JPWO2018179398A1 - sewing machine - Google Patents

Abstract

The sewing machine has a sword that has a sword that captures the loop of the upper thread formed when the sewing needle inserted into the sewing product moves from the bottom dead center to the top dead center, and the rotation of the motor that rotates the hook. A rotation information detector (302) that detects information and a skip detection signal when the occurrence of a skip is monitored based on rotation information detected during a period when the hook tip catches the upper thread. And a monitoring unit (503) for outputting the signal. According to the present invention, it is possible to detect the occurrence of skipping with a simple configuration with few additional parts.

Description

  The present invention relates to a sewing machine that includes a sewing needle, a hook, a balance, and an intermediate presser to form a seam.

  In the conventional sewing machines disclosed in Patent Documents 1 and 2, in order to obtain various controllability and design flexibility, a needle bar that moves the sewing needle up and down and a hook that captures the upper thread with the sword tip are separated from each other. It drives with the drive source of. However, in this type of sewing machine, unless the movement of the needle bar and the shuttle is controlled with high precision by synchronous control, the needle tip of the hook cannot catch the loop of the upper thread formed by the vertical movement of the sewing needle. Jump occurs.

  Patent Documents 3 to 6 disclose detectors used as skip detection means. In Patent Document 3, the amount of movement of the upper thread is detected from the frictional sound of the upper thread that is generated while the sewing machine performs the sewing operation for one stitch by using a sound detection sensor mounted on the thread guide near the balance. Accordingly, a technique is disclosed in which a stitch skip is detected based on a result of comparing an appropriate upper thread movement amount stored in advance with a detected upper thread movement amount. Patent Document 4 uses a photoelectric detector that is sensitive to reflected light, and skips when the loop of the upper thread that has been trapped up does not show the behavior across the surface of the bobbin case that is stored in the hook. Techniques for detecting are disclosed. In Patent Document 5, a position detector that detects whether or not a thread take-up spring having a yarn hooking portion provided in a thread tensioner is positioned at an initial position is used, and a balance bottom dead center that is a specific upper shaft angle is used. A technique for detecting a stitch skip based on the behavior of a thread take-up spring within a range of +60 [°] is disclosed. Patent Document 6 uses a motor that rotates a rotating body around which the upper thread is wound as the detector when the upper thread is unwound from a thread supply source. Techniques for detecting skipping when not done are disclosed.

Japanese Patent Laid-Open No. 5-23472 JP 2003-126777 A JP-A-8-276088 JP 2000-197786 A JP2013-48710A JP, 2006-202437, A

  However, in any case, the stitch skip detection means disclosed in Patent Documents 3 to 5 needs to be provided with a dedicated mechanism, a sensor, and a sensor wiring for detecting the behavior of the upper thread. This increases the overall manufacturing cost. The stitch skip detection means disclosed in Patent Document 6 detects the tension generated in the upper thread and the amount of movement of the upper thread when the shuttle pulls the upper thread based on the behavior of the motor. Since a motor that generates tension on the upper thread is required, the manufacturing cost increases as in the techniques disclosed in Patent Documents 3 to 5. Further, when using the stitch skip detection means disclosed in Patent Document 6, a motor is installed in the middle of the yarn path for supplying the upper thread, but when the motor is arranged at a location away from the sewing needle. The upper thread expands and contracts and the detection accuracy of the tension and the movement amount decreases. When the motor is installed near the sewing needle, for example, by integrating it with the thread tension device, there arises a problem that the installation space in the arm portion of the sewing machine and the ease of assembly cannot be secured. Further, the stitch skip detection means disclosed in Patent Document 6 is easily affected by the sliding surface of the rotating body around which the upper thread is wound, and particularly when the friction between the upper thread and the sliding surface is low and slipping occurs. In this case, the reliability of the detected tension value decreases. Further, the stitch skip detection means disclosed in Patent Documents 3 to 6 increases the number of parts of the entire sewing machine in any case, so that the man-hours at the initial start-up, failure due to environmental changes or aging deterioration, There was a problem that the maintenance man-hours for avoiding false detections increased significantly.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a sewing machine that can detect the occurrence of skipping with a simple configuration with few additional parts.

  In order to solve the above-described problems and achieve the object, the sewing machine of the present invention is an upper thread formed by moving a sewing needle inserted into a sewing product from a bottom dead center to a top dead center. A rotary information detector that detects rotation information of a rotary hook that has a sword tip that captures the loop, a motor that rotates the rotary hook, and occurrence of skipping based on rotation information detected during the period when the rotary hook sword tip captures the upper thread And a monitoring unit that outputs a skip detection signal when the skip is detected.

  According to the present invention, it is possible to detect the occurrence of skipping with a simple configuration with few additional parts.

1 is a perspective view showing the overall configuration of a sewing machine according to Embodiment 1. FIG. The perspective view which shows the upper shaft mechanism of the sewing machine which concerns on Embodiment 1. FIG. The perspective view which shows the lower shaft mechanism of the sewing machine which concerns on Embodiment 1. FIG. Block diagram showing a control configuration of the sewing machine according to the first embodiment FIG. 3 is a block diagram showing details of a lower shaft motor control calculation unit of the sewing machine according to the first embodiment. FIG. 3 is a block diagram showing details of a lower shaft deviation suppressing unit of the sewing machine according to the first embodiment. FIG. 3 is a block diagram showing details of the monitoring unit of the sewing machine according to the first embodiment. The figure which shows the signal waveform at the time of detecting a skip by the sewing machine which concerns on Embodiment 1. FIG. FIG. 6 is a block diagram showing details of a lower shaft motor control calculation unit of the sewing machine according to the second embodiment. Block diagram showing details of the monitoring unit of the sewing machine according to the second embodiment FIG. 9 is a block diagram showing details of a lower shaft motor control calculation unit of a sewing machine according to a third embodiment. The figure which shows the signal waveform at the time of detecting a skip by the sewing machine which concerns on Embodiment 3. FIG. 9 is a block diagram showing details of a lower shaft motor control calculation unit of a sewing machine according to a fourth embodiment. Block diagram showing details of the monitoring unit of the sewing machine according to the fourth embodiment FIG. 9 is a block diagram showing details of a lower shaft motor control calculation unit of a sewing machine according to a fifth embodiment. Block diagram showing details of a rotation information detector for a sewing machine according to Embodiment 5 The figure which shows the 1st hardware structural example of the control panel of the sewing machine which concerns on Embodiment 1-5. The figure which shows the 2nd hardware structural example of the control panel of the sewing machine which concerns on Embodiment 1-5.

  Hereinafter, a sewing machine according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
In the first embodiment, a configuration example of an industrial electronic sewing machine that performs a sewing operation while moving a sewing object that is a sewing material such as cloth or leather with a conveying device such as an XY table will be described. However, this is also applied to devices in which seams are formed by catching the upper thread loop formed by the vertical movement of the sewing needle, for example, general sewing machines, occupational sewing machines, household sewing machines, embroidery machines, etc. A configuration example of the form can be applied. First, a configuration example of the sewing machine 100 according to the first embodiment will be described based on FIGS. 1 to 3.

  FIG. 1 is a perspective view showing the overall configuration of the sewing machine according to the first embodiment. FIG. 2 is a perspective view showing an upper shaft mechanism of the sewing machine according to the first embodiment. FIG. 3 is a perspective view showing a lower shaft mechanism of the sewing machine according to the first embodiment. However, in FIGS. 1 to 3, in the right-handed XYZ coordinates, the direction in which the sewing needle 212 moves up and down is the Z-axis direction, the direction orthogonal to the Z-axis direction is the X-axis direction, and the Z-axis direction and the X-axis direction The direction orthogonal to both of these is defined as the Y-axis direction. The X-axis direction is equal to the longitudinal direction of the bed 104 described later.

[overall structure]
The main part of the sewing machine 100 shown in FIG. 1 includes a housing mechanism P0, a feed mechanism P1, a control device P2, an upper shaft mechanism P3 shown in FIG. 2, and a lower shaft mechanism P4 shown in FIG. . The upper shaft mechanism P3 is disposed above the sliding plate 106 included in the housing mechanism P0 of FIG. The lower shaft mechanism P4 is disposed below the sliding plate 106 in FIG.

