JPS6214308B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a sewing machine, and in particular to a drive for driving a swinging member that reciprocates around a fixed axis, such as a needle bar support and a feed adjuster. The present invention relates to a sewing machine having features in its device.

Prior Art In conventional sewing machines, swinging members such as a needle bar support and a feed adjuster are driven by converting the rotation of the main shaft of the sewing machine into swinging motion by a motion conversion mechanism. This motion conversion mechanism generally requires many parts, which increases the cost of the device, and also has the disadvantage that it is difficult to manufacture a sewing machine compactly. Furthermore, when many parts are combined, it is inevitable that frictional resistance and play will occur between each part.
These causes a decrease in energy efficiency and a deterioration in the positioning accuracy of the swinging member, and furthermore, the high-speed response performance is limited by the inertia of each component.

In order to eliminate such problems, the applicant has
By making the drive device for the various swinging members in a sewing machine capable of directly driving these swinging members, the mechanism of the sewing machine is simplified, energy efficiency and sewing accuracy are improved, and high-speed operation is possible. He developed a sewing machine that could increase the degree of freedom in design, and filed a patent application. This is the case currently being filed in Japanese Patent Application No. 135764/1983. The driving device for the needle bar support and the feed adjuster, which are the swinging members of this sewing machine, consists of a swinging body attached to the sewing machine frame so as to be able to swing around one fixed axis, and integrated with the swinging body. a movable part that is configured to swing around the fixed axis, and a fixed part that is mounted on the sewing machine frame opposite to the movable part, and between the movable part and the fixed part. A step drive device capable of moving the movable part in steps relative to the fixed part to position the movable part in a plurality of positions by generating electromagnetic force; A drive command device for supplying a drive command is included, and the rocking body in which the movable part is integrally formed is directly driven.

The arcuate curved surface that is the opposing surface between the movable part and the fixed part of the step drive device generally has
An appropriate number of salient poles are each made of a magnetic material such as electromagnetic mild steel, and a wire is wound around the salient poles to form an excitation coil, or one of the salient poles is a permanent magnet of that shape. It was hot. For this reason, the step drive device becomes unstable above the maximum drive frequency determined in principle for starting and driving the step drive device, and it has been impossible to obtain response characteristics higher than that. In addition, since the appropriate number of salient poles must be precisely formed on the facing surfaces of the movable part and the fixed part, there is a drawback that the machining thereof makes these parts expensive.

Furthermore, a sewing machine such as that described in Japanese Patent Application Laid-Open No. 53-51045 has been considered, in which various swinging members are directly swung by their drive devices. That is, a driving device such as a linear motor connected to the other end of a substantially L-shaped lever that loosely grips the needle bar at one end determines the horizontal swing position of the needle attached to the needle bar. In addition, the drive device connects its output arm to the feed adjuster via a link, etc., and applies rotational force to the feed adjuster, so that processing can be performed using the feed dog connected to the feed adjuster via the arm, etc. This is a type of sewing machine that controls the amount of cloth fed. However, in this type of sewing machine, an L-shaped lever is interposed between the needle bar and the drive device, and the drive device is driven from a position relatively distant from the needle bar. There were cases where a certain amount of error occurred in the positional accuracy of In addition, since a link, etc. is interposed between the feed adjuster and the drive device together with an output arm to supply the rotational force, the device becomes complicated, and the swing position of the movable part is not controlled by the drive device. When a position detector is provided for detection, sufficient accuracy of the position detector cannot be obtained.

Purpose The present invention has been made against the background of the above circumstances, and its purpose is to further simplify and inexpensively direct drive devices for various swinging members in sewing machines, and to improve response characteristics. This was done for the purpose of making stable and highly high-speed driving possible.

Solution To achieve this object, a sewing machine according to the present invention includes: (1) a needle bar to which a needle is fixed at the lower end; (2) a needle bar that supports the needle bar so as to be able to reciprocate up and down; (3) a needle bar support mounted on a sewing machine frame so as to be swingable about a horizontal fixed axis to impart a lateral swinging motion to the needle; A movable part placed and held on the lower part of the needle bar support, a fixed part mounted on the sewing machine frame facing the movable part, and an electromagnetic force generated between the movable part and the fixed part. The movable part has a coil wound around at least one of the movable part and the fixed part in order to continuously move the movable part with respect to the fixed part by generating electromagnetic force between the fixed part and the fixed part. (4) a position detector for detecting the position of the movable part with respect to the fixed part and outputting a position signal; (6) a position control circuit that controls the horizontal swing position of the needle by adjusting the magnitude and direction of the coil drive current; The sewing machine is configured such that the needle, which is given an oscillating motion according to the operation of the drive device and which reciprocates up and down, and the work cloth that is fed in synchronization with the up and down reciprocation work together to perform a desired sewing operation. be done.

