JPS5949024B2 - Sewing machine with automatic thread tension control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of controlling the lateral oscillation of a sewing needle by using a oscillation amplitude information group, a feed information group, and a thread tension information group that are stored in advance as electrical or magnetic signals in a storage device. This relates to sewing machines that automatically control movement, feed of work cloth, and thread tension, and in particular automatic thread tension that controls thread tension according to each stitch pattern in order to form a wide variety of stitch patterns. Regarding a sewing machine with a control.

As is well known, even if the thread tension applied by the thread tension applying device is constant, the winding condition of the sewing thread, such as the upper thread, during stitch formation depends on various factors, such as the needle lowering position, the feeding direction of the work cloth, and the feeding direction of the work cloth. amount.

Because it is affected by the amplitude of the lateral swing of the sewing needle, whether it is lockstitch or chain-stitch, etc., it is difficult to obtain the optimal thread reeling condition for each type of stitch pattern to be formed, especially in pattern stitch sewing machines. Furthermore, it is difficult to obtain uniform thread tightness for each stitch in the same stitch pattern.

In addition, the conditions for obtaining a uniform thread reeling condition due to the above factors are partly due to the structure of the sewing machine, but
Generally speaking, with respect to the needle lowering position, the thread tension is set higher when descending to the right than when descending to the left, the thread tension is set higher when moving forward than when moving backwards regarding the feeding direction of the work cloth, and the feed pitch is small when it comes to the feed amount. The thread tension is higher when the feed pitch is larger than when the feed pitch is larger than when the feed pitch is larger than when the feed pitch is larger than when the feed pitch is larger than when the feed pitch is larger. This means increasing the tension.

If the yarn tension is set in consideration of these conditions, a relatively uniform yarn reeling condition can be obtained.

By the way, one typical example of prior art that automatically controls thread tension is to expose or not expose the bobbin thread of a different color from the upper thread to the upper surface of the workpiece fabric by controlling the tension of the upper thread. This system is designed to obtain a dotted color pattern using a cam, and the thread tension information is stored in a cam.

In order to apply this technology to sewing machines that form many types of seam patterns and eliminate the above-mentioned drawbacks, it is necessary to prepare many types of cams that correspond to various types of seam patterns, and Since the shape of the cam and the structure of its mechanical displacement transmission mechanism are complicated, it is not practical to mechanically control the thread tension as in cam control.

In addition, as another prior art, there is a technique that automatically controls thread tension according to the sewing speed so as to obtain a constant thread reeling condition regardless of changes in the sewing speed of the work cloth. Thread tension is controlled by a single factor called sewing speed, and cannot be applied to sewing machines for forming many types of stitch patterns, which control thread tension by taking into account multiple factors.

The present invention has been made in view of the above-mentioned circumstances, and its object is to control the lateral vibration of a sewing needle by using a large number of vibration amplitude information groups and feed information groups stored in advance as electrical or magnetic signals. In a sewing machine that selectively and automatically forms many types of stitch patterns by controlling dynamic movement and feed of the workpiece cloth, thread tension information for each stitch is calculated by changing the thread tension information for each stitch. Amplitude information and feed information are stored in advance so as to form a set, and when forming a stitch, the thread tension to be applied to the sewing thread for each stitch is adjusted according to the type of stitch pattern using the stored thread tension information. Alternatively, by adopting a configuration in which automatic control is performed according to the formation circumstances of each seam forming the seam pattern, the optimal thread winding condition can be obtained regardless of the difference in the type of seam pattern, or the same thread winding condition can be obtained. The optimal thread winding condition can be obtained for each stitch in the stitch pattern, and the thread tension can be easily controlled to form a stitch pattern that has a complex shape and consists of a large number of stitches. To provide a sewing machine with automatic thread tension control.

Hereinafter, details of the present invention will be explained by way of an embodiment with reference to the drawings.

In FIGS. 1 and 2 showing an overview of the mechanism of a sewing machine to which the present invention is applied, a sewing machine frame 1 includes a stand 2, a support 3 rising from the stand 2, and an arm extending horizontally from this support. 4 and connected to each other via a known drive mechanism (not shown) in a time-related manner.
and a lower shaft 6, and the upper shaft 5 is rotated by a drive motor (not shown) via a main pulley 7.

8 is a needle rocking device that gives a horizontal rocking motion to the sewing needle 9;
Detailed illustration of the structure is omitted since known means are sufficient, but the swing support 10 directly contributes to the swing movement.
This is provided with a needle bar 11 that moves up and down reciprocally in conjunction with the upper shaft 5, and a sewing needle 9 is connected to this needle bar 11.

The swinging support 10 provides a lateral swinging motion to the sewing needle 9.
is adapted to be swung by a drive link 12,
For this purpose, one end of the drive link 12 is connected to the swing support 10.
The other end is connected to an amplitude control actuator 14, which will be described later, and the amplitude of the lateral swing of the sewing needle 9 is controlled by the amplitude control actuator 14.

Reference numeral 15 denotes a feeding device that imparts a feeding motion to the workpiece cloth in synchronization with the up and down reciprocating movement of the sewing needle 9;
Since a known configuration is sufficient for the present invention, only those parts useful for understanding the present invention are illustrated.

In the feed device 15, the feed drive shaft 16 is rotationally driven from the lower shaft 6 via a gear mechanism 17.
The rotation of the feed drive shaft 16 is controlled by the cam 18 and the cam holding rod 19.
, and via the shaft 20 to the link 21 as a rocking motion, which in turn excites the feed dog 23 via the feed bar 22 to a feed movement.

As is well known, the shaft 20 slides in a groove 25 provided in a grooved member 24 so as to control the feed amount (feed increment) and the feed direction of the work cloth by one feed movement of the feed dog 23. It has pieces that play.

The grooved member 24 is integrally connected to a lock shaft 24a, and a lock arm 24b is attached to this lock shaft 24a.
is connected to the lock arm 24b, and an adjustment rod 2 is connected to the lock arm 24b.
6, and when this adjustment rod 26 is mechanically displaced in the longitudinal direction, the lock shaft 24a is rotated via the lock arm 24b, so that the grooved member 24 is rotated, thus controlling the inclination angle of the groove 25.

As is well known, the angle of inclination of the groove 25 and the direction of its rotation determine the feed increment and the direction of feed of the work cloth.

Adjustment rod 2 is used to control such feed increment and direction.
A feed control actuator 28 is provided to apply a mechanical displacement to 6.

Next, in detail, this feed control actuator 28 essentially corresponds to a direct current type reversible linear motor, and is equipped with a U-shaped magnetic yoke 29, on each inner surface of the opposite side. The permanent magnet plates 30, 30 are fixed in such a manner that their opposing surfaces have the same polarity, and a neutral magnetic leg 31 is magnetically attached to the intermediate portion between the opposing permanent magnet plates 30, 30 by a screw 32. It is located in a state where it is fixed to the yoke 29.

An extremely lightweight bobbin 34 wound with a coil 33 is inserted into the neutral magnetic leg 31 so as to be linearly movable.

35 is a cover plate made of magnetic material fixed to the neutral magnetic leg 31 by screws 36, and a pair of throwers 37 and 37 of this cover plate 35 are connected to an arm 38 integrated with the bobbin 34.
．． 38 protrudes through the arm 38, and one end 41 of a lever 40 is supported by a single shaft 39 between the tips of each arm 38, 38, and a retaining ring 42 prevents the shaft 39 from being removed.

A support plate 43 is connected to the lower part of the cover plate 35 via a connection means (not shown), and a plurality of support protrusions formed on the support plate 43 have an intermediate portion of the lever 40 attached to a rotation shaft 44. The pivot shaft 44 is supported by the lever 4.
It is designed to rotate together with 0.

The adjustment rod 26 is connected to the other end 45 of the lever 40.

The pivot shaft 44 of such a feed control actuator 28
A sliding shaft 47 of a well-known resistance type potentiometer 46 is connected to.

According to this feed control actuator 28, the coil 33
When a direct current is applied to the permanent magnet plate 30, this current and the permanent magnet plate 30
A linear movement force proportional to the current value is generated in the coil 33 by the magnetic field generated by the magnetic field 30, and when the bobbin 34 moves along the neutral magnetic leg 31, the lever 40 moves the rotation axis 44 in the corresponding direction. It rotates along with the center, and the rotation causes the sliding shaft 47 of the potentiometer 46 to rotate.

