JPS5950351B2 - Sewing machine thread tension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thread tension device for a sewing machine that automatically controls thread tension according to various factors that affect sewing work, such as the type of stitch pattern and sewing conditions.

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. It is affected by the amount of stitching, the amplitude of the needle's lateral swing, whether it is lock stitch or chain stitch, etc., so it is difficult to obtain the optimal thread reeling condition each time the type of stitch pattern to be formed is different, especially in pattern stitch sewing machines. It is difficult and
It is also difficult to obtain a uniform thread winding condition 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 adopted structure of the sewing machine, but in general, regarding the needle lowering position, the thread tension when descending to the right is higher than when descending to the left. is set to be large, the thread tension is set to be larger when moving forward than when moving backward in the feed direction of the work cloth, the thread tension is set to be larger when the feed pitch is large than when the feed pitch is small, and the oscillation amplitude is set to be larger. The aim is to set the thread tension larger when the amplitude is high than when the amplitude is large, and to set the thread tension larger when sewing the chain line than when lockstitching.

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

By the way, is the thread tension automatically controlled? As a representative example of the prior art, a dotted colored pattern is obtained by controlling the tension of the upper thread to expose or not expose the lower thread of a different color from the upper thread on the upper surface of the workpiece cloth. There is a system that stores the thread tension information 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 configuration of these mechanical displacement transmission mechanisms are complicated, it is extremely difficult to automate yarn tension control using a method using a cam mechanism, and it is also difficult to obtain accurate yarn tension.

The present invention has been made in view of the above circumstances, and its purpose is to enable automatic control of the thread tension by electrically controlling the thread tension using an electromagnetic actuator, and to reduce the thread tension. To provide a thread tension device for a sewing machine which allows accurate setting and also allows extremely easy release of thread tension in accordance with the characteristics of sewing work.

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 second support, and an arm extending horizontally from the support. 4 and are provided with an upper shaft 5 and a lower shaft 6 which are temporally connected to each other via a known drive mechanism (not shown), and the upper shaft 5 is connected to a drive motor (not shown) via a main pulley 7. It is designed to be rotated by

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 configured to move 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 feed device that imparts a feeding motion to the work cloth in synchronization with the up and down reciprocating movement of the work cloth 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 that the feed amount (feed increment) and feed direction of the work cloth can be controlled 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 film 31 is magnetically attached to the intermediate portion between the opposing permanent magnet plates 30, 30 by screws 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 film 31 so as to be linearly movable.

Reference numeral 35 denotes a cover plate made of a magnetic material that is fixed to the neutral magnetic film 31 with screws 36. An arm 38 integrated with the bobbin 34 is inserted through a pair of slots 37° 37 in the cover plate 35.
, 38 protrude through the lever 40, and one end 41 of a lever 40 is supported by a 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 rotation shaft 41 of such a feed control actuator 28
The sliding shaft 47 of the well-known resistance type potentiometer 46 is shown in FIG.
are connected.

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 angle 30°, and when the bobbin 34 moves along the neutral magnetic film 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.

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

In addition, 50 shown in FIG. 1 is each unit of the electric circuit mentioned later, and FIG. 1 shows the arrangement|positioning row.

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 actuator for controlling thread tension that is screwed to the arm portion 4 of the sewing machine frame 1 via a support plate 53. This actuator is composed of an electromagnetic solenoid, and a plunger 54 is installed inside it. A magnetic cavity 55 is formed in which a magnetic hole 55 is loosely inserted.

Reference numerals 56 and 57 denote a pair of thread tension members, ie, thread tension discs, for applying tension to the sewing thread, especially the upper thread. has been done.

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 a switch means for controlling the supply and cutoff of power to the electromagnetic actuator 52 for thread tension in connection with the operation of the workpiece presser device 68 for pressing the workpiece cloth, and is attached to the arm portion 4 by a screw 69. It is attached to a supported mounting plate 70.

Reference numeral 71 denotes a switch opening/closing lever, which is rotatably supported by a stepped screw 73 on the fixed plate 61 through a sleeve 72 provided thereon. The screw spring 74 engaged with the opening/closing lever 71 rotates the lever clockwise in FIG. ing.