In this way, the drive current whose magnitude and direction are controlled by the position control circuit in accordance with the position signal and the command signal is supplied to the coil of the drive device, and the movable part and the fixed part are connected to each other. Since the movable part is continuously moved relative to the fixed part by generating an electromagnetic force during This imparts a lateral rocking motion to the needle. Therefore, the needle bar support is directly driven by the drive device, eliminating the need for a connecting member between the needle bar support and the drive device, and improving the positioning accuracy of the needle bar support. This has the effect of providing a sewing machine equipped with a drive device that is simple and inexpensive, and has high responsiveness, compared to the conventional case of using a step drive device.

In addition, since the movable part of the drive device is arranged below the needle bar support, the distance between the needle bar and the drive device is relatively short, and the distance between the needle bar and the drive device is relatively short. The effect is that the positional accuracy of the swinging motion is improved.

In another aspect, (1) a feed dog for imparting a feed motion to the workpiece cloth to be sewn, and (2) a sewing machine frame to control the feed motion of the workpiece cloth by the feed dog. (3) a feed adjuster connected to a swingably supported adjustment shaft and swingable around the axis of the adjustment shaft; (3) a movable part fixed to the adjustment shaft; The sewing machine has a fixed part attached to the sewing machine frame, and a coil wound around at least one of the movable part and the fixed part to generate electromagnetic force between the movable part and the fixed part. , a drive device capable of continuously moving the movable part with respect to the fixed part, and (4) a part of the movable part extending from the adjustment shaft for detecting the position of the movable part with respect to the fixed part. (5) a position command device that outputs a command signal for determining the adjustment position of the feed adjuster; 6) a position control circuit that controls the magnitude and direction of the drive current of the coil according to the position signal and the command signal, the workpiece cloth being given a feed motion according to the operation of the drive device in an up-down direction; The sewing machine is configured to cooperate with the reciprocating needle to perform a desired sewing operation.

Operation and Effect of the Invention In this way, the drive current whose magnitude and direction are controlled by the position control circuit is supplied to the coil in accordance with the position signal and the command signal, and the movable part and the fixed part of the drive device are connected to each other. Due to the electromagnetic force generated during this period, the movable part is continuously moved relative to the fixed part, and the feed adjuster connected to the adjustment shaft fixed to the movable part swings around the axis of the adjustment shaft. As a result, the feed movement of the work cloth by the feed dog is controlled. Therefore, also in this aspect,
Similar to the above embodiment, since the feed adjuster is directly driven by the drive device, a connecting member between the feed adjuster and the drive device is not required, improving the positioning accuracy of the feed adjuster. Therefore, the device is simple and inexpensive, and high responsiveness can be obtained.

Furthermore, in this aspect, since the position detector for detecting the position of the movable part with respect to the fixed part is provided in the part extending from the adjustment shaft of the movable part that directly drives the feed adjuster, Compared to conventional sewing machines in which a member such as a link is interposed between the drive device and the feed adjuster, the detection accuracy of the position detector is improved.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing only the characteristic parts of the sewing machine according to the present invention, and the sewing machine frame 1 is removed to clearly show the internal mechanism, and only the position is shown with two-dot chain lines. Since the parts other than those shown here are the same as those of known sewing machines, the explanation will be omitted.

The sewing machine frame 1 has a bed 2 and a support 3 above it.
and a head 5 disposed supported by the arm 4.

A needle bar support 6, which is one of the swinging members, is provided inside the head 5, with a boss 7 formed at its upper end pivotally connected to a fixed frame (not shown) by a pivot 8. There is. The needle bar support 6 has a needle bar support part 9 and a needle bar support part 11 (shown in FIG. 2) at its upper and lower parts, and these allow the needle bar 12 to slide in the axial direction. I support it. A sewing machine needle 13 is attached to the lower end of the needle bar 12 by a needle holder 14. On the other hand, a needle bar support shaft 16 is fixed to the intermediate portion of the needle bar 12 by a needle bar support 15, and the needle bar crank rod 1 into which this needle bar support shaft 16 is slidably fitted is fixed.
7 is connected to a needle bar crank 18. Since the needle bar crank 18 is fixed to one end of a sewing machine main shaft 19 that is horizontally disposed within the arm 4 and is rotationally driven by a sewing machine motor (not shown), the needle bar 12 rotates as the sewing machine main shaft 19 rotates. is caused to reciprocate up and down.

In order to perform sewing work other than straight stitching, it is necessary to give the needle bar 12 a lateral oscillating motion in addition to the above-mentioned vertical reciprocating motion. The device is amplitude motor 2
It is 0. As shown in FIGS. 2 and 3, this amplitude motor 20 is attached to a bracket 21 fixed to the sewing machine frame 1 by a set screw (not shown).
A fixing portion 23 screwed onto the fixing screw 22 by a fixing screw 22
and a movable part 26 in which a mounting shaft 24 is fixed with a nut 25 at the lower part of the needle bar support 6 near the fixed position of the needle 13.