The amplitude control actuator 14 described above also has the same configuration as the feed control actuator 28 described above, and is equipped with a similar potentiometer 48.
2 is connected to a lever 40 in the amplitude control actuator 14.

49 is a timing pulse (directly a first timing pulse BCP for amplitude control, which will be described later) in conjunction with the upper shaft 5.
This pulse generator generates timing pulses in synchronization with the up and down reciprocating movement of the sewing needle 9.

Note that 50 shown in FIG. 1 is each unit of an electric circuit to be described later, and FIG. 1 shows an example of the arrangement thereof.

Next, the thread tension device 51 (not shown in FIG. 1) shown in FIGS. 3 to 5 will be described.

That is, 52 is a thread tension electromagnetic solenoid for controlling thread tension, which is screwed to the arm portion 4 of the sewing machine frame 1 via a support plate 53, and a magnetic cavity 55 into which a plunger 54 is loosely inserted is provided inside the solenoid. is formed.

Reference numerals 56 and 57 designate a pair of thread tension discs for applying tension to the sewing T-thread, especially the upper thread, and these discs are loosely inserted and supported by a pair of pins 59 protruding from another support plate 58 in a two-ply state. ing.

Reference numeral 60 denotes a push rod whose one end 60a presses one thread tension disc 56 against the other thread tension disc 57, and this is supported by a fixed plate 61 so as to be able to reciprocate.
2 is fixed to the arm portion 4.

A fulcrum of a plunger interlocking lever 63 is pivotally attached to the fixed plate 61 by a stepped screw 64, one end 63a of which is brought into contact with the other end 60b of the push rod 60, and the other end 63b is connected to the tip of the plunger 54. It is rotatably connected within the formed groove 65 by a pin 66.

Reference numeral 67 denotes an auxiliary switch, which is an opening/closing device that controls the supply and cutoff of electric power applied to the thread tension electromagnetic solenoid 52 in connection with the operation of the workpiece presser device 68 for pressing the workpiece cloth. It is attached to a mounting plate 70 supported by 69.

Reference numeral 71 denotes a switch opening/closing lever, which is rotatably supported by stepped screws 73 on the fixed plate 61 through a sleeve 72 provided thereon, and normally each end provided on the sleeve 72 is connected to the fixed plate 61 and the fixed plate 61. The screw spring 74 engaged with the switch opening/closing lever 71 rotates the lever clockwise in FIG. I have to.

In the workpiece presser device 68, 76 is a presser bar which has a presser foot (not shown) at its lower end, and whose intermediate portion is supported by the arm portion 4 in a vertically movable manner; A cam receiving plate 79 that slides on a cam surface 78 of the presser foot lifting cam 77 is fixed to the presser foot lifting cam 77, and a fulcrum portion of the presser foot lifting cam 77 is pivotally attached to the arm portion 4 by a stepped screw 80.

A presser foot lifting lever 81 is integrated with the presser foot lifting cam 77.
protrudes outside the arm portion 4.

Reference numeral 82 denotes a rotating lever that is linked to the vertical movement of the presser bar 76. The fulcrum of this lever is pivotally attached to an appropriate part of the arm 4 by a stepped screw 83, and one end 82a of the lever 82 is attached to the upper surface of the cam receiving plate 79. The other end 82b faces the other end 71b of the switch opening/closing lever 71 at a position where it can abut and engage.

In the above, the electromagnetic solenoid 52 has a pair of thread tension discs 56 and 57 to ensure tension is applied to the upper thread.
With no needle thread inserted between them, and with the support plate 58. In a state in which the thread tension discs 57, 56, push rod 60, and plunger interlocking lever 63 are in contact with each other in sequence,
Terminal surface 55a of magnetic cavity 55 and end surface 5 of plunger 54
4a so that there is a slight gap (for example, 0.1 mm in the moving direction of the plunger).

When the upper thread is inserted between the thread tension discs 56 and 57, the gap between the end surface 55a of the magnetic cavity 55 and the end surface 54a of the plunger 54 is approximately 0.4 mm at most in the direction of movement of the plunger. Therefore, as long as the plunger 54 is located within its movement range, the electromagnetic solenoid 52
In this embodiment, an electromagnetic solenoid is used which has a characteristic that the attraction force depends only on the magnitude of the supplied current and does not depend on the attraction position of the plunger.

In FIG. 5, 84 is a slot for guiding the upper thread from an unillustrated upper thread supply source to the thread tension discs 56 and 57, 85 is a thread guide, and 86 is a thread take-up spring.

Next, regarding the needle hole switching device, see Figures 6 to 9 (in addition, Figure 1
(not shown in the figure) will be explained.

Reference numerals 87 and 88 denote a first electromagnetic solenoid and a second electromagnetic solenoid used for needle hole switching, etc., and plungers 89 and 90 loosely inserted into these are of a type that protrudes and moves when energized. In each groove 91 formed at the tips of 89 and 90, both ends 93a of the connecting plate 93,
93b is loosely inserted, and both ends 93a, 93b are pivotally supported within each split groove 91 by pins 92.

Stoppers 94 and 95 are fixed to appropriate stationary parts, respectively, and these stoppers face the tips of the plungers 89 and 90 to restrict the amount of protrusion.

96 is a stepped screw 9 attached to a suitable stationary member 97 at the fulcrum part in the middle.
One end of the lever is rotatably connected to the intermediate portion of the connecting plate 93 by a stepped screw 99, and the other end of the lever 96 is connected to a pivot rivet 100.
It is connected to one end of the operating frame 101 via.

This operating frame 101 is always urged by a spring 102 in a direction opposite to the direction of arrow 102a.

The other end of the operating frame 101 is connected to a known mechanism for selectively performing zigzag lockstitching, straight lockstitching, and silver border. This corresponds to the operating rod 26 shown in Publication No. 50-31944.

FIGS. 8 and 9 show parts of the mechanism, particularly those related to needle hole switching, in order to facilitate understanding of the present invention.
This is an excerpt from Publication No. 31944.

In FIG. 8, 103 is an opening 104 for the feed dog 23.
, a horizontally long hole 105 for zigzag sewing, and the horizontally long hole 105
This is a throat plate formed with a round hole 106 for straight stitching connected to the center front edge of the throat plate. This relationship is established within the fitting range between the pin 109 implanted on the lower surface of the slide groove 103 and the elongated hole 110 formed in the sliding groove 108 .

In FIG. 9, reference numeral 111 is a tri-arm-shaped intermediate lever, the center of which is pivotally connected to a fixed shaft 112, and the spring is always attached to the lever.
13 in the clockwise direction, one arm 114 of which abuts a pin 115 provided on the operating frame 101, and the throat plate is inserted into an open groove 117 formed in the other arm 116. The lower end of the pin 109 implanted in the pin 103 is configured to engage with the lower end.

The left end of the operating frame 101 in FIG. 9 is connected to a silver edge mechanism, which is similar to the mechanism disclosed in Japanese Patent Application Laid-open No. 49-120761 cited in the aforementioned Japanese Patent Application Laid-open No. 50-31944.
However, since the structure described therein is not the only structure directly related to the present invention, the explanation thereof will be omitted.

Now, FIG. 6 shows a state in which the first electromagnetic solenoid 87 is de-energized and the second electromagnetic solenoid 88 is energized, but the first and second electromagnetic solenoids 87 and 88 are energized at the same time. In this case, each plunger 89,90 is projected to a position where each tip thereof abuts a stopper 94,95, so that the connecting plate 93 as a whole is moved a distance 11 in the direction of arrow 118, so that the stepped screw 99 is moved. A lever 96 connected to the intermediate portion of the connecting plate 93 via a stepped screw 9
8 in the direction of arrow 119, the operating frame 1
01 moves the spring 10 in the direction of the arrow 102a by a distance corresponding to the moving distance 11 of the connecting plate 93 in the direction of the arrow 118.
The pin 115 provided on the operating frame 101 is thereby moved to the MP2 position in FIG. 9.

This position corresponds to the chain gutter operating position.

