JPH0567320B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention has two needle bars placed at intervals on the left and right, and a method for vertically moving these two needle bars as the main shaft of the sewing machine rotates. There is a two-needle sewing state in which two needle bars are interlocked with the needle bar driving means to perform two-needle sewing, and a one-needle sewing state in which one needle bar is paused at a corner. The present invention relates to a two-needle corner stitch sewing machine equipped with a switching mechanism that switches between a single-needle sewing state and a sewing state based on the operation of a needle bar drive means.

[Problems to be solved by conventional technology and invention]

In a conventional two-needle corner stitch sewing machine, when setting the single-needle sewing state after stopping both needles in the needle-down position in the double-needle sewing state, both needles are driven one stitch further, and one The needle is made to rest in the needle-up position. However, in this case, since the feed device applies one pitch of feed to the workpiece cloth while driving one stitch, in the position where both needles are stopped in the double needle sewing state, It was not possible to turn the fabric around one needle. Therefore, it is not possible to form a single-needle stitch that connects both ends of the parallel stitches in a straight line at the corner of the work cloth, and for example, it is not possible to form a stitch with a special shape as shown in Figure 6e. I was unable to sew.

This invention was made in order to solve the above-mentioned problem, and its purpose is to sew corners of various shapes by using one of the needle bars at the end of the two-needle sewing. To provide a two-needle corner stitch sewing machine capable of stopping the machine downward, setting the single-needle sewing state at that position, and turning the work cloth.

[Means to solve the problem]

In order to achieve the above object, this invention
a pitch changing means capable of changing a predetermined feed pitch of the work cloth to zero; and when the two needle bars are stopped downward, the pitch changing means is actuated to change the feed pitch to zero; A control means is provided for switching the switching mechanism to a single needle sewing state and driving the needle bar driving means by at least one stitch, so that either one of the needle bars can be stopped downward at the position where double needle sewing is completed. It is said that

[Effect]

According to this invention, when the two needle bars are stopped downward after double needle sewing is completed, the control means
The pitch changing means is operated to change the feed pitch to zero, the switching mechanism is switched to the single needle sewing state, and the needle bar driving means is activated to change the feed pitch to zero.
The needle is driven. As a result, either one of the needle bars is stopped downward at the position where the two-needle sewing is completed.

〔Example〕

Hereinafter, one embodiment of a two-needle corner stitch sewing machine embodying the present invention will be described in detail with reference to the drawings.

(Mechanical Part of Sewing Machine) Hereinafter, one embodiment of a two-needle corner stitch sewing machine embodying the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 2a and 2b, a needle bar support frame 2 is swingably supported within the arm portion 1 of the sewing machine frame, and swings along the cloth feeding direction as the operating shaft 3 swings. be done. A pair of needle bars 4 and 5 extending vertically in parallel are supported by the needle bar support frame 2 so as to be movable up and down, and needles 4a and 5a are respectively attached to the lower ends of the needle bars 4 and 5. Both needle bars 4, 5 are provided with a drive coupling device 9 for selectively transmitting the rotational movement of the main shaft 6 of the sewing machine to each needle bar 4, 5 via a crank 7 and a crank rod 8.
At the same time, one of the needle bars 4 and 5, which has been disconnected from the sewing machine main shaft 6, is held at rest in the needle-up position by the drive coupling device 9 on the upper part of the needle bar support frame 2. A locking device 10 is installed for holding the vehicle in place.

The drive coupling device 9 includes a cylindrical body 9a inserted through both needle bars 4 and 5 so as to be movable relative to each other. Further, an operating lever 91 is swingably supported in grooves 4b and 5b formed in the intermediate portions of each needle bar 4 and 5 at a portion located above the intermediate portion. Correspondingly, locking recesses 92, 93 are formed in each needle bar 4, 5. Said cylinder 9a
A pair of removable locking pieces 14 and 15 are movably inserted into the lower locking recess 93 of each needle bar 4 and 5 and the lower end of the operating lever 91, respectively. When placed in a position where it engages with the lower locking recess 93, the rotation of the sewing machine main shaft 6 is transmitted to each needle bar 4, 5 by the locking pieces 14, 15, and the sewing machine separates from the locking recess 93. When in position, said power transmission is interrupted.

