JPH01308588A - Two-needle angular-sewing machine - Google Patents

Abstract

PURPOSE:To enable a processed cloth piece to be turned, by a method wherein a pitch changing means is worked to change a feed pitch to zero, and wherein a change-over machanism is changed over to be in a one-needle sewing state, to drive a needle bar driving means by one stitch component, and wherein one side needle bar is stopped on a lower side at a position where two-needle sewing is completed. CONSTITUTION:When two needle bars 4, 5 are stopped on a lower side, then by a controlling means, a pitch changing means is worked, and a feed pitch is changed to zero, and change-over mechanisms 9, 10, 32 are changed over to be in a one-needle sewing state, and needle bar driving means 7, 8 are driven by one stitch component at least. At a position where two-needle sewing at a sewing step S1 is completed, a left side needle 5a is rested at a needle upper- position, and a right side needle 4a can be stopped at a needle lower-position. Then, with the center of the right side needle 4a, a processed cloth piece is turned, and stitches for connecting both the ends of parallel stitches formed by the two-needle sewing can be certainly formed by the only right side needle 4a, and sewing at angular sections in various shapes can be certainly performed.

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.

[Prior art and problems to be solved by the invention] In a conventional two-needle corner stitch sewing machine, when setting the single-needle sewing state after stopping both needles at the needle down position in the double-needle sewing state,
Both hands are further driven by one stitch, and one of the hands is brought to rest at the counting position. However, in this case, since the feed device applies one pin-notch feed to the workpiece fabric while the workpiece is being driven for one stitch, at 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 FIG. 6(e). I was unable to sew the pattern.

This invention was made to solve the above problem, and its purpose is to sew corners of various shapes by attaching one needle bar to the other 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, the present invention includes a pitch changing means that can change a predetermined feed pitch of the work cloth to zero, and a pitch changing means that can change the feed pitch of the work cloth to zero when the two needle bars are stopped downward. control means for operating the needle bar drive means to change the feed pitch to zero, switch the switching mechanism to a single needle sewing state, and drive the needle bar drive means by at least one stitch;
Either needle bar can be stopped downward at the position where double needle sewing is completed.

[Effect]

According to this invention, when double needle sewing is completed and the two needle bars are stopped downward, the pitch changing means is operated by the control means to change the feed pitch to zero, and the switching mechanism is switched to a single needle sewing state, and the needle bar driving means is driven by at least one stitch. As a result, 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, an 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. 2(a) and 2(b), a needle bar support frame 2 is swingably supported in the arm l of the sewing machine frame, and as the operating shaft 3 swings, it moves in the cloth feeding direction. swung along. The needle bar support frame 2 has a pair of needle bars 4 extending vertically in parallel.
5 is supported to be able to move up and down, and the needles 4a, 5a are attached to the lower end of the needles 4a, 5a.
are installed on each. Both needle bars 4 and 5 are equipped 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 and 5 via a crank 7 and a crank rod 8. At the upper part of the support frame 2, there is a locking device 10 for locking and holding either one of the needle bars 4, 5, which has been disconnected from the sewing machine main shaft 6 by the drive connecting device 9, in a resting state at the needle-up position. It is installed.

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. In addition, 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 closer to the upper side than the intermediate portion. Correspondingly each needle bar 4
, 5 are formed with locking recesses 92 and 93. The cylindrical body 9a has a pair of locking pieces 1 which are removably connected to a locking recess 93 below each needle bar 4.5 and a lower end of the operating lever 91.
4.15 is movably inserted and each locking piece 14.15 is arranged in a position where it engages with the lower locking recess 93, the rotation of the sewing machine main shaft 6 is controlled by the locking piece 14.15. When the power is transmitted to the needle bar 4.5 and disposed at a position where it is disengaged from the locking recess 93, the power transmission is interrupted.

A pair of swing levers 12 and 13 are swingably supported in the upper part of the cylindrical body 9a at their intermediate portions, and are rotatably connected to respective locking pieces 14 and 15 at the lower ends by connecting pins 94. ing. Then, the upper end of each swing lever 12.13 and the cylinder body 9
Each swing lever 1 is moved by a spring 95 interposed between the
2.13, each of the locking pieces 14.15 is urged to move in the direction of engagement with the locking recess 93.