Next, as shown in FIG. 6, the first electromagnetic solenoid 87
is cut off and the plunger 89 is in the retracted state,
At the same time, when the second electromagnetic solenoid 88 is energized and its plunger 90 is in the protruding state, the moving distance 12 of the connecting plate 93, especially the stepped portion 99, in the direction of the arrow 118 is determined from the above-mentioned 11. is also smaller, and the operating frame 101 also moves in the direction of the arrow 102a by a distance smaller than that described above.

At this time, the pin 115 reaches the illustrated MPI position, and this position corresponds to the straight lockstitch position.

Next, when the first and second electromagnetic solenoids 87, 88 are de-energized at the same time, both the husband's plungers 89, 90 are retracted, so that the connecting plate 93 as a whole is moved most in the direction of the arrow 118. The operating frame 101 is moved backward in the opposite direction, and the operating frame 101 is also moved the most in the direction opposite to the direction of the arrow 102a.
The pin 115 of is located at the illustrated MPO.

Now, when the pin 115 is in the MPO position, the intermediate lever 111 is rotated most counterclockwise at the position where one arm 114 is in contact with the pin 115 due to the rotation of the intermediate lever 111 by the spring 113. position, and the pin 109 integrated with the throat plate 103 is brought into contact with the rear end (lower end in FIG. 8) of the elongated hole 110 through the open groove 117; The horizontally elongated hole 105 formed in is located at a position that coincides with the needle lowering position,
This is the zigzag lockstitch position of the throat plate 103.

Also, the pin 115 of the operating frame 101 is moved from MPO to MP as shown in the figure.
When the intermediate lever 111 is moved to I, the intermediate lever 111 is also further rotated clockwise, so that the pin 109 integrated with the throat plate 103
The long hole 110 is opened by the open groove 117 of the intermediate lever 111.
The needle plate 103 is also moved in the same direction so that the circular hole 106 of the throat plate 103 coincides with the needle lowering position, and a straight stitch operation is performed at this position.

Next, we will explain the feed control of this sewing machine, especially for the processed cloth, and the sewing needle 9.
A control circuit that electrically performs swing amplitude control, sewing thread tension control, and needle hole switching control will be described.

The overall configuration of this electrical control circuit is shown in FIG.

A group of oscillation amplitude information corresponding to various types of stitch patterns that will be understood later.

A selection device 121 operated by an operator to selectively enable three information groups, a feed information group and a thread tension information group, generally includes a pattern selection switch group 122 and an encoder 1.
23 and a selection code holding circuit 124.

The pattern selection switch group 122 includes eight pattern selection switches SO to S that are closed only while applying pressure with fingers.
7, each of which corresponds to the various stitch patterns shown with the same reference numerals in FIGS. 16A to 16H, and is used to select one of them.

One end of each pattern selection switch SO to S7 is a low potential terminal (
For example, the terminal is connected to the zero potential terminal), and each other end is connected to the encoder 1.
23 input terminals.

This encoder 123 is connected to pattern selection switches SO and SL.
...S6. Each S7 has a decimal number of 0. 1...
...6 and 7 are assumed, and the pattern selection switch group SO
When any one of S7 to S7 is closed, the decimal number assumed for this is converted into a binary code, and each bit of the decimal number is converted into a corresponding line Ll for each bit.1. L12. L1
4, and a reset line L15 provided separately that changes from a low level to a high level when any one of the pattern selection switches SO to S7 is closed and returns to a low level after a certain period of time. A signal CP1 is generated.

This reset signal CP1 is applied to the inverter 125. resistance 12
6 and an integrating circuit 12 formed by a capacitor 127
8, is input to a waveform conversion circuit 131 consisting of a NAND circuit 129 and an inverter 130 and is converted into a reset pulse R5P, which is output to a reset output terminal 132 of the waveform conversion circuit 131.

The selection code holding circuit 124 receives corresponding bits from the encoder 123 on lines L11, L12 . L14
Three flip-flop circuits FFI, FF2 . We have FF4, and these are
When the reset pulse R3P is input to each tarok input terminal CK via the lead wire 133, the encoder 12
Store each bit from 3.

In this way, when any one of the pattern selection switches SO to S7 is closed, the selection code holding circuit 124 stores it as a binary code coded code, that is, as a 3-bit selection code. , and when one of the other pattern selection switches SO to S7 is closed, the selection code of the newly closed one is re-stored in synchronization with the reset pulse R8P, and the currently stored selection code is re-stored in synchronization with the reset pulse R8P. The code corresponds to bit line L21
．． L22. It is output to L24.

On the other hand, when the sewing machine is in operation, the pulse generator 49 generates a first timing pulse BCP for amplitude control as shown in FIG.

In this FIG. 15, 134 represents the vertical movement locus of the needle tip when 135 shown by a straight line is the upper surface of the throat plate, and 136
indicates a period during which the feed dog 23 protrudes upward from the upper surface 135 of the throat plate to apply feed to the work cloth.

In order to obtain a second timing pulse FCP for feed control and yarn tension control as shown in FIG. 15 in relation to the first timing pulse BCP, and for reasons that will be understood later, the reset output The terminal 132 is connected to the NAND circuit 1 via a delay circuit 137 and an inverter 138.
39, and is also connected to the first timing pulse BCP output line L31 of the pulse generator 49.
is connected to the other input terminal of the NAND circuit 139, the output line L31 is connected to the counting input terminal of a first address counter 140 corresponding to a reading device, and the output line L32 of the NAND circuit 139 is Second address counter 1 corresponding to another reading device
41 and the third address counter 142, and the reset output terminal 132 is connected to each reset input terminal RT of the address counters 140, 141, and 142.

Here, delay circuit 137. The inverter 138 and the NAND circuit 139 constitute a pulse distributor 143 as a whole.

Since the reset output terminal 132 is always at zero level, that is, generally at a low level potential except for the period during which the reset pulse R3P is generated, the output of the inverter 138 is at a high level, and therefore, the output of the inverter 138 is at a high level. When one timing pulse BCP is applied to the other input terminal of the NAND circuit 139, the output line L3 of the NAND circuit 139
2, a second timing pulse FCP corresponding to the phase-inverted version of the first timing pulse BCP is output.

the first to third address counters 140, 141,
142 has a reverse binary counter configuration, and when any one of the pattern selection switches SO to S7 is selected and closed, the reset pulse R8P changes the number to decimal (0).
After that, the first address counter 140 counts the pulse CP2 generated at the falling edge of the first timing pulse BCP input thereto, and the second and third address counters 141, 142 counts pulses CP3 (see FIG. 15) generated at each falling edge of the second timing pulse FCP.

Therefore, as is clear from FIG. 15, the second and third address counters 141 regarding feed control and yarn tension control
．． 142 is counted in synchronization with time TO when the sewing needle 9 descends from the top dead center and reaches a position slightly below the throat plate 103.

On the other hand, the first address counter 140 relating to the horizontal swing amplitude control of the sewing needle 9 counts in synchronization with time T1 when the sewing needle 9 rises from the bottom dead center and is removed from the work cloth.

Therefore, the second and third address counters 141, 142
is always in a relationship that the count content is incremented by one with respect to the first address counter 140.

Reference numeral 144 denotes a first semiconductor memory device, which has a large number (eight in this embodiment) that controls the lateral oscillating movement of the sewing needle 9 to form the various stitch patterns shown in FIG. This is to obtain a group of vibration amplitude information.

As shown in each "amplitude information" column in FIGS. 17A to 17H, each - vibration amplitude information group is composed of six pieces of 4-bit vibration amplitude information.

These vibration amplitude information determine the lowering position of the sewing needle 9 for forming one stitch, that is, the needle position coordinates (see FIGS. 16 and 17).

Now, the first address decoder 145 in the first semiconductor memory device 144 transfers the counted contents of the first address counter 140 to the output line L41. Input the binary code as an address code through L42 and L44, convert it to a decimal number, and output a low level potential to one of the address designation terminals DO to D5 corresponding to the numerical value. The other terminals are kept at high level.

To explain this with an example, the address code output from the first address counter 140 is guaranteed to have its output line L41 as the least significant digit, and its output line L44 as the most significant digit. All codes according to the example are 8. 4. 2. 1 code is used, so if the count value of the first address counter 140 is (2), the address code input to the first address decoder 145 has the logical code sequence roloJ from the top, and is Only the terminal D2 corresponding to the decimal number (2) is set to low level, and if the count value is (3), the address code becomes rollJ, and only the terminal D3 corresponding to the decimal number (3) is set to the low level.