A pair of swing levers 1 are provided at the upper part of the cylinder 9a.
2 and 13 are swingably supported at their intermediate portions,
Each locking piece 14, 15 is connected by a connecting pin 94 at the lower end.
is rotatably connected to. A spring 95 interposed between the upper end of each swing lever 12, 13 and the cylindrical body 9a causes each of the locking pieces 14, 15 to move into the locking recess via each swing lever 12, 13. 9
3 and is biased to move in the direction of engagement.

A pair of locking levers 96 and 97 are provided at the lower part of the cylinder body 9a to lock the respective locking pieces 14 and 15 in a position where they are removed from the lower locking recess 93, and the locking levers 96 and 97 are swingable at their intermediate portions. It is supported and biased to swing clockwise in FIG. 2b by springs 96a and 97a. Moreover, between each swing lever 12, 13,
A release pin 18 that engages each locking lever 96, 97 from above is inserted and supported in the center of the cylinder 9a.

When each locking piece 14, 15 is engaged with the lower locking recess 93, each swing lever 12, 1
Through the engagement between the connecting pin 95 of No. 3 and one end of each locking lever 96, 97, the other end of each locking lever 96, 97 engages with the locking recess 14a, 1 of each locking piece 14, 15.
5a, and when the locking pieces 14, 15 are moved in the direction of separating from the lower locking recess 93, the other end of each locking lever 96, 97 is locked in the locking recess 14a, 15a. When combined, each locking piece 14,
15 is held in the disengaged position.

A pair of holding pieces 16 and 17 are slidably inserted into the upper part of the needle bar support frame 2 and are detachable from the locking recesses 92 above the needle bars 4 and 5 and the upper end of the operating lever 91, respectively. At the same time, the cover 98 is attached,
A spring 99 interposed between the cover 98 and each holding piece 16 , 17 urges each holding piece 16 , 17 in a direction to engage with each locking recess 92 . A locking device 10 is constituted by both holding pieces 16 and 17, a cover 98, and a spring 99.

A switching lever 11 having a protrusion 11a is slidably mounted on the needle bar support frame 2 between both devices 9 and 10, and as the switching lever 11 slides, the protrusion 11a changes as shown in FIG. It is switched to an intermediate position shown in a, and to a left movement position and a right movement position which are respectively moved from the intermediate position by a predetermined distance in the left and right direction. Then, with the protrusion 11a disposed at the predetermined switching position, as the needle bars 4 and 5 rise, the locking recesses 92 above the needle bars 4 and 5 are arranged to face each of the holding pieces 16 and 17. When the levers 12 and 13 of the drive coupling device 9 are engaged selectively with the protrusion 11a, the engagement causes one of the swing levers 12 and 13 to move in the opposite direction as shown in FIG. 2b. One of the locking pieces 14, 15 is swung clockwise.
After selectively disengaging from the locking recess 93 below the needle bars 4, 5, it is held in the disengaged position by one of the locking levers 96, 97, and the operating lever 91 is moved based on its own weight balance. 2b in the counterclockwise direction, so that the upper end of the holding piece 1
6, 17.

As a result, the connection between the needle bars 4, 5 and the sewing machine main shaft 6 by one of the locking pieces 14, 15 is selectively interrupted, and at the same time, one of the holding pieces 16, 17 is connected to one of the needle bars 4, 5. One of the needle bars 4 and 5 is held in the needle-up position by being engaged with the upper locking recess 92,
The main needle sewing state is set.

Further, one of the locking pieces 14 and 15 is held at the release position by one of the locking levers 96 and 97, and one of the needle bars 4 and 5 is held at the needle up position by one of the holding pieces 16 and 17. When the other needle bars 4 and 5 are raised while the needle bars 4 and 5 are held in place, and the release pin 18 of the drive coupling device 9 is engaged with the protrusion 11a, the release pin based on the engagement is 18, the pair of locking levers 96, 97 are released by the spring 96.
The one locking lever 96, 97 is swung counterclockwise in FIG.
The holding of one of the locking pieces 14 and 15 by the locking members 14 and 15 is released. As a result, one of the locking pieces 14, 15 is engaged with the locking recess 93 below the corresponding needle bar 4, 5 by the biasing force of the spring 95, and the two-needle sewing state is set.