In the workpiece presser device 68, reference numeral 76 denotes a presser bar which has a presser foot (not shown) at its lower end and whose middle part is supported by the arm part 4 so as to be movable up and down; A plate 79 is fixed to a cam receiver that slides on a cam surface 78 of 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 rotary lever that is linked to the vertical movement of the presser bar 76, the fulcrum of which is pivotally attached to an appropriate part of the arm 4 by a stepped screw 83, and the other end 82b is connected to the switch opening/closing lever 71 and other parts. They face each other at a position where they can abut and engage with the end 71b.

In the foregoing, the electromagnetic actuator 52 includes a pair of thread tension discs 56, in order to ensure that tension is applied to the upper thread.
57, and in a state where the support plate 58, the thread tension plate 57'56, the push rod 60, and the 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 has such characteristics that the attraction force of the electromagnetic actuator 52 depends only on the magnitude of the supplied current and does not depend on the attraction position of the plunger. is used in this example.

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 punch 101 via.

This operating punch 101 is normally biased by a spring 102 in a direction opposite to the direction of arrow 102a.

The other end of the operating punch 101 is connected to a known mechanism for selectively performing zigzag lockstitch, straight lockstitch and chain stitch,
Specifically, the operating punch 101 corresponds to the operating lever 26 shown in the above-mentioned known publication, JP-A-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 needle plate is provided with a circular hole 106 for straight stitching connected to the center front edge of the needle plate, and is slidably disposed in a sliding groove 108 of the support plate 107, 103
This relationship is established within the fitting range between the pin 109 implanted on the lower surface of the slide groove 108 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 is in contact with a pin 115 provided on the operating punch 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 punch 101 in FIG. 9 is connected to a chain line mechanism, which is as described in detail in the aforementioned Japanese Patent Application Laid-Open No. 50-31944, and the structure described therein is the only one. Since it is not directly related to the present invention, the explanation will be omitted.

Now, FIG. 6 shows that when the first electromagnetic solenoid 87 is de-energized and the second electromagnetic solenoid 88 is energized at the same time, each plunger 89, 90 has a stopper 94 at its tip.
95, the connecting plate 93 as a whole is moved a distance l□ in the direction of the arrow 118, so that the lever 96 connected to the intermediate portion of the connecting plate 93 via the stepped screw 99 is moved. Since it is rotated in the direction of arrow 119 around the stepped screw 98, the operating punch 101 is rotated in the direction of arrow 119 of the connecting plate 93.
Move the arrow 1 by a distance corresponding to the moving distance 1 in the 18 directions.
The pin 11 provided on the operating punch 101 is moved in the direction 02a while resisting the tensile force of the spring 102.
5 is moved to the MP2 position in FIG.

This position corresponds to the chain gutter operating position.

Next, as shown in FIG. 6, the first electromagnetic solenoid 87 is de-energized and its plunger 89 enters the power bow 1 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 1□ of the connecting plate 93, especially the stepped portion 99, in the direction of the arrow 118 is as described above. 11, and the actuating punch 101 also moves in the direction of the arrow 102 by a distance less 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 and 88 are de-energized at the same time, both the plungers 89 and 900 are in a state where the force bow is 1, so the connecting plate 93 as a whole is oriented in the direction of the arrow 118. The operating punch 101 is moved most backward in the opposite direction, and the operating punch 101 is also moved the most in the direction opposite to the direction of the arrow 102a.
01 pin 115 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 punch 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.

In order to selectively enable three information groups, which are the oscillation amplitude information group, the feed information group, and the thread tension information group, which are electrical signals corresponding to various types of stitch patterns as will be understood later. Pattern selection device 121 that is selectively operated by the operator
generally consists of a pattern selection switch group 122, an encoder 123, 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 includes pattern selection switches SO, SL,
...S6. S7 has decimal number O11, etc.
6.7 is assumed, and when any one of the pattern selection switches SO to S7 is closed, the assumed decimal number is converted into a binary code, and each bit of it is converted into a binary code. Line Ll corresponding to each bit 1. L12. L14
In addition to outputting through the line L15 provided separately,
When any one of the pattern selection switches SO to S7 is closed, a reset signal CP1 is generated which changes from a low level to a high level and returns to a low level after a certain period of time.

