JPH03292996A - Sewing machine with needle thread embroidery function - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sewing machine equipped with an embroidery function for forming an embroidery pattern on a work cloth using only a needle thread.

[Prior art]

Conventionally, in electronically controlled zigzag sewing machines, the needle bar vertical movement mechanism, thread take-up mechanism, cloth feed mechanism, thread ring capture mechanism, etc.
They were each driven via an upper shaft and a lower shaft driven by a sewing machine motor. Recently, with the aim of downsizing sewing machines, improving design freedom, and reducing costs by eliminating many mechanical parts, individual drive systems have been introduced in which each of these mechanisms is driven individually by a dedicated stamping motor. It has been proposed that the

Therefore, in this individual drive type sewing machine, each mechanism can be controlled freely, so in addition to practical stitches such as straight stitches and zigzag stitches, it is also possible to sew various complicated patterns such as letters, symbols, and marks. There is.

[Problem to be solved by the invention]

By the way, if you want to add a simple needle thread embroidery function to the above-mentioned individually driven electronically controlled sewing machine to embroider on work fabric using only needle thread (embroidery thread), In order to form, at the plurality of pattern forming points,
It is necessary to pierce the upper thread into the fabric and form a loop underneath it to prevent the upper thread from unraveling. However, as in normal sewing, when the upper thread is fed to the eye of the sewing needle via the normal thread path from the thread spool to the thread take-up, the needle thread is caught by the tip of the thread loop catcher on the underside of the workpiece fabric. The loop is enlarged, but since the bobbin thread is not used, the needle bar moves to the uppermost position and the needle thread is pulled up by the thread take-up, causing the needle thread to come out of the fabric, making it impossible to embroidery on the fabric.

Therefore, it is conceivable to directly supply the needle thread from the thread spool to the eye hole, stop driving the thread ring catching mechanism, and drive only the needle bar vertical movement mechanism. However, when the sewing needle rises from its lowest position to a predetermined uppermost position, the upper thread loop temporarily formed on the underside of the workpiece cloth is broken by the upward movement of the sewing needle to the uppermost position, so that There is a problem that embroidery patterns cannot be formed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sewing machine equipped with a needle thread embroidery function that can easily and reliably form an embroidery pattern on a workpiece cloth using the needle thread by changing the uppermost position of the needle bar.

[Means to solve the problem]

As shown in the functional block diagram of FIG. 1, a sewing machine equipped with a needle thread embroidery function according to the present invention includes a needle bar that is supported to be able to reciprocate up and down and has a sewing needle attached to its lower end, and a needle bar that is driven to reciprocate up and down. a first actuator for controlling the first actuator, a first control means for controlling the first actuator, a thread ring catcher, a second actuator for driving the thread ring catcher, and a second actuator for controlling the second actuator. In a sewing machine equipped with a control means, for selectively setting an upper thread embroidery mode in which an embroidery pattern is formed on a workpiece cloth with the upper thread, and a sewing mode in which a stitch is formed on the workpiece cloth with the upper thread and the bobbin thread. a mode setting means, and a needle bar top position control for instructing the first control means to change the needle bar top position so that the tip of the sewing needle at the top position is in the vicinity of the top surface of the workpiece cloth when in the needle thread embroidery mode. and thread catcher stop control means for instructing the second control means to stop the thread loop catcher when in the needle thread embroidery mode.

[Effect]

In the sewing machine equipped with a needle thread embroidery function according to the present invention,
When the mode setting means selectively sets the needle thread embroidery mode, the needle bar uppermost position control means causes the first control means to control the needle bar so that the tip of the sewing needle at the uppermost position is in the vicinity of the upper surface of the workpiece cloth. A change in the uppermost position is commanded, and the thread ring catcher stopping means commands the second control means to stop the thread ring catcher.

Therefore, the first control means controls the first actuator by changing the uppermost position of the needle bar based on the command, so that the work cloth can be fed, and the work cloth can be moved up and down by the vertical movement of the needle bar (sewing needle). The needle thread loop formed on the underside of the embroidery is kept as large as possible, and embroidery is performed on the work cloth.