As shown in FIG.
Both electromagnetic solenoids 20, 21
A movable body 23 common to both is inserted and supported so as to be movable left and right. Below both electromagnetic solenoids 20.21, an operating rod 24 is supported by a guide body 25 so as to be movable left and right. , 27 are fitted. Each spring receiver 26.
A pair of springs 28 and 29 are attached to the actuating rod 24 between the actuating rod 27 and the protruding piece 25a to hold the actuating rod 24 itself in an intermediate position.

Further, a connecting lever 30 is rotatably supported between the movable body 23 and the actuating rod 24,
One end thereof is rotatably connected to the intermediate portion of the movable body 23, and the other end is rotatably connected to one end of the actuating rod 24. Further, a connecting member 31 is fixed to the other end of the actuating rod 24, and a protrusion 31a thereof
is engaged with the recess 11b of the switching lever 11. Both the electromagnetic solenoids 20, 2
1 is selectively excited, the moving body 23
The actuating rod 24 and the connecting member 31 are switched to any one of the right movement position, the intermediate position, and the left movement position via the connection lever 30, and the arrangement position of the switching lever 11 is changed in accordance with the switching of the arrangement. . In this embodiment, a switching device 32 is constituted by the electromagnetic solenoids 20 and 21, the movable body 23, the connecting member 31, the switching lever 11, and the like.

In addition, as shown in FIG.
a pair of pause hand selection keys 34 for pausing the
35, and four types of cloth feeding pitches (in this embodiment, 1P, 3/4P, 1/2P, 1/4P,
Pitch setting keys 36 to 39 are provided for setting the reference pitch (P = reference pitch), and lamps 34a to 34a are provided on each key 34 to 39, which can be lit when the key is operated.
39a is attached.

[Operation panel configuration]

The sewing machine in this embodiment includes an operation panel 40 shown in FIG. 4, on which various keys are arranged in the order of operation. That is, a program sewing key 41 is provided at the left end of the operation panel 40 and is operated to set a program mode at the start of creating a sewing pattern as shown in FIG. 6 and at the start of sewing based on the sewing pattern. has been done.

Arranged on the right side of this key 41 are a creation key 43 and a reproduction key 44, which are operated respectively to set a sewing pattern creation mode and a sewing execution mode based on the sewing pattern. On the right side of both keys 43 and 44 are arranged four pattern specification keys 45 which are operated to specify the sewing pattern, and on the right side of the pattern specification key 45 are arranged the needle 4
A cloth thickness sensing key operated to adjust the sensitivity of a cloth edge detector 46 (see FIG. 1a) that detects the edge of the workpiece cloth W on the bed of the sewing machine on the cloth feeding side than a and 5a. 47 are arranged.

On the right side of the cloth thickness sensing key 47, the sewing end point on the sewing trajectory formed at each sewing step S1 to S4 when creating the sewing pattern shown in FIG. 6, and the workpiece cloth W intersecting the sewing trajectory are displayed. The periphery of Wa
to set a seam allowance Bn, and also to set a cloth edge detection sewing mode in which the sewing after detecting the edge Wa of the work cloth W by the cloth edge detector 46 is controlled according to the set seam allowance Bn. The step width key 48 and the fixed size stitch count sewing mode, that is, for setting the number of stitches (number of stitches) required to form a stitch of a predetermined length, or for reproducing the sewing for that number of stitches. A fixed size stitch number key 49 for setting a mode and a free stitch key 50 for setting a mode for freely sewing a desired length during setting of the program mode are arranged side by side.

On the right side of the free stitching key 50, a pair of paused needle selection keys 51 and 52 are provided for selecting the needles 4a and 5a to be paused for single-needle sewing during program mode setting and setting the single-needle sewing mode. It is being

A seam allowance Bn is provided around each of the keys 48 to 52.
When setting, add or subtract in 0.1mm increments,
An addition key 53 and a subtraction key 54 are arranged for adding and subtracting each "1" when setting the number of corner stitches In for single-needle sewing.
A first numerical display section 55 that displays the seam allowance Bn to be set, an enter key 56 that is operated when inputting the numerical value displayed on the display section 55 to the control device of the sewing machine, and the number of corner stitches to be set. A second numeric display section 57 that displays In, an enter key 58 that is operated when inputting the numeric value displayed on the display section 57 into the control device of the sewing machine, and a clear key 59 that clears each of the displayed numeric values. are placed respectively. Incidentally, when the sizing stitch number key 49 is operated, the sizing stitch number Dn is displayed on the first display section 55.