This reset signal CP1 is applied to the inverter 125 and the resistor 12.
6 and an integrating circuit 12 formed by a capacitor 127
8, a NAND circuit 129, and an inverter 130, and is converted into a reset pulse R8P, 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 Ll1. L12,
Three flip-flop circuits FFI, FF2 . FF4 is provided, and these input the reset pulse R3P to each tarlock input terminal CK.
When input through lead wire 133, encoder 1
Each pip 1~ from 23 is memorized.

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 another one of the 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 R3P, and the currently stored selection code is re-stored in synchronization with the reset pulse R3P. 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 142, and the reset output terminal 132 is connected to each reset input terminal RT of address counters 140, 141, and 142.

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

Since the reset output terminal 132 is always at zero level, that is, generally at a low level, except during the period in which the reset pulse R3P is generated, the output of the inverter 138 is at a high level, and therefore, when the sewing machine is running. , when the first timing pulse BCP is applied to the other input terminal of the NAND circuit 139, the output line L of the NAND circuit 139
At 32, a second timing pulse FCP corresponding to the phase-inverted first timing pulse BCP is output.

the first to third address counters 140, 141,
Reference numeral 142 has a reverse binary counter configuration, and when any one of the pattern selection switches SO to S7 is selectively closed, the reset pulse R3P converts the decimal number (0
), and then 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 the pulses cp3 (see FIG. 15) generated at each falling edge of the second timing pulse FCP.

Therefore, as is clear from FIG. 15, second and third address counters for feed control and yarn tension control.

141 and 142, the sewing needle 9 descends from the top dead center and reaches the throat plate 1.
Counting is performed in synchronization with the time TO which reaches slightly below 03.

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) of the sewing needles 9 for controlling the lateral oscillating movement of the sewing needles 9 in order 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 of the - vibration amplitude information groups 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. Since all the codes according to the embodiment use the 8.4.2.1 code, 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 rol from the top.
oJ, 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 the terminal D corresponding to the decimal number (3) is set to low level.
Only 3 are made low level.

On the other hand, the first semiconductor memory device 144 has an information setting circuit network 146 and a first multiplexer group 147, and this first multiplexer group 147 has four multiplexers 1
48 to 151, these are the first
As shown in the "amplitude information" column in Figure 7, four bits correspond to each bit of the oscillation amplitude information for one stitch. The multiplexer 151 corresponds to the most significant bit, and in the "amplitude information" column of FIG. 17, the rightmost bit in the figure corresponds to the least significant digit, and the leftmost bit corresponds to the most significant 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.
input terminals PI and P2 of 8, input terminal P1 of multiplexer 149, and input terminal PI of multiplexer 150.

P2 and the input terminal P1 of the multiplexer 151, respectively, and the output line L41 is connected to the line L52 via the inverter 152, and this line L5
2 to input terminal P4.2 of multiplexer 148. P6 and multiplexer 1500 Å power terminal P4. Commonly connected to P6.

Line 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 input terminals PO, P5 . P7 are commonly connected by a line L57, and this line L57 is further connected to a low potential terminal.

Lines L21, L22 . . . corresponding to each bit are connected to the output side of the selection code holding circuit 124. L24 is the first
As shown in FIG. 2, each selection input terminal Ll, L2 . Connect to L4 so that the digit positional relationship matches each other.1. The selection code outputted from the selection code holding circuit 124 is multiplied.

The signal is supplied to lexers 148 to 151.

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

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",
Also, 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). In this case, the bit contents of the input terminal P2 are outputted 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 end P0, and similarly, a total of four input terminals P1 are used to control the oscillation of each stitch for forming a zigzag stitch selected by the pattern selection switch S1. Amplitude information is created, and each of the other four input terminals P2 to P7 receives oscillation amplitude information regarding each stitch for forming different types of stitch patterns shown in FIGS. 16C to H in the same manner as above. create.

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.
Yl contains the code content r1000. shown in the "amplitude information" column of FIG. 17A. In the same way, when the other pattern selection switches S1 to S7 are selected, the vibration amplitude information of the code contents shown in the "amplitude information" column of FIGS. 17B to H is output in sequence. Bit output terminal Y4. Y3. Y2
．． 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 output to Yl with the code contents shown in each "amplitude information" column in FIG. 17 is input to the bit input terminals X4. X3. X2. XI, and both analog signals, such as DC voltage E1, according to the code contents are 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 differential voltage E3 between the two is 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 feed information groups for controlling the feed movement, 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, L62. A second address decoder receives the address code via L64, 160 is a second multiplexer group consisting of multiplexers 161 to 164 similar to the above, and Yll to Y14 are the multiplexers 161 to 1.
64 bit output terminal, 165 bit input terminal X11
to X14 and a second DA converter similar to the above having an analog output terminal XOI, 166 is an information setting circuitry, and selection input terminal L of each multiplexer 161 to 164.
l, L2. The lines L21 .L4 are connected to the lines L21 . L22. L
A selection code is provided via 24.