A pair of locking levers 96 and 97 are provided at the lower part of the cylinder body 9a and are swingable at their intermediate portions for locking each of the locking pieces 14 and 15 in a position where they are removed from the lower locking recess 93. It is supported and biased to swing clockwise in FIG. 2(b) by springs 96a and 97a. Also, each swing lever 12.13
At the center of the cylindrical body 9a are locking levers 96.
A release pin 18 that engages with 97 from above is inserted and supported.

When each locking piece 14, 15 is engaged with the lower locking recess 93, the connecting pin 9 of each swing lever 12, 13
5 and one end of each locking lever 96,97,
The other end of each locking lever 96.97 separates from the locking recess 14a, 15a of each locking piece 14.15, and the locking piece 14.
15 is moved in the direction of leaving the lower locking recess 93, the other end of each locking lever 96,97 is engaged with the locking recess 14a, '15a, and 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, a cover 98 is attached, and the cover 98 and each holding piece 1
Each holding piece 16.17 is biased in the direction of engagement with each locking recess 92 by a spring 99 interposed between the holding pieces 16.17 and 6.17.

And both holding pieces 16.1? , cover 98 and spring 99
The locking device 10 is configured by:

Between the reassembly 9 and 10, the needle bar support frame 2 has a protrusion 11.
A switching lever 11 having a shape formed thereon is slidably mounted, and as the switching lever 11 slides, its protrusion 11a
is switched to an intermediate position shown in FIG. 2(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, 5 rise, the locking recesses 92 above the needle bars 4, 5 are arranged to face each holding piece 16, 17. When the drive coupling device 9 is turned on, the pair of swing levers 12.13 of the drive coupling device 9 are selectively engaged with the protrusion 11a, and the engagement causes one of the swing levers 1
2.13 is swung counterclockwise in FIG.
After selectively disengaging from 3, one locking lever 96.9
7 and is held in the disengaged position by the actuating lever 91.
is rotated counterclockwise in FIG. 2(b) based on its own weight balance, and its upper end is attached to one of the holding pieces 16 and 17.
distance from.

Thereby, the needle bars 4, 5 by one locking piece 14.15
At the same time, one of the holding pieces 16, 17 is engaged with the locking recess 92 above one of the needle bars 4, 5, and the connection between the needle bar 4 and the main shaft 6 of the sewing machine is selectively interrupted. , 5 are held at the needle-up position, and the single-needle sewing state is set.

Also, one locking piece 14.15 is connected to one locking lever 96.
97, and one needle bar 4,
5 is locked and held in the counting position by one holding piece 16.17, the other needle bar 4.5 is raised, and accordingly, the release pin 18 of the drive coupling device 9 is released from the protrusion 11.
When the levers 96 and 97 are engaged, the pair of locking levers 96 and 97 are released by the springs 96 and 97 due to the downward movement of the release pin 18.
It is swung counterclockwise in FIG. 2(b) against the biasing forces of a and 97a, and the holding of one of the locking pieces 14 and 15 by the one of the locking levers 96 and 97 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.degree. 5 by the biasing force of the spring 95, and the two-needle sewing state is set.

As shown in FIG. 3, a pair of electromagnetic solenoids 20.21 are attached to the back of the arm part 1 via a bracket 22, and a movable body 23 common to both electromagnetic solenoids 20.21 can move left and right. It is inserted through and supported. 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.
Spring receivers 26 and 27 are fitted to the actuating rod 24 so as to be located on both sides of the actuating rod 24. Between each spring receiver 26° 27 and the protruding piece 25a, the actuating rod 24 has an actuating rod 24
A pair of springs 28, 29 for holding itself in an intermediate position
is installed.

Further, a connecting lever 3 is provided between the movable body 23 and the actuating rod 24.
0 is rotatably supported in the middle, one end of which is rotatably connected to the intermediate portion of the movable body 23, and the other end 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 protruding piece 31a of the connecting member 31 is engaged with the recess 11b of the switching lever 11. Both the electromagnetic solenoids 20, 2
1 is selectively excited, the actuating rod 24 and the connecting member 31 are switched to any of the cloth moving position, the intermediate position, and the left moving position via the movable body 23 and the connecting lever 30. Switching lever 1 when changing the arrangement
The arrangement position of 1 is switched. In this embodiment, the electromagnetic solenoids 20, 21. Mobile object 23. Connecting member 3
1, the switching lever 11, and the like constitute a switching device 32.