An input key 60 is provided on the right side of the pause needle selection keys 51 and 52 for inputting sewing data created in the setting state of each mode to the control device of the sewing machine for each step S1 to S4 of the sewing pattern. Arranged on the upper right side of the key 60 are a third numerical display section 61 for displaying the step number and a step change key 62 for changing the step number forward or backward for each step.

Further, on the right side of the input key 60, there is a sewing end key 6 which is operated to end sewing after the thread trimming operation.
3 is provided, and below it there is an automatic key 64 that is operated to automatically perform one step of sewing in the playback mode, and an automatic key 64 that divides the single-needle sewing section of the corner into multiple steps. A corner stitch division key 65 is used to set the division sewing mode to be executed, and a free key is operated to set the normal sewing mode, which is unrelated to program sewing, when the sewing machine is stopped in an emergency during the regeneration mode. 66 are arranged.

Further, a lamp 67 is attached to the main key among the above-mentioned keys, and a pause needle selection key 5
Operation panel 40 between 1, 52 and input key 60
A sewing lamp 68 that is lit to remind you to operate the sewing machine is provided above, and on the surface of the operation panel 40 there are arrows 69 indicating the order of operation of each key when sewing according to each mode, and explanatory characters for the sewing lamp 68. 70 is attached.

[Sewing machine control device]

The sewing machine control device in this embodiment has a first
As shown in Figure a, the CPU 7 serves as a corner stitch setting means, a split stitch mode setting means, and a control means.
1, and its CPU 71 includes a ROM 72 that stores control programs corresponding to various modes and a RAM 73 that stores sewing pattern data.

The CPU 71 is equipped with various counters shown in FIG. 1b. That is, cloth edge stop counter N1: counts the number of stitches executed from when a cloth edge is detected until sewing is stopped in the cloth edge detection sewing mode.

Corner stitch counter N2: Counts the number of stitches in the single needle sewing steps S1a to S4a shown in FIG.

Fixed size stitch number counter N3: Counts the number of fixed size stitches executed in the fixed size stitch number sewing mode.

Further, the RAM 73 has storage areas for storing four sewing patterns corresponding to the pattern designation keys 45, and each storage area stores various data shown in FIG. 1c. That is, cloth edge detection sewing flag An: is set when the cloth edge detection sewing mode is set.

Seam allowance Bn: Distance between the sewing end point on the sewing trajectory and the edge Wa of the workpiece cloth W that intersects with the sewing trajectory.

Fixed size sewing flag Cn: Set when setting fixed size stitch count sewing mode.

Number of fixed size stitches Dn: Number of stitches executed in fixed size stitch number sewing mode.

Free stitching flag En: Set when free stitching mode is set.

One-side corner stitch flag Fn: Set when the left needle 5a is paused and one-needle sewing is performed with the right needle 4a.

Other side corner stitch flag Gn: Set when the right needle 4a is paused and single needle sewing is performed with the left needle 5a.

Corner stitch division flag Hn: Set when setting the division stitch mode in which the one-needle sewing section of the corner is divided into two or more processes.

Number of corner stitches (number of corner stitches) In: Number of corner stitches set in single needle sewing mode.

End flag Ln: Set when the sewing end key 63 is operated.

Thread trimming flag Mn: Set when the operation pedal is pressed down to the rear, which will be described later.

Basic pitch stitch count K: Number of stitches executed at the fabric feed pitch set in advance when setting the fabric edge detection sewing mode.

Correction stitch count J: This is the number of stitches executed at a correction pitch smaller than the cloth feed pitch preset when setting the cloth edge detection sewing mode, and is a preset constant.

Here, the subscript n indicates each step number in the sewing pattern.