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 input terminals 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 172 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 terminal PO of the multiplexer 161,
P.I.

P2. P4. P7 and the input terminals PO, PI, P3 . P7 and the input terminal P2 of multiplexer 163. They are commonly connected to P4.

The output terminal of the NAND circuit 177 is connected to the input terminal P5. of the multiplexer 162 via an inverter 178. Commonly connected to P6.

Further, in the other changeover switch 173 of the manual automatic changeover switch device 171 for feed, one fixed contact a is connected to the analog output terminal X01 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 .

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.

Reference numeral 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. The third address decoder is input as an address code in the 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, line L90. L
91. L92. L93, L94 and L95 are respectively connected to the corresponding address designation terminals DO to D5 of the third address recorder 183, respectively.

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.

Line L92. L94 is connected to different input terminals of the NAND circuit 191, and its output terminal is connected to the input terminal P4 of the multiplexer 186 via an inverter 192.

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

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 via inverter 197 to multiplexer 1850 input terminal P4.

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 is also connected to 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 given to each of the multiplexers 185, 186, 187 through the bit negation output terminals Y21n, Y22n, Y23n of any of the input terminals PO to P7 specified by the selection code. A bit is generated that negates the bit content from, respectively,
These bits are input to the lower three phase bit input terminals X21 . 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 having the above configuration, the line L98 is the leftmost bit of the most significant digit among the four bits of the "thread tension information" width shown in FIGS. 17A to H, and
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.

The third semiconductor storage device 182 and the third DA converter 201 constitute a thread tension command circuit for outputting an electric signal instructing the thread tension disks 56 and 57 to control the strength of the thread tension. do.

Now, the third address decoder 183, the information setting circuit network 188, and the third D-A converter 201 collectively determine the strength of the thread tension corresponding to each stitch pattern by adjusting the thread tension adjustment. 56 and 57 constitute a thread tension command circuit that generates an electrical signal for commanding control, and a third multiplexer group 184 controls the pattern selection device 121.
This corresponds to a signal selection circuit that selects a thread tension command electric signal corresponding to the selected stitch pattern in response to the operation of (receiving signals from lines L21, L22, L24).

In this embodiment, the specific contents of each piece of thread tension information shown in FIG. 17 include the descending 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. It is determined by comprehensive consideration, that is, in relation to the oscillation amplitude information and the feed information group, and thereby the optimal thread winding condition for each stitch pattern is determined regardless of the difference in the type of stitch pattern. Each stitch in the same stitch pattern is determined in advance so that a uniform thread winding condition can be obtained.

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. According to the code content of each yarn tension information, it is converted into an analog signal, 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, which is an electric signal adjustment circuit to which the DC voltage E31 is applied, is connected to the analog output terminal XO2, and a sliding terminal 202a of this is connected to a thread tension manual/automatic changeover switch 203. It is connected to the contact piece C, and one of the fixed contact pieces a is connected to a low potential terminal via another variable voltage dividing resistor 204 for the electric signal adjustment circuit.

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 operational amplifier 207 is used to control the amount of power supplied to the electromagnetic actuator 52 for thread tension in cooperation with a transistor 208, and the collector of the transistor 208 is connected to the thread tension electromagnetic actuator 52 to which a freewheel diode 209 is connected in parallel. It is connected to the high potential terminal 210 via the electromagnetic actuator 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 operational amplifier 207 and the resistor 208 constitute a control circuit 213 that controls the power supplied to the electromagnetic actuator 52 as described above, and the above-mentioned connection of the resistor 212 is performed within the control circuit 213. current circuit 20
Form 6.

