the machine frame 5 of the sewing machine head 7
A balance 31 for supplying and tightening the upper thread is pivotally supported on the fixed shaft 29 provided at the base end portion thereof so as to be capable of reciprocating between a thread take-up position and a thread loosening position. Figure 2
As shown in FIG. 3, one side of the base 31 of the balance 31 has a fan-shaped tooth 3
4 is integrally formed with the balance 31, and its tooth surface is formed in a fan shape around the rotation axis of the balance 31. Further, balance detection shutters 34a and 34b for detecting the reciprocating position of the balance 31 are formed on both sides of the fan-shaped tooth 34, respectively. Then, the balance photo interrupter 39 for detecting the balance detecting shutter 34a detects the balance detecting shutter 34a when the balance 31 reaches the lowest position, which is the thread relaxing position.
Is arranged in the machine frame 5 so that the detection light path between the light projecting and receiving elements is blocked. Further, the balance detection shutter 34b
The photo interrupter 40 for detecting the balance is a balance 31
Is arranged in the machine frame 5 so that the detection light path between the light projecting and receiving elements is blocked by the balance detecting shutter 34b when the thread reaches the uppermost position which is the thread picking up position.

At the lowest position of the balance 31, the balance detecting shutter 34a crosses between the light emitting and receiving elements of the photo interrupter 39 for the balance (only the projection 39a incorporating the light emitting element is shown). The balance photo interrupter 39 outputs a balance lowest position signal.

At the uppermost position of the balance 31, the balance detection shutter 34b crosses between the light projecting and receiving elements of the photo interrupter 40 for balance (only the projection 40a in which the light projecting element is incorporated is shown). The balance photo interrupter 40 outputs a balance top position signal.

Since the fan-shaped teeth 34 mesh with the pinion 37 fixed to the motor shaft of the balance drive motor 35 fixed in the machine frame 5 at a tooth number ratio larger than 1.0,
The sector teeth 33 are decelerated with respect to the pinion 37.

As the balance drive motor 35, a normal rotation /
A reversible pulse motor is employed, and when the exciting coil is energized, the balance 31 is moved between a yarn relaxing position (the lowest position of the balance) and a yarn picking position (the highest position of the balance).

A reset switch 70 is provided on the operator's side of the sewing machine head 7 to output a signal for initializing each motor when the operator presses the signal.

As shown in FIG. 3, the sewing machine of this embodiment is
A control device based on the CPU 55 is provided. This C
The main switch 49, the photo interrupters 22, 39, 40, 48, a feed dog photo interrupter (not shown), and a reset switch 70 are connected to the input side of the PU 55, and the output side thereof has a needle. A drive circuit 57 for driving the drive motor 21, a drive circuit 59 for driving the balance drive motor 35, a drive circuit 61 for driving the shuttle drive motor 45, and a drive circuit 6 for driving the needle swing control motor 27.
3, a drive circuit 6 for driving the feed dog front-back drive motor 51
5, a drive circuit 67 for driving the feed dog vertical drive motor 53
Are connected respectively.

The CPU 55 drives the motors according to the ROM 69 which stores the programs for driving the drive motors when the power is turned on, and the photo interrupters 2 are driven.
Signals are respectively output from the photo interrupters for feeding teeth 2, 39, 48, etc., and in response to the signals, the respective members are moved to the initial positions, and then the respective motors are stopped. ROM6 by pressing
9. The motor is driven in accordance with a drive program for each motor from the RAM 71 that stores sewing patterns and the like, and a stitch forming mode for forming a desired stitch is executed.

The operation of the sewing machine configured in this way is shown in FIG.
This will be described with reference to the flowchart of.

First, when a power switch (not shown) is turned on, the CPU 55 executes the initial setting mode according to the program in the ROM 69, drives the balance drive motor 35, and moves the balance 31 downward. Then, the photointerplanter 39 for the balance detects the balance detection shutter 34a and outputs the balance origin position signal which is the balance lowest position signal to the CPU5.
5, the CPU 55 reverses the balance drive motor 35, moves the balance 31 to the uppermost position, and then stops the balance drive motor 35 to set the initial position of the balance 31 (step S1, hereinafter simply referred to as "step S1"). Abbreviated as S1). The CPU 55 also sets the outer hook 3, the needle bar 13, and the feed dog to the initial positions in the same manner.