Further, as shown in FIG. 2, a pair of pause needle selection keys 34 and 35 for stopping either needle 4a or 5a are provided on the operating section 33 provided on the front surface of the arm portion 1. In addition, there are four types of cloth feed pitches (IP, 3/3 in this example).
Pitch setting keys 36 to 39 are provided for setting 4 P, 1/2 P, 1/4 p, p=reference pitch),
Lamps 34a to 39a are attached to each of the keys 34 to 39, which can be turned on when the keys are operated.

[Operation panel configuration]

The sewing machine in this embodiment has an operation panel 4 shown in FIG.
0, and various keys are arranged on the operation panel 40 according to 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.

On the right side of this key 41 are a creation key 43 and a playback key 44, which are operated respectively to set a sewing pattern creation mode and a sewing execution mode based on the sewing pattern.
are arranged. To the right of both keys 43 and 44 are arranged four pattern designation keys 45 which are operated to designate a sewing pattern, and to the right of the pattern designation key 45 are the needles 4a.

A cloth edge detector 46 for detecting the edge of the workpiece cloth W on the bed of the sewing machine on the cloth feeding side than 5a [Fig.
) frost thickness sensing keys 47 are arranged to be operated to adjust the sensitivity.

On the right side of the frost thickness detection key 47, each sewing step 5L-34 is displayed when creating the sewing pattern shown in FIG.
The distance between the sewing end point on the sewing trajectory formed at each time and the edge Wa of the workpiece cloth W that intersects with the sewing trajectory, that is, the seam allowance B
n is set, and the edge Wa of the work cloth W is detected by the cloth edge detector 46.
The stitching mode key 48 is used to set the cloth edge detection sewing mode in which the sewing after detection is controlled according to the set seam allowance Bn, and the fixed size counting sewing mode, that is, the count required to form a stitch of a predetermined length. (Stitch v1.) or to set the mode for reproducing the sewing of the number of stitches, and the fixed size counting key 49 for freely sewing the desired length while setting the program mode. A free sewing key 50 for setting the mode is arranged in parallel.

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

Around each of the keys 48 to 52, when setting the seam allowance Bn, addition and subtraction are performed in O and 1 mm increments, and when setting the number of corner stitches In for single needle sewing, addition and subtraction are performed in increments of "1", An addition key 53 and a subtraction key 54 for performing subtraction are arranged, and a first numerical display section 55 displays the seam allowance Bn to be set, and the numerical value displayed on the display section 55 is displayed on the sewing machine control device. an enter key 56 that is operated when inputting the number of corner stitches In, a second numerical display section 57 that displays the set number of corner stitches In, and a second numerical display section 57 that is operated when inputting the numerical value displayed on the display section 57 to the sewing machine control device. An enter key 58 to be operated and a clear key 59 to clear each of the displayed numerical values are provided. Incidentally, when the sizing stitch number key 49 is operated, the sizing stitch count Dn is displayed on the first display section 55.
is displayed.

On the right side of the pause needle selection keys 51 and 52, an input key 60 is provided for inputting sewing data created in the setting state of each mode to the control device of the sewing machine for each step 81 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 one step at a time.

Further, on the right side of the human key 60, a sewing end key 63 is provided, which is operated to end sewing after the thread cutting operation.
Below it are an automatic key 64 that is operated to automatically perform one step of sewing in the playback mode, and a split stitch that divides the single-needle sewing section of the corner into multiple processes and executes them. A corner stitch division key 65 for setting the mode and a free key 66 that is operated to set the normal sewing mode unrelated to program sewing when the sewing machine is stopped in an emergency during the regeneration mode are arranged. ing.

Furthermore, there is a lamp 67 on the main key among the above-mentioned keys.
A sewing lamp 68 is provided on the operation panel 40 between the pause needle selection keys 51, 52 and the input key 60, and is lit when urging operation of the sewing machine. Arrows 69 indicating the order of operation of each key during sewing according to each mode and explanatory characters 70 for the sewing lamp 68 are attached to the surface of the sewing machine.