On the other hand, the first semiconductor memory device 144 has an information setting circuit network 146 and one first multiplexer group 147,
This first multiplexer group 147 is made up of four multiplexers 148 to 151, and as shown in the "amplitude information" column of FIG. In this embodiment, the multiplexer 1 corresponds to each bit of the information.
48 corresponds to the least significant bit, and multiplexer 151 corresponds to the most significant bit, while in the "amplitude information" column of FIG. 17, the rightmost bit in the figure is the least significant bit, and the leftmost bit is the most significant bit. Corresponds to a digit.

Next, detailed wiring connections shown in FIG. 12 will be explained.

That is, in FIG. 12, the output line L41 is
51 and connect this line L51 to multiplexer 14.
8 input terminals P1 and P2, input terminal P1 of multiplexer 149, input terminal PI of multiplexer 150, P
2 and the input terminal P1 of the multiplexer 151, and furthermore, the output line L41 is connected to the input terminal P1 of the inverter 15.
2 to line L52, which is connected to input terminal P4.2 of multiplexer 148. P6 and input terminal P4. of multiplexer 150. Commonly connected to P6.

Lines L53, L54. L55 and L56 are respectively connected to addressing terminals D2. D3. D4 and D5, among which lines L53. L54. L55 are respectively connected to the input terminals of the NAND circuit 153, and the lines L54. L
55. L56 is connected to the input terminal of the NAND circuit 154, and the line L55 is further connected to each input terminal P3 of the multiplexers 148 to 151.
56 is each input terminal P of multiplexers 149 and 151
The output terminal of one NAND circuit 153 is connected to each input terminal P2 of multiplexers 149 and 151, and the output terminal of the other NAND circuit 154 is connected to each input terminal P6 of multiplexers 149 and 151.

Also, the respective input terminals PO5P5 . P7 are commonly connected by a line L57, and this line L57 is further connected to a low potential terminal.

A line L21 .corresponding to each bit is connected to the output side of the selection code holding circuit 124 . L22 and L24 are the first
As shown in FIG. 2, each selection input terminal Ll, L2 . L4 so that the digit positions match each other, and the selection code output from the selection code holding circuit 124 is sent to the multiplexer 14.
8 to 151.

These multiplexers 148 to 151 each have one bit output terminal Y1 to Y4, and each bit input terminal XI, X2 . They are connected to X3 and X4, respectively.

In the circuit of FIG. 12, a low potential level corresponds to a logic code "0", a high level corresponds to a logic code "1",
Moreover, in the multiplexer 151, its three input terminals PO, P5 . P7 is open and the logic code is always
1” state.

Since the multiplexers 148 to 151 have the same function, the selection input terminals Ll, L2 . If L4 receives a selection code and the numerical content of the selection code is (1), the bit content (logical value 0 or 1) of input terminal P1 is output to bit output terminal Y1, and the numerical content is ( 2), the bit contents of the input terminal P2 are output to the bit output terminal Y1.

Each input terminal P of each multiplexer 148 to 151
O sends the vibration amplitude information of each stitch forming the straight stitch corresponding to the pattern selection switch SO among the stitch patterns of the type selected by the pattern selection switches SO to S7 to the multiplexers 148 to 151. A four-bit configuration is created based on the bit contents of each input terminal PO, and similarly, a total of four input terminals P1 are used to determine the oscillation amplitude of each stitch for forming a zigzag stitch selected by the pattern selection switch S1. create information,
Similarly to the above, each of the other four input terminals P2 to P7 creates swing amplitude information regarding each stitch for forming different types of stitch patterns shown in FIGS. 16C to H, respectively.

In this embodiment, as described above, six pieces of oscillation amplitude information are collected to form one oscillation amplitude information group, and the structure of this group is such that, for example, the pattern selection switch SO in each multiplexer 148 to 151 is selected. 6 oscillations for each stitch pattern based on the principle that the bit contents of the input terminal PO are sequentially rewritten as set by the information setting circuitry 146 as the count of the first address counter 140 progresses. It is configured to consist of amplitude information.

Therefore, in FIG. 12, for example, the pattern selection switch S
If O is selected, the first address counter 140
Each time it counts from (0) to (5) in decimal as shown in FIG. 17A, bit output terminal Y4. Y3. Y2,
The oscillation amplitude information of the code content r1000J shown in the "width information" column of FIG. 17A is sequentially output to Yl, and the The oscillation amplitude information of the code contents shown in the "oscillation width information" column in FIGS. 17B to H is output from the bit output terminal Y4. Y3. Y
2. The wiring is such that the signals are sequentially output to Yl.

Then, the bit output terminals Y4 . of multiplexers 148 to 151. Y3. Y2. The oscillation amplitude information sequentially outputted to Yl with the code content shown in each "oscillation width information" column in FIG. 17 is input to the bit input terminal X4. X3. X2. An analog signal, for example, a DC voltage E1, of an amount corresponding to the code content is inputted to XI, and is applied from the analog output terminal XO to the positive input terminal of the first comparator 156, and the negative input terminal is supplied from the potentiometer 48. A feedback voltage E2 corresponding to the rotational position of the sliding shaft 47 is applied.

Then, the first DA converter 155 is connected to both voltages E1. E
The two differential voltages are supplied to the coil 33 in the amplitude control actuator 14 via the amplitude control driver 157.

. Next, reference numeral 158 shown in FIG. 13 is a second semiconductor memory device, which is used to control the feed teeth 23 of the feed device 15 in order to form various kinds of stitch patterns as shown in FIG. It is used to obtain a large number (eight in this embodiment) of information groups for controlling the feeding motion, and is essentially the same as the first semiconductor memory device 144 shown in FIG. 12.

That is, in this second semiconductor memory device 158, 15
9 is the output line L6 from the second address counter 141.
1. A second address decoder receives the address code via L62 and L64; 160 is a second multiplexer group consisting of multiplexers 161 to 164 similar to the above; Yll to Yl4 are the multiplexers 161 to 1;
64 bit output terminal, 165 bit input terminal X11
A second DA converter 166 having analog output terminals X14 to X14 and an analog output terminal X01 is an information setting circuitry, and selection input terminals L1, L2 . The lines L21, L22 . . . L4 are connected to the lines L21, L22 .
A selection code is given via L24.

The addressing terminals DO, D3 of the second address decoder 159 are connected to different input terminals of a NAND circuit 167, and the output terminals are connected to the line L through an inverter 168.
71 and connect this line L71 to multiplexer 16.
3.164 each input terminal P5. Commonly connected to P6.

Addressing terminal D4 of second address decoder 159
．． D5 is connected to different input terminals of NAND circuit 169, and its output terminal is connected to input terminal P3 of multiplexer 163 via inverter 170.

171 is two changeover switches 172 and 17 that are interlocked with each other.
3, one fixed contact piece a of one changeover switch 172 is directly connected to a low potential terminal, and the other fixed contact piece a is connected to a high potential terminal 175 via a resistor 174. and connect the movable contact piece C to the line L72.

This line L72 is connected to one input terminal of a NAND circuit 177 via an inverter 176, and the output terminal of the NAND circuit 167 is connected to the other input terminal.

Furthermore, the line L72 is connected to the line L73, and this line L73 is connected to the input terminals PO, P of the multiplexer 161.
I, P2. P4, P7, and input terminals PO, PI, P3 . P7 and multiplexer 1
63 input terminal P2. They are commonly connected to P4.

The output terminal of the NAND circuit 177 is commonly connected to the input terminals P5 and PO of the multiplexer 162 via an inverter 178.

In addition, in the other changeover switch 173 of the manual automatic changeover switch device 171 for feed, one fixed contact piece a is connected to the analog output terminal XOI of the second DA converter 165, and this connection point is changed to a variable type. It is connected to the low potential terminal via the voltage dividing resistor 179, and the other fixed contact piece is connected to the variable voltage dividing resistor 1.
79, and the movable contact piece C is connected to the positive input terminal of a second comparator 180, and the negative input terminal of the second comparator 180 is connected to the sliding terminal 179a of the feed control actuator 28. A feedback voltage E1□ from the potentiometer 46 is applied.

The output terminal of the second comparator 180 is connected to the coil 33 of the feed control actuator 28 via a feed control driver 181.