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 each flip-flop circuit FF1, FF2 . The line L2 of FF4
1. L22゜Line L derived from the same part as L24
IO1, 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 an inverter 217, and the output terminal thereof and the lines L102 and L104 are connected to different input terminals of a NAND circuit 218, and are connected to different input terminals of another NAND circuit 219, respectively. LIO1, 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. When S6 is selectively closed, both electromagnetic solenoids 87 and 88 are de-energized, and the pin 115 of the operating rod 101 is in position MPO. Based on the same principle, when the pattern selection switch 5O5S5 is selectively closed, the pin 115 is in the position MPO. When the pattern selection switch S7 is selectively closed, the pin 115 is at 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 effect will be explained in detail below.

It is now assumed that the yarn tension manual/automatic changeover switch 203 has been switched to the automatic control side TAU, and the changeover switches 172 and 173 in the feed manual/automatic changeover switch device 171 have been 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 formation principle of this cross stitch pattern is based on the numbers (0) to (5) shown in the stitch pattern in Figure 16G. This is repeated, and as is clear from Fig. 17G, which shows the control contents in this unit of pattern formation, the number of stitches required to form each stitch from number (0) to number (5) is The descending position of the sewing needle 9 is determined by the needle position coordinates (5), (0), (5),
(10), (15), (10).

In addition, in the feed increment, the formation of stitch number (0) is
5) Since it is performed after the formation of the number, (5)
Feed increment (-) for stitch number (0) after forming stitch number
5) is given, and the feed increment is the needle position coordinates (5), (
0), (5), (10), (15), (10), the feed increment is (-5), (+5), (+5),
The order is (-5), (+5), and (+5).

Furthermore, regarding the thread tension, the formation of stitch number (0) is different from the formation of stitch number (5).
Since this is carried out after the formation of the stitch number (5), the thread tension for the stitch number (0) (8) is determined after the formation of the stitch number (5).
is given, so the thread tension is (8) in the stitch order,
(10), (10), (8), (11), (11
) is given.

By giving the needle position coordinates, feed increment, and thread tension in this way, the cross-cut pattern shown in FIG. 16G is formed.

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 transferred to the line L21. L2
2. Selection input terminals Ll of multiplexers 148 to 151, 161 to 164, and 185 to 187 in the first semiconductor storage device 144, second semiconductor storage device 158, and third semiconductor storage device 182 through L24,
L2. Therefore, among the input terminals PO to P7 of each multiplexer 148 to 151, 161 to 164 and 185 to 187,
One input terminal P6 corresponding to the numerical value (6) that is the content of the selection code is specified, and the bit content of the input terminal P6 is changed to each bit output terminal Y1 to Y4. Yl 1 to Y
14 and bit negation output terminals Y21n to Y23n.

On the other hand, the first to third address counters 140.141
, 142 is reset by a reset pulse R3P accompanying the closing of the pattern selection switch S6, and its address code content is roooJ.

Also, by closing the pattern selection switch S6, the line L101. L102 and L104 become 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,
Both the plungers 89 and 90 of the first and second electromagnetic solenoids 87 and 88 are retracted, and as a result, the pin 115 of the operating frame 101 is positioned at MPQ, 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 rooo, and in particular, the output line L41 is the logical code "0". ” Therefore, in the first semiconductor memory device 144, the line L
Since 52 becomes "1", multiplexers 148 and 150
The bit content of each input terminal P6 becomes 11'', which is output as is to the respective bit output terminals Yl and Y3,
Also, since the address code is roooJ, the address designation terminal DO of the first address decoder 145
For D5 to D5, only one address designation terminal DO is “0”.
” and the others are “1”, so line L54. L55.
Both L56 are "1" and the output of the NAND circuit 154 is "0", so the multiplexers 149 and 151
The bit contents of the input terminal P6 of Y2 . It is output as is to Y4.

Therefore, when the count value of the first address counter 140 is (0) in decimal notation, the bit output terminals Y4, 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 the potentiometer 4 of this DC voltage E1
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 E3 until the differential voltage E3 becomes zero, thereby moving the drive link 12 towards the sewing needle 9.
is controlled so that the lowered position of is at the needle position coordinate (5), 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
olJ, and therefore the first semiconductor memory device 14
Each line in L51.4 is line L51. The potential of only L52 is inverted, and the others remain at the same potential as when forming stitch No. (0). Therefore, since the line L52 has the logic code "0", each input terminal P6 of the multiplexers 148 and 150 The bit content of is "0".

Also, other Maltiffs. The bit contents of each input terminal P6 of the lexers 149 and 151 remain unchanged and remain "0".