[Sewing machine control device]

The control device of the sewing machine in this embodiment is shown in Fig. 1(a).
As shown in FIG.
The PU 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 includes various counters shown in FIG. 1(b). That is, cloth edge stop counter Nl: In cloth edge detection sewing mode,
Counts the number of counts executed from the time the fabric edge is detected until the sewing is stopped.

Corner stitch counter N2: Single needle sewing process 5l shown in Fig. 6
Count the count in a-34a.

Fixed size stitch number counter N3: In the fixed size stitch number sewing mode,
Count the sizing measurements performed.

Further, the RAM 73 includes a storage area for storing four sewing patterns corresponding to the pattern designation keys 45,
Each storage area stores various data shown in FIG. 1(C). That is, cloth edge detection sewing flag An: is set when the cloth edge detection sewing mode is set.

Seam allowance n: the 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 the fixed size counting sewing mode.

Number of sizing stitches Dn: n: Counting executed at the time of sizing stitch count.

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

One-side fishing flag Fn: Set when the left needle 53 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) Ins Number of corner stitches set when 1-needle stitching is performed.

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 number of stitches: Counting performed at the fabric feed pitch set in advance when setting the fabric edge detection sewing mode.

Correction number of stitches J: Counting 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. which detects the vertical position of the needles 4a, 5a. A synchronization signal generator 75 that generates a synchronization signal in response to the rotation of the sewing machine main shaft. Pitch detection 376 and sewing machine motor 77 for detecting cloth feed pitch
The electrical signals outputted from these pedals, the detection signal outputted from the material edge detector 46, and the key human power signal are input to the input interface. CPU via 79
7 Input at t. Moreover, each key 3 on the operation section 33
Input signals from 4 to 39 are similarly input to the cpU 71. Furthermore, as shown in FIG. 1(a), 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 71 selects the return destination of the program from the sewing step at the beginning of the sewing pattern and from the sewing step following the sewing step where the emergency stop was performed. Steps and settings to select.

Further, the CPU 7 i operates a servo solenoid 80 for changing the pitch of the sewing machine motor 77 and an electromagnetic solenoid 20 .
21, an output interface 81 and each drive circuit 82
, 83, 84 to output a drive control signal. Furthermore,
The CPU 7■ responds to the control program and various data and displays each numerical value display section 55 through the display drive circuit 85, etc.
7.61 and each lamp 34a to 39a, 67°68.

Note that the needle position detector 74 and synchronization signal generator 75 in this embodiment. The structure of the pitch detector 76 and the pitch changing servo solenoid 80 is disclosed in Japanese Patent Application Laid-Open No. 1989-1996 by the applicant.
This is the same as that described in Japanese Patent No. 1-217197, so please refer to it if necessary.

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

(Data Creation Mode) Now, as shown in FIG. 5(a), when the program sewing key 41 and the creation key 43 are sequentially operated, the CPU 71
In routine 101, step number n is set to zero. Next, by operating the pattern designation key 45,
After the storage area of the RAM 73 is specified, the CPU 71 stores each counter N1 to N3 . Each data Bn, Dn, In and each flag An, Cn, En, Fn, On, Hn, Ln, M
Reset all n.

Then, the cloth edge detector 46 is activated by operating the right limit detection key 47.
After completing the sensitivity adjustment, the CPU 71 presses the stitch width key 48 in routine 102 shown in FIG. 5(b). It waits for either the fixed size stitch number key 49 or the free stitch key 50 to be operated. Here, in order to execute the sewing in sewing step S1, for example, the stitch width key 48 is operated, and the routine 1
When the determination in step 02 becomes YES, the step number n is updated, the flag An is set, and the cloth edge detection sewing mode is set.

Next, the program proceeds to a seam allowance setting routine 103, where a seam allowance Bn (n=1) is set in response to the operation of each of the keys 53, 54, 56, and 59.

Displayed blue routine 1 in this seam allowance setting routine 103
03a, each time the addition key 53 and the subtraction key 54 are operated, the numerical value is added or subtracted by 0.1 am, and the first
It is displayed on the 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 cents of the seam allowance Bn, the CPU 71 turns on the corner stitch division key 65 and the lamp 67 on the paused needle selection key s1.52.
and the sewing lamp 68, and press each of the keys 65 and 5.
Actual sewing operation is prompted by the selection operation of 1.52 and the forward depression of the operating pedal 78. Therefore, for example, Fig. 6 (a
), a single needle sewing step Sla is performed at the corner of the work cloth W.