Now, in the above second semiconductor storage device 158, each - piece of feed information is for giving a feed increment to the work cloth for forming each seam, and is shown in the "Feed Increment" column in FIG. (+1), (+5), (-5)...
The numbers such as ・ etc. are shown for convenience to indicate the degree of feed amount, and the (+) and (-) signs indicate that the direction of feed of the processed cloth is forward and backward, respectively.

As shown in FIG. 17, each feed information group corresponding to a different type of stitch pattern is composed of six pieces of four-bit feed information collected into one feed information group, and in this embodiment, the 16th Eight feed information groups shown in FIG. 17 are created corresponding to each stitch pattern shown in the figure.

182 shown in FIG. 14 is a third semiconductor memory device that stores the yarn tension information group shown in the "Yarn tension information" column of FIGS. 17A to H, and 183 is the third address counter corresponding to a reading device. From 142, the count contents are output line L.
81°L82. A third address decoder is input as an address code in a binary code configuration via L84, and is provided with address designation terminals DO to D5.

Here, the output line L81 corresponds to the least significant digit, and the output line L84 corresponds to the most significant digit.

184 is a third multiplexer group similar to the above, which is composed of three multiplexers 185, 186, and 187;
These each have input terminals PO to P7 for inputting information as described above, and these input terminals PO to P7 are connected to the information setting circuitry 188.

Next, the detailed wiring will be described. That is, Raisin L90.
L91. L92. L93°L94 and L95 are respectively connected to corresponding addressing terminals DO to D5 of the third address decoder 183.

Above line L91. L92 and L93 are NAND circuits 189
and its output terminal is connected to the input terminal P2 of the multiplexer 187.

Lines L90, L94. L95 is connected to different input terminals of NAND circuit 190, and its output terminal is connected to input terminal P2 of multiplexer 186.

Lines L92 and L94 are connected to different input terminals of a NAND circuit 191, whose output terminal is connected via an inverter 192 to an input terminal P4 of a multiplexer 186.

Lines L94 and L95 are connected to different input terminals of the NAND circuit 193, and their output terminals are branched into two, one branch end being connected to the input terminal P3 of the multiplexer 186, and the other branch end being connected to the inverter 194. is connected to the input terminal of

The output terminal of this inverter 194 is the multiplexer 18
It is connected to input terminals P3 and PO of 5.

Lines L90°L93 are connected to different input terminals of the NAND circuit 195, and its output terminal is connected to the multiplexer 186.
input terminal P5. P6 and the input terminal P5 of another multiplexer 185 are connected in common.

Line L90. L95 is connected to different input terminals of NAND circuit 196, and its output terminal is connected to input terminal P4 of multiplexer 185 via inverter 197.

A line L96 derived from the output line L81 of the least significant bit of the third address counter 142 is connected to each input terminal P1 of the multiplexer 186 and 187.

Further, the line L96 is connected to the input terminal P1 of the multiplexer 185 and the input terminal P4 of another multiplexer 187 via inverters 198 and 199, respectively.

Further, the line L97 connected to the low potential terminal is connected to each input terminal P7 of the multiplexers 185 and 186, and the input terminal PO of the other multiplexer 187,
It is also commonly connected to P7.

Line L98 connected to high potential terminal 200 is connected to input terminals PO, P2 of multiplexer 185, input terminal PO of multiplexer 186, input terminal P5. It is commonly connected to P6.

Further, each selection input terminal Ll, L2 . Similarly to the above, lines L21, L22 . L24
The selection code is applied via the bit output terminals Y21, Y22 . At Y23, bits are generated that are the negation of the bit contents from any of the input terminals PO to P7 specified by the selection code, and these bits are respectively generated from the bit input terminals X21 to X21 of the third DA converter 201. Lower three phase bit input terminal X2 of X24
1. X22. A line L98 connected to the high potential terminal 200 is connected to the bit input terminal X24 of the most significant digit.

In the third semiconductor memory device 182 configured as described above, line L98 generates the leftmost most significant bit of the four bits of "thread tension information" Kiryu shown in FIGS. 17A to H,
The relationship is such that multiplexer 185 generates the least significant bit.

As is clear from FIG. 17, each yarn tension information is composed of four bits, and one yarn tension information group is created by gathering six pieces of yarn tension information, and these yarn tension information groups are
Eight pieces are created corresponding to the different types of stitch patterns shown in FIGS. 6A to 6H.

In this embodiment, the specific contents of each thread tension information shown in FIG. 17 include the lowering position of the sewing needle 9 and its swing amplitude, the feed direction and feed increment of the work cloth, the type of stitch pattern, etc. In other words, it is determined in relation to the oscillation amplitude information group and the feed information group, and thereby the optimal seam tightening degree for each stitch pattern is determined regardless of the difference in the type of stitch pattern. It is predetermined in advance so that each stitch in the same stitch pattern can have a uniform tightening degree.

The numbers shown in the "thread tension" column in FIG. 17 are numerical representations of the degree of thread tension to be applied to the sewing thread for convenience.

Among the eight yarn tension information groups, the selection code holding circuit 12
Each piece of yarn tension information within one yarn tension information group specified by the selection code output from 4 is sequentially output to the third DA converter 201 according to the counting operation of the third address counter 142. The analog signal corresponding to the code content of each yarn tension information is converted into, for example, a DC voltage E31, and this is sent to the analog output terminal XO2 of the D-A converter 201.
is output to.

A variable voltage dividing resistor 202 to which the DC voltage E31 is applied is connected to the analog output terminal XO2, and its sliding terminal 202a is connected to the manual automatic changeover switch 203 for thread tension.
One fixed contact piece a is connected to a low potential terminal via another variable voltage dividing resistor 204.

The sliding terminal 204a of the variable voltage dividing resistor 204 is connected to the other fixed contact piece of the manual automatic changeover switch 203 for thread tension, and this connection point is connected to the operational amplifier of the constant current circuit 206 via a lead wire 205. It is connected to the positive input terminal of 207.

The arithmetic amplifier 207 is for supplying a constant current to the electromagnetic solenoid for thread tension, and for this purpose is provided with a transistor 208, the collector of which is connected to the thread tension electromagnetic solenoid in parallel with a freewheel diode 209. It is connected to the high potential terminal 210 via the electromagnetic solenoid 52 and the auxiliary switch 67, and a spark extinguishing capacitor 211 is connected in parallel with the auxiliary switch 67.

The emitter of the transistor 208 is an operational amplifier 207
is connected to the negative terminal of
The output terminal of the operational amplifier 207 is connected to the output terminal of the operational amplifier 207 via.

Here, the circuit consisting of the manual automatic changeover switch 203 for thread tension, the variable voltage dividing resistors 202 and 204, the constant current circuit 206, and the auxiliary switch 67 corresponds to the thread tension control device 213.

Next, the control circuit for the needle hole switching device shown in FIGS. 8 and 9 will be described. In FIG. 11, 214 is a gate circuit, and flip-flop circuits FFI, FF2 . FF4's line L
21. L22. Line LIOI derived from the same part as L24, L102. L104, which are connected to different input terminals of a NOR circuit 215, and whose output terminal is connected to an input terminal of an inverter 216.

The line L102 is connected to the input terminal of the inverter 217, and the output terminal thereof and the lines L101 and L104 are connected to different input terminals of the NAND circuit 218, and the lines are connected to different input terminals of another NAND circuit 219, respectively. LIOI, L102. L104 is connected.

The output terminals of the inverter 216 and the NAND circuits 218 and 219 are connected to different input terminals of another NAND circuit 220, and the output terminal thereof is connected to the signal output terminal 221a.

The output terminal of the NAND circuit 219 is connected to another signal output terminal 221b via an inverter 222.

One of the signal output terminals 221a is connected to the needle hole switching driver 2.
It is connected to the base of a transistor 226 through a diode 224 and a resistor 225 of the illustrated polarity within 23, and its collector is connected to a high potential terminal 227 through the second electromagnetic solenoid 88.

The other signal output terminal 221b is branched into two, one branch end is connected to the cathode side of the diode 224 via a diode 228, and the other branch end is connected to the transistor 231 via a diode 229 and a resistor 230.
The collector is connected to the high potential terminal 227 via the first electromagnetic solenoid 87.