[Case mechanism P0]
As shown in FIG. 1, the casing mechanism P0 of the sewing machine 100 includes an arm 101 that houses an upper shaft shaft 204 included in the upper shaft mechanism P3 of FIG. 2 and an upper shaft motor that is connected to the upper shaft shaft 204 of FIG. 201, an upper shaft motor case 102 that stores 201, a sewing machine head 103 that performs sewing work of an upper shaft mechanism P3 described later at the tip of the arm 101, a bed 104 that stores an XY stage 111 included in the feed mechanism P1, and an arm The support leg 105 which supports 101 and the bed 104 from an installation floor, and the sliding board 106 are provided.

  The sliding plate 106 is fixed to the upper surface of the bed 104 and supports the holding device 112 included in the feeding mechanism P1 slidably on a plane. The casing mechanism P0 is a rigid material such as a high-rigidity steel plate or casting that is designed to withstand mechanical destruction due to an impact when the sewing machine 100 operates, or a flexible material that disperses and absorbs the impact. Consists of.

  1 shows the position of the upper shaft motor 201 in FIG. 2, the upper shaft motor case 102 is arranged to be connected to one end of the arm 101, but the length of the upper shaft shaft 204 in FIG. 2 is shortened. 2 may be installed inside the arm 101 to increase the torsional rigidity of the upper shaft shaft 204. Further, the upper shaft motor 201 in FIG. 2 may be installed in a form integrated with the sewing machine head 103, not inside the arm 101. In such an installation, it is not necessary to provide the upper shaft motor case 102 at the end of the arm 101 away from the sewing machine head 103, so that the torsional rigidity of the upper shaft shaft 204 of FIG. The degree of freedom of design can be expanded.

[Feed mechanism P1]
The feed mechanism P1 of the sewing machine 100 includes an XY stage 111, a holding device 112, and an air cylinder 113. The XY stage 111 is driven in the X-axis direction and the Y-axis direction by an X-axis drive motor and a Y-axis drive motor (not shown), and the holding device 112 connected to the movable part of the XY stage 111 is placed in a horizontal plane on the sliding plate 106. Move with. The holding device 112 performs switching between holding and non-holding of the sewing product using the air cylinder 113 as a drive source. The holding device 112 holds and transfers the sewing product so that the insertion position of the sewing needle 212 with respect to the sewing product is a specific position designated by the user of the sewing machine 100 using the operation panel 121. I do. The input device for designating the needle insertion position is not limited to the operation panel 121. For example, even if the needle insertion position is input from the computer outside the sewing machine 100 to the control panel 122 via the communication device. good.

  In this embodiment, the air cylinder 113 is used to secure the holding force of the holding device 112, but the present invention is not limited to this, and other means such as an electromagnetic press or a hydraulic press are used. May be. In the present embodiment, in order to apply the present invention to an industrial sewing machine, a feed mechanism P1 that is a transport unit that transports a sewing product by the XY stage 111 and the holding device 112 is used. Is not limited to these. For example, the stitch skip detection method of the present embodiment can be applied to other types of sewing machines that transport a sewing product using a feed dog or a sewing machine that transports a sewing product using a robot. Further, the stitch skip detection method of the present embodiment can be applied to a sewing machine that does not include the feed mechanism P1 and that conveys the sewing product by another means including manual work.

[Control device P2]
The control device P2 of the sewing machine 100 includes an operation panel 121, a control panel 122, and a foot switch 123. A user of the sewing machine 100 gives a sewing command signal for driving the sewing machine 100 to the control panel 122 based on sewing data such as sewing pattern data created on the operation panel 121. The control panel 122 controls the conveyance work by the feed mechanism P1, and further controls the speed and timing of the sewing work by cooperation of an upper shaft mechanism P3 and a lower shaft mechanism P4 described later. The foot switch 123 is switched between an operation start signal for starting control of the sewing machine 100 when the user of the sewing machine 100 presses a button, a touch panel, or the like, and holding or non-holding of the sewing product by the holding device 112. And a holding signal for performing control to the control panel 122.

[Upper shaft mechanism P3]
As shown in FIG. 2, the upper shaft mechanism P3 of the sewing machine 100 includes an upper shaft motor 201, a rotation information detector 202 that detects rotation information of the upper shaft motor 201, a coupling 203, an upper shaft shaft 204, An intermediate presser drive mechanism 205 that is connected to the upper shaft shaft 204 to prevent the workpiece from being lifted, an intermediate presser 206, a balance drive mechanism 207 that is connected to the upper shaft shaft 204, and a small hole 208 through which the upper thread is inserted. The balance 209 has a needle bar drive mechanism 210 connected to the upper shaft 204, and a sewing needle 212 attached to the tip of the needle bar 211.

  The small hole 208 of the balance 209 is normally driven so as to reach the top dead center when the rotation angle of the upper shaft motor 201 rotates about 60 degrees after the sewing needle 212 reaches the top dead center. In the present embodiment, the intermediate presser 206, the balance 209, and the needle bar 211 are simultaneously driven using the upper shaft motor 201 as a drive source. The intermediate press drive mechanism 205, the balance drive mechanism 207, and the Since the needle bar drive mechanism 210 is a well-known technique, detailed description using an enlarged view is omitted. The upper shaft mechanism P3 cooperates with the lower shaft mechanism P4 to perform a sewing operation for forming a seam on the workpiece.

  If the sewing needle 212 of FIG. 2 is driven so that the sword tip 308 of the rotary hook 309 shown in FIG. 3 can catch the upper thread, the intermediate presser 206, the balance 209, and the needle bar 211 are separately provided. It may be driven by the drive source. In addition, the drive source is not only a rotary electric machine such as a servo motor or a stepping motor (not shown) but also a drive source such as a plurality of linear motors, planar motors, and spherical motors from a technical viewpoint ignoring manufacturing costs. May be. By configuring the upper shaft mechanism P3 in this way, the operation states of the intermediate presser 206, the balance 209, and the needle bar 211 can be grasped from individual drive sources. Therefore, the added value of preventive maintenance and failure detection can be given to the sewing machine 100, or the design of the entire sewing machine can be given flexibility.

[Lower shaft mechanism P4]
As shown in FIG. 3, the lower shaft mechanism P <b> 4 of the sewing machine 100 includes a lower shaft motor 301, a rotation information detector 302 that detects rotation information of the lower shaft motor 301, a coupling 303, and a lower shaft motor shaft 304. A large-diameter gear 305 connected, a small-diameter gear 306 that meshes with the large-diameter gear 305, a lower shaft rotary shaft 307 connected to the small-diameter gear 306, and a lower shaft rotary shaft 307, which are formed by the vertical movement of the sewing needle 212. And a hook 309 having a sword 308 that captures the loop of the upper thread to be played.

  The hook 309 includes a bobbin case that stores a bobbin (not shown) wound with a bobbin thread with an inner hook (not shown) and stores the bobbin so that the bobbin does not fall out of the hook 309. The lower shaft mechanism P4 cooperates with the upper shaft mechanism P3 to perform a sewing operation for forming a seam on the workpiece.

  In the present embodiment, the case where a full rotation hook is adopted as the hook 309 is illustrated, but the present invention is not limited to this. For example, the hook 309 may be a half-turn hook, a horizontal hook, or a vertical hook as long as it catches the upper thread loop. Further, in the case of using the full rotation hook, it is necessary to drive the hook at a double speed with respect to the needle bar 211 shown in FIG. 2, and therefore, in this embodiment, the large diameter gear 305 and the small diameter gear 306 are configured. However, the hook 309 may be directly driven by the lower shaft motor 301 without using the double speed machine. Since the configuration of the full rotation shuttle is a well-known technique, a detailed description of the internal configuration using an enlarged view is omitted.

[Sewing work by upper shaft mechanism P3 and lower shaft mechanism P4]
Details of the sewing work performed by the upper shaft mechanism P3 and the lower shaft mechanism P4 in cooperation are as follows. First, by rotating the upper shaft motor 201, the sewing needle 212 having an upper thread passed through the needle hole is inserted into the sewing product from the upper side to the lower side of the sliding plate 106. By the operation of the sewing needle 212, the upper thread is supplied to the lower side of the sewing product. Thereafter, when the sewing needle 212 rises from the bottom dead center, the upper thread forms a loop on the lower side of the sewing product due to friction with the sewing product. At the timing when the upper thread loop is formed, the blade tip 308 of the rotary hook 309 rotating with the lower shaft motor 301 as a drive source captures the upper thread and entangles the upper thread and the lower thread. Thereafter, when the sewing needle 212 is removed from the sewing product, the upper thread is pulled out to the upper surface of the sewing product. Then, when the balance 209 pulls the upper thread upward to the sewing product, the upper thread is tightened and a seam is formed. At this time, the intermediate presser 206 presses the sewing object so that the sewing object is not lifted or fluttered as the sewing needle 212 or the balance 209 is raised.