On the other hand, the sewing machine of this embodiment has a needle position detector 74 that detects the vertical position of the needles 4a and 5a, a synchronization signal generator 75 that generates a synchronization signal in response to the rotation of the main shaft of the sewing machine, and a cloth feed pitch that is detected. It is equipped with an operation pedal 78 for starting/stopping a pitch detector 76 and a sewing machine motor 77 and for operating a thread trimming device (not shown), and detects the electric signals output from these and the detection output from the material edge detector 46. Signals and key input signals are sent via the input interface 79.
It is input to the CPU 71. Similarly, input signals from each of the keys 34 to 39 on the operation section 33 are
It is input to the CPU 71. Furthermore, as shown in FIG. 1a, in the sewing machine of this embodiment, when the operation of the sewing machine is stopped in an emergency by operating the free key 66 during the programmed sewing operation according to the sewing pattern, the program after the emergency situation is resolved is stopped. A changeover switch 86 is provided for specifying the return destination, and based on the switching operation of this changeover switch 86, the CPU
Step 71 selects and sets the return destination of the program to the first sewing step of the sewing pattern and the next step after the sewing step where the emergency stop was performed.

Further, the CPU 71 controls the sewing machine motor 77, the servo solenoid 80 for changing the pitch, and the electromagnetic solenoids 20 and 21 for changing the needle, based on the control program stored in the ROM 72 and in response to various data stored in the RAM 73. , outputs a drive control signal via the output interface 81 and each drive circuit 82, 83, 84. Furthermore, CPU71
responds to the control program and various data,
Each numerical display unit 55,
57, 61 and each lamp 34a to 39a, 67,
68 is operated and controlled.

Note that the needle position detector 7 in this embodiment
4. The configurations of the synchronizing signal generator 75, pitch detector 76, and pitch changing servo solenoid 80 are the same as those described in Japanese Patent Application Laid-Open No. 61-217197 by the applicant, so they can be replaced if necessary. Please refer.

Next, the operation of the sewing machine configured as described above will be explained.

(Data Creation Mode) Now, as shown in FIG. 5a, when the program sewing key 41 and creation key 43 are operated in sequence,
In routine 101, CPU 71 sets step number n to zero. Next, after the storage area of the RAM 73 is specified by operating the pattern specification key 45, the CPU 71 selects each of the counters N1 to N.
3. Each data Bn, Dn, In and each flag An, Cn,
Reset all En, Fn, Gn, Hn, Ln, and Mn.

When the sensitivity adjustment of the fabric edge detector 46 by operating the fabric thickness sensing key 47 is completed, the CPU 71 executes the routine 102 shown in FIG. Wait for some operation. Here, in order to perform sewing in sewing step S1, for example, when the stitch width key 48 is operated and the determination in the routine 102 becomes YES, the step number n is updated, and then the flag An is set and the cloth edge Detection sewing mode is set.

Next, the program executes seam allowance setting routine 10.
3, a seam allowance Bn (n=1) is set in response to the operation of each key 53, 54, 56, 59.
In the display subroutine 103a in this seam allowance setting routine 103, the addition key 53 and the subtraction key 5
Each time 4 is operated, the numerical value is added or subtracted by 0.1 mm and displayed on the first numerical display section 55. When the continuous pressing time of each of the keys 53 and 54 reaches a predetermined time or more, the speed of changing the numerical display is increased.

After setting the seam allowance Bn, the CPU 71 turns on the corner stitch division key 65 and the lamp 67 and sewing lamp 68 above the paused needle selection keys 51 and 52,
Actual sewing operation is prompted by selection operations of the keys 65, 51, 52 and front depression of the operating pedal 78. Therefore, as shown in FIG. 6a, for example, single needle sewing steps S1a and S2a are performed at the corners of the work cloth W.
If the numbers of stitches are the same, one of the pause stitch selection keys 51 and 52 is operated without operating the corner stitch division key 65 in the one-leg stitch count setting routine 104 shown in FIG. Then each key 5
In response to the operations 1 and 52, one side or other side corner stitching flags Fn and Gn are set, and the corner stitching mode is set in combination with the cloth edge detection sewing mode.

Furthermore, as shown in FIGS. 6b to 6e, when the number of stitches in at least one of the single-needle sewing processes S1a to S4a at the corners of the work cloth W is different from the number of stitches in the other sewing processes. , the pause needle selection key 51,
When the corner stitch division key 65 is operated prior to the operation of 52, the corner stitch division flag Hn is set.
The divided corner sewing mode is set in combination with the cloth edge detection sewing mode.