If the counts in S2a are equal, in the one-leg stitch count setting routine 104 shown in FIG. 5(c), the corner stitch division key 6 is pressed.
5 without operating either one of the pause hand selection keys 5.
Operate 1.52. Then, one side or other side corner stitching flags Fn, Gn are set in accordance with the operation of each key 51, 52, and the corner stitching mode is set in combination with the cloth edge detection stitching mode.

Moreover, as shown in FIGS. 6(b) to 6(e), among the single-needle sewing steps 5la-34a at the corners of the work cloth W, the count of at least one sewing step is different from the count of the other sewing steps. If they are different, if the corner stitch division key 65 is operated prior to operating the paused needle selection keys 51 and 52, the corner stitch division flag Hn is set, and the divided corner stitch mode changes to the fabric edge detection stitching mode. Set in combination.

After setting the seam allowance, the single needle sewing process Sl in sewing step S1 is started by operating each key 53, 54, 58, 59.
When the setting of the number of corner stitches In of a is completed, the program proceeds to the sewing subroutine 105 shown in FIGS. 5(c) and 5(f).

In this subroutine 105, each flag Hn, Fn' in the sewing step immediately before the current sewing step is
, Gn, the electromagnetic solenoid 20.2
1 is controlled.

Incidentally, in the first sewing step S1, since each of the flags is reset, in response to the forward depression of the operation pedal 78 in the routine 105a of the sewing subroutine 105, the presser foot activation solenoid (path shown) is activated.
is turned off, and the work cloth W is
is pressed onto the workpiece fabric support surface of the sewing machine, the sewing machine is operated with two needles sewing, and the program is as shown in Figure 5 ('c).
.

The process returns to the main routine shown in (d).

Then, the CPU 71 executes the routine 106 in FIG. 5(d).
, the cloth feed pitch during operation of the sewing machine is detected by an input signal from a pitch detector 76. Also, as the sewing machine is operating, the edge of the workpiece cloth W is detected by the cloth edge detector 46.
When detected, in the feed amount calculation subroutine and calculation subroutine in the routine 106, the work cloth W is detected.
The feed amount of the transferred workpiece cloth W is calculated after detecting the edge of the workpiece cloth W until the needles 4a, 5a next penetrate the workpiece cloth W, and the feed amount data and the preset cloth are calculated. Based on the feed pitch (basic pitch) and the corrected number J of sewing stitches (3 in this embodiment), which is also set in advance, the reduction rate of the cloth feed pitch and the number K of stitches to be sewn at the basic pitch are calculated.

This arithmetic processing is described in the above-mentioned Japanese Patent Application Laid-open No. 61-2.
It is described in Japanese Patent No. 17197, so please refer to it if necessary.

Next, in routine 107, according to the cloth end stop counter N1,
Counting is started from the time the edge of the work cloth W is detected until the sewing stops. The program is shown in Figure 5(d).
The process proceeds to the pitch change subroutine 108 shown in (g), (h), and (i), and the subroutine 108
In the first routine 108a, based on the previously set number of corner stitches In and the calculation results of the calculation subroutine, etc.
The need for pitch reduction is determined.

That is, if it is necessary to reduce the pitch and the set number of corner stitches In is larger than the corrected number of stitches J, the determination in routine 108b becomes YES, and the value of the counter N1 becomes +J-In. The basic pitch sewing is performed until the basic pitch is reached (routine 108c). Then, flag Fn,
It is determined whether or not Gn is set, and each electromagnetic solenoid 20, 21 is energized according to the determination result, whereby one needle 4a, 5a corresponding to each flag is paused, and a single needle sewing state is established. is set (routine 108d).

Next, sewing is performed at the basic pitch until the value of the cloth end stop counter N1 matches the basic pitch stitch number K, and then the pitch changing servo solenoid 8° is activated to perform a pitch reduction operation. +J to the value of cloth end stop counter Nl
Sewing is performed using the reduced pitch until the distance is reached (routine 108e). 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
The routine jumps to routine 108f shown in FIG. If the determination is No, in routine 108g, after sewing corresponding to the number of basic pitch stitches K is performed, a pitch reduction operation is performed, and sewing with the reduced pitch is performed until the value of counter N1 reaches +J-In. is executed. Then, in routine 108h, the single-needle sewing state is set, and sewing is performed at reduced pitch until the value of the material end stop counter N1 reaches -1-J, and then the program returns to the main routine. do.