That is, FIG. 5 to FIG. 8 and FIG. 10 to FIG.
As shown in FIG. 3, when the sewing needle 9 attached to the lower end of the needle bar descends to its lowest position, the needle thread 36 is not caught by the tip of the thread loop catcher.

When the needle bar rises to the uppermost position, a needle thread loop is formed and held at the needle thread portion 36b due to the frictional resistance between the needle thread 36 and the work cloth W. At this time, if the needle thread 36 is pulled up using a thread take-up lever, for example, so that the needle thread portion 36a disappears in FIG.
A needle thread loop is formed. Then, by sequentially dropping the sewing needles 9 at desired positions on the work cloth W, an embroidery pattern can be formed on the work cloth W using the needle thread 36.

[Effects of the Invention] According to the sewing machine equipped with the needle thread embroidery function according to the present invention, by providing the mode setting means, the needle bar uppermost position control means, and the thread catcher stop control means, the needle thread embroidery mode can be changed. When,
When the needle bar rises to the highest position, the tip of the sewing needle is reliably pulled up to a position close to the top surface of the workpiece cloth, and the drive of the thread ring catcher is stopped, allowing the workpiece cloth to be fed while still being able to move under the workpiece cloth. A needle thread loop as large as possible can be formed on the side, and an embroidery pattern can be easily and reliably formed on the work cloth with the needle thread.

〔Example〕

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

In this embodiment, the present invention is applied to an electronically controlled zigzag sewing machine in which a needle bar vertical drive mechanism, a needle bar swing drive mechanism, a horizontal hook drive mechanism, etc. are individually driven by dedicated stepping motors.

As shown in FIG. 2, a needle bar vertical drive mechanism, a needle bar swing drive mechanism, and a thread take-up drive mechanism are built into the arm portion 2 of the sewing machine 1. The needle bar stand 4, which is arranged in the vertical direction, is attached to the machine frame 6 at its upper end.
A needle bar 8 is supported on the needle bar base 4 so as to be movable up and down, and a sewing needle 9 is attached to the lower end of the needle bar 8. There is.

A pin 10 fixed to the needle bar 8 passes through the slit 5 of the needle bar base 4 and projects forward, and the front end of the bin 10 fits into a notch 12 of a rack member 11 supported so as to be movable in the vertical direction. The rack 13 of this rack member 11 is meshed with a drive gear 14 fixed to a drive shaft of a stepping motor 45 for driving the needle bar. Therefore, the needle bar 8 and the sewing needle 9 are caused to reciprocate up and down by the forward and reverse rotation of the stepping motor 45 for driving the needle bar. The lower end of the needle bar stand 4 is connected to a needle bar swinging stepping motor 46 (see FIG. 3) via a connecting rod 15.
6 causes the sewing needle 9 to swing via the needle bar stand 4 and the needle bar 8.

A sector gear 17 is rotatably supported on a pivot shaft 16 fixed to the machine frame 6 of the head 3. A balance 18 is formed at the upper end of the sector gear 17, and a gear portion 19 of the sector gear 17 is meshed with a drive gear 20 fixed to a drive shaft of a stepping motor 47 for driving the balance. Therefore, the balance 18 is caused to reciprocate up and down via the sector gear 17 by the forward and reverse rotations of the stepping motor 47 for driving the balance.

On the other hand, a horizontal hook driving mechanism and a cloth feeding mechanism (path shown in the figure) are incorporated in the bed section 30. To explain the outline, the outer hook 32 of the horizontal hook 31 is connected to the machine frame through a shaft 33. The gear portion 34 of the outer hook 32 is rotatably supported in a horizontal plane.
is meshed with a drive gear 35 fixed to a drive shaft of a stepping motor 49 for driving the hook. Therefore, the rotation of the hook driving stepping motor 49 in a predetermined direction rotates the outer hook 32 in a fixed direction.