  2 is provided with a rotation information detector 202 that detects information such as the angle of the rotor relative to the stator of the motor, the angular velocity, and the angular acceleration. . In this embodiment, the rotation information detector 202 is described as an optical encoder that detects the angle of the rotor with respect to the stator. Additional information such as the angular velocity and angular acceleration of the rotor can be obtained by differentiating the rotor angle.

  Similarly, the lower shaft motor 301 that is a drive source of the lower shaft mechanism P4 shown in FIG. 3 is provided with a rotation information detector 302 that detects information such as the angle, angular velocity, and angular acceleration of the rotor with respect to the stator of the motor. It is done. In the present embodiment, the rotation information detector 302 is described as an optical encoder that detects the angle of the rotor with respect to the stator. Additional information such as the angular velocity and angular acceleration of the rotor can be obtained by differentiating the rotor angle.

  Next, the control configuration of the sewing machine according to the present embodiment will be described with reference to FIG. FIG. 4 is a block diagram illustrating a control configuration of the sewing machine according to the first embodiment. A control panel denoted by reference numeral 122A corresponds to the control panel 122 shown in FIG. Before describing the control configuration of the sewing machine 100, an outline of the operation of the sewing machine 100 will be described.

  In the sewing machine 100, when the foot switch 123 is pressed and a holding signal is sent to the command generating unit 405 of the control panel 122A, the air cylinder 113 is operated by the holding command signal output from the command generating unit 405, and the sewing product is The holding device 112 shown in FIG. 1 is held so as to be transportable. After that, when the foot switch 123 is pressed and an operation start signal is sent to the control panel 122A, the X-axis motor 410, the Y-axis motor 412, and the drive mechanisms P1, the upper shaft mechanism P3, and the lower shaft mechanism P4 are the drive sources. The upper shaft motor 201 and the lower shaft motor 301 are operated, and the sewing machine 100 starts to form a seam at a specific position of the sewing product that is specified in advance by the user of the sewing machine 100 using the operation panel 121. The input device for designating a specific position is not limited to the operation panel 121, and may be a computer outside the sewing machine 100, for example. In this case, the specific position is input from the computer to the control panel 122A via the communication device. Is done.

[Configuration of operation panel]
As shown in FIG. 4, the operation panel 121 of the sewing machine 100 includes a display 401, a processor 402, a storage device 403 that stores sewing pattern data D1, and an input device 404. The user of the sewing machine 100 inputs the sewing pattern data D1 for each stitch by operating the input device 404 including a push-down button or a touch panel while referring to the display 401. As a result, the sewing pattern data D1 is stored in the storage device 403 of the operation panel 121. The operating system of the operation panel 121 is operated by the processor 402. By using the sewing pattern data D1 stored in the storage device 403, the sewing pattern can be easily created, edited, and duplicated.

  The sewing pattern data D1 created on the operation panel 121 is converted into a sewing command signal by the processor 402 and transmitted to the command generation unit 405 of the control panel 122A. The sewing pattern data D1 is data for determining the position and shape of the seam formed on the sewing product and the operating speed of the sewing machine 100.

  The display 401 of the operation panel 121 receives the skip detection signal output from the lower shaft motor control calculation unit 407 of the control panel 122A, and indicates that the skip has occurred when the skip is detected. Display to the user. The display 401 is not limited to the display provided inside the operation panel 121, and may be a display such as a liquid crystal panel or a traffic light existing outside the operation panel 121. In this case, the display and the control panel 122A. Communication with can be either wired communication or wireless communication. The storage device 403 is not limited to the one provided inside the operation panel 121, and may be a storage device that exists outside the operation panel 121. In this case, communication between the storage device and the control panel 122A is wired. Either communication or wireless communication may be used.

[Control panel configuration]
As shown in FIG. 4, the control panel 122A for controlling the sewing machine 100 includes at least a command generation unit 405, an upper shaft motor control calculation unit 406, a lower shaft motor control calculation unit 407, and an X axis motor control calculation unit 408. And a Y-axis motor control calculation unit 409. In addition to these, a solenoid that performs thread trimming when the sewing operation is completed, a notification sensor that notifies that the thread has run out, a control circuit that drives a position sensor that causes the feed mechanism P1 to return to the origin, and a power supply circuit are provided. In some cases, these are not directly related to the effects of the present invention, and thus the description thereof is omitted.

  The control panel 122A is a sewing command signal output from the processor 402 of the operation panel 121, a holding signal and an operation start signal output from the foot switch 123, and an upper signal output from the rotation information detector 202 of the upper shaft motor 201. An upper shaft rotation signal that is rotation information of the shaft motor 201 is input. The control panel 122 </ b> A also outputs a lower shaft rotation signal that is rotation information of the lower shaft motor 301 that is output from the rotation information detector 302 of the lower shaft motor 301, and an X that is output from the rotation information detector 411 of the X axis motor 410. An X-axis rotation signal that is rotation information of the axis motor and a Y-axis rotation signal output from the rotation information detector 413 of the Y-axis motor 412 are input.

  Based on these signals, the control panel 122A, the upper axis control current for driving the upper axis motor 201, the lower axis control current for driving the lower axis motor 301, and the X axis control current for driving the X axis motor 410, The Y-axis control current for driving the Y-axis motor 412, the hold command signal for driving the air cylinder 113, and the skip detection signal output from the lower-axis motor control calculation unit 407 are output.

  The command generation unit 405 of the control panel 122A receives the sewing command signal output from the processor 402 of the operation panel 121, the holding signal and the operation start signal output from the foot switch 123, and receives the upper axis command signal, A lower axis command signal, an X axis command signal, a Y axis command signal, and a hold command signal are output. The upper axis command signal, the lower axis command signal, the X axis command signal, and the Y axis command signal are respectively rotated by the upper axis motor 201, the lower axis motor 301, the X axis motor 410, and the Y axis motor 412. It is an electrical signal for designating an angle, and is calculated inside the command generation unit 405 according to the sewing pattern data D1.

  The holding signal output from the foot switch 123 is an electric signal that specifies the pressure of the air cylinder 113 so that the sewing product is held by the holding device 112. As for the operation start signal output from the foot switch 123, the command generation unit 405 converts the upper axis command signal, the lower axis command signal, the X axis command signal, and the Y axis command signal into the upper axis motor control calculation unit 406, respectively. And an electric signal for designating timing for starting transmission to the lower-axis motor control calculation unit 407, the X-axis motor control calculation unit 408, and the Y-axis motor control calculation unit 409.

  The upper shaft motor control calculation unit 406 of the control panel 122A receives the upper shaft command signal and the upper shaft rotation signal, and rotates the upper shaft motor 201 so that the difference between the upper shaft command signal and the upper shaft rotation signal becomes zero. Outputs the upper axis control current.

  Lower shaft motor control calculation unit 407 of control panel 122A receives lower shaft command signal and lower shaft rotation signal as input, and rotates lower shaft motor 301 so that the difference between lower shaft command signal and lower shaft rotation signal becomes zero. Outputs the lower axis control current. Further, the lower shaft motor control calculation unit 407 is based on the lower shaft rotation signal input during the period in which the sword tip of the rotary hook 309 shown in FIG. 3 captures the upper thread when the sewing machine 100 performs a normal operation of forming the seam. The occurrence of a skip is monitored, and a skip detection signal is output when the occurrence of a skip is detected. When a full-rotation rotary hook that rotates twice between one needle is used, during the period when the sword tip of the rotary hook 309 is capturing the upper thread, the sewing needle 212 is raised from the bottom dead center and the sword tip of the rotary hook 309 is the upper thread. This is a period from when the loop is wound until the time when the sewing needle 212 is at the top dead center as 0 degree and the rotary hook 309 rotates once and a half, that is, 540 degrees. The timing at which the sword tip of the rotary hook 309 hits the loop of the upper thread is normally within a range in which the rotary hook 309 rotates from 360 degrees to 450 degrees, with 0 degrees when the sewing needle 212 is at the top dead center. When the timing at which the sword tip of the rotary hook 309 crawls the loop of the upper thread cannot be specified precisely, when the rotary hook 309 rotates 360 degrees with the sewing needle 212 being at the top dead center, or the tip of the sewing needle 212 May be monitored from when the sliding plate 106 moves from above to below.