After setting the seam allowance, use corner keys 53, 54, 58, 5
When the setting of the number of corner stitches In of the single needle sewing process S1a in the sewing step S1 is completed by the operation in step 9, the program proceeds to the sewing subroutine 105 shown in FIGS. 5c and 5f. In this subroutine 105, each flag Hn, Fn, Gn in the sewing step immediately before the current sewing step is selected.
The electromagnetic solenoid 2 is activated to change from a single needle sewing state to a double needle sewing state according to
0 and 21 are controlled.

Incidentally, in the first sewing step S1, since each of the flags has been reset, in response to the forward depression of the operation pedal 78 in routine 105a of the sewing subroutine 105, the presser foot actuating solenoid (not shown) is turned off. being operated,
After the workpiece cloth W is pressed onto the workpiece cloth support surface of the sewing machine by the presser foot (not shown), the sewing machine is operated in a two-needle sewing state, and the program returns to the main routine shown in FIGS. 5c and 5d. do.

Then, the CPU 71 executes routine 1 of FIG.
At step 06, the cloth feed pitch during operation of the sewing machine is detected based on the input signal from the pitch detector 76. Also, as the sewing machine operates, the processed cloth W
When the edge of is detected by the cloth edge detector 46,
In the feed amount detection subroutine and the calculation subroutine in the routine 106, the feed of the workpiece cloth W transferred between the time when the edge of the workpiece cloth W is detected and the time when the needles 4a and 5a next penetrate the workpiece cloth W. The amount is calculated, and the cloth feed pitch is reduced based on the feed amount data, a preset cloth feed pitch (basic pitch), and a preset correction stitch number J (3 in this example). The number K of stitches to be sewn is calculated based on the stitch rate and basic pitch. This arithmetic processing is described in the aforementioned Japanese Patent Laid-Open No. 61-217197, so please refer to it if necessary.

Next, in routine 107, the cloth end stop counter N1
As a result, counting of the number of stitches from the time the edge of the work cloth W is detected until the sewing is stopped is started. The program then proceeds to the pitch change subroutine 108 shown in FIG.
In the first routine 108a of No. 08, the necessity of pitch reduction is determined based on the previously set number of corner stitches In and the calculation results of the calculation subroutine.

That is, if it is necessary to reduce the pitch and the set number of corner stitches In is greater than the corrected number of stitches J, the determination in routine 108b becomes YES, and the value of the counter N1 becomes K+J-In. Basic pitch sewing is performed until (routine 10)
8c). Next, it is determined whether or not the flags Fn and Gn are set, and in accordance with the determination result, the electromagnetic solenoids 20 and 21 are energized, so that one of the hands 4a and 5a corresponding to each flag is stopped. Single needle sewing state is set (routine 10)
8d).

Next, sewing is performed using the basic pitch until the value of the cloth edge stop counter N1 matches the basic pitch stitch number K, and then the pitch changing servo solenoid 80
is activated, the pitch reduction operation is performed, and sewing with the reduced pitch is executed until the value of the cloth edge stop counter N1 reaches K+J (routine 108).
e). The program then returns to the main routine.

On the other hand, if there is a need to reduce the pitch, but the number of corner stitches In is smaller than the corrected number of stitches J, the program jumps to routine 108f shown in FIG. A determination is made as to whether or not there is one. If the determination is NO, in routine 108g, after sewing corresponding to the basic number of pitch stitches K is performed, a pitch reduction operation is performed, and sewing with reduced pitch is performed until the value of counter N1 becomes K+J-In. executed. And after that,
In routine 108h, when the single needle sewing state is set and sewing is performed using the reduced pitch until the value of the cloth end stop counter N1 reaches K+J,
The program returns to the main routine.

On the other hand, the number of corner stitches In is set to zero,
If the determination of the routine 108f is YES,
In routine 108i, after sewing corresponding to the basic number of pitch stitches K is performed, a pitch reduction operation is performed, and sewing with reduced pitch is performed until the value of the counter N1 becomes K+J. Then, in routine 108j, each flag Fn,
When the set state of Gn is determined and corner stitching is not performed in the first sewing step S1, the process returns to the main routine shown in FIG. 5d.

Further, in the routine 108j, when it is determined that either corner stitching flag Fn or GN is set, the CPU 71 controls each electromagnetic solenoid 20,
21 is excited, in routine 108k, the pitch changing servo solenoid 80 is controlled to set the cloth feed pitch to zero. In that state, until the value of counter N1 reaches K+J+1,
operate a sewing machine. That is, one needle 4a, 5a is moved back and forth once with the feed amount being zero (routine 108l). Then, in routine 108m, the pitch changing servo solenoid 80 changes the cloth feed pitch to the basic pitch, and the program returns to the main routine.