Therefore, the first address counter 140 is (1) in decimal notation.
bit output terminals Y4 . of the first multiplexer group 147. Y3. Y2. The code content of the oscillation amplitude information output from Yl is rooooJ, which means the needle position coordinate (0), so the following (1
) will be formed.

Prior to the above operation, at time TO when the sewing needle 9 descends from above the throat plate 103 to form the stitch number (0) and reaches a position slightly below the throat plate upper surface 135, the second timing The second and third address counters 141 and 142 count the pulse CP3 generated at the falling edge of the pulse FCP (these address counters 141 and 142 are set to one step higher than the first address counter 140).

) and convert the count content into a decimal number (1), that is, the code content from roooJ to roolJ.

Among these, the output of the second address counter 141 is “001
” as the address code, the second address decoder 159 of the second semiconductor memory device 158 has only the address designating terminal D1 among its addressing terminals Do to D5 as the logic code “0” and the others as the logic code “0”. 1”.

Therefore, focusing on the input terminals P6 of the multiplexers 161 to 164 specified by the selection code, first, the output of the NAND circuit 167 is the address specification terminal DO, D
3 are both "1" and become "0", and line L71 becomes "1", so the multiplexers 163 and 1
64 input terminals P6 respectively bit output terminals Y1
3. Since the bit content of Y14 is "1" and the inverter 176 receives a low level potential through the contacts c and a of the changeover switch 172 and outputs "1", the NAND circuit 177 Those two inputs are "0" and "1"
The input terminal P6 of the multiplexer 162 which receives this through the inverter 178 outputs "1" and outputs "0".
”, and the bit content of the bit output terminal Y12 becomes “0”.
”.

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

In this way, when the count content of the second address counter 141 is (1) in decimal notation, the second multiplexer group 1
60 each bit output terminal Y14. Y13. Y12. Yl
The code content of the feed information output from l is rllol in order from the most significant digit, which means that the feed increment prior to forming stitch number (1) is (+5), and based on the code content. The DC voltage E1□ with a specific value is converted to the second D
-A converter 165 is generated, and the changeover switch 17
It is applied to the positive input terminal of the second comparator 180 through contact piece c-a of No. 3.

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 (T
2-T3), a feed increment (+5) is applied to the work cloth prior to forming the next stitch number (1).

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 ro11. is supplied as an address code to the third address decoder 183, so among the address designating terminals DO to D5, only the terminal D1 is set to "0".
The other values are "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 input terminal P6 of the lowest digit multiplexer 185 in the third multiplexer group 184 becomes "1". The negation, ``0'', is output to the bit negation output terminal Y21n.

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 negation output terminal Y22H.

In addition, since the input terminal P6 of the multiplexer 187 is always "1" due to the line L98 connected to the high potential terminal 200, the bit negation output terminal Y23H is "1".
0" is output.

These bit negation output terminals Y21n, Y22n, Y2
3n is input to the bit input terminal X21.3n of the third DA converter 201. X22. X23, and the bit input terminal X24 of the most significant digit is always connected to the line L98.
1'' is given, so the code content of the thread tension information outputted from the third semiconductor storage device 182 to the third DA converter 201 is the “counter value” column in FIG. 17G. Consistent with what is written in the "thread tension information" column corresponding to (1), "1010" (corresponding to a thread tension degree of 10) starts from the most significant digit, and this is the above value after forming the stitch number (0). During the period (between T2 and T3), the period (0
) It is used as an electrical signal to command the strength of thread tension to tighten the stitches.

That is, the thread tension information r1010J is the third I)-
In the A 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,
A DC voltage E32 proportional to this is applied from the sliding terminal 202a to the positive input terminal of the operational amplifier 207 in the constant current circuit 206 via the contact piece c-1) 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, and the collector current depending on the differential voltage E34 adjusts the yarn. It is supplied to the child side electromagnetic actuator 52.

In this way, the amount of power supplied to the electromagnetic actuator 52 is controlled by a control circuit consisting of an operational amplifier 207 and a transistor 208 in accordance with the electrical signal E31 output from the third p-A converter 201.

Then, this electromagnetic actuator 52 generates an attractive force depending on the value of input power, and the plunger 54 moves as indicated by the arrow 23 in FIG.
Move in 3 directions.