Next, when the main switch 49 is pressed (S2
・ YES), the CPU 55 executes the stitch forming mode according to the program in the ROM 69, and the balance 31 and the needle bar 3
-The outer hook 3 and the respective motors of the feed dog are driven to perform their respective operations to form a desired stitch (S3).

At this time, the photointerplanter 3 for the balance is placed at the lowest position and the highest position of the reciprocating motion of the balance 31.
9, 40 are outputting signals to the CPU 55 (S4),
Whether or not the signal is output in the excitation phase of the balance drive motor 35 specified in the program of the ROM 69
U55 is discriminating (S5). If the determination result is abnormal (NO in S5), the CPU 55 causes the balance photointerplanter 39 to detect the balance detection shutter 34a and output it to the balance lowermost position signal CPU 55, and then the balance drive motor 35 to 1 After the pulse is reversed, the balance drive motor 35 is stopped. At the same time, the needle bar 13 and the outer hook 3
The CPU 55 moves the feed dog to the initial position, stops each motor (S6), and releases the excitation of each motor (S7). When the operator presses the reset switch 70 (S8, YES), the CPU
55 drives each motor to initialize each member (S
9).

In S5, when the determination result by the CPU 55 is normal (S5, YES) and the main switch 49 is pressed (S10, YES), the CPU 55 causes the balance 3
1, the needle bar 13, the outer hook 3, and the feed dog are moved to the initial positions to stop the respective motors (S11).

In the sewing machine constructed as described above, when the balance driving motor 35 is out of step due to overload due to thread entanglement and the reciprocating position of the balance 31 changes, the balance 31 and the needle bar 1
Since the motor 3, the outer hook 3, and the feed dog are moved to predetermined positions to stop the respective motors, the balance drive motor 35 with the reciprocating position of the balance 31 being changed is not driven, and Needle breakage and thread breakage can be prevented.

Further, by stopping the balance 31 at the lower position,
By releasing the excitation of the motor 35, it becomes easy to deal with the trouble in the yarn path of the upper yarn.

Further, since the photointerplanter 39 for the balance serves both to detect the reciprocating position of the balance 31 during sewing and to detect the origin position of the reciprocating motion, no member is required for initial setting.

Further, since the reciprocating position of the balance 31 during sewing is detected at two positions, namely, the thread lowermost position which is a thread loosening position and the thread uppermost position which is a thread picking position, the reciprocating motion of the balance 31 is carried out. It is possible to quickly determine that the moving position has changed.

In this embodiment, the reciprocating position of the balance 31 during sewing is detected at two positions, namely, the thread lowermost position which is the thread loosening position and the thread uppermost position which is the thread picking position. Alternatively, the reciprocating position of the balance 31 during sewing may be detected at one place that also serves to detect the origin position of the reciprocating motion of the balance 31.

In addition to the above, the present invention can be variously modified without departing from the spirit of the invention.

[0044]

As is apparent from the above description, in the sewing machine of the present invention, when the reciprocating position of the balance changes, each motor can be stopped to prevent sewing failure and prevent needle breakage and thread breakage. Has the advantages that

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a sewing machine showing an embodiment of the present invention.

FIG. 2 is a side view of the balance device of the sewing machine.

FIG. 3 is a block diagram of an electric control system that controls each operating member of the sewing machine.

FIG. 4 is a flowchart showing the operation of the sewing machine.

FIG. 5 is a schematic configuration diagram showing a conventional sewing machine.

[Explanation of symbols]

13 needle bar 21 Needle bar drive motor 31 Balance 34a Balance detection shutter 34b Balance detection shutter 35 Balance drive motor 39 Photointerrupter for balance 40 Photo interrupter for balance 55 CPU 69 ROM

Claims (2)

[Claims] 1. A balance supported reciprocally between a yarn pick-up position and a yarn loosening position, a balance driving means for driving the balance, a needle bar supported so as to be vertically movable, and the balance. In a sewing machine having a needle bar driving means for driving the needle bar in conjunction with the reciprocating movement of the balance by a driving means, a balance position detecting means for detecting a predetermined position of the reciprocating movement of the balance by the balance driving means, A sewing machine comprising: control means for determining whether or not the result of detection of the reciprocating position of the balance by the balance position detecting means is normal, and stopping the reciprocating motion of the balance if the result is not normal. 2. The sewing machine according to claim 1, wherein the balance position detecting means detects the predetermined position of the reciprocating motion of the balance and the origin position of the reciprocating motion.