  X-axis motor control calculation unit 408 of control panel 122A receives X-axis command signal and X-axis rotation signal as input, and rotates X-axis motor 410 so that the difference between X-axis command signal and X-axis rotation signal becomes zero. Outputs X-axis control current.

  The Y-axis motor control operation unit 409 of the control panel 122A receives the Y-axis command signal and the Y-axis rotation signal as inputs, and rotates the Y-axis motor 412 so that the difference between the Y-axis command signal and the Y-axis rotation signal becomes zero. Outputs Y-axis control current.

  Next, a method for detecting a skip of the sewing machine 100 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a block diagram showing details of the lower shaft motor control calculation unit of the sewing machine according to the first embodiment. FIG. 6 is a block diagram illustrating details of the lower-axis deviation suppressing unit of the sewing machine according to the first embodiment. FIG. 7 is a block diagram showing details of the monitoring unit of the sewing machine according to the first embodiment. FIG. 8 is a diagram illustrating a signal waveform when a stitch skip is detected by the sewing machine according to the first embodiment. FIG. 8 shows a timing chart when the monitoring unit 503 in FIG. 5 outputs a skip detection signal.

[Detailed configuration for skipping detection]
As illustrated in FIG. 5, the lower shaft motor control calculation unit 407 of the control panel 122A includes a lower shaft deviation suppression unit 501, a current control unit 502, and a monitoring unit 503, which are motor control units. The lower shaft deviation suppression unit 501 is a lower shaft command signal that is a motor rotation command output from the command generation unit 405 and a lower shaft rotation that is rotation information output from the rotation information detector 302 included in the lower shaft motor 301. This signal is a motor drive signal for driving the lower shaft motor 301 so that the difference between the lower shaft command signal and the lower shaft rotation signal becomes zero with the signal and the skip detection signal output from the monitoring unit 503 as inputs. Outputs the lower shaft motor drive signal.

  The current control unit 502 generates a lower shaft control current for rotating the lower shaft motor 301 based on the lower shaft motor drive signal, and supplies the lower shaft control current to the lower shaft motor 301. Then, when the sewing machine 100 performs a normal operation of forming a seam, the monitoring unit 503 generates a stitch skip based on the lower shaft rotation signal input during the period in which the sword tip of the hook 309 shown in FIG. 3 captures the upper thread. Monitoring is performed, and when a skip is detected, a skip detection signal is output.

  As shown in FIG. 6, the lower axis deviation suppression unit 501 of the lower axis motor control calculation unit 407 includes a switch 601, a difference unit 602, and a deviation suppression compensator 603. The switch 601 receives the lower axis command signal output from the command generation unit 405 and the skip detection signal output from the monitoring unit 503, and skips occur while the sewing machine 100 is performing the sewing operation. When this is detected, the change in the value of the lower axis command signal is stopped based on the skip detection signal, and the rotation of the lower shaft motor is stopped in conjunction with the occurrence of the skip. The differencer 602 calculates a difference between the lower axis command signal output from the switch 601 and the lower axis rotation signal output from the rotation information detector 302 and outputs a deviation signal. The deviation suppression compensator 603 outputs a lower shaft motor drive signal that drives the lower shaft motor 301 so that the deviation signal converges to zero. The deviation suppression compensator 603 includes at least one of a proportional compensator that performs proportional calculation, an integral compensator that performs integral calculation, and a differential compensator that performs differential calculation in order to converge the deviation signal to 0. . In the present embodiment, it is described that PI control using a proportional compensator and an integral compensator is employed in the deviation suppression compensator 603.

  As shown in FIG. 7, the monitoring unit 503 of the lower shaft motor control calculation unit 407 includes a filter processing unit 701, a recording unit 702, and a comparator 703. The filter processing unit 701 reduces the noise component, which is the frequency component of the lower shaft rotation signal higher than the rotation frequency of the hook 309 shown in FIG. 3, and the frequency component of the lower shaft rotation signal lower than the rotation frequency of the hook 309. Any one or more of a calculation that reduces the noise component, a calculation by a phase filter that is an all-pass filter that changes the phase of the lower axis rotation signal, and a proportional calculation that changes the amplitude by multiplying the gain To calculate and output an evaluation signal.

  For example, a bandpass filter combining a low-pass filter that reduces frequency components higher than the rotation frequency of the hook 309 and a high-pass filter that reduces frequency components lower than the rotation frequency of the hook 309 shown in FIG. 3 may be used. When the 309 sword tip captures the upper thread loop, noise other than the fluctuating component can be greatly removed. Further, a notch filter may be used locally if the frequency of the noise to be reduced is far from the rotation frequency of the hook 309. Further, by using the phase filter, the detection delay and transmission delay of the rotation information detector 302, the calculation delay in the control panel 122A, and the like can be corrected, and the accuracy of the skip detection time can be improved. In addition, the skip detection signal can be normalized to an arbitrary detection specification by performing a proportional operation of multiplying the gain and changing the amplitude.

  The recording unit 702 receives an evaluation signal during a period from when the sword tip of the hook 309 shown in FIG. 3 captures the upper thread during the sewing operation before one stitch until the sword tip of the hook 309 releases the upper thread. Is recorded, and the recorded evaluation signal is output in synchronism with the current sewing timing. Therefore, the recording unit 702 may be a delay computer that generates a delay of a period obtained by multiplying the time required for one stitch. The recording unit 702 may calculate and output feature quantities such as the maximum value, minimum value, and average value of the recorded evaluation signal. In this way, it is possible to easily grasp the change in the current evaluation signal with respect to the previous stitch. For example, the change rate of the current evaluation signal with respect to one needle before can be obtained by the ratio of the difference between the current maximum value and the minimum value with respect to the difference between the maximum value and the minimum value before one needle.

  The comparator 703 detects a skip detection signal when the rate of change of the current evaluation signal output from the filter processing unit 701 is greater than a specific value with respect to the evaluation signal one stitch before output from the recording unit 702. Is output.

  In the present embodiment, the monitoring unit 503 is included in the control panel 122A, but the monitoring unit 503 may be mounted outside the control panel 122A to change the layout and wiring of the sewing machine 100. In addition, depending on a special application such as when skipping is desired by intentionally generating skipping, it is not necessary to stop the change of the lower axis command signal by the switch 601 in order to continue the sewing operation.

[Detection of skipping]
In FIG. 8, in order from the top, the waveform of the lower shaft rotation signal indicating the rotation angle within one rotation of the lower shaft motor 301, the rotation angle of the rotary shaft that is the angle within one rotation of the rotary hook 309, and the position of the sewing needle 212 The waveform of the evaluation signal output from the filter processing unit 701 configured by the band pass filter and the waveform of the skip detection signal output from the monitoring unit 503 are shown.

  In FIG. 8, the position of the sewing needle 212 shown in the third row from the top is the upper position when the lower end of the sewing needle 212 is above the sliding plate 106, and the lower end of the sewing needle 212 is below the sliding plate 106. If so, it is assumed to be in the lower position. The fourth evaluation signal from the top indicates a signal obtained by performing processing by the bandpass filter on the angular velocity obtained by differentiating the rotation angle of the lower shaft motor 301 measured by the rotation information detector 302. ing. At this time, the cutoff frequency of the low-pass filter is set to one half of the rotation frequency of the hook 309, and the cutoff frequency of the high-pass filter is set to twice the rotation frequency of the hook 309. Also, periods ta and tc in the figure are periods during which the monitoring unit 503 monitors the evaluation signal. The start timing of the periods ta and tc is when the position of the sewing needle 212 moves from the upper position to the lower position described above, and the end timing of the periods ta and tc is when the rotation angle of the lower shaft is 0 degree. When the hook 309 is rotated from 0 degree to one and a half rotations, that is, 540 degrees as a reference.

  First, referring to the lowermost rotation signal of the uppermost stage and counting the intervals at which the rotation angle of the lower shaft motor 301 rotates from 0 degrees to 360 degrees, in FIG. 8, a total of four stitches from the Nth stitch to the (N + 3) th stitch. It can be seen that the minute waveform is shown. N is a natural number of 1 or more.