The fixing part 23 includes a plate body 27 and a container body 28 made of silicon steel, which together form a thin rectangular parallelepiped-shaped container whose upper surface and opposing side surfaces are open surfaces, and the plate body 28.
Permanent magnets 29 and 30 in the shape of a thin rectangular parallelepiped magnetized to form magnetic poles on the surface to be attracted to 7 and the surface opposite thereto, and a resistor 3 for a potentiometer.
4. These magnets 29 and 30 are vertically adjacent to each other and are attracted to the plate 27 so that their different magnetic poles are in contact with each other. Since the container body 28 having a horizontal oval through hole and two fixing screw holes is combined,
A uniform magnetic field is formed in the gap between the permanent magnets 29 and 30 and the container body 28, which is perpendicular to the magnetic pole faces of the permanent magnets 29 and 30 and has a different direction corresponding to the permanent magnets 29 and 30. -ing The plate body 27 and the container body 28 are fixed by attraction forces acting on each other because the magnetic flux from the permanent magnets 29 and 30 passes through them to form a magnetic circuit. Therefore, the plate body 27 can be easily removed, making maintenance and inspection easy.

On the other hand, the movable part 26 has a vertical rectangular plate shape,
A coil 31 in which a conductive wire is wound in a plane, a mounting shaft 24 integrally projecting slightly below the center thereof,
It is provided with a brush 33 at its lower part and is formed thin and integrally. This structure makes the movable part 26 lighter and reduces its inertia, and also narrows the gap between the container body 28 and the permanent magnets 29 and 30 in which the movable part 26 is housed, so that a stronger magnetic field can be generated. This has the advantage of increasing the electromagnetic force generated in the movable portion 26.

The movable part 26 is housed in the gap in the fixed part 23 so as to be able to swing freely around the movable part 26 with a slight gap therebetween. The maximum swing range of the movable portion 26 is 3°12', which corresponds to ±5 mm at the tip of the sewing machine needle 13.

Therefore, when a driving current is applied to the coil 31, the strength of the magnetic field in the same direction received by the upper and lower sides of the coil 31 is equal, and the electromagnetic force generated on each side follows the so-called Fleming's law. Therefore, since they are generated in opposite directions on the winding surface of the coil 31, they cancel each other out, but since the direction of the magnetic field received by the left side and the right side is opposite, the direction of the electromagnetic force generated on each side is It is the same on the winding surface of the coil 31 and is in the right or left direction. As a result, the sum of the electromagnetic forces generated on both the left and right sides becomes the driving force for the movable portion 26.

In addition, since the potentiometer resistor 34 is fixed to the plate 27 so that the brush 33 comes into contact with it, the brush 33 slides on the resistor 34 in association with the swinging of the movable part 26. The potentiometer 32 is configured as follows. These brushes 33, terminals on both sides of the resistor 34, and the coil 31 are connected to a needle position control circuit by conductive wires (not shown).
Connected to BC.

Returning to FIG. 1, 35 is a presser bar, which is constantly urged downward by a spring 36.
It is also possible to hold it in the raised position by a known mechanism (not shown). A presser foot 38 is fixed to the lower end of the presser bar 35 by a thumbscrew 37.

A needle plate (not shown) is provided on the bed 2 below the presser foot 38, and a feed dog 41 is arranged below the needle plate. The feed dog 41 is screwed to a feed base 42, and when the feed base 42 is operated by a known feed drive mechanism (not shown), the feed dog 41 is processed in cooperation with the aforementioned presser foot 38 and throat plate. Gives feed to the cloth.

In the sewing machine of this embodiment, this feed dog 41
A feed adjuster 43 for adjusting the feed direction and feed amount of the work cloth is also driven by the feed adjuster motor 50. The feed adjuster 43 is provided with a guide groove 44 having a rectangular cross section on its end surface, and is supported by a bearing portion 47 (see FIG. 4) fixed to the bed 2 to support a feed adjuster shaft 45 rotatably disposed. It is fixed at one end by a set screw 48. A feed angle top 46 is slidably fitted into the guide groove 44 of the feed adjuster 43, and the feed angle top 46 is moved up and down within the guide groove 44 by a feed drive mechanism (not shown). However, if the guide groove 44 is not vertical but inclined at this time, a horizontal motion component will occur in the feed angle piece 46, and this horizontal motion component will be transmitted to the feed base 42 via the feed drive mechanism. , giving a feed motion to the feed dog 41. The size of this feeding movement,
In other words, the larger the inclination of the guide groove 44 is, the greater the feed amount becomes.If the direction of the inclination of the guide groove 44 is reversed, the feed direction can be reversed. It is necessary to swing a predetermined angle in the opposite direction, and the feed adjuster motor 50 is used as the drive mechanism.

As shown in FIG. 4, the feed adjuster motor 50 includes a fixed part 51 fixed to the sewing machine frame 1 with a screw (not shown), and a movable part fixed to the feed adjuster shaft 45 with a set screw 62. 52.