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 r1010J at the (0) stitch. It is applied to tighten the seams after they are formed.

Swing information is selected from among the three information groups shown in the columns of "width information,""feedinformation," and "thread tension information" in FIG. The amplitude information, feed information, and thread tension information are sequentially read out as a set by the timing pulses BCP and FCP, so that each stitch for the cross stitch pattern is set from number (0) to number (5) in the optimal thread tension state. It is formed according to the information content up to the number.

In particular, the first to third address counters 140
, 141, 142 are leftward counters, so (0)
When the stitches from number to (5) are formed, the counting contents are r
By returning to ooo and repeating the counting again, the same cross-hatched pattern is repeatedly formed in succession.

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 actuator 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 actuator 52 regardless of the temperature change of 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-1) is in the open state. , First, since the output of the inverter 176 is always "0", the NAND circuit 1
The output of P5. P6
is always "O", and on the other hand, the line L73 is also always kept at "1" by the selector switch 172, so that the input terminals PO, PI, P2 . P
4. Pl, input terminal PO of multiplexer 162,
Pl, P3. Pl, and input terminal P2 of multiplexer 163. As can be understood, P4 is always set to "1", and furthermore, among the input terminals PO to P7 of the multiplexers 161 to 164, some terminals are always set to "1" because they are open terminals. , pattern selection switches SO, Sl, S2. When S4 and S7 are selectively closed, the bit output terminals Y14 . Y13, Yl 2. The code content of the sending information output from Yl 1 is always rlllllJ regardless of the counting content of the second address counter 141, and the corresponding DC voltage E□4 is applied to the second I)-A converter 165. The signal is output from the analog output terminal X01 and applied between the terminals of the 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 180 via the contacts c-1) of the changeover switch 173. is applied to the positive input terminal of , so that work cloth feed control is performed with 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 is applied to the positive input terminal of the operational amplifier 207. Therefore, by manual adjustment of the sliding terminal 204a of the variable voltage dividing resistor 204, the voltage depending on the position of the variable voltage dividing resistor 204 Similarly to the case of No. 202, it is possible to obtain the optimum thread tension according to the sewing conditions and special sewing circumstances.

In this sewing machine, a thread tension electromagnetic actuator 52
An auxiliary switch 67 that opens and closes in conjunction with the presser foot lifting lever 81 cuts off the power supply when the lever 81 is in the presser foot lifting position.

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 actuator 52 for thread tension is cut off, and the tension applied to the needle thread is released.

Therefore, sewing operations such as embroidery and basting that are performed by releasing the pressure on the workpiece fabric, or operations such as changing the direction of the workpiece cloth and attaching and detaching the workpiece cloth, can be easily performed without being hindered by strong thread tension. Since the thread tension is released by lifting the presser foot, the operation does not become complicated, and the electromagnetic actuator 52 is not energized when the presser foot is raised when the sewing operation is interrupted. Since the actuator 52 is automatically cut off, it is possible to prevent the actuator 52 from overheating, thereby extending its life and saving power consumption.

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 fabric to be processed for some reason, the pattern selection switches SO to S7 are pressed.
If one of them is selectively closed, the reset pulse R8P 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 BC 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.
By the falling edge of the signal, the count code contents of the second and third address counters 141, 142 change from the most significant digit to "00".
1'', 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; for example, information may be stored as a magnetic signal, and in the above-mentioned embodiments, when the presser foot lifting lever is lifted, the power supplied to the electromagnetic actuator is is shut off and the thread tension is completely released. However, if you want to maintain a slight thread tension even when the presser foot lifting lever is in the lifted state, you can always apply weak spring pressure to the thread tension member. The present invention can be modified in various ways without departing from the spirit of the invention, such as by adding additional configurations.

As described above, the present invention includes a thread tension command circuit 182 and 201 that outputs an electric signal for commanding the strength of thread tension applied to the sewing thread by the thread tension members 56 and 57;
an electromagnetic actuator 52 that acts on the thread tension member;
A control circuit 206 to 208 that controls the amount of power supplied to the actuator according to the electric signal, and a control circuit 206 to 208 that opens and closes in conjunction with a presser foot lifting lever '-81 of the sewing machine, and supplies power to the actuator when the lever is in the presser foot lifting position. The device is characterized in that it includes a switch means 67 for cutting off the supply.