  Next, in the second stage from the top, the hook 309 rotates at twice the frequency with respect to the lower shaft motor 301, and the timing of the end of the periods ta and tc is indicated by the hook rotation angle. Next, in the third row from the top, the timing of the start of the periods ta and tc is indicated by indicating the position of the sewing needle 212.

  Next, in the fourth row from the top, occurrence or non-occurrence of skipping can be determined from the evaluation signal. Specifically, in the Nth stitch and the (N + 1) th stitch, the change in the maximum value and the minimum value of the evaluation signal becomes large, and the sword tip of the hook 309 captures the upper thread loop to form a normal stitch. On the other hand, in the (N + 2) stitch and the (N + 3) stitch, the change in the maximum value and the minimum value of the evaluation signal is small, and the tip of the hook 309 does not catch the upper thread loop, and the stitch skip occurs. It is shown. Regarding the rate of change of the evaluation signal of the (N + 1) stitch with respect to the (N + 1) stitch, for example, the maximum and minimum values of the (N + 1) stitch are normalized to 100% and 0%, and the maximum and minimum values of the (N + 2) stitch are normalized. What is necessary is just to evaluate with the comparator 703 how much has fallen. In the example of FIG. 8, in consideration of variation for each stitch, occurrence of skipping is detected when the change rate of the evaluation signal is less than 70%, for example, compared to the previous stitch.

  Then, referring to the bottom of FIG. 8, the output timing of the skip detection signal is shown, and the monitoring unit 503 outputs a skip detection signal indicating that a skip has occurred after monitoring the evaluation signal in the period tc. Output.

  FIG. 8 shows an example of measurement when the switch 601 is not switched. In the (N + 2) stitch and the (N + 3) stitch, two stitches are continuously generated. When it is desired to stop the sewing operation when the skipping occurs, the change of the value of the lower axis command signal is stopped by the switch 601, and the upper shaft mechanism P3 and the feed mechanism P1 are used by using the same switch as the switch 601. It is desirable to stop the driving of the motor. In this case, the switches for stopping the driving of the upper shaft mechanism P3 and the feed mechanism P1 are the upper shaft motor control calculation unit 406, the lower shaft motor control calculation unit 407, the X axis motor control calculation unit 408, and the Y axis motor calculation. May be provided, or the command generation unit 405 may be provided. By using a switch similar to the switch 601, the upper shaft mechanism P3 and the feed mechanism P1 are driven by stopping the change in the values of the upper shaft command signal, the lower shaft command signal, the X axis command signal, and the Y axis command signal. Can be stopped.

  In addition, when using a fully rotating hook as in the present embodiment, the hook 309 rotates twice during one needle, but when the tip of the hook 309 catches the loop of the upper thread in the first rotation, it rotates twice. With the eyes, the tip of the hook 309 rotates without catching the upper thread loop. Therefore, as shown in FIG. 8, the recording unit 702 performs a period tb after the sword tip of the rotary hook 309 releases the upper thread before one stitch until the sword tip of the rotary hook 309 acquires the upper thread again. Record the evaluation signal. Next, the monitoring unit 503 determines the difference d1 between the maximum value and the minimum value of the evaluation signal in the period tb recorded by the recording unit 702, and the maximum value and the minimum value of the current evaluation signal output from the filter processing unit 701 in the period tc. Calculate the value difference d2. The monitoring unit 503 may output a skip detection signal when the rate of change of the difference d2 with respect to the difference d1 is smaller than a specific value. Thereby, the trouble of setting the threshold value for detecting the skipping can be saved. In the measurement example of FIG. 8, the difference between the maximum value and the minimum value d2 of the evaluation signal in the period tc is compared with the difference d1 between the maximum value and the minimum value of the evaluation signal in the period tb in consideration of the variation for each needle. The occurrence of skipping is detected when the rate of change does not exceed three times.

[Effect of this embodiment]
As described above, since the sewing machine 100 according to the present embodiment utilizes information on the driving source that drives the shuttle 309, the design flexibility of the sewing machine 100 is increased, and a simple configuration with few additional parts is required. The occurrence of jumps can be detected. In addition, it is easier to ensure space around the arm and ease of assembly than when detecting skipping from the behavior of the motor that drives the rotating body wound with the upper thread, and the sliding of the rotating body wound with the upper thread is easier. The occurrence of skipping can be detected without being affected by the moving surface.

  Further, according to the present embodiment, since the occurrence of skipping is detected based on the operation information of the driving source that drives the shuttle 309, it is possible to provide the sewing machine 100 with a simple configuration with few additional parts and a small number of maintenance steps. . Further, the number of maintenance steps can be reduced as compared with the configuration in which a sensor for detecting skipping is added.

  Further, when the switch 601 detects that a stitch skip has occurred while the sewing machine 100 is performing a sewing operation, the switch 601 can stop the change in the lower axis command signal based on the stitch skip detection signal. By doing in this way, the sewing machine 100 which concerns on Embodiment 1 can stop rotation of the hook 309 at the time of skipping. That is, the hook 309 can be controlled so that the sewing machine 100 does not perform an unnecessary sewing operation after the skipping occurs.

  Further, based on the skip detection signal, the operations of the intermediate presser 206, the balance 209, the needle bar 211, the XY stage 111, and the holding device 112 included in the sewing machine 100 are stopped, or returned to the original position, or It is easy to change the operation pattern. For example, in FIG. 4, a skip detection signal is input to the command generation unit 405, and the command generation unit 405, when detecting a skip, an upper axis command signal that stops or continues the sewing operation, and a lower axis command signal, The X-axis command signal, the Y-axis command signal, and the holding command signal are changed and output. That is, the monitoring means for detecting the skipping can be combined with a sewing mechanism or a feeding mechanism other than the hook. In order to stop the driving of the upper shaft mechanism P3 and the feed mechanism P1 in synchronization with the occurrence of the skipping, the upper shaft motor control calculation unit 406, the lower shaft motor control calculation unit 407, and the X axis motor control calculation unit 408 are used. In addition, the Y-axis motor calculation unit may include a switch similar to the switch 601. Further, the command generation unit 405 may include a switch similar to the switch 601. With this configuration, it is possible to notify the user of the sewing machine 100 of the occurrence of stitch skipping and to control the sewing machine so as not to execute an unnecessary sewing operation. In addition, the return operation of the sewing machine 100 can be performed without delay, and the downtime of the sewing machine 100 when the skipping occurs can be reduced.

  In addition, since the sewing machine 100 according to the first embodiment drives the sewing needle 212 and the hook 309 with different drive sources, the sword tip of the hook 309 catches the upper thread loop by changing the lower shaft command signal. The timing can be easily fine-tuned. By doing so, various controllability can be exhibited and the frequency of occurrence of skipping can be reduced. Further, according to the sewing machine 100 according to the first embodiment, it is possible to detect the occurrence of skipping without adding a dedicated mechanism, a sensor, and a sensor wiring for detecting the behavior of the upper thread.

Embodiment 2. FIG.
Based on FIG. 9 and FIG. 10, the configuration and operation of the sewing machine 100 according to the second embodiment will be described. FIG. 9 is a block diagram illustrating details of the lower shaft motor control calculation unit of the sewing machine according to the second embodiment. FIG. 10 is a block diagram showing details of the monitoring unit of the sewing machine according to the second embodiment. The control panel indicated by reference numeral 122B in FIG. 9 corresponds to the control panel 122 shown in FIG.

  In the sewing machine 100 according to the second embodiment, the configuration of the monitoring unit 503 provided in the lower shaft motor control calculation unit 407 of the control panel 122B and the data stored in the storage device 403 of the operation panel 121 are related to the first embodiment. Unlike the sewing machine 100, other configurations and operations are the same as those of the sewing machine 100 according to the first embodiment. For this reason, description of the same part is omitted.

  As shown in FIG. 9, the lower shaft motor control calculation unit 407 of the control panel 122B includes a lower shaft command signal output from the command generation unit 405 and a lower shaft output from the rotation information detector 302 of the lower shaft motor 301. The rotation signal and the setting parameter D2, which is data stored in the storage device 403 of the operation panel 121, are input using the input device 404, and the current control unit 502 outputs the lower shaft control current to the lower shaft motor 301. The monitoring unit 503 outputs a skip detection signal to the display 401 and the lower axis deviation suppression unit 501. The setting parameter D2 may be set in a computer outside the operation panel 121, and the setting parameter D2 output from the computer may be input to the control panel 122B.