The fixed part 51 includes a plate body 53 and a container body 54 made of silicon steel plates, which together form a semicircular container with an open top surface, and magnetic poles formed on the surface that attracts the plate body 53 and the surface that faces it. Permanent magnets 55, 56, 57, 58 in the shape of fan-shaped plates magnetized so as to
The potentiometer resistor 60 is also provided.
These magnets 55, 56, 57, and 58 are attracted to the plate 53 in a radial manner centered on the center point of a semicircle that is the shape of the plate 53 so that adjacent magnets have different magnetic poles. At the same time, the plate body 53 is combined with a semicircular container body 54 in which a strip plate is integrally formed at right angles to the circumference, so that the permanent magnets 55, 56, 57, 58,
In the gap between the container body 54 and the magnetic pole surface of the permanent magnets 55, 56, 57, 58, there are uniform magnets with different directions perpendicular to the magnetic pole faces of the permanent magnets 55, 56, 57, 58. A strong magnetic field is created. The plate body 53 and the container body 54 are fixed together by the attraction force acting on each other because the magnetic flux from the permanent magnets 55, 56, 57, and 58 passes through them to form a magnetic circuit. has been done.
Therefore, the plate body 53 can be easily removed, making maintenance and inspection easy.

On the other hand, the movable part 52 includes a boss part 61 having a set screw 62 for attaching it to the feed adjuster shaft 45.
It integrally includes two coils 63 and 64 in which conductive wires are wound flat in a fan shape and a brush 56,
A thin fan-shaped portion 66 is fixed thereto.
This structure makes the movable part 52 lighter and reduces its inertia, and also makes it possible to narrow the gap between the permanent magnets 55, 56, 57, 58 in which the movable part 52 is housed and the container body 54, making it even stronger. This has the advantage of forming a magnetic field and strengthening the electromagnetic force generated in the movable part 52.

A U-shaped notch is formed near the center of the semicircular plate 53 and container body 54 that constitute the fixed part 51, so that the movable part 52 is attached to the center of the U-shaped notch. A fan-shaped part 66 of the movable part 52 is swingably housed in a gap in the fixed part 51 with a slight gap around it so that the axial center of the feed regulator shaft 45 coincides with the axial center of the feed regulator shaft 45. . The swing range of this movable portion 52 is approximately 40°.

Therefore, when a drive current is applied to the coils 63 and 64, the electromagnetic force generated in the arc-shaped portions of the coils 63 and 64 is on the coil winding surface according to Fleming's left hand rule. Since it occurs in the radial direction of the feed adjuster shaft 45, it does not contribute to driving the movable part 52 in the rotational direction. However, since magnetic fields in opposite directions are applied to the linear portions of the fan-shaped radial direction of the coils 63 and 64, the electromagnetic force generated in each portion is on the coil winding surface and is applied to that portion. The direction is perpendicular to the direction of rotation and the same direction of rotation as the feed adjuster shaft 45. As a result,
The sum of the electromagnetic forces generated in the linear portions of the respective coils becomes the driving force of the movable part 52.

In principle, there is no problem even if the movable part 52 has a single coil, but if the coil is wound to obtain the necessary driving force, the arc-shaped portion of the coil that does not contribute to the driving force becomes large, and the feed adjuster motor 50 becomes larger. As it becomes larger in the radial direction, the amount of heat generated increases, so
A movable part 52 equipped with a coil divided into a plurality of parts to increase the linear portion in the radial direction that contributes to the driving force.
is more desirable. Incidentally, since the potentiometer resistor 60 is fixed to the plate 53 so that the brush 65 comes into contact with it, the brush 65 moves against the resistor 60 in relation to the swinging of the movable part 52.
A potentiometer 59 is configured to slide on the top. The brush 65, the terminals on both sides of the resistor 60, and the coils 63, 64 are connected to the feed adjuster shaft position control circuit FC by conductive wires (not shown).

As shown in the block diagram of FIG. 5, the sewing machine configured as described above includes a position command device PC,
It is controlled by a control circuit consisting of a needle position control circuit BC and a feed adjuster shaft position control circuit FC.

The timing pulse generator 70 is connected to the sewing machine main shaft 19
The output terminal of the timing pulse generator 70 is connected to the clock terminal CK of the address counter 71 in order to supply one timing pulse to the address counter 71 every time the clock reaches a specific rotational phase. The address counter 71 is reset when the power-on signal SN is input to its reset terminal RT, counts the timing pulses supplied to the terminal CK, and outputs a count signal SC representing the count contents. Since the count signal SC specifies the address of the stitch information storage device 72 according to its contents, the output terminal of the address counter 71 is connected to the input terminal of the stitch information storage device 72 by a transmission line.