On the other hand, if the number of corner stitches In is set to zero and the determination in the routine 108f is YES, the routine 1
At step 081, after sewing corresponding to the number of basic pitch stitches K is performed, a pitch reduction operation is performed, and sewing with the reduced pitch is performed until the value of the counter N1 reaches +J. Then, in routine 108j, each flag Fn.

The set state of On is determined, and the first sewing step S1
When corner stitching is not to be performed, the process returns to the main routine shown in FIG. 5(d).

Further, in the routine 108j, when it is determined that either corner stitching flag Fn or Gn is set, C
After energizing each of the electromagnetic solenoids 20 and 21, the PU 71 controls the pitch changing servo solenoid 80 to set the cloth feed pitch to zero in routine 108k.

In this state, the sewing machine is operated until the value of the counter Nl reaches +J+1. In other words, one needle 4a, 5a is moved back and forth once with the feed amount being zero (routine 1081).
). Then, in routine 108m, when the pitch changing servo solenoid 80 changes the cloth feed pitch to the basic pitch, the program returns to the main routine.

Furthermore, there is no need to reduce the pitch, and the corner sewing needle GI n
If the value of is zero, the program executes routines 108a to 108n shown in FIG.
After that, the process proceeds to routine 1080, and the basic pitch stitch number K is
After the sewing corresponding to is executed, routine 108p, 1
In 08q, 108r, 108s, the routine 1
At 083°108, substantially the same processing as at 1081 and 108m is performed, and the process returns to the main routine.

If the number of corner stitches In is not zero and the determination in routine 108n is No, sewing is performed at the basic pitch in routine 108[ until the value of counter N1 reaches -1n, and then the routine returns to In step 108H, the single needle sewing state is set, and in routine 108V, sewing is continued until the value of counter Nl reaches K.

The program then returns to the main routine.

As described above, when the sewing according to the pitch change subroutine 108 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 (routines 109 and 110). Through the above processing, the sewing of the sewing step S1 including the one-needle sewing step Sla is completed on the work cloth W shown in FIG. 6, and the creation of count data regarding the step St is also completed.

When the processing up to this point has been completed, the CPU 71 executes the process shown in FIG.
) waits for the operation of the input key 60, and in response to the operation, stores each count data in the RAM 7.
The data is stored in the working area No. 3 (not shown). Subsequently, in order to create sewing data for the next sewing step S2, the work cloth W is turned around the needle on the outside of the corner, and then single-needle sewing is performed, for example, as shown in FIG. 6(a). If the numbers of stitches in steps 31a and S2a are equal, follow the arrow 69 on the operation panel 40 and operate the stitch width key 48 again in the routine 102 of FIG. 5(b).

Then, as described above, since the cloth edge detection sewing mode is set, the seam allowance Bn for the next sewing step S2 can be set, and then each key 51, 52, 65
The corner stitching mode for the next corner can be set by operating .

Subsequently, the program proceeds to the sewing subroutine 105, and in the routine 105a, after the front depression operation of the operating pedal 78 is performed again, each flag Hn, F at the previous sewing step (in this case, the first sewing step Sl) is set.
The set status of n and Gn is determined, and the corner stitch division flag I is set.
When n is not set and the one side or other side corner stitch flags Fn and Gn are set, the sewing machine is operated and the sewing in the single needle sewing step S2a is executed, and accordingly, the corner stitching flags Fn and Gn are set. The value of counter N2 is the previous 1
When the number of corner sewing stitches In in the main needle sewing process Sla is reached, the electromagnetic solenoid 20 corresponding to each flag Fn, Gn.
21 is demagnetized and switched to the two-needle sewing state. Thereafter, the program returns to the main routine shown in FIG. 5(d).

After the program returns to the main routine, Routine 1
When the processing from 06 onwards is repeated, count data regarding sewing step S2 is created.

Then, by repeating the above process, it is possible to complete the creation of sewing data regarding sewing steps S3, S34, etc. subsequent to sewing step S2.