As a result, the yarn tension is controlled by controlling the electromagnetic actuator using an electric signal, making it possible to automate yarn tension control.Moreover, since the strength of the yarn tension depends on the power supplied to the electromagnetic actuator, the yarn tension can be controlled easily. Can be set accurately.

Furthermore, since a constant current circuit is provided to prevent the current supplied to the electromagnetic actuator from changing due to a change in resistance caused by a rise in temperature i of the winding, it is possible to always obtain a pre-tightening effect that matches the electrical signal. can.

On the other hand, a switch means interlocked with the presser foot lifting lever is provided, and this switch means is used to supply or cut off power to the electromagnetic actuator.
Sewing operations such as basting stitches that are performed by releasing pressure can be easily performed without being hindered by strong thread tension, and this release of thread tension is achieved by lifting the presser foot lever. This does not make the operation 1 more complicated, and also prevents the electromagnetic actuator from overheating, which has many beneficial effects.

[Brief explanation of drawings]

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 parts related to the present invention, FIG. 2 is an exploded perspective view of an actuator, and FIGS. The figures are a side view, a top view, and a front view of the thread tensioning device, FIGS. 6 and 7 are a plan view and a front view of the electromagnetic solenoid device portion of the needle hole switching device, and FIG. 8 is a plane view of the throat plate portion. 9 is a plan view of the needle hole switching portion, and FIG. 10 is a block diagram for explaining the horizontal swing amplitude control of the sewing needle, the feed control of the work cloth, and the thread tension control.
FIG. 1 is a circuit configuration diagram mainly showing a selection device section and an electromagnetic solenoid driving section, and FIGS. 12 to 14 are circuit configurations showing a first semiconductor memory device to a third semiconductor memory device, respectively, together with their associated circuits. 15 is a time chart for explaining the embodiment, FIG. 16 is a diagram showing different types of stitch patterns, FIG. 17 is a diagram showing control details for each stitch pattern, and FIG. - and is a diagram for explaining the operation of the second electromagnetic solenoid. 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 actuator for thread tension, 54 is a plunger, 56 and 57 are thread tension discs (thread tension member), and 60 is a push rod. , 63 is a plunger interlocking lever, 67 is an auxiliary switch (switch means), 68 is a workpiece presser device, 71 is a switch opening/closing lever, 76 is a presser bar,
77 is a presser foot lifting lever, 79 is a cam receiving plate, 81 is a presser foot lifting lever, 82 is a rotating lever, 87 and 88 are first and second electromagnetic solenoids, 93 is a connecting plate, 94.95 is a stopper, 96 is the lever, 101 is the operating frame, 103 is the throat plate,
105 is a horizontally long 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 an 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 S7 to S7 are pattern selection switches, 137 is a delay circuit, 140
is a first address counter (readout device), 141 is a second address counter (readout device), 142 is a third address counter (readout device), 143 is a pulse distributor, 144 is a first semiconductor memory device, 146 is an information setting circuit network, 145 is a first address decoder, 14
7 is a first multiplexer group, 148 to 151 are multiplexers, 155 is a first DA converter, 156 is a first comparator, 157 is an amplitude control driver, 158 is a second semiconductor storage device, 159 is a second address decoder,
160 is a second multiplexer group, 161 to 164 are multiplexers, 165 is a second DA converter, 166
171 is an information setting circuit, 171 is a manual automatic changeover switch 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, and 183 is a third semiconductor memory device. 184 is a third multiplexer group, 185 to 187 are multiplexers, 188 is an information setting circuit network, 201 is a third D-
A converter, 20"3 is a manual automatic changeover switch for thread tension,
206 is a constant current circuit, 207 is an operational amplifier, 208 is a transistor, 213 is a control circuit, and 214 is a gate circuit.

Claims (1)

[Claims] 1 Thread tension command circuits 182 and 201 that output electrical signals for commanding the strength of thread tension applied to the sewing thread by the thread tension members 56 and 57, an electromagnetic actuator 52 that acts on the thread tension members, and A control circuit 213 has a constant current circuit 206 for keeping the amount of current supplied to the actuator constant at the amount of current according to the electric signal, and the control circuit 213 opens and closes in conjunction with the presser foot lifting lever 81 of the sewing machine, so that the lever is in the presser foot lifting position. a switch means 67 for cutting off power supply to the actuator when the actuator is in position.