  As shown in FIG. 10, the monitoring unit 503 of the control panel 122B includes a filter processing unit 701, a recording unit 702, a comparator 703, and a proportional calculation unit 704, and is output from the rotation information detector 302. The shaft rotation signal and the setting parameter D2 of the storage device 403 are input, and a skipping detection signal is output. The filter processing unit 701 of the control panel 122B receives the lower axis rotation signal output from the rotation information detector 302 and the setting parameter D2, and outputs the current evaluation signal with an arbitrary noise component reduced for skipping detection. Output.

  The recording unit 702 of the control panel 122B can input the setting parameter D2, change the period for recording the evaluation signal, and synchronize the evaluation signal recorded during the previous sewing operation with the current sewing timing. The time is output as if The comparator 703 of the control panel 122B compares the sewing record one stitch before output from the recording unit 702 with the proportional evaluation signal output from the proportional calculation unit 704, and outputs a skip detection signal. The proportional calculation unit 704 multiplies the current evaluation signal output from the filter processing unit 701 by the gain set by the setting parameter D2, and outputs a proportional evaluation signal. The setting parameter D2 is a plurality of numerical values for changing the time constant and cutoff frequency of the filter processing unit 701, changing the recording period of the recording unit 702, and changing the gain value multiplied by the proportional calculation unit 704. .

  The monitoring unit 503 according to the second embodiment performs proportional evaluation output from the proportional calculation unit 704 with respect to the evaluation signal one stitch before recorded in the recording unit 702 in the period ta in FIG. 8 illustrated in the first embodiment. When the signal value is small, a skip detection signal is output. Alternatively, the monitoring unit 503 skips when the value of the proportional evaluation signal output from the proportional calculation unit 704 is larger than the previous evaluation signal recorded in the recording unit 702 during the period tb in FIG. A detection signal is output.

  By doing in this way, the sewing machine 100 according to the second embodiment detects the occurrence of skipping based on the operation information of the driving source that drives the shuttle 309, so that it has a simple configuration with few additional parts and maintenance man-hours. Can be reduced.

  Further, in the sewing machine 100 according to Embodiment 2, the monitoring unit 503 skips the skip based on the evaluation signal one stitch before output from the recording unit 702 and the proportional evaluation signal obtained by setting the setting parameter D2. Detect. For this reason, by changing the setting of the setting parameter D2, the user of the sewing machine 100 can set the stitching detection sensitivity for each stitch.

  Also, by setting the setting parameter D2, the user of the sewing machine 100 can set the time constant and the cutoff frequency of the filter processing unit 701 for each stitch. Therefore, when the user changes the value of the setting parameter D2 during the sewing operation, the thickness or hardness of the sewing object is changed during the sewing operation and the tension of the upper thread is remarkably changed, or the sewing operation is performed. Even when the speed of the sewing machine is changed during sewing, it is possible to improve the detection accuracy of the skipping.

  In the second embodiment, the value of the evaluation signal one stitch before output from the recording unit 702 of the monitoring unit 503 may be constant as needed based on the input of the setting parameter D2. That is, the proportional evaluation signal may be used as a threshold for detecting skipping. In this way, skipping can be detected when the characteristic value of the current evaluation signal exceeds or falls below the value of the setting parameter D2, regardless of whether the evaluation signal before the stitch is fluctuating or not. By doing so, the recording area of the recording unit 702 is greatly reduced, and the configuration of the monitoring unit 503 can be simplified.

Embodiment 3 FIG.
Based on FIG. 11, the structure of the sewing machine 100 which concerns on Embodiment 3 is demonstrated. FIG. 11 is a block diagram illustrating details of the lower shaft motor control calculation unit of the sewing machine according to the third embodiment. The control panel denoted by reference numeral 122C corresponds to the control panel 122 shown in FIG.

  In the sewing machine 100 according to the third embodiment, the configuration of the monitoring unit 503 provided in the lower shaft motor control calculation unit 407 of the control panel 122C and the data stored in the storage device 403 of the operation panel 121 are related to the second embodiment. Unlike the sewing machine 100, other configurations and operations are the same as those of the sewing machine 100 according to the first and second embodiments. For this reason, description of the same part is omitted.

  As shown in FIG. 11, the monitoring unit 503 of the control panel 122 </ b> C has a lower axis motor drive signal output from the lower axis deviation suppression unit 501 and a setting parameter D <b> 3 that is data stored in the storage device 403 of the operation panel 121. And a skip detection signal is output to the display 401 and the lower axis deviation suppression unit 501. The setting parameter D3 may be set in a computer outside the operation panel 121, and the setting parameter D3 output from the computer may be input to the control panel 122C.

  In the third embodiment, a lower shaft motor drive signal is input to the filter processing unit 701 of the monitoring unit 503 shown in FIG. 10 instead of the lower shaft rotation signal output from the rotation information detector 302.

  Next, the operation of the sewing machine 100 according to the third embodiment will be described with reference to FIG. FIG. 12 is a diagram illustrating a signal waveform when a stitch skip is detected by the sewing machine according to the third embodiment. The upper part of FIG. 12 is the waveform of the evaluation signal output from the filter processing unit 701 of the control panel 122C, and the lower part is the skip detection signal output from the comparator 703 of the control panel 122C.

  Referring to the upper stage, when the evaluation signal is obtained by inputting the lower shaft motor drive signal to the filter processing unit 701, the evaluation of the period tc is performed on the evaluation signal of the period ta as in the case of inputting the rotation information. It can be seen that the signal has a smaller difference between the maximum value and the minimum value. During the period ta, the tip of the hook 309 is capturing the upper thread loop, so that a large amount of torque is required to rotate the lower shaft motor 301, whereas during the period tc, the tip of the hook 309 is the upper thread. This is because the loop cannot be captured.

  On the other hand, the output timing of the skip detection signal is shown in the lower part, and the comparator 703 of the monitoring unit 503 outputs a signal indicating that a skip has occurred after monitoring the evaluation signal in the period tc. .

  By doing in this way, since the sewing machine 100 according to the third embodiment detects the occurrence of skipping based on the operation information of the drive source that drives the shuttle 309, it has a simple configuration with few additional parts, and maintenance man-hours. Can be reduced.

  In the sewing machine 100 according to the third embodiment, the monitoring unit 503 detects the skipping based on the lower shaft motor drive signal and the setting parameter D3. In the first embodiment, the angular velocity obtained by differentiating the rotation angle of the lower shaft motor 301 is used as the lower shaft rotation signal. However, this differential calculation is required by using the lower shaft motor drive signal as an input to the monitoring unit 503. Calculation cost can be reduced.

  When a servo motor is used as the lower shaft motor 301, the lower shaft motor drive signal corresponds to the q-axis current command of the dq-axis vector current control system, and thus the angular acceleration or torque dimension is obtained, and the angular velocity is sent to the monitoring unit 503. Since it becomes easier to detect a change in the evaluation signal than in the case of inputting, it is possible to improve the skip detection accuracy.

  In the third embodiment, the monitoring unit 503 inputs a lower shaft motor drive signal and outputs a skip detection signal, but the lower shaft rotation signal is output during the period when the tip of the hook 309 is capturing the upper thread. If the internal signal of the control panel 122C reflects the fluctuation, the skip can be detected even if a signal other than the lower shaft motor drive signal is input. For example, a deviation signal output from the differentiator 602 of the lower axis deviation suppression unit 501 illustrated in FIG. 6 may be input to the monitoring unit 503. Further, a current value for energizing the lower shaft motor 301 may be input to the monitoring unit 503.

Embodiment 4 FIG.
Based on FIG. 13 and FIG. 14, the configuration and operation of the sewing machine 100 according to the fourth embodiment will be described. FIG. 13 is a block diagram illustrating details of the lower shaft motor control calculation unit of the sewing machine according to the fourth embodiment. FIG. 14 is a block diagram illustrating details of the monitoring unit of the sewing machine according to the fourth embodiment. The control panel indicated by reference numeral 122D in FIG. 13 corresponds to the control panel 122 shown in FIG.