Furthermore, if there is no need to reduce the pitch and the value of the number of corner stitches In is zero, the program proceeds from the routine 108a shown in FIG. 5g to the routine 108n shown in FIG. After sewing corresponding to the number of pitch stitches K is executed,
Routines 108p, 108q, 108r, 108
s, the routines 108j, 108k,
Almost the same processing as 108l and 108m was performed,
Return to main routine.

Also, the number of corner stitches In is not zero and routine 10
If the judgment of 8n is NO, routine 108t
In , basic pitch sewing is performed until the value of the counter N1 reaches K-In, and then in the routine 108u, the single needle sewing state is set, and in the routine 108v, the value of the counter N1 becomes K-In. Sewing continues until .
The program then returns to its main routine.

As described above, pitch change subroutine 108
When the sewing is completed, the CPU 71 stops the sewing machine at the needle down position and drives the presser foot solenoid to raise the presser foot (routine 1).
09,110). Through the above processing, sewing of the sewing step S1 including the one-needle sewing step S1a on the work cloth W shown in FIG. 6 is completed, and the creation of the number of stitches data regarding the step S1 is also completed.

When the processing up to this point is completed, the CPU 71 presses the input key 6 in the routine 111 shown in FIG. 5e.
0 operation is waited for, and in response to the operation, each stitch number data is stored in a working area (not shown) of the RAM 73. Continue to the next sewing step
In order to create sewing data for S2, after turning the work cloth W around the needles on the outside of the corners, the number of stitches in the single needle sewing steps S1a and S2a is determined as shown in FIG. 6a, for example. If they are equal, follow the arrow 69 on the operation panel 40 and operate the stitch width key 48 again in routine 102 of FIG. 5b.

Then, as mentioned above, the fabric edge detection sewing mode is set, so the seam allowance Bn for the next sewing step S2 can be set, and then the next corner can be set by operating the keys 51, 52, and 65. You can set the corner stitch mode for the section.

The program continues with sewing subroutine 10.
5, and in routine 105a, after the front depression operation of the operating pedal 78 is performed again, the previous sewing step (in this case, the first sewing step
The setting status of each flag Hn, Fn, and Gn in step S1) is determined, and if the corner stitch division flag Hn is not set and the one side or other side corner stitch flag Fn,
When Gn has been set, the sewing machine is operated and the sewing in the single-needle sewing process S2a is executed, and accordingly, the value of the corner stitch counter N2 changes to the number of corner stitches In in the previous single-needle sewing process S1a. When this is reached, the electromagnetic solenoids 20 and 21 corresponding to each flag Fn and Gn are demagnetized and the state is switched to the two-needle sewing state. Thereafter, the program returns to the main routine shown in FIG. 5d.

After the program returns to the main routine, when the processes from routine 106 onwards are repeated, stitch count data regarding sewing step S2 is created.
Then, if you repeat the above process, the sewing step will be completed.
The creation of sewing data regarding sewing steps S3, S4, etc. subsequent to S2 can be completed.

On the other hand, as shown in FIGS. 6b to 6e, each step S1a
~When sewing different numbers of stitches for each S4a,
In step S1, sewing is performed using a combination of the cloth edge sensing sewing mode and the corner sewing mode in the same way as in the previous case, and when the program returns to routine 102 after completing the sewing in the single needle sewing step S1a,
Operate the corner stitch division key 65. Then, the corner stitch division mode is set. Therefore, each key 53,
Single needle sewing process by operations 54, 58, and 59
For sewing S2a, the number of corner stitches In, which is different from that in the sewing step S1a, is input.

The program then proceeds to routine 102a. Here, the sewing machine is operated after the presser foot is lowered based on the operation of the operation pedal 78.
Sewing for the set number of stitches In is performed in a single-needle sewing state based on the operation of count N2. The program then returns to routine 109 of FIG. 5d, where the sewing machine is stopped and the presser foot is raised. Next, by operating the input key 60, the creation of data regarding the single needle sewing process S2a can be completed.