A freewheel diode 232 is connected in parallel to each of the electromagnetic solenoids 87 and 88, and the emitter of each transistor 226 and 231 is connected to a low potential terminal.

According to the gate circuit 214 configured as above, the pattern selection switches SO to S7 are pressed and closed, and the signal output terminal 221a,
221b and each transistor 226
, 231 are as shown in FIG.

Therefore, as is clear from FIG. 18, the pattern selection switches Sl, S2. S3. S4. S6
When the pattern selection switches SO and S5 are selectively closed, both electromagnetic solenoids 87 and 88 are de-energized, and the pin 115 of the operating frame 101 is in the position MPO. Based on the same principle, when the pattern selection switches SO and S5 are selectively closed, the pin 115 is in the position MPO. becomes the position MPI, and when the pattern selection switch S7 is selected and closed, the pin 115 becomes the position MP2.

In this sewing machine configured as described above, each of the eight swing amplitude information groups, the feed information group, and the thread tension information group is a selection code that is output from the selection code holding circuit 124 by operating the pattern selection switches SO to S7. They are combined as shown in FIG. 17 to correspond to different types of stitch patterns.

Then, from among the above three information groups corresponding to one stitch pattern, a set of oscillation amplitude information regarding one stitch formation, feed information, and thread tension information is sent to each of the address counters 140, 141, 142. They are sequentially read out according to the counting operation of , and desired control is thereby performed.

The operation will be described in detail below.Now, the manual automatic changeover switch 203 for thread tension is switched to the automatic control side TAU,
It is also assumed that the changeover switches 172 and 173 in the manual/automatic feed changeover switch device 171 are switched to the automatic control side CAU.

In addition, in order to form the cross-hatched pattern shown in FIG. 16G,
It is assumed that the pattern selection switch S6 is closed.

The principle of formation of this cross stitch pattern is that the numbers 0 to 5 given in the stitch pattern in Figure 16G are repeated in multiple units, with stitches formed in this order as one unit. In forming this one unit of pattern, as is clear from FIG. Needle position coordinates5. 0. 5. 10. 15. 1
It is 0.

In addition, regarding the feed increment, since the formation of stitch No. 0 is performed successively after the formation of stitch No. 5, the feed increment (-5) for stitch No. 0 is given after the formation of stitch No. 5. and the feed increment is based on the needle position coordinates 5. 0. 5. 10. 1
5. 10, the feed increment (-5), (+
5), (+5), (-5), (+5),
(+5).

Furthermore, regarding the thread tension, since the formation of stitch No. 0 is performed successively after the formation of stitch No. 5, a thread tension of 8 for stitch No. 0 is given after the formation of stitch No. 5, and therefore, the thread tension 8 in the order of stitches. 10. 10. 8°11.1
1 is given.

In this way, the needle position coordinates, feed increment, and thread tension are given to create the cross-cut pattern shown in FIG. 16G.

The specific effects of this control will be described below.

That is, when the pattern selection switch S6 is closed, the assumed numerical value 6 is converted into a binary code by the encoder 123 and stored as a selection code in the selection code holding circuit 124, and the selection code is stored on the lines L21, L22, .
The first semiconductor storage device 144, the second semiconductor storage device 158, and the third semiconductor storage device 182 via L24.
multiplexers 148 to 151 and 161 to 16 within
4 and each selection input terminal Ll, L2 . L
Therefore, each multiplexer 148 to 151, 161 to 164 and 185
to 187 input terminals PO to P7, each - input terminal P corresponding to the numerical value 6 which is the content of the selection code
6 is specified, and the bit contents of the input terminal P6 are the bit contents of each bit output terminal Y1 to Y4, Yll to Y14, and Y
21 to 23 are output.

On the other hand, the first to third address counters 140, 141
, 142 is reset by a reset pulse R5P accompanying the closing of the pattern selection switch S6, and its address code content is roooJ.

Also, by closing the pattern selection switch S6, lines L101, L102 . LiO2 becomes rollJ in this order, and as shown in FIG. 18, the signal output terminals 221a and 221b are both "0", so the transistors 226 and 231 are both off,
The plungers 89.90 of the first and second electromagnetic solenoids 87.88 are both retracted, and as a result, the pin 115 of the actuating rod 101 is located at MPO, and the horizontally elongated hole 105 of the throat plate 103 is opened to the sewing needle 9. located within the lowering position.

In the above state, when the sewing machine is started, for example, from the needle up position, the output (address code) of the first address counter 140 is "000" at first, and especially the output line L41 is a logic code. Since it is "0", the line L52 becomes "1" in the first semiconductor memory device 144, so the multiplexer 148.15
The bit content of each input terminal P6 of 0 becomes "1", which is output as is to the respective bit output terminals Y1 and Y3, and since the address code is roooJ, the address designation terminal of the first address decoder 145 becomes "1". D
O to D5, only one address designation terminal DO is
0" and the others are "1", so line L54. L55
, L56 are both "1", and the output of the NAND circuit 154 is "0", so the multiplexer 149.151
The bit content of the input terminal P6 becomes "0", and this is output as is to the respective bit output terminals Y2 and Y4.

Therefore, when the count value of the first address counter 140 is (0) in decimal notation, the bit output terminal Y4 of the first multiplexer group 147. Y3. Y2. The code contents of the oscillation amplitude information output from Yl are r in order from the most significant digit.
It becomes ololJ.

Based on this code content, the first DA converter 155 outputs a DC voltage E1 having a value specific to the code content and applies it to the positive input terminal of the first comparator 156. 156 is this DC voltage E□ and potentiometer 4
8 (voltage having a value corresponding to the current position of the drive link 12), and the difference voltage E3 is applied to the coil 33 in the amplitude control actuator 14.

As a result, the bobbin 34 of the amplitude control actuator 14 moves in the direction corresponding to the polarity of the differential voltage until the differential voltage becomes zero, thereby moving the drive link 12 so that the lowered position of the sewing needle 9 is at the needle position. The needle position is controlled to be at the coordinate 5 position, and stitch number 0 is formed at the needle position coordinate 5.

Thereafter, when the sewing needle 9 reaches a position above the throat plate upper surface 135, the first address counter 140 counts the pulse CP2 (time TI) generated at the falling edge of the first timing pulse BCP and its code. ro the contents from the most significant digit
oiJ, and therefore the first semiconductor storage device 14
4, the potential of only lines L51 and L52 is inverted, and the other lines remain at the same potential as when forming stitch No. 0. Therefore, line L52 has a logic code of "0", so multiplexer 148 , 150, the bit content of each input terminal P6 is "0".

In addition, each input terminal P of the other multiplexers 149 and 151
The bit contents of bit 6 remain unchanged and remain "0".

Therefore, when the first address counter 140 is changed to (1) in decimal notation, the bit output terminal Y4 . Y3. Y2. The code content of the oscillation amplitude information output from Yl is "0000", which means needle position coordinates 0, so the next No. 1 stitch will be formed at this position.

Prior to the above operation, the sewing needle 9 descends from above the throat plate 103 to form the stitch No. 0 described above, and
5, the second and third address counters 141, 142 count the pulse CP3 generated at the falling edge of the second timing pulse FCP (these address counters 141, 142 are counted by the first address counter The count content is one step higher than 140.

) and change the count content to decimal number (1), that is, the code content from roooJ to rooIJ.

Among these, the output ro01 of the second address counter 141
The second address decoder 159 of the second semiconductor memory device 158 that received J as an address code has only the address designating terminal D1 of its addressing terminals DO to D5 as logic code "0" and the others as "0". 1”.

Therefore, focusing on the input terminals P6 of the multiplexers 161 to 164 designated by the selection code, first, the output of the NAND circuit 167 is the address designation terminal Do, D3
Since both are "1", it becomes "0", and the line L
Since 71 becomes "1", multiplexer 163.16
According to the input terminal P6 of 4, the respective bit output terminal Y13
．． Since the bit content of Y14 is "1" and the inverter 176 receives a low level potential through the contacts (ca) of the changeover switch 172 and outputs "1", it is a NAND circuit. 177 has two inputs of “0” and “1”.
” and outputs “1”, and input terminal P6 of multiplexer 162 which receives this via inverter 178 outputs “1”.
0” and the bit content of the bit output terminal Y12 becomes “
0".