Further, although not shown, the feed dog performs a cloth feeding motion via a feed dog vertical drive mechanism and a feed dog vertical drive mechanism of a general configuration driven by a cloth feeding stepping motor 48 (see FIG. 3).

The machine frame 6 of the head 3 has a needle thread embroidery mode in which an embroidery pattern is formed on the work cloth W with the needle thread 36, and a stitch is formed in the work cloth W with the needle thread 36 and the bobbin thread (path shown). A mode setting knob 37 for selectively setting the sewing mode and an automatic/manual setting knob 38 for setting cloth feed to automatic or manual when the needle thread embroidery mode is set are used to instruct the start and stop of sewing operation. A start/stop button 39 is provided on the machine frame 6 of the pillar section (path shown) to select a desired sewing pattern and a pattern selection switch 40 (see FIG. 3) consisting of a numeric keypad to set the sewing speed. Speed adjustment knob 41 (see Figure 3)
are provided respectively.

Next, the control system of the sewing machine 1 is constructed as shown in the block diagram of FIG.

Each stepping motor 45 to 49 is connected to each drive circuit 50 to 5.
4, each switch 40, 55-57, A/D converter 59, and timing signal generator 60 are connected to an input/output interface 62 of the control device C, respectively.

To briefly explain the timing signal generator 60, a plurality of slits are provided at predetermined intervals on the periphery of a circular disk that is rotated once in one sewing cycle by the cloth feeding stepping motor 48. The sensor detects these slits using the top position of 9 as a reference position and outputs a detection signal (clock signal).By counting these detection signals, each stepping motor 45 to 49 is controlled. There is.

Furthermore, in the needle thread embroidery mode, the timing signal generator 60 outputs a processing start timing signal for the needle bar 8 in order to move the needle bar 8 up and down along the movement curve shown in FIG.

The control device C includes a CPU 63, an input/output interface 62 connected to the CPU 63 via a bus 64 such as a data bus, a ROM 70, and a RAM 65.

The program memory 71 of the ROM 70 stores a set speed signal output from the speed volume 58, a start signal and a stop signal output from the start/stop switch 55, a timing signal from the timing signal generator 60, and stitch pattern data. A control program for controlling each of the stepping motors 45 to 49, a sewing control program, and the like are stored therein.

The stitch pattern data memory 72 stores needle position data for each sewing operation for each of a large number of stitch patterns such as letters, symbols, and marks in correspondence with pattern numbers.

The needle bar uppermost position data memory 73 stores uppermost position data L in the number of pulses that determines the uppermost position based on the lowest position of the needle bar 8 in the normal sewing mode. Top position data that determines the top position based on the bottom position! is stored as a number of pulses.

The RAM 65 is provided with various types of memories, counters, etc. that temporarily store the results of calculations performed by the CPU 63.

Here, the up and down reciprocating movement of the needle bar 8 will be explained based on FIG. 4.

The control program is preset so that the needle bar 8 basically moves up and down in a movement curve shown in FIG. 5 in the normal sewing mode and in the needle thread embroidery mode.

In the sewing mode, the stepping motor 45 has a phase angle of 0.
' During period A extending from the reference position to a phase angle of 180°, the motor is driven with positive rotation equal to the number of pulses and the phase angle is 180°.
During period B ranging from 0° to a phase angle of 360°, the needle bar 8 is driven in reverse rotation by the number of pulses, so that the needle bar 8 reciprocates up and down from the normal uppermost position to the lowermost position. However, in the needle thread embroidery mode, the stepping motor 45 has a pulse count of ! Since the needle bar 8 is driven with forward rotation and reverse rotation by several degrees Celsius in the period from a phase angle of 180°, the needle bar 8 is shown by a dashed line from a phase angle of about 2806° to a phase angle of about 85°. As such, the tip of the sewing needle 9 is held at the uppermost position near the upper surface of the work cloth W.