In particular, the single needle sewing process S2a shown in FIG. 6c
Regarding the sewing of step S2, if the stitch width key 48 is operated again in routine 102 without setting the number of corner stitches In after the sewing of the single needle sewing step S1a is completed, the sewing can proceed to the next step S2. I can do it.

In this embodiment, when the creation of the sewing pattern data described above is completed, after depressing the operating pedal 78 in the routine 112 shown in FIG. 5e, if the end key 63 is operated in the routine 114, the automatic After the thread cutting operation is performed, each stitch number data and the like are transferred from the working area of the RAM 73 to a predetermined storage area and stored therein.

In this embodiment, sewing data can be created by combining fixed size sewing mode or free sewing mode with one side or other side corner sewing mode, etc., but a detailed explanation thereof will be omitted.

Next, when sewing the sewing patterns shown in FIGS. 6a to 6e, when the program sewing key 41 and the playback key 44 are sequentially operated, the CPU 71 sets the playback mode. Therefore, when a sewing pattern created in the creation mode is specified, each flag and each stitch number data making up the pattern are read out in sequence, and the sewing machine is controlled based on them. Therefore, the sewing pattern can be easily reproduced.

As mentioned above, in this example, the number of corner stitches In
Since it is possible to perform single-needle sewing by setting the value to zero, for example, as shown in FIG.
The left needle 5a can be stopped at the needle up position, and the right needle 4a can be stopped at the needle down position.
Therefore, after turning the work cloth around the right needle 4a, the stitches connecting both ends of the parallel seams formed by the two-needle sewing are securely made using only the right needle 4a. can be formed into Therefore,
It is possible to reliably sew corners of various shapes.

Also, in this embodiment, keys 37 to 39 are provided that can set multiple types of pitches smaller than the basic pitch, so by operating the keys 37 to 39, the pitch changing servo solenoid 80 is actuated to change the feed pitch. can be reduced to multiple stages, and the final stitch can be formed at a desired position when setting the fixed size stitch count mode, free stitch mode, etc.

〔Effect of the invention〕

As described in detail above, in order to perform sewing on corners of various shapes, the present invention stops one of the needle bars downward at the position where two-needle sewing is completed, and one needle bar stops at that position. It exhibits the excellent effect of being able to set the needle stitching state and turn the workpiece cloth.

[Brief explanation of the drawing]

Fig. 1a is a block diagram showing a control device of a sewing machine embodying the present invention, Figs. 1b and c are explanatory diagrams of the CPU and RAM, Fig. 2a is a front cross-sectional view of the sewing machine, and Fig. 2b is a Partially enlarged sectional view of the needle bar mechanism, 3rd
4 is a front view of the operation panel, FIGS. 5 a to i are flowcharts, and FIGS. 6 a to e are explanatory diagrams of sewing patterns. 4, 5...Needle bar, 6...Sewing machine main shaft, 7...Crank, 8...Crank rod which constitutes needle bar drive means together with the above 7, 9...Drive coupling device, 10
...Locking device, 32...Switching device (said 9, 1)
0,32 constitute a switching mechanism),
71...CPU as control means, 80...Servo solenoid as pitch changing means.

Claims (1)

[Scope of Claims] 1. Two needle bars 4 and 5 arranged at intervals on the left and right, and a needle bar for vertically moving these two needle bars 4 and 5 as the sewing machine main shaft 6 rotates. Drive means 7, 8
and is provided between the needle bar driving means 7, 8 and the two needle bars, and performs two-needle sewing by interlocking the two needle bars 4, 5 with the needle bar driving means 7, 8. a switching mechanism 9 that switches between a two-needle sewing state and a single-needle sewing state in which one needle bar is stopped at a corner to perform single-needle sewing based on the operation of the needle bar drive means 7 and 8; 10, 32, a pitch changing means 80 capable of changing a predetermined feed pitch of the work cloth W to zero, and the two needle bars 4, 5 stopped downward. When it was done,
The pitch changing means 80 is operated to change the feed pitch to zero, and the switching mechanism 9, 10, 32
a control means 7 which switches the needle bar drive means 7 and 8 to a single needle sewing state and drives the needle bar drive means 7 and 8 by at least one stitch;
1, and one of the needle bars 4, 5 can be stopped downward at the position where the two-needle sewing is completed.