In addition, since the input terminal P6 of the multiplexer 161 is always open and is "1", its bit output terminal Yll
The bit content of is always "1".

In this way, when the count content of the second address counter 141 is (1) in decimal notation, each bit output terminal Y14 of the second multiplexer group 160. Y13. Yl 2.
The code contents of the feed information output from Yl 1 are rlloIJ in order from the most significant digit, which means that the feed increment prior to the formation of the first stitch is (+5), and a unique code based on the code contents. The second D-A converter 165 generates a DC voltage E1□ of the value
It is applied to the positive input terminal of the second comparator 180 via the contact piece (C-a) of 73.

This second comparator 180 compares the DC voltage E1 with the feedback voltage E1□ from the potentiometer 46, and supplies the difference voltage E13 to the coil 33 of the feed control actuator 28 via the feed control driver 181.

As a result, the bobbin 34 is moved in the direction according to the polarity of the differential voltage E13 to the position where the differential voltage E13 becomes zero, and the adjusting rod 26 is thereby controlled and the feed dog 23 is moved to the 15th position.
In the period indicated by 136 in the figure, that is, the period in which the formation of stitch No. 0 is completed and the sewing needle 9 is located approximately near the needle top dead center (T2-
Between T3), the feed increment (
+5) is applied to the work cloth.

On the other hand, as mentioned above, the second address counter 141
The third address counter 142, whose count content is changed to 1 at the same time, receives the signal roo1. is supplied as an address code to the third address decoder 183, so among the addressing terminals DO to D5, only the terminal D1 becomes "0" and the others become "1".

Therefore, the output of the NAND circuit 193 is "0", the output of the inverter 194 is "1", and the bit content of the large input terminal P6 of the lowest digit multiplexer 185 in the third multiplexer group 184 is "1". The negation "0" is output to the bit output terminal Y21.

Also, since the output of the NAND circuit 195 becomes "0", the bit content of the input terminal P6 of the multiplexer 186 becomes "0".
Therefore, "1" is output to the bit output terminal Y22.

Furthermore, since the input terminal P6 of the multiplexer 187 is always "1" due to the line L98 connected to the high potential terminal 200, "0" is output to its bit output terminal Y23.

Each of these bit output terminals Y21, 22 . The output of Y23 is input to the bit input terminal X21. X
22. X23, and since "1" is always given to the most significant bit input terminal The code contents of the thread tension information to be output match those described in the "thread tension information" column corresponding to "counter value" column 1 in FIG. This corresponds to the period after the formation of stitch No. 0 (T2-T
This is used as thread tension information for tightening the No. 0 stitch in approximately the same period as the 0th stitch.

That is, the yarn tension information r1010J is the third D-A.
In the converter 201, it is converted into a DC voltage E31 having an analog quantity specific to the code content, and this is applied from the analog output terminal XO2 to the variable voltage dividing resistor 202, and a DC voltage E3□ proportional to it is applied from the sliding terminal 202a. It is applied to the positive input terminal of the operational amplifier 207 in the constant current circuit 206 via the contacts (C-b) of the manual automatic changeover switch 203 for thread tension.

Then, the operational amplifier 207 outputs a differential voltage E34 with respect to the DC voltage E33 (described later) applied to the negative terminal, and applies this to the base of the transistor 208 via the resistor 208a, so that the collector current depending on the differential voltage hole 4 is It is supplied to the adjustment electromagnetic solenoid 52.

Therefore, this electromagnetic solenoid 52 generates an attractive force depending on the value of the input current, and the plunger 54 moves in the direction of arrow 233 in FIG. 4.

Therefore, the plunger interlocking lever 63 is rotated clockwise in FIG. By being pressed by the thread tension disc 57, the needle thread interposed between the thread tension discs 56 and 57 has a thread tension of 10 according to the thread tension information rlo10J, which is applied to the needle thread after the thread number 0 stitch is formed. It is given to tighten the eyes.

The oscillation amplitude is selected from among the three information groups shown in the columns of "amplitude information", "feed information" and "thread tension information" in FIG. Information, feed information, and thread tension information are sequentially read out as a set by timing pulses BCP and FCP, so that each stitch for the cross stitch pattern can be read from number 0 to number 5 with the optimal thread tension. It is formed as follows.

In particular, the first to third address counters 140
, 141, and 142 are large inversion counters, so when stitches numbered 0 to 5 are formed, the counting contents return to roooJ, and by repeating the counting again, the same cross stitch pattern is repeated so that it continues. It is something that can be done.

The control operations regarding the other types of stitch patterns shown in FIGS. 17A to F and H are also the same as those described above, and therefore their explanations will be omitted.

Next, the significance of the existence of the constant current circuit 206 will be explained.

That is, since the thread tension electromagnetic solenoid 52 is continuously energized while the sewing machine is sewing work cloth, the temperature of the winding increases and the internal resistance increases, so the current supplied to the winding is based on thread tension information. The current value changes to a different current value from the current value corresponding to , and the thread tension also changes.

However, a change in the winding current due to a change in resistance due to a rise in the temperature of the winding appears as a fluctuation in the terminal voltage E33 of the resistor 212 in FIG. 14, and this terminal voltage E33
is applied to the negative terminal of the operational amplifier 207, thereby controlling the base current of the transistor 208 in a direction that suppresses changes in the collector current due to a rise in temperature of the winding.

In this way, a constant current corresponding to the thread tension information is supplied to the thread tension electromagnetic solenoid 52 regardless of temperature changes in its winding, thereby ensuring a desired thread tension level.

Next, we will discuss the case where the changeover switches 172 and 173 of the feed manual and automatic changeover switch device 171 are switched to the manual control side CMA so that the contact piece (C-b) is in the closed state. First, since the output of the inverter 176 is always "0", the NAND circuit 1
The output of P5. P6
is always "0", and on the other hand, the line L73 is also always kept "1" by the changeover switch 172, so that the input terminals PO, PI, P2 . P4.
PI, input terminals PO, PI of multiplexer 162,
P3. PI, and input terminal P of multiplexer 163
2゜P4 is always set to “1”, and multiplexer 1
As can be understood from the fact that among the input terminals PO to P7 of 62 to 164, there is a terminal that is always set to "1" because it is an open terminal, the pattern selection switches So,
Sl, S2. When S4 and S7 are selectively closed,
Bit output terminal Y14 of second multiplexer group 160
．． Y13°Y12. The code content of the sending information output from Yll is always rllllJ regardless of the count content of the second address counter 141, and the DC voltage E14 corresponding to this is applied to the analog output terminal of the second DA converter 165. It is output from X01 and applied between the terminals of variable voltage dividing resistor 179.

Therefore, if the sliding terminal 179a of the variable voltage dividing resistor 179 is manually adjusted, the divided voltage determined by this adjustment is transferred to the second comparator via the contacts (C-b) of the changeover switch 173. 180, so that workpiece feed control is provided in manually adjusted feed increments.

In addition, when the manual automatic changeover switch 203 for thread tension is switched to the manual control side TMA, the variable voltage dividing resistor 204
A voltage depending on the position of the sliding terminal 204a of the variable voltage dividing resistor 204 will be applied to the positive input terminal of the operational amplifier 207, so that a yarn tension depending on the manual adjustment of the sliding terminal 204a of the variable voltage dividing resistor 204 is obtained.

In this sewing machine, the electric power supply to the thread tension electromagnetic solenoid 52 is cut off when the presser foot of the presser foot device is raised.

That is, in FIGS. 3 to 5, when the presser foot lifting cam 77 is rotated clockwise in FIG. At the same time as the rod 76 is raised and the presser foot (not shown) is raised, the rotary lever 82, whose one end 82a abuts and engages the upper surface of the cam receiving plate 79, rotates around the stepped screw 83 as shown in FIG. It is rotated clockwise, and the other end 82b presses and moves the other end 71b of the switch opening/closing lever 71 in the direction of arrow 235 in FIG.

As a result, the switch opening/closing lever 71 is rotated counterclockwise in FIG. 4 to separate its one end 71a from the actuator 75 of the auxiliary switch 67, turning the auxiliary switch 67 into the OFF state.

As a result, the electromagnetic solenoid 52 for thread tension is cut off.
The tension applied to the upper thread is released.

Therefore, the ease of changing the direction of the work cloth, attaching and detaching the work cloth, etc. is ensured.