Next, the operation of forming an embroidery pattern on the workpiece cloth W using the needle thread 36 in the needle thread embroidery mode will be described with reference to FIGS. 5 to 8.

A needle thread storage groove 43 is formed on the needle thread supply side of the eye hole 42 of the sewing needle 9, extending upward from the eye hole 42 for a predetermined length.

Therefore, when the sewing needle 9 descends from the uppermost position shown in FIG. 5 to the lowermost position shown in FIG. 6, a loop of the upper thread 36 is formed by the eye hole 42 on the back side of the work cloth W. As shown in FIG. 7, while the sewing needle 9 is rising, the needle thread portion 36a from the eye hole 42 accommodated in the needle thread accommodation groove 43 to the workpiece cloth W is accommodated in the needle thread accommodation groove 43, so that the needle thread portion 36a is not processed. Cloth W
Since almost no pressing force acts on this upper thread portion 36a,
rises together with the sewing needle 9. However, one end of the needle thread portion 36b from the eye hole 42 where the needle thread storage groove 43 is not provided to the work cloth W cannot be moved due to the eye hole 42, and the other end portion is between the sewing needle 9 and the work cloth W. Since it cannot be moved due to the pressing force, a loop is formed at this upper thread portion 36b. From the time when the eye hole 42 passes through the work cloth W to the uppermost position shown in FIG. The upper thread amount is paid out from a thread supply source (path shown). Moreover,
Since the upward movement of the sewing needle 9 is stopped when its tip is near the upper surface of the work cloth W, the upper thread portion 36b is located on the back side of the work cloth W.
The loop is maintained in a formed state. Therefore,
An embroidery pattern is formed on the work cloth W by sequentially dropping the sewing needles 9 at desired positions on the work cloth W. Thereafter, adhesive tape is applied to the back side of the work cloth W in order to hold this embroidery pattern. However, in this mode, the needle thread 36 is directly supplied to the eye hole 42 of the sewing needle 9 from the thread spool (path shown).

Next, a sewing control routine performed by the control device of the sewing machine 1 will be described with reference to the flowchart shown in FIG. In addition, 5i (i=1.2.3...) in the figure is each step.

When the power is turned on, this control is started, initial settings such as setting each stepping motor 45 to 49 to the initial setting position are executed (S1), and when the start/stop switch 55 is turned on (S2). : Yes), in the normal sewing mode (S3: NO), the top position data L in the sewing mode is read from the needle bar top position data memory 73 (S4), and the pattern selected by operating the pattern selection switch 40 is read out from the needle bar top position data memory 73. The stitch pattern data corresponding to the number is read out (S5
), based on this stitch pattern data, the timing signal from the timing signal generator 60, and the set speed signal from the A/D converter 59, the stepping motors 45 to 49 are respectively controlled to create a desired stitch pattern. Formed on the work cloth W (
S6). In this sewing mode, the stepping motor 45
is driven by the number of pulses of the uppermost position data L, so the needle bar 8 moves up and down along a normal movement curve (see FIG. 4). Then, when the start/stop switch 55 is turned off (
S7: Yes), the sewing operation is stopped and the process returns to S2.

On the other hand, when sewing starts, the embroidery mode is set by the mode setting knob 37 (S2, S4: Yes), and the automatic
When automatic operation is set by the manual setting knob 38 (S8: Yes), the top position data in embroidery mode! is read out (S9), and the stitch pattern data corresponding to the pattern number selected by the pattern selection switch 40 is read out (S9).
SlO), the control of the stepping motors 47 and 49 is stopped, and the stepping motors 45, 46, and 48 are controlled based on the stitch pattern data, the timing signal, and the predetermined speed signal, so that the desired embroidery pattern is formed on the work cloth W. formed (Sl
l). At this time, the steering and ping motor 45 is controlled to rotate in the forward direction at each lowering start timing. In this embroidery mode,
Stepping motor 45 is the highest position data! The uppermost position of the needle bar 8 is changed and moved up and down so that the tip of the sewing needle 9 is in the vicinity of the upper surface of the workpiece cloth W (see FIG. 4). And start/stop switch 5
5 is turned off (312: Yes), the embroidery operation is stopped and the process returns to S2.