Each address of the stitch information storage device 72 stores needle position (amplitude) information and feed information for forming a predetermined stitch, and when the sewing machine main shaft 19 rotates once, the specified address of the address counter 70 is stored. Each time the needle position command signal SB and feed adjuster shaft position command signal SF change, one set of the needle position command signal SB and the feed adjuster shaft position command signal SF are sent to the corresponding needle position control circuit BC and feed adjuster shaft position control circuit FC, respectively.
It is output with a phase difference of about half a rotation of the main shaft 19 of the sewing machine.

The above-described timing pulse generator 70, address counter 71, and stitch information storage device 72 constitute the position command device PC.

The needle position control circuit BC includes a D/A converter 73 for converting the needle position command signal SB, which is a digital signal, into an analog signal and outputting it to the comparator 74;
Comparator 74, amplitude motor drive circuit 75, movable part 26 of amplitude motor 20, and potentiometer 3
The control loop is composed of a closed control loop formed by No. 2 for performing negative feedback control. This movable part 26
The dashed line between and potentiometer 32 indicates the mechanical connection.

The circuit configuration of the needle position control circuit BC is shown in FIG. Here, the output terminal of the D/A converter 73 is connected to the +input terminal of the operational amplifier constituting the comparator 74 via a series resistor R1, and the +input terminal is connected to the +input terminal via a resistor R2. Grounded. Since the output signal of the comparator 74 is the drive command signal for the amplitude motor drive circuit 752, the output terminal of the operational amplifier is connected to the base terminals of input transistors 76 and 77 that constitute the input terminals of the amplitude motor drive circuit 75. has been done.

The amplitude motor drive circuit 75 has an NPN transistor 76 and an NPN transistor 76 for input so that it can output a positive or negative current for driving the amplitude motor 20 according to the drive command signal from the comparator 74.
It consists of a PNP transistor 77, and a PNP transistor 78 and an NPN transistor 79 for output. NPN transistor 76 and PNP
The base terminal and emitter terminal of the transistor 77 are commonly connected to each other, and the emitter terminal is grounded, and the collector terminal of the NPN transistor 76 is connected to the PNP transistor 7.
The collector terminal of the PNP transistor 77 is connected to the base terminal of the NPN transistor 79. PNP transistor 78 and
The emitter terminals of the NPN transistors 79 are connected to the positive power supply +VS and the negative power supply -VS, respectively, and their respective collector terminals are commonly connected to form an output terminal.

The coil 31 of the movable part 26 has one end connected to the amplitude motor drive circuit 75 in order to generate an electromagnetic force that drives the needle bar support 6, which is the swinging member.
The other end is connected to the output terminal of the drive current limiting resistor R3, and the other end is connected to the ground via the drive current limiting resistor R3.
It is connected to the -input terminal of the operational amplifier, which is the comparator 74, via a feedback resistor R4 for stable operation.

The dotted lines in the figure indicate mutual mechanical relationships, meaning that the electromagnetic force generated in the coil 31 moves the movable part 26, and the brush 33 fixed to the movable part 26 moves. .

The potentiometer 32 is a position detector for electrically detecting the swinging position of the needle bar support 6, which is a swinging member, and both terminals of the resistor 34 of the potentiometer 32 are connected to a positive voltage. Connected to power supply +VC and negative voltage power supply -VC, potentiometer 3
The second brush 33 is connected to the − input terminal of the operational amplifier 81 of the level setting circuit 80 via the resistor R5.

The level setting circuit 80 absorbs variations in the parts constituting the device and electrically matches the signal indicating the actual needle position.
and the comparator 74, and is comprised of an operational amplifier 81, a potentiometer 82 for level setting operation, and the like. Both terminals of the resistor of the potentiometer 82 are connected to the positive voltage power supply +VC and the negative voltage power supply -VC, respectively, and the brush of the potentiometer 82 is connected to the + input terminal of the operational amplifier 81 via the resistor R6. . Also,
The output terminal of the operational amplifier 81 is connected to the -input terminal of the operational amplifier, which is the comparator 74, via a resistor R7, and is feedback-connected to its -input terminal via a resistor R8. That is, the operational amplifier 81 also has a comparison function, and responds to the input signal deviation depending on whether the position detection level by the potentiometer 32 is lower than the level set by the potentiometer 82. It generates a positive or negative output voltage.

In the feed adjuster shaft position control circuit FC, the needle position command signal SB in the aforementioned needle position control circuit BC becomes the feed adjuster shaft position command signal SF, the amplitude motor drive circuit 75 becomes the feed adjuster motor drive circuit 83,
The movable part 26 is replaced by a movable part 52, and the potentiometer 32 as a needle position detector is replaced by a potentiometer 59 as a feed adjuster shaft position detector. The explanation will be omitted.