Next, the significance of the existence of the delay circuit 137 will be explained.

That is, as is clear from the foregoing, the feed information and thread tension information are read out by the pulse CP3 generated at time T4 immediately after the sewing needle 9 descends from the needle top dead center and pierces the workpiece cloth. The principle is that the feed information serves as information for the feed movement prior to forming the next stitch, and the thread tension information serves as information for tightening the stitch that is currently being formed.

Now, when the sewing needle 9 is stuck in the workpiece cloth for some reason, the pattern selection switches SO to S7 are pressed.
If one of them is selectively closed, the reset pulse R3P generated at the reset output terminal 132 at this time causes the first to third address counters 140, 141,
142 is reset to the decimal (0) state.

However, the reset pulse R8P is
The first timing pulse BO is delayed for a certain period of time by
P high level period (from time TO to time T shown in FIG.
1) through an inverter 138 to a NAND circuit 139
During this period, a signal that temporarily falls to a low level is generated from the output terminal of the NAND circuit 139.
The falling edge causes the count code contents of the second and third address counters 141, 142 to change from the most significant digit to roo.
lJ, and as a result, the feed information and yarn tension information are read out as described above.

In this way, a constant time relationship for readout between feed information and thread tension information and swing amplitude information is maintained as scheduled.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be modified in various ways without departing from the spirit of the invention, for example, information may be stored as magnetic signals. It is.

As can be understood from the description of the embodiments described above, the present invention allows the sewing needle to be oscillated in the lateral direction by using a large number of oscillation amplitude information groups and feed information groups that are stored in advance as electrical or magnetic signals. In a sewing machine that selectively and automatically forms many types of stitch patterns by controlling motion and controlling the feed of the workpiece cloth, thread tension information for each stitch is converted into oscillation amplitude for each stitch. The information and feed information are stored in advance so as to form a set, and when forming a stitch, the thread tension applied to the sewing thread is adjusted to the type of stitch pattern for each stitch using the stored thread tension information. By adopting a configuration that automatically controls according to the formation circumstances of each seam forming the seam pattern, the optimal thread line condition for each seam pattern can be achieved regardless of the difference in the seam pattern. Or, even though there are many types of stitch patterns and a huge number of thread tension information groups, it is possible to obtain a uniform thread line condition for each stitch in the same stitch pattern. Since the information is stored as an electrical or magnetic signal, it is possible to provide a sewing machine with automatic thread tension control that does not require complicated and bulky mechanical components.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention; FIG. 1 is a perspective view of the internal structure of a sewing machine showing only the parts related to the present invention, FIG. 2 is an exploded perspective view of an actuator, and FIGS. Side view, top view, front view of the thread tension device, No. 6, respectively.
7 and 7 are a plan view and a front view of the electromagnetic solenoid device portion of the needle hole switching device, FIG. 8 is a plan view of the throat plate portion, FIG. 9 is a plan view of the needle hole switching portion, and FIG. 10 is a sewing machine. A block diagram for explaining needle lateral swing amplitude control, work cloth feed control, and thread tension control; FIG. 11 is a circuit configuration diagram mainly showing the selection device part and the electromagnetic solenoid driving part; FIGS. 14 is a circuit configuration diagram showing the first to third semiconductor memory devices together with their associated circuits, FIG. 15 is a time chart for explaining the embodiment, and FIG. 16 is a diagram showing a different type of semiconductor memory device. FIG. 17 is a diagram showing the control contents of each stitch pattern, and FIG. 18 is a diagram for explaining the operation of the first and second electromagnetic solenoids. In the drawing, 5 is an upper shaft, 6 is a lower shaft, 7 is a main pulley, 8 is a needle swing device, 9 is a sewing needle, 10 is a swing support, 12 is a drive link, 14 is an amplitude control actuator, and 15 is a sewing needle. A feeding device, 16 a feeding drive shaft, 19 a cam holding rod, 20 a shaft, 2
3 is a feed dog, 24 is a grooved member, 24a is a lock shaft, 24
b is a lock arm, 26 is an adjustment rod, 28 is a feed control actuator, 30 is a permanent magnet plate, 33 is a coil, 34 is a bobbin, 44 is a rotating shaft, 46 is a potentiometer, 47
is a sliding shaft, 48 is a potentiometer, 49 is a pulse generator, 51 is a thread tension device, 52 is an electromagnetic solenoid for thread tension, 54 is a plunger, 56 and 57 are thread tension discs, 60 is a push rod, and 63 is a plunger movement Lever, 67 is an auxiliary switch (opening/closing device), 68 is a workpiece presser device, 71 is a switch opening/closing lever, 76 is a presser bar, 77 is a presser foot lifting cam, 7
9 is a cam receiving plate, 82 is a rotating lever, 87 and 88 are number-1
and a second electromagnetic solenoid, 93 is a connecting plate, 94.95
96 is a lever, 101 is an operating frame, 103 is a throat plate, 105 is an oblong hole, 106 is a round hole, 111 is an intermediate lever, 115 is a pin, 121 is a selection device, 122 is a group of pattern selection switches, 123 is a encoder, 124 is a selection code holding circuit, 131 is a waveform conversion circuit, BCP is a first timing pulse, FCP is a second timing pulse,
SO to S7 are pattern selection switches, 137 is a delay circuit,
140 is a first address counter (reading device), 1
41 is a second address counter (reading device); 14
2 is the third address counter (reading device), 143
144 is a pulse distributor, 144 is a first semiconductor memory device, and 14 is a pulse distributor;
6 is an information setting circuit network, 145 is a first address decoder, 147 is a first multiplexer group, 148 to 151
is a multiplexer, 155 is a first D-A converter, 15
6 is a first comparator, 157 is an amplitude control driver, 158
159 is a second address decoder; 160 is a second multiplexer group; 161 to 1;
64 is a multiplexer, 165 is a second DA converter,
166 is an information setting circuit network, 171 is a manual automatic switching device for feeding, 179 is a variable voltage dividing resistor, 180 is a second comparator, 181 is a feed control driver, 182 is a third semiconductor storage device, 183 is a third address decoder, 1
84 is a third multiplexer group, 185 to 187 are multiplexers, 188 is an information setting circuit network, 201 is a third D-A converter, 203 is a manual automatic changeover switch for thread tension, 206 is a constant current circuit, and 213 is a Thread tension control device, 2
14 is a gate circuit.

Claims (1)

[Claims] 1. A sewing needle capable of vertical reciprocating movement and lateral rocking movement;
A feeding device for applying a feeding motion to the work cloth in synchronization with the vertical reciprocating movement of the sewing needle, a thread tension device for applying tension to the sewing thread, and controlling the horizontal oscillating movement of the sewing needle. an information group including a plurality of sets of oscillation amplitude information for each stitch, feeding information for controlling the feeding movement of the feeding device, and thread tension information for controlling the thread tension for forming each stitch; ,
A storage device storing a large number of stitch patterns corresponding to each of a plurality of predetermined stitch patterns, and one type of stitch pattern among the plurality of stitch patterns stored in the storage device. a selection device that selectively activates the information group corresponding to the information group in relation to an operator's operation; a pulse generator that generates a timing pulse in synchronization with the up and down reciprocating movement of the sewing needle; and the selection device a readout device that sequentially reads out a set of oscillation amplitude information, feed information, and yarn tension from the information group validated by in response to the timing pulse, and the oscillation amplitude read out by the readout device. an operating device that respectively operates the sewing needle and the feeding device according to the information and the feeding information; and an operating device that operates the thread tension device in accordance with the thread tension information read out together with the swing amplitude information and the feeding information to apply the tension to the sewing thread. 1. A sewing machine with automatic thread tension control, comprising a thread tension control device for controlling thread tension. 2. The sewing machine with automatic thread tension control according to claim 1, wherein the thread tension device includes an electromagnetic solenoid. 3. A patent characterized in that the thread tension control device includes an opening/closing device for supplying and cutting off electric power applied to the electromagnetic solenoid in connection with the operation of the cloth presser device for pressing the work cloth. A sewing machine with automatic thread tension control according to claim 2. 4. The sewing machine with automatic thread tension control according to claim 2, wherein the thread tension control device includes a constant current circuit for supplying a constant current to the electromagnetic solenoid.