  In the sewing machine 100 according to the fourth embodiment, the configuration of the monitoring unit 503 provided in the lower shaft motor control calculation unit 407 of the control panel 122D and the data stored in the storage device 403 of the operation panel 121 are implemented from the first embodiment. Unlike the sewing machine 100 according to the third embodiment, other configurations and operations are the same as those of the sewing machine 100 according to the first to third embodiments. For this reason, description of the same part is omitted.

  As illustrated in FIG. 13, the lower shaft motor control calculation unit 407 of the control panel 122D includes a lower shaft command signal output from the command generation unit 405 and a lower shaft output from the rotation information detector 302 of the lower shaft motor 301. The rotation signal and the setting parameter D4 that is data stored in the storage device 403 of the operation panel 121 are input using the input device 404, and the current control unit 502 outputs the lower shaft control current to the lower shaft motor 301. The monitoring unit 503 outputs a skip detection signal to the display 401 and the lower axis deviation suppression unit 501. The setting parameter D4 may be set in a computer outside the operation panel 121, and the setting parameter D4 output from the computer may be input to the control panel 122D.

  As shown in FIG. 14, the monitoring unit 503 of the control panel 122D receives a filter processing unit 701 that receives a motor drive signal, a recording unit 702, a comparator 703, a proportional calculation unit 704, and a lower axis rotation signal. A filter processing unit 705, a state estimation unit 706, and a differentiator 707 are provided as inputs. The setting parameter D4 of the storage device 403, the lower-axis motor drive signal output from the lower-axis deviation suppression unit 501, and rotation information The lower shaft rotation signal output from the detector 302 is input, and a skip detection signal is output.

  The filter processing unit 701 of the control panel 122D receives the lower shaft motor drive signal and the setting parameter D4, and outputs an evaluation signal in which an arbitrary noise component is reduced for skip detection. By changing the setting parameter D4, the time constant and cutoff frequency of the filter used for reducing the noise component can be adjusted.

  The recording unit 702 of the control panel 122D receives the setting parameter D4 and the estimated disturbance signal output from the differentiator 707, and synchronizes the estimated disturbance signal recorded during the previous sewing operation with the current sewing timing. The time is output as if In the recording unit 702, the period during which the evaluation signal is recorded can be changed by changing the value of the setting parameter D4.

  The comparator 703 of the control panel 122D compares the estimated disturbance signal one stitch before output from the recording unit 702 with the proportional evaluation signal output from the proportional calculation unit 704, and outputs a skip detection signal. The proportional calculation unit 704 of the control panel 122D multiplies the estimated disturbance signal output from the differentiator 707 by the gain set by the setting parameter D4 and outputs a proportional evaluation signal.

  A filter processing unit 705 that receives the lower-axis rotation signal as input performs filter operation processing for reducing the same noise component as the filter processing unit 701. By changing the setting parameter D4, the time constant and cutoff frequency of the filter used for reducing the noise component can be adjusted. The state estimation unit 706 estimates the motor drive signal from the lower shaft rotation signal by simulating the inverse characteristic of the transfer function from the lower shaft motor drive signal to the lower shaft motor rotation signal, and outputs the estimated drive signal. For example, the transfer function Gm (s) from the lower shaft motor drive signal to the lower shaft motor rotation signal can be expressed by the following equation (1). Here, Jm is the inertia of the motor shaft, Jl is the inertia of the rotating part connected to the motor shaft, D is the viscous friction coefficient of the motor, and s is the Laplace operator. The state estimation unit 706 has an inverse characteristic of a model simulating at least the inertia component of the rotating unit rotated by the lower shaft motor 301, that is, the inertia Jl.

  The differentiator 707 calculates the difference between the evaluation signal output from the filter processing unit 701 and the estimated drive signal output from the state estimation unit 706, and outputs an estimated disturbance signal. The estimated disturbance signal is a signal for estimating a disturbance to the lower shaft motor 301 including the tension of the upper thread loop applied to the blade tip 308 of the hook 309.

  The setting parameter D4 is a plurality of numerical values for changing the time constants and cutoff frequencies of the filter processing units 701 and 705, changing the recording period of the recording unit 702, and changing the gain value multiplied by the proportional calculation unit 704. It is.

  The monitoring unit 503 according to the fourth embodiment performs proportional evaluation output from the proportional calculation unit 704 with respect to the disturbance estimation signal one stitch before recorded by the recording unit 702 in the period ta in FIG. 8 illustrated in the first embodiment. When the signal value is small, a skip detection signal is output. Also, the monitoring unit 503 detects skipping when the value of the proportional evaluation signal output from the proportional calculation unit 704 is larger than the estimated disturbance signal one stitch before recorded by the recording unit 702 in the period tb in FIG. Output a signal. The skip detection sensitivity can be changed by adjusting the gain of the proportional calculation unit 704 that is changed by the setting parameter D4.

  By doing in this way, the sewing machine 100 according to the fourth embodiment detects the occurrence of skipping based on the operation information of the drive source that drives the shuttle 309, so that it has a simple configuration with few additional parts and has a maintenance man-hour. Can be reduced.

  Further, the sewing machine 100 according to the fourth embodiment estimates the disturbance applied to the lower shaft motor 301 based on the model of the lower shaft mechanism calculated by the state estimation unit 706. For this reason, the skip detection accuracy can be improved when a highly accurate model of the lower shaft mechanism can be constructed.

  In the fourth embodiment, the value of the previous evaluation signal output from the recording unit 702 of the monitoring unit 503 may be constant as needed based on the input of the setting parameter D4. That is, the estimated disturbance signal may be used as a threshold for detecting skipping. In this way, skipping can be detected when the current estimated disturbance signal simply exceeds or falls below the threshold set by the setting parameter D4, regardless of the fluctuation or variation of the estimated disturbance signal one stitch before. By doing so, the recording area of the recording unit 702 is greatly reduced, and the configuration of the monitoring unit 503 of the control panel 122D can be simplified.

Embodiment 5. FIG.
The configuration and operation of sewing machine 100 according to Embodiment 5 will be described based on FIGS. 15 and 16. FIG. 15 is a block diagram showing details of the lower shaft motor control calculation unit of the sewing machine according to the fifth embodiment. FIG. 16 is a block diagram showing details of the rotation information detector for the sewing machine according to the fifth embodiment. The control panel denoted by reference numeral 122E corresponds to the control panel 122 shown in FIG.

  The difference between the sewing machine 100 according to the fourth embodiment and the sewing machine 100 according to the fifth embodiment is that the sewing machine 100 according to the fifth embodiment includes a rotation information detector 504 that detects rotation information of the lower shaft motor 301. The control panel 122E is configured in the lower shaft motor control calculation unit 407, and the current control unit 502 supplies a lower shaft control current to the lower shaft motor 301 and outputs a voltage command signal and a lower shaft current signal. . Other configurations and operations are the same as those of sewing machine 100 according to the fourth embodiment. For this reason, description of the same part is omitted.

  As shown in FIG. 15, the lower shaft motor control calculation unit 407 of the control panel 122E receives the lower shaft command signal output from the command generation unit 405 and the setting parameter D4 as inputs. The setting parameter D4 is data stored in the storage device 403 of the operation panel 121 using the input device 404. Further, the current control unit 502 of the lower shaft motor control calculation unit 407 outputs the lower shaft control current to the lower shaft motor 301, and the monitoring unit 503 of the lower shaft motor control calculation unit 407 displays the skip detection signal on the display 401. And output to the lower axis deviation suppression unit 501.

  The current control unit 502 of the control panel 122E detects an inverter circuit (not shown) and the value of the lower axis control current flowing in the lower axis motor 301 as a lower axis current signal in order to flow the lower axis control current to the lower axis motor 301. A current detection unit 505 is provided. The current control unit 502 receives the lower shaft motor drive signal as an input, calculates a voltage command signal for driving the inverter circuit, and outputs a lower shaft control current, a voltage command signal, and a lower shaft current signal. The rotation information detector 504 of the control panel 122E receives the voltage command signal and the lower axis control signal and outputs a lower axis rotation signal. As shown in FIG. 16, the rotation information detector 504 of the control panel 122E includes a motor model 506, a speed estimator 507, a difference unit 508, and a position estimator 509. The motor model 506 is a magnetic flux observer that receives the voltage command signal output from the current control unit 502, the estimated speed output from the speed estimator 507, and the output signal from the differentiator 508. By giving the impedance as an eigenvalue, the current and magnetic flux of the lower shaft motor 301 are estimated, and the current estimated value and the magnetic flux estimated value are output. The speed estimator 507 receives the estimated magnetic flux output from the motor model 506 as an input, estimates the rotational speed of the lower shaft motor 301, and outputs the estimated speed. The differentiator 508 receives the estimated current value and the lower axis current signal as inputs, and outputs the difference between the two. If the motor model is updated so that the output of the differentiator 508 becomes zero, it is possible to improve the estimation accuracy of the estimated magnetic flux value output from the motor model 506. The position estimator 509 estimates the position of the lower shaft motor 301 by inputting one or both of the magnetic flux estimated value and the speed estimated value, and outputs a lower shaft rotation signal. The rotation information detector 504 may output the estimated speed value as a lower axis rotation signal.