Operation of the Embodiment The operation of the amplitude motor 20 that drives the needle position will be described below. In order to perform sewing operations other than straight stitching, it is necessary to drive the needle bar support 6 that supports the needle bar 12 to give it an oscillating motion. Therefore, the needle position command signal SB is inputted from the position command device PC to the D/A converter 73 at a predetermined timing.
The commanded position of the needle is converted into an analog signal representing the voltage, and the signal is input to the + input terminal of the comparator 74. On the other hand, a voltage signal representing the needle position from the potentiometer 32, which is a needle position detector, is inputted to the − input terminal of the comparator 74 via the level setting circuit 80. The comparator 74 compares these input signals and outputs a signal having a sign and voltage value corresponding to the mutual signal difference to the amplitude motor drive circuit 75. In other words, when the needle position command signal SB exceeds the signal representing the actual needle position, it is a positive voltage output signal, and in the opposite case, it is a negative voltage output signal, and the output voltage value is a deviation signal SE that is proportional to the deviation between the above two signals. It is.

When the positive voltage deviation signal SE is input to the amplitude motor drive circuit 75, the base potential of the NPN transistor 76 rises higher than the emitter potential, so a base current flows between its collector and emitter. A current with amplified width flows. This amplified current forms the base current of the PNP transistor 78, and a current amplified by the base current flows between its emitter and collector, so that the amplified current proportional to the deviation signal SE becomes positive. The voltage flows from the voltage power supply +VS through the PNP transistor 78, through the coil 31, and through the resistor R3 to the ground terminal.

Contrary to the above, when the negative potential deviation signal SE is input to the amplitude motor drive circuit 75, the base potential is lower than the emitter potential of the PNP transistor 77, so a base current flows and the collector and emitter of the PNP transistor 77 are connected to each other. In between, a current whose base current is amplified flows. This amplified current forms the base current of the NPN transistor 79, and a current amplified by the base current flows between its collector and emitter, so that an amplified current proportional to the deviation signal SE is grounded. It flows from the terminal through the resistor R3, through the coil 31 in the opposite direction to the above, and through the NPN transistor 79 to the negative voltage power supply -VS.

The current direction of the coil 31 is determined so that the direction of the electromagnetic force generated when the drive current flows through the coil 31 is always in the direction of rotation approaching the position represented by the needle position command signal SB, and the amplitude is adjusted. Since the motor drive circuit 75 is connected, when the drive current flows, the movable part 26 is rotated in a direction that reduces the deviation signal SE and with a driving force proportional to the deviation signal SE. .

The rotational position of the movable part 26 is determined by the potentiometer 32.
is converted into an electrical signal by the level setting circuit 8.
After being compared with a preset level signal at 0 and adjusted, it is returned to the comparator 74. The above control operation is continuously performed until the deviation signal SE disappears, and the movable part 26 is rotated and then positioned.

Needle position command signal SB indicating the rotational position opposite to the above
Even in the case where is input, the drive current flowing through the movable portion 26 is reversed, and the same explanation can be applied only that the rotation direction is reversed.

Therefore, when the needle position command signal SB from the stitch information storage device 72 is sequentially transmitted, the needle bar support 6 swings, and this swing movement and the vertical movement of the needle bar 12 Combined with reciprocating motion,
This provides the movement of the sewing needle 13 necessary to form various stitch patterns.

Next, the operation of the feed regulator 43 will be explained. In order to perform sewing work, it is necessary to drive the feed adjuster shaft 45, which adjusts the feed direction and feed amount of the work cloth, to provide a swinging motion. Therefore, the feed adjuster shaft position command signal SF is input from the position command device PC to the feed adjuster shaft position control circuit FC at a predetermined timing. As described above, in this feed adjuster shaft position control circuit FC, the needle position command signal SB in the needle position control circuit BC is used as the feed adjuster shaft position command signal, and the amplitude motor drive circuit 75 is used as the feed adjuster motor drive circuit 83. The movable part 26 is connected to the movable part 52, and the potentiometer 32 as a needle position detector is connected to the potentiometer 59 as a feed adjuster shaft position detector.
Except for the name change, this circuit is composed of the same circuit as the hand position control circuit BC, and operates in the same manner, so a brief explanation will be given below.

The feed regulator shaft position command signal SF is converted into a voltage signal by a D/A converter and then input to a comparator. The comparator includes a potentiometer 59 which is a feed adjuster shaft position detector to a feed adjuster shaft 45.
Since a voltage signal representing the rotational position of the feed controller is inputted, this signal and the output signal of the D/A converter representing the feed adjuster axis command position are compared by the comparator, and the mutual signal difference is calculated. A deviation signal having a number and voltage value corresponding to is transmitted to the feed regulator motor drive circuit 83.

The feed regulator motor drive circuit 83 amplifies the input deviation signal and supplies a drive current to the movable part 52.

In the movable part 52, like the above-mentioned movable part 26, the direction of the electromagnetic force generated when the drive current flows through the coils 63 and 64 always approaches the position represented by the feed adjuster shaft position command signal SF. The direction of energization of the coils 63 and 64 is determined so that the rotation occurs in the direction of rotation, and is connected to the feed adjuster motor drive circuit 83. Therefore, when the drive current flows through the coils 63 and 64, the movable part 52
is rotated in a direction that reduces the deviation signal and with a driving force proportional to the deviation signal.