Also, when manual embroidery mode is selected (S
2. S3: Yes, S8: No), the uppermost position data l in the embroidery mode is read out (S13), the control of the stepping motors 46 to 49 is stopped, and the stepping motor 4
Only 5 is controlled (S14). However, at this time,
The stepping motor 45 is continuously controlled to rotate forward and backward by the number of pulses of the uppermost position data l. That is, by manually moving the work cloth W to a desired position, any embroidery pattern can be formed. When the start/stop switch 55 is turned off (S15: Yes), the embroidery operation is stopped and the process returns to S2. Note that when the embroidery mode is set, the embroidery speeds in Sll and S14 are forcibly set to a very slow predetermined speed so that the loop of the upper thread 36 formed on the lower side of the work cloth W is not broken. .

As explained above, in the needle thread embroidery mode, the uppermost position of the needle bar 8 is changed so that the tip of the sewing needle 9 is in the vicinity of the upper surface of the work cloth W, and the drive of the outer hook 32 is stopped. Therefore, a needle thread loop as large as possible can be formed on the lower surface side of the work cloth W while making cloth feeding possible, and an embroidery pattern can be easily and reliably formed on the work cloth W with the needle thread 36.

In addition, as shown in FIGS. 10 to 13, the needle thread storage groove 43
When using a normal sewing needle 9A without a needle, the needle thread 36 may be pulled up by a thread take-up 18, for example, at the uppermost position of the needle bar 8 shown in FIG. 13 to eliminate loops caused by the needle thread portion 36a.

It goes without saying that the present invention can be applied to sewing machines equipped with various hook drive mechanisms such as a swing hook, and various electronically controlled sewing machines equipped with various needle bar vertical drive mechanisms driven by motors. It is.

[Brief explanation of drawings]

Figure 1 is a functional block diagram showing the configuration of the present invention, Figures 2-
Fig. 13 shows an embodiment of the present invention, Fig. 2 is a perspective view showing the internal mechanism of the sewing machine, Fig. 3 is a block diagram of the control system of the sewing machine, and Fig. 4 shows the vertical movement of the needle bar. The time chart, Figures 5 to 8 are explanatory diagrams of the operation when forming an embroidery pattern with needle thread, Figure 9 is a schematic flowchart of the sewing control routine, and Figures 10 to 13 are diagrams of normal sewing needles, respectively. FIG. 4 is an explanatory diagram of the operation when forming an embroidery pattern with the upper thread when using the needle thread. 1.Electronically controlled zigzag sewing machine, 8.Needle bar, 9.
・Sewing needle, 31..Horizontal hook, 32..Outer hook, 45..
Stepping motor for needle bar drive, 49...Stepping motor for hook drive, 56...Mode setting switch,
63...CPU, 65...RAM, 70...R
OM, 71...Program memory, 73...Needle bar top position data memo/control device, W...Working cloth.

Claims (1)

[Claims] (1) a needle bar that is supported to be able to reciprocate up and down and has a sewing needle attached to its lower end; a first actuator that drives the needle bar back and forth up and down; and a first control means that controls the first actuator; A sewing machine including a thread ring catcher, a second actuator for driving the thread ring catcher, and a second control means for controlling the second actuator, the sewing machine comprising: forming an embroidery pattern on a workpiece cloth with a needle thread; A mode setting means for selectively setting an upper thread embroidery mode and a sewing mode in which stitches are formed on a workpiece cloth using upper thread and bobbin thread; needle bar uppermost position control means for instructing the first control means to change the needle bar uppermost position so that the needle bar is at a position near the upper surface of the work cloth; 1. A sewing machine equipped with a needle thread embroidery function, characterized in that the sewing machine is equipped with a thread wheel catcher stop control means for instructing a second control means.