On the other hand, as shown in FIG. 6(b) to (e), each process 5l
When sewing a different number of stitches for each axS4a, in step S1, sewing is performed using a combination of the cloth edge sensing sewing mode and the corner sewing mode as in the above case, and the sewing in the single needle sewing step S13 is completed. Later, when the program returns to the routine 102, the corner stitch division key 65 is operated.

Then, the corner stitch division mode is set. Therefore, by operating the keys 53, 54, 58, and 59, the number of corner sewing stitches In, which is different from that in the sewing process Sla, is manually set for sewing in the single needle sewing process S2a.

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 operating pedal 78, and sewing for the set number of stitches In is performed in a single-needle sewing state based on the operation of the counter N2. Thereafter, the program returns to routine 109 of FIG. 5(d), and after the sewing machine is stopped, 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, regarding the sewing in the single needle sewing process S2a shown in FIG. 6(C), after the sewing in the single needle sewing process Sla is completed,
If the number of corner stitches In is not set and the stitching key 48 is operated again in routine 102, the sewing can proceed to the next step S2.

In this embodiment, when the creation of the sewing pattern data described above is completed, after depressing the back of the operation pedal 78 in the routine 112 shown in FIG. ,
After the automatic thread trimming operation is performed, each count data etc.
It is transferred from the working area of M73 to a predetermined storage area and stored.

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 each sewing pattern shown in FIGS. 6(a) to (e), the program sewing key 41 and the reproduction key 4
4, the CPU 71 sets the playback mode. Therefore, when a sewing pattern created in the creation mode is specified, each flag and each count data making up the pattern are sequentially read out, and the sewing machine is controlled based on them. Therefore, the sewing pattern can be easily reproduced.

As described above, in this embodiment, the number of corner stitches In can be set to zero to perform single-needle sewing, so that, for example, as shown in FIG. At the position where needle sewing is completed, the left needle 5a can be stopped at the 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, it is possible to reliably form a stitch connecting both ends of the parallel stitches formed by the two-needle sewing only with the right needle 4a. can. Therefore, it is possible to reliably sew corners of various shapes.

In addition, in this embodiment, keys 37 to 39 are provided that can set a plurality 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 counting mode, free sewing 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. 1(a) is a block diagram showing the control device of a sewing machine embodying the present invention, FIGS. 1(b) and (C) are explanatory diagrams of the CPU and RAM, and FIG. 2(a) is a block diagram showing the control device of the sewing machine. 2(b) is a partially enlarged sectional view of the needle bar mechanism, FIG. 3 is a partial rear view of the sewing machine, FIG. 4 is a front view of the operation panel, and FIGS. 5(a) to (i) are Flowchart, Figures 6(a) to (e)
) is an explanatory diagram of a sewing pattern. 4.5...Needle bar, 6...Sewing machine main shaft, 7...Crank, 8...Crank lock, which constitutes needle bar drive means together with the above 7, 9...Drive coupling device, IO... - Locking device, 32... switching device (switching mechanism is constituted by the aforementioned 9, 10, 32), 71... CPU as control means, 80... servo solenoid as pitch changing means. Patent applicant Brother Industries, Ltd. Agent
Patent Attorney On 1) Hironobu Figure 1 (b) (a) (S2a)

Claims (1)

[Claims] 1. Two needle bars (4, 5
), and as the sewing machine main shaft (6) rotates, these two needle bars (4,
needle bar drive means (7, 8) for vertically moving the needle bars (5); and needle bar drive means (7, 8) provided between the needle bar drive means (7, 8) and the two needle bars, , 5) and the needle bar drive means (7,
a two-needle sewing state in which two-needle sewing is performed in conjunction with 8);
A switching mechanism (9, 10, 32) that switches based on the operation of the needle bar driving means (7, 8) to a single needle sewing state in which one needle bar is stopped at a corner and one needle sewing is performed. A two-needle corner stitch sewing machine comprising: a pitch changing means (80) capable of changing a predetermined feed pitch of the work cloth (W) to zero; and two needle bars (4).
, 5) is stopped downward, the pitch changing means (8
0) to change the feed pitch to zero, and switch the switching mechanism (9, 10, 32) to the single needle sewing state,
A control means (71) for driving the needle bar driving means (7, 8) by at least one stitch is provided, and at the position where the two-needle sewing is completed, one of the needle bars (4, 5) is moved downward. A two-needle corner stitch sewing machine characterized by being stoppable.