The rotation position of the movable part 52 is determined by a potentiometer 59.
is converted into an electrical signal by the converter and sent back to the comparator via a level setting circuit. The above control operations are continuously performed until the deviation disappears, and the movable part 5
2 is rotated and then positioned.

Even when the feed adjuster shaft position command signal SF indicating a rotational position opposite to that described above is input, the current flowing through the movable part 52 is reversed, and the same explanation can be applied only that the rotation direction is reversed.

Therefore, when the feed adjuster shaft position command signal SF is sequentially transmitted from the stitch information storage device 72 every time the sewing machine main shaft 19 makes one revolution, the feed dog 41 receives the necessary feed amount and feed direction for the work cloth. A predetermined sewing operation is automatically performed by a combination of this feeding movement and the above-mentioned lateral rocking movement of the sewing machine needle 13.

As explained above, in this embodiment, the position command device PC and the potentiometers 32, 5
Based on the signal difference between the needle position command signals SB and SF output from the needle position command signals SB and SF and the voltage signal which is a position signal, the amplitude motor drive circuit 75 and the feed adjuster motor drive circuit 83 send signals to the amplitude motor 20 and the feed adjuster motor drive circuit 83. A drive current is supplied to the motor 50,
Between the movable part 26 and the fixed part 23, and the movable part 5
2 and the fixed part 51, and the movable part 26 and the movable part 52 are respectively rotated, the needle bar support 6 and the feed adjuster 43 are respectively swung, and the needle is rotated. The swing movement position of the feed dog 13 and the feed direction and feed momentum of the feed dog 41 are adjusted.

Therefore, according to this embodiment, the amplitude motor 20 and the feed adjuster motor 50 control the needle bar support 6 and the feed adjuster under the control of the needle position control circuit BC and the feed adjuster shaft position control circuit FC. Vessel 4
3, the needle bar support 6, the feed adjuster 43, and the amplitude motor 20.
This eliminates the need for a connecting member between the needle bar support 6 and the feed adjuster motor 50, improving the positioning accuracy of the needle bar support 6 and the feed adjuster 43, and making the device simple and inexpensive, resulting in high responsiveness. It will be done.

In addition, in this embodiment, the amplitude motor 20
Since the movable part 26 is fixed to the lower part of the needle bar support 6 close to the fixed position of the needle 13, the needle bar support 6 is swung as the movable part 26 rotates, thereby positioning the needle 13. The position accuracy of the needle 13 is improved, and the potentiometer 59 for detecting the position of the movable part 52 with respect to the fixed part 51 of the feed adjuster motor 50 is a movable part that directly drives the feed adjuster 43. Since the potentiometer 52 is provided on a portion extending from the feed adjuster shaft 45, compared to conventional sewing machines in which a member such as a link is interposed between the drive device and the feed adjuster, the potentiometer 5
The effect of improving the detection accuracy of No. 9 can be obtained.

Although one example of the present invention has been described above, the present invention should not be interpreted as being limited to this, and can be implemented with various changes without departing from the spirit of the present invention.

Since the present invention utilizes the electromagnetic force received by the current in the magnetic field as the driving force for the swinging member, what generates the magnetic field is not only the permanent magnets 29, 30 and 55 to 58, but also the excitation coil. The plates 27, 53 and containers 28, 54 constituting the magnetic circuit may be made of not only silicon steel plates but also other magnetic materials.

In the motors 20, 50 of the above embodiments, the fixed parts 23, 51 form a magnetic field, and the movable parts 26, 5
2 is a moving coil type with a coil that receives electromagnetic force in the magnetic field, but since electromagnetic force acts relatively, the moving part forms the magnetic field and the fixed part has the coil. A movable magnet type configuration may also be used. Since the moving coil type motor can have a coreless moving part, the reactance of the moving part is small, the rise of the coil current, that is, the magnetization is fast, and the motor has low inertia, making it possible to obtain high responsiveness. . This is suitable for swinging a lightly loaded needle bar support section that is housed in a narrow space. On the other hand, movable magnet type motors can radiate heat from the coil installed in the fixed part using the core part and the entire sewing machine frame, so they can generate high torque by passing a relatively large current through the coil in the fixed part. can be obtained. Therefore, this movable magnet type motor is suitable for driving a swinging member with a relatively large load, which is placed in a place where there is sufficient storage space.

Further, the control method in the needle position control circuit BC and the feed adjuster shaft position control circuit FC is not limited to proportional control, but may also include differential control to improve control characteristics and integral control to eliminate so-called offset.