  By doing in this way, the sewing machine 100 according to the fifth embodiment does not need to install a sensor such as an encoder or resolver at the shaft end of the lower shaft motor 301, and uses a sensorless motor, that is, has few additional parts. Skips can be detected with a simple configuration, and man-hours spent for calibration work of detection accuracy can be eliminated as compared with the case of installing a sensor. Note that the rotation information detector 302 of the lower shaft motor 301 used in the sewing machine 100 according to the first to fourth embodiments can be replaced with the rotation information detector 504 as in the fifth embodiment.

  Each function provided in the control panel of the sewing machine 100 according to the first to fifth embodiments can be realized using a processing circuit. The functions are a command generation unit 405 and a lower shaft motor control calculation unit 407. FIG. 17 is a diagram illustrating a first hardware configuration example of the control panel of the sewing machine according to the first to fifth embodiments. FIG. 18 is a diagram illustrating a second hardware configuration example of the control panel of the sewing machine according to the first to fifth embodiments. FIG. 17 shows an example in which the above processing circuit is realized by dedicated hardware such as the dedicated processing circuit 60. FIG. 18 shows an example in which the processing circuit is realized by the processor 61 and the storage device 62.

  As shown in FIG. 17, when using dedicated hardware, the dedicated processing circuit 60 includes a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), and an FPGA (Field). Programmable Gate Array) or a combination thereof. Each of the above functions may be realized by a processing circuit, or may be realized by a processing circuit collectively.

  As shown in FIG. 18, when the processor 61 and the storage device 62 are used, each of the above functions is realized by software, firmware, or a combination thereof. Software or firmware is described as a program and stored in the storage device 62. The processor 61 reads and executes the program stored in the storage device 62. It can also be said that these programs cause a computer to execute the procedures and methods executed by each of the above functions. The storage device 62 includes a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (registered trademark) (Erasable Programmable Read Only Memory), or an EEPROM (Electrically Available Memory). To do. The semiconductor memory may be a nonvolatile memory or a volatile memory. In addition to the semiconductor memory, the storage device 62 corresponds to a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc).

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  60 dedicated processing circuit, 61, 402 processor, 62, 403 storage device, 100 sewing machine, 101 arm, 102 upper shaft motor case, 103 sewing machine head, 104 bed, 105 support leg, 106 sliding plate, 111 XY stage, 112 holding Device, 113 Air cylinder, 121 Operation panel, 122, 122A, 122B, 122C, 122D, 122E Control panel, 123 Foot switch, 201 Upper shaft motor, 202, 302, 411, 413, 504 Rotation information detector, 203, 303 Coupling, 204 Upper shaft, 205 Medium press drive mechanism, 206 Medium press, 207 Balance drive mechanism, 208 Small hole, 209 Balance, 210 Needle bar drive mechanism, 211 Needle bar, 212 Sewing needle, 301 Lower shaft motor, 304 Lower shaft motor shaft, 05 large-diameter gear, 306 small-diameter gear, 307 lower shaft rotary shaft, 308 blade tip, 309 hook, 401 indicator, 404 input device, 405 command generator, 406 upper shaft motor control calculator, 407 lower shaft motor control calculator, 408 X-axis motor control calculation unit, 409 Y-axis motor control calculation unit, 410 X-axis motor, 412 Y-axis motor, 501 Lower axis deviation suppression unit, 502 Current control unit, 503 Monitoring unit, 505 Current detection unit, 506 Motor model , 507 Speed estimator, 508, 602, 707 Differencer, 509 Position estimator, 601 switch, 603 Deviation suppression compensator, 701, 705 Filter processing unit, 702 Recording unit, 703 Comparator, 704 Proportional operation unit, 706 state Estimator.

To solve the above problems and achieve the object, a sewing machine of the present invention, the upper thread is formed by moving to the top dead center挿針been sewing needle from the bottom dead center to the workpiece The rotation information detector that detects the rotation information of the rotary hook that has the sword tip to be captured and the motor that rotates the rotary hook, and the occurrence of skipping is monitored based on the rotation information that is detected during the period in which the rotary hook sword tip captures the upper thread. And a monitoring unit that outputs a skip detection signal when the skip is detected.

Claims (11)

A bite having a sword that captures the loop of the upper thread formed by the sewing needle inserted into the workpiece being moved from the bottom dead center to the top dead center;
A rotation information detector for detecting rotation information of a motor for rotating the rotary hook;
A monitoring unit that monitors the occurrence of a skip based on the rotation information detected during a period when the tip of the rotary hook captures the upper thread, and outputs a skip detection signal when a skip is detected;
A sewing machine comprising: A motor control unit that generates a motor drive signal for driving the motor so that a difference between the rotation command of the motor and the rotation information is small;
The monitoring unit monitors an increase or decrease in an evaluation signal calculated by performing a specific calculation on the motor drive signal during a period in which the tip of the hook catches the upper thread. The sewing machine according to 1.   The sewing machine according to claim 2, wherein the monitoring unit outputs the skipping detection signal when the evaluation signal exceeds or falls below a setting parameter from outside the monitoring unit. An operation for reducing a frequency component higher than the rotation frequency of the kiln, an operation for reducing a frequency component lower than the rotation frequency of the kiln, and an all-pass filter for changing the phase of the rotation information with respect to the motor drive signal A filter processing unit that calculates the evaluation signal by performing any one or a plurality of operations of the calculation according to (2) and the calculation of changing the amplitude by multiplying the gain,
The sewing machine according to claim 2 or 3, wherein the monitoring unit changes a time constant or a gain of the filter processing unit according to one or more setting parameters input from the outside of the monitoring unit. A recording unit for recording the evaluation signal in a period after the hook tip of the hook releases the upper thread before the first needle until the hook tip of the hook catches the upper thread again;
The said monitoring part outputs the said skip detection signal when the said evaluation signal output from the said filter process part is smaller than a specific value compared with the recording of the said recording part. The sewing machine according to 1. The monitoring unit estimates a rotation state of the motor by inputting a signal obtained by performing calculation by the filter processing unit on the rotation information to a model that simulates at least inertia of a driving unit that rotates the motor. A state estimation unit,
The monitoring unit uses, as the evaluation signal, an estimated disturbance signal obtained from a difference between a signal obtained by performing the calculation by the filter processing unit on the motor drive signal and an output signal of the state estimation unit. The sewing machine according to claim 4 or 5.   The sewing machine according to any one of claims 2 to 6, wherein the motor control unit includes a switch that stops a change in the value of the rotation command based on the skipping detection signal.   The rotation information detector includes a model of the motor that simulates and outputs the magnetic flux of the motor, with the voltage command value of the motor calculated based on the motor drive signal and the current value of the motor as inputs. 8. The sewing machine according to claim 2, wherein the rotation information of the motor is detected on the basis of the sewing machine. The monitoring unit;
A balance having a small hole through which the upper thread is inserted, and forming a seam by pulling up the upper thread from the sewing product by raising the bottom hole from the bottom dead center to the top dead center;
A presser for preventing the sewing product from being lifted;
A transport unit for transporting the sewing product;
A command generation unit that changes any one or a plurality of driving methods of the sewing needle, the shuttle, the balance, the balance, the presser, and the transport unit based on the skipping detection signal. The sewing machine according to any one of claims 1 to 8.   The command generation unit outputs a signal for stopping one or more of the sewing needle, the shuttle, the balance, the presser, and the transport unit based on the skipping detection signal. The sewing machine according to claim 9, wherein:   The sewing machine according to any one of claims 1 to 10, further comprising a display that displays that a skip has occurred based on the skip detection signal.

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