Furthermore, the swinging member is also the same as the needle bar support 6 of the above-mentioned embodiment.
For example, as known in Japanese Patent Publication No. 35-14086, the sewing machine needle can be adjusted by swinging the needle bar around a vertical axis. A needle bar support of the type that obtains a lateral oscillating movement or a needle bar support that achieves a lateral movement of the sewing machine needle by precessing the needle bar is known from U.S. Pat. No. 3,782,311. It is also possible to apply the present invention to a drive device for a needle bar support of the type that obtains needle bar supports. Further, as is well known, the feed adjuster is provided with a guide groove for guiding a square piece operated by a forked rod that is engaged with a cam provided on the main shaft of the sewing machine and caused to swing. The present invention can also be applied to a drive device for a feed adjuster similar to the device 43, and in short, it can be applied to a sewing machine equipped with a member that swings around a fixed axis and needs to be positioned at multiple positions. If so, the present invention can be similarly applied.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of a sewing machine which is an embodiment of the present invention. 2 is a perspective view of the amplitude motor in the sewing machine of FIG. 1. FIG. 3 is a perspective view showing the inside of the amplitude motor of FIG. 2. FIG. Fourth
1. This figure is a perspective view showing the inside of the feed regulator motor in the sewing machine of FIG. 1. FIG. 5 is a block diagram of the control circuit of the sewing machine of FIG. 1. FIG. 6 is a circuit diagram of the needle position control circuit of FIG. 5. 1: Sewing machine frame, 6: Needle bar support, 12: Needle bar, 13: Needle, 20: Amplitude motor (drive device), 23, 51: Fixed part, 26, 52: Movable part, 29, 30, 55, 56, 57, 58: Permanent magnet, 31, 63, 64: Coil, 32, 59:
Potentiometer (position detector), 41: Feed dog, 43: Feed adjuster, 45: Feed adjuster shaft (adjustment axis), 50: Feed adjuster motor (drive device),
SB: Needle position command signal (command signal), SF: Feed adjuster axis position command signal (command signal), BC: Needle position control circuit (position control circuit), FC: Feed adjuster axis position control circuit (position control circuit) ), PC: Position command device.

Claims (1)

[Scope of Claims] 1. A needle bar to which a needle is fixed at the lower end, and one horizontal fixed axis for supporting the needle bar so that it can move vertically and reciprocatingly and imparting lateral swinging motion to the needle. a needle bar support mounted on a sewing machine frame so as to be able to swing around the needle; a movable part placed and held on a lower portion of the needle bar support near the fixed position of the needle; and a movable part thereof. a fixed part mounted on the sewing machine frame opposite to the part;
A coil is wound around at least one of the movable part and the fixed part in order to generate an electromagnetic force between the movable part and the fixed part, and the movable part is connected to the fixed part. a drive device capable of continuous movement; a position detector for detecting the position of the movable part relative to the fixed part and outputting a position signal thereof; and a lateral oscillating position of the needle relative to the workpiece cloth to be sewn. a position command device that outputs a command signal for determining the position of the needle; and a position command device that controls the horizontal swing position of the needle by adjusting the magnitude and direction of the drive current of the coil according to the position signal and the command signal. A position control circuit is provided, and the needle, which is given an oscillating motion according to the operation of the drive device and which reciprocates up and down, and the work cloth that is fed in synchronization with the up and down reciprocation work together to perform a desired sewing operation. A sewing machine that does 2. The coil is wound in a plane parallel to the swing plane of the movable part so that the direction of the magnetic field generated between the fixed part and the movable part is perpendicular to the swing plane of the movable part. A sewing machine according to claim 1, characterized in that: 3. A feed dog for imparting a feed motion to the work cloth to be sewn, and an adjustment shaft that is swingably supported on the sewing machine frame to control the feed motion of the work cloth by the feed dog; a feed adjuster that can swing around the axis of the adjustment shaft; a movable part fixed to the adjustment shaft; a fixed part mounted on the sewing machine frame opposite to the movable part; and the movable part. and a coil wound around at least one of the movable part and the fixed part in order to generate an electromagnetic force between the movable part and the fixed part, and the movable part is continuously connected to the fixed part. a drive device capable of moving the movable part; provided on a portion of the movable part extending from the adjustment shaft in order to detect the position of the movable part with respect to the fixed part, and outputting a position signal regarding the swinging position of the movable part; a position detector for outputting a command signal for determining the adjustment position of the feed adjuster; and a position command device for outputting a command signal for determining the adjustment position of the feed adjuster; and a position control circuit for controlling the sewing machine, the sewing machine performs a desired sewing operation in cooperation with a needle that reciprocates up and down on a work cloth to which a feed motion is applied in accordance with the operation of the drive device. 4. The coil is wound in a plane parallel to the swing plane of the movable part so that the direction of the magnetic field generated between the fixed part and the movable part is perpendicular to the swing plane of the movable part. 4. A sewing machine according to claim 3, characterized in that: 5. The movable part includes the coil, the fixed part includes a permanent magnet arranged opposite to the coil, and the coil is divided into a plurality of phases and wound in a swinging direction of the movable part. A sewing machine according to claim 4, characterized in that: