CN111748923A

CN111748923A - Sewing machine

Info

Publication number: CN111748923A
Application number: CN202010143508.2A
Authority: CN
Inventors: 中野元就; 中山一树
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 2019-03-28
Filing date: 2020-03-04
Publication date: 2020-10-09
Anticipated expiration: 2040-03-04
Also published as: JP2020162659A; CN111748923B; JP7215295B2

Abstract

The invention relates to a sewing machine, which can count the occurrence frequency of bad sewing aiming at each category and inform the operator. The sewing machine obtains the tension of the upper thread when sewing is started. The sewing machine detects a sewing failure based on the acquired tension. The sewing failure at least comprises broken thread, skipping stitch and take-up failure. The sewing machine counts a first number of times of detecting thread breakage, a second number of times of detecting stitch skipping, and a third number of times of detecting poor thread take-up. The sewing machine displays the first count, the second count and the third count obtained by counting on a display unit to inform an operator.

Description

Sewing machine

Technical Field

The present invention relates to a sewing machine.

Background

A sewing machine disclosed in Japanese patent laid-open No. 33866 of 1998 includes a head, a sewing machine control device, and a thread breakage detection device. The thread breakage detection device receives the signal output by the head part, judges whether thread breakage occurs or not, and outputs the judgment result to the sewing machine control device. The sewing machine control device counts the number of thread breakage occurrences (thread breakage number) based on the determination result output by the thread breakage detection device. The sewing machine control device displays the number of thread breakage times obtained by counting on a display unit.

As a type of sewing failure that may occur in a sewing machine, there are stitch skipping, thread take-up failure, and the like in addition to thread breakage. The sewing machine does not inform the occurrence frequency of the sewing failure of the categories except the thread breakage frequency, so that the operator cannot grasp the occurrence frequency of the sewing failure for each category. Therefore, the operator may not perform appropriate processing according to the type of defective sewing.

Disclosure of Invention

The invention aims to provide a sewing machine which can count the occurrence frequency of poor sewing aiming at each category and inform the operator.

The sewing machine according to claim 1 is characterized by comprising: an acquisition unit that acquires the tension of the upper thread; a detection unit that detects a defective sewing including at least a broken thread, a skip stitch, and a defective take-up thread based on the tension acquired by the acquisition unit; a first counting unit that counts the number of times the detection unit detects the defective sewing, the first counting unit counting a first number of times the detection unit detects the thread breakage, a second number of times the detection unit detects the stitch skipping, and a third number of times the detection unit detects the defective thread take-up; and a first notification unit that notifies the first count, the second count, and the third count obtained by the counting by the first counting unit.

The sewing machine can count the frequency of the sewing failure aiming at each type of the sewing failure, namely, broken thread, skip stitch and take-up failure, and inform the operator. Therefore, the operator can properly handle the sewing machine according to the type of the sewing failure notified by the sewing machine.

In the sewing machine according to claim 2, the first counting unit may count the number of times the detecting unit detects the defective sewing in a predetermined period. The operator can grasp the number of occurrences of a sewing failure in a predetermined period for each sewing failure category.

The sewing machine according to claim 3 may further include a cutting mechanism configured to cut the upper thread and the lower thread, wherein the predetermined period is any one of a first period, a second period, and a third period, the first period being a period after the upper thread and the lower thread are cut by the cutting mechanism until the upper thread and the lower thread are cut by the cutting mechanism next time, the second period being a period set by an operator via an input unit, and the third period being a period after the operator initializes the number of times via the input unit until the operator initializes the number of times next time. The operator can grasp the number of occurrences of defective sewing in various periods for each type of defective sewing.

The sewing machine according to claim 4 may further include a first setting unit configured to set validity or invalidity of the count performed by the first counting unit for each of the first count, the second count, and the third count, wherein the first counting unit counts the number of times set to be valid by the first setting unit among the first count, the second count, and the third count, and wherein the first notifying unit notifies the number of times set to be valid by the first setting unit among the first count, the second count, and the third count. The operator can efficiently grasp the number of occurrences of sewing defects of a desired type.

The sewing machine according to claim 5 may further include: a determination unit that determines whether or not the first count, the second count, and the third count counted by the first counting unit are equal to or greater than corresponding thresholds; a stopping section that stops the sewing operation when the determining section determines that at least one of the first frequency, the second frequency, and the third frequency is equal to or greater than the corresponding threshold; and a second notifying section that notifies the sewing failure corresponding to the first frequency, the second frequency, and the third frequency which are judged to be equal to or greater than the corresponding threshold value by the judging section when the stopping section stops the sewing operation. The sewing machine can prevent the sewing from continuing in a state of poor sewing, thereby preventing the quality from being reduced due to the poor sewing. By notifying the sewing machine of the corresponding sewing failure, the operator can grasp the type of the sewing failure which is a main cause of stopping the sewing operation.

The sewing machine according to claim 6 may further include a second setting unit that sets the corresponding threshold values corresponding to the first count, the second count, and the third count, and the determination unit may determine whether or not the first count, the second count, and the third count counted by the first counting unit are equal to or greater than the corresponding threshold values set by the second setting unit. The operator can adjust the condition of stopping sewing operation of the sewing machine according to each type of sewing failure.

The sewing machine according to claim 7 may further include a second counting unit that counts the number of stitches from the start of the sewing operation, and the first notification unit may notify the first count, the second count, and the third count counted by the first counting unit in association with the number of stitches counted by the second counting unit. The operator can grasp the number of occurrences of the sewing failure and the number of stitches for each sewing failure category in association with each other.

Drawings

Fig. 1 is an overall perspective view of the sewing machine 1.

Fig. 2 is an overall perspective view of the sewing apparatus 100.

Fig. 3 is a partially enlarged view of the head 5.

Fig. 4 is a partially enlarged view of the panel portion 220.

Fig. 5 is an electrical block diagram of the sewing machine 1.

Fig. 6 is a flowchart of the sewing process.

Fig. 7 is a flowchart subsequent to fig. 6.

Fig. 8 is a flowchart subsequent to fig. 7.

Fig. 9 is a flowchart subsequent to fig. 8.

Fig. 10 is a flowchart of a sewing failure processing.

Fig. 11 is a flowchart of the process at the time of disconnection.

Fig. 12 is a flowchart of the process at the time of stitch skipping.

Fig. 13 is a flowchart of the processing when the wire take-up is defective.

Detailed Description

A sewing machine 1 according to an embodiment of the present invention will be described. The following description uses the left and right, front and back, and up and down shown by arrows in the drawings.

Referring to fig. 1 to 3, the structure of the sewing machine 1 will be described. The sewing machine 1 has a table 9 and a sewing device 100. An opening 9A is provided in the upper surface of the table 9. The right front portion of the table 9 has a panel portion 220. The sewing device 100 has a base 2, a column 3, and an arm 4. The base part 2 is fitted at the opening 9A, and the base part 2 extends in the left-right direction. The housing part 2 is equipped with a needle plate 7 on the upper surface. The operator places the cloth on the bed 2 and the needle plate 7. The needle plate 7 has a needle receiving hole 8 and a feed dog hole 14. The pin receiving hole 8 has a circular shape in plan view. The feed sprocket 14 has a long diameter in the front-rear direction, and the feed sprocket 14 is located at the left, rear, right, and front of the needle accommodating hole 8, respectively. The column part 3 extends upward from the right end of the seat part 2. The arm portion 4 extends leftward from the upper end of the column portion 3 and faces the upper surface of the base portion 2. The arm unit 4 has a first input unit 24 and a first display unit 25 at a substantially central portion in the left-right direction of the front surface. The first input portion 24 is three input buttons. The operator inputs various instructions by operating the first input unit 24 while looking at the first display unit 25. The arm part 4 has a thread passing rod (Japanese vertical rod) 20 protruding upward on the left side of the upper surface. The thread take-up lever 20 is penetrated by the upper thread 6 drawn out from the thread spool.

The arm portion 4 includes an upper shaft 15 and a main motor 27 (see fig. 5) therein. The upper shaft 15 extends in the left-right direction and is connected to an output shaft of the main motor 27 via an upper shaft pulley. The upper shaft pulley is fixed to the right end of the upper shaft 15. The arm portion 4 has a head portion 5 at a left end portion. The head 5 protrudes downward from the arm 4 and faces the needle plate 7 from above. The head 5 supports the needle bar 11 so that the needle bar 11 can move up and down. The lower end of the needle bar 11 is fitted with a needle 10 and projects downward from the head 5. The needle bar 11 is connected to the upper shaft 15 by an up-and-down movement mechanism. The needle bar 11 is moved up and down by the up-down movement mechanism in accordance with the rotation of the upper shaft 15. The needle 10 moves up and down together with the needle bar 11 while holding the needle thread 6 (see fig. 3) passing through the needle eye. The needle 10 can be passed through the needle-receiving hole 8. The lower end of the movable range of the needle 10 is a bottom dead center.

The base unit 2 includes therein a shuttle, a thread cutting mechanism 17 (see fig. 5), and a cloth feeding mechanism. The shuttle is provided below the needle plate 7 and houses a bobbin around which a lower thread is wound. The shuttle has a tip, and can be rotated by power of the main motor 27, and catches the upper thread 6 passing through the eye of the needle 10 with the tip, and interweaves the upper thread 6 with the lower thread. The thread cutting mechanism 17 includes a fixed blade, a movable blade, and a thread cutting solenoid 17A (see fig. 5). The movable blade is connected to the tangent line electromagnetic element 17A. The movable knife is moved relative to the fixed knife by driving the thread cutting solenoid 17A, and the thread cutting mechanism 17 cuts the surface thread 6 and the ground thread by cooperation of the movable knife and the fixed knife.

The cloth feeding mechanism includes upper and lower cloth feeding shafts, a cloth feeding table, cloth feeding teeth 13, a horizontal cloth feeding shaft, and a cloth feeding motor 123 (see fig. 5). The upper and lower cloth feed shafts extend in the right and left direction inside the machine base 2 and are connected to the upper shaft pulleys via belts. The cloth feeding table is arranged to be capable of swinging and is connected with the upper and lower cloth feeding shafts. When the up-down feed shaft is rotated by the driving force of the main motor 27, the feed table moves in the up-down direction. The feed dog 13 is supported on the feed table. The horizontal feed shaft extends in the left-right direction at a position forward of the upper and lower feed shafts, and connects the feed motor 123 and the feed table. When the horizontal cloth feeding shaft is rotated by the driving force of the cloth feeding motor 123, the cloth feeding table moves in the front-rear direction. The cloth feeding table swings as the main motor 27 and the cloth feeding motor 123 are driven, and the cloth feeding teeth 13 protrude from or retreat into the cloth feeding sprocket holes 14. The cloth feed dog 13 moves in the front-rear direction while protruding upward from the cloth feed dog hole 14, and feeds the cloth.

As shown in fig. 3, the head 5 includes a sub thread gripper 26, a main thread gripper 60, a thread guide 21, a thread tension detection mechanism 130, a thread take-up lever 23, a guide hook 29, and the like in this order from the thread spool to the upstream side of the feed path of the upper thread 6 of the needle 10.

The sub-chuck 26 is provided at the upper right portion of the front surface of the head 5. The main gripper 60 is provided below the sub gripper 26 and is a front surface of the head 5. The sub-gripper 26 and the main gripper 60 respectively give tension to the upper thread 6. The sub-gripper 26 applies tension to the surface thread 6, which is required when the surface thread 6 and the lower thread are cut by the thread cutting mechanism 17. The main thread gripper 60 adjusts the tension applied to the upper thread 6 in accordance with the sewing operation of the sewing device 100. The wire guide 21 is provided on the left of the main wire gripper 60. The thread guide 21 folds back the upper thread 6 passing through the main thread gripper 60 toward the thread tension detecting mechanism 130 and the thread take-up lever 23. The wire tension detecting mechanism 130 is fixed to a recess 5A recessed rearward from the front surface of the head 5 by a screw 90, and is located at a vertical position between the sub wire gripper 26 and the main wire gripper 60. The line tension detecting mechanism 130 includes a magnetic sensor 105 (see fig. 5). The thread tension detecting means 130 can detect the tension acting on the upper thread 6, that is, the upper thread tension, based on the output voltage of the magnetic sensor 105. The thread take-up lever 23 is provided on the left side of the sub-gripper 26 and has a through hole 23A through which the upper thread 6 passes. The thread take-up lever 23 moves up and down in accordance with the driving of the main motor 27. The guide hook 29 is provided on the left of the wire tension detecting mechanism 130. The guide hook 29 guides the upper thread 6 passing through the through hole 23A of the thread take-up lever 23 toward the needle bar 11.

The header 5 has a header amplifier 200 and a protrusion 210. The head amplifier 200 is provided on the rear upper surface of the head 5. On the upper front surface of the head amplifier 200, a disconnection LED200A, a jumper LED200B, and a take-up LED200C are provided in this order from the right. The disconnection LED200A, the jumper LED200B, and the take-up LED200C can emit light in a lighted or blinking manner. The disconnection LED200A emits light when a disconnection occurs. The jumper LED200B emits light when a jumper occurs. The take-up LED200C emits light when a take-up failure occurs. The poor sewing of broken thread, skipping stitch and winding thread.

The projection 210 is provided near the needle bar 11 and below the thread guide portion 21. The protrusion 210 protrudes forward from the lower end portion of the head 5, and then bends downward and extends. The projection 210 has a needle bar LED210A at the lower portion. The needle bar LED210A can illuminate in a lighted or blinking manner. The needle bar LED210A lights up when a poor thread take-up occurs, and lights off after stopping the sewing operation. The needle bar LED210A may blink the number of times of occurrence of poor take-up when a poor take-up occurs.

As shown in fig. 4, the panel portion 220 includes a second display portion 221, a second input portion 222, and a speaker 223 (see fig. 5). The second display unit 221 is an LCD, and can display numbers, characters, and the like. The second input unit 222 is provided on the left and below the second display unit 221. The operator operates the second input unit 222 while looking at the second display unit 221 to input various instructions. Hereinafter, the first input unit 24 (see fig. 2) and the second input unit 222 are collectively referred to as an input unit.

The second display unit 221 includes a first screen 221A, a second screen 221B, a third screen 221C, and a fourth screen 221D in this order from the right. The first frame 221A mainly displays the number of times of occurrence of disconnection. The second screen 221B mainly displays the number of times of stitch skipping. The third frame 221C mainly displays the number of times of poor wire rewinding. The fourth screen 221D mainly displays a detection level described later. The second display unit 221 can also display the needle fall frequency of the needle 10 during a period from when the sewing machine 1 starts the sewing operation to when each sewing failure occurs.

The first display part 25, the second display part 221, the head amplifier 200 and the protrusion part 210 all give information when a sewing failure occurs. Hereinafter, the first display unit 25, the second display unit 221, the head amplifier 200, and the protrusion 210 are collectively referred to as a notification unit.

Referring to fig. 5, an electrical structure of the sewing machine 1 is explained. The control device 30 of the sewing machine 1 has a CPU 91. The CPU91 controls the operation of the sewing machine 1. The CPU91 is connected to a ROM92, a RAM93, a storage device 94, and an I/O interface (hereinafter referred to as I/O) 45. The ROM92 stores programs and the like for executing various processes such as a sewing process (see fig. 6) described later. The RAM93 temporarily stores various values. The storage device 94 is a non-volatile storage device.

The I/O45 is connected to the drive circuits 81 to 83. The drive circuit 81 is connected to the main motor 27. The drive circuit 82 is connected to the cloth feed motor 123. The drive circuit 83 is connected to the clamp motor 16. The main motor 27, the cloth feeding motor 123, and the thread take-up motor 16 include an encoder 27A, an encoder 123A, and an encoder 16A, respectively. The encoder 27A detects the rotational position of the output shaft of the main motor 27. The detection result of the encoder 27A indicates the rotational angle phase of the upper shaft 15, i.e., the upper shaft angle. The encoder 123A detects the rotational position of the output shaft of the cloth feeding motor 123. The encoder 16A detects the rotational position of the output shaft of the clamp motor 16. The CPU91 acquires the detection results of the

encoders

27A, 123A, and 16A, and sends control signals to the drive circuits 81 to 83. Therefore, the CPU91 controls the driving of the main motor 27, the cloth feeding motor 123, and the thread take-up motor 16. Hereinafter, the main motor 27, the cloth feeding motor 123, and the thread take-up motor 16 will be collectively referred to as a drive motor.

The I/O45 is connected to the drive circuits 84 to 88, the first input unit 24, the second input unit 222, the pedal 38, and the magnetic sensor 105. The drive circuit 84 is connected to the tangent electromagnetic element 17A. The driving circuit 85 is connected to the first display unit 25. The driver circuit 86 is connected to the head amplifier 200. The drive circuit 87 is connected to the needle bar LED 210A. The drive circuit 88 is connected to the second display unit 221 and the speaker 223. The CPU91 sends control signals to the drive circuits 84 to 88 to control the tangent solenoid 17A, the first display unit 25, the head amplifier 200, the needle bar LED210A, the second display unit 221, and the speaker 223. The first input unit 24 and the second input unit 222 output the input result of the operator to the CPU 91. The pedal 38 outputs the operation direction and the operation amount of the pedal 38 by the operator to the CPU 91. The magnetic sensor 105 outputs an output voltage indicating the face line tension to the CPU 91.

The sewing failure of the sewing machine 1 will be described. The sewing failure indicates that a normal stitch is not formed in the sewing operation. The sewing failure comprises poor winding, broken thread and stitch skipping. The poor take-up is poor balance between the upper thread 6 and the lower thread which form a stitch on the cloth when the upper thread 6 is lifted by the take-up lever 23. For example, when the face thread 6 is too strongly interwoven with the ground thread, the cloth near the stitch shrinks. The thread breakage is a defect that the upper thread 6 is broken during sewing and a stitch is not formed on the fabric. The skip stitch is a failure in catching the needle thread 6 by the shuttle in sewing and is a failure in forming a normal stitch on the cloth. The sewing machine 1 sets detection references corresponding to a broken thread, a skip stitch, and a defective take-up respectively.

With reference to fig. 2 and 3, an outline of the operation of the sewing machine 1 will be described. The operator places the cloth on the needle plate 7. The upper shaft 15 moves the needle bar 11 and the thread take-up lever 23 up and down by the driving of the driving motor, and the shuttle rotates. When the needle 10 is inserted into the fabric and then ascends after descending to the bottom dead center, the shuttle catches the endless upper thread 6 held by the eye of the needle 10 with the tip of the shuttle and weaves the upper thread 6 with the lower thread. The needle 10 is withdrawn upward from the fabric. At this time, the feed dog 13 is driven by the feed motor 123 and the main motor 27 to project upward from the feed dog hole 14 and swing rearward. Therefore, the cloth moves rearward. The thread take-up lever 23 lifts the upper thread 6 interlaced with the lower thread by the shuttle, thereby forming a stitch on the fabric. The cloth is sewn by repeating the above operations by the upper shaft 15, the needle 10, the shuttle, the thread take-up lever 23, and the cloth feeding mechanism.

The sewing process will be described with reference to fig. 6 to 13. The CPU91 counts the number of times of detection of a wire breakage, a skip stitch, and a wire rewinding failure in three periods (a first period, a second period, and a third period). The first period is a period after the upper thread 6 and the lower thread are cut by the thread cutting mechanism 17 until the upper thread 6 and the lower thread are cut by the thread cutting mechanism 17 next time. The second period is a period set by the operator via the input unit. The third period is a period after the operator initializes the number of detections via the input unit until the next time the operator initializes the number of detections. The CPU91 counts the number of detections in each period using the number of detections J (1), J (2), J (3), K (1), K (2), K (3), L (1), L (2), and L (3) stored in the storage device 94. The detection times J (1), J (2), and J (3) are the detection times of disconnection. The detection times K (1), K (2) and K (3) are the detection times of the skipping needle. The detection times L (1), L (2) and L (3) are the detection times of poor take-up. The detection times J (1), K (1), and L (1) are the detection times of defective sewing detected in the first period. The detection times J (2), K (2), and L (2) are the detection times of defective sewing detected in the second period. The detection times J (3), K (3), and L (3) are the detection times of defective sewing detected in the third period. The detection times J (1), J (2), and J (3) are not distinguished and are collectively referred to as the detection times J. The detection times K (1), K (2), and K (3) are collectively referred to as the detection times K when they are not distinguished. The detection times L (1), L (2), and L (3) are not distinguished and are collectively referred to as the detection times L. The CPU91 notifies the detected count J, K, L as a result of counting the number of times that sewing failure is detected when sewing processing is executed.

When the operator turns on the power of the sewing machine 1, the CPU91 reads out the program from the ROM92 to start the sewing process. The CPU91 sets each flag stored in the storage device 94 to 0. The case where each flag is set to 0 is referred to as "off flag", and the case where each flag is set to 1 is referred to as "on flag".

As in fig. 6, the CPU91 executes initialization processing (S1). At this time, the CPU91 sets the variable N stored in the RAM93 to 0. The variable N is a counter for counting the number of needle drops of the needle 10 by the vertical movement of the needle bar 11 as the number of needles.

The CPU91 determines whether or not the non-notification setting signal is received (S2). When the operator operates the setting for invalidating the count of the number of detection times in each sewing failure due to thread breakage, stitch skipping, and thread take-up failure through the input unit, the CPU91 receives the non-notification setting signal. When determining that the non-notification setting signal is not received (S2: no), the CPU91 shifts the process to S21 (see fig. 7).

When it is determined that the non-notification setting signal is received (S2: YES), the CPU91 determines whether or not the disconnection non-notification signal is received (S3). When the operator operates the setting of invalidating the count of the number of times of detection of disconnection by the input unit, the CPU91 receives the disconnection non-notification signal. When determining that the disconnection notification signal is not received (S3: no), the CPU91 shifts the process to S5. When determining that the disconnection non-notification signal has been received (S3: YES), the CPU91 turns on the disconnection non-notification flag (S4), and the process proceeds to S5.

The CPU91 determines whether the skip pin non-notification signal is received (S5). When the operator operates the setting for invalidating the count of the number of times of detection of the stitch through the input unit, the CPU91 receives the stitch non-notification signal. When determining that the jumper pin non-notification signal is not received (S5: no), the CPU91 shifts the process to S7. When determining that the skip pin non-notification signal is received (S5: yes), the CPU91 turns on the skip pin non-notification flag (S6), and the process proceeds to S7.

The CPU91 determines whether a poor wire take-up non-notification signal is received (S7). When the operator operates the setting for invalidating the count of the number of times of detection of the wire rewinding failure through the input unit, the CPU91 receives the wire rewinding failure notification signal. When determining that the wire-rewinding failure notification signal has not been received (S7: no), the CPU91 shifts the process to S21 (see fig. 7). When determining that the wire rewinding failure notification signal has been received (S7: yes), the CPU91 turns on the wire rewinding failure notification flag (S8), and the process proceeds to S21 (see fig. 7).

As shown in fig. 7, the CPU91 determines whether or not the correspondence threshold signal has been received (S21). The corresponding threshold values comprise a broken line threshold value corresponding to broken lines, a jump pin threshold value corresponding to jump pins and a line receiving threshold value corresponding to poor line receiving. The CPU91 compares each corresponding threshold with the detection count J, K, L in the processing described later, and ends the sewing operation when the detection count J, K, L is equal to or greater than the corresponding threshold (see fig. 11 to 13). When the operator operates the setting of the corresponding threshold through the input unit, the CPU91 receives a corresponding threshold signal. When determining that the correspondence threshold signal has not been received (S21: no), the CPU91 shifts the process to S41 (see fig. 8).

When determining that the corresponding threshold signal is received (S21: YES), the CPU91 determines whether the disconnection threshold signal is received (S22). When the operator operates the setting of the disconnection threshold through the input unit, the CPU91 receives a disconnection threshold signal. Upon determining that the disconnection threshold signal has not been received (S22: NO), the CPU91 shifts the process to S24. When determining that the disconnection threshold signal has been received (S22: YES), the CPU91 sets a disconnection threshold value in accordance with the operation result of the operator operating the input unit (S23), and the process proceeds to S24.

The CPU91 determines whether the skip needle threshold signal is received (S24). When the operator operates the setting of the stitch threshold through the input unit, the CPU91 receives a stitch threshold signal. Upon determining that the jumper threshold signal has not been received (S24: NO), the CPU91 shifts the process to S26. When determining that the stitch skipping threshold signal has been received (S24: YES), the CPU91 sets a stitch skipping threshold value in accordance with the operation result of the operator operating the input unit (S25), and the process proceeds to S26.

The CPU91 determines whether a wire takeup threshold signal is received (S26). When the operator operates the setting of the wire takeup threshold through the input section, the CPU91 receives the wire takeup threshold signal. When determining that the wire takeup threshold signal is not received (S26: no), the CPU91 shifts the process to S41 (refer to fig. 8). When determining that the wire takeup threshold signal has been received (S26: yes), the CPU91 sets a wire takeup threshold value in accordance with the operation result of the operator operating the input unit (S27), and the process proceeds to S41 (see fig. 8).

As shown in fig. 8, the CPU91 determines whether to start the sewing operation of the sewing machine 1 based on the detection result of the pedal 38 (S41). The CPU91 receives the close signal when the operator is not stepping on the pedal 38. At this time, the CPU91 judges that the sewing operation is not started (NO in S41) and waits.

The operator places the cloth on the needle plate 7, and after placing the cloth, steps on the pedal 38. At this time, the CPU91 receives an ON signal from the pedal 38 and determines that the sewing operation is started (S41: YES). The CPU91 starts processing for updating the variable N based on the detection result of the encoder 27A (see fig. 5) (S42). Specifically, the CPU91 determines the upper shaft angle of the upper shaft 15 based on the detection result of the encoder 27A. The CPU91 adds 1 to the variable N every time the needle shaft 11 moves up and down based on the discriminated upper shaft angle (S42). The CPU91 continuously updates the variable N during the sewing operation. The CPU91 starts driving the drive motor (S43) to start the sewing operation.

The CPU91 executes tension acquisition processing (S44). In the tension acquisition process, the CPU91 acquires the upper thread tension based on the detection result of the magnetic sensor 105. The CPU91 judges whether or not any sewing failure of the thread breakage, the stitch skipping, and the thread take-up failure has occurred based on the acquired upper thread tension (S45). When it is determined that the sewing failure has not occurred (S45: NO), the CPU91 shifts the process to S48.

When it is determined that a sewing failure of a certain type has occurred (yes in S45:), the CPU91 determines the type of the sewing failure (S46) and executes a sewing failure processing (see FIG. 10) (S47). As shown in fig. 10, the CPU91 executes the disconnection process (see fig. 11) (S101).

As shown in fig. 11, the CPU91 determines whether or not a thread breakage has occurred based on the sewing failure determined in S46 (see fig. 8) (S111). When it is determined that thread breakage has not occurred (S111: NO), the CPU91 ends the thread breakage processing and returns to the sewing failure processing (FIG. 10). When it is determined that disconnection has occurred (YES in S111), the CPU91 determines whether or not the disconnection non-notification flag is on (S112). When the thread breakage non-notification flag is turned on (yes in S112), the CPU91 ends the thread breakage processing and returns to the sewing failure processing (see fig. 10).

When it is determined that the disconnection non-notification flag is off (S112: NO), the CPU91 adds 1 to the number of times J of detection of disconnection (S113). The CPU91 determines whether or not the updated detection count J is equal to or greater than the disconnection threshold (S114). When the number of detection times J is smaller than the thread breakage threshold value (S114: NO), the CPU91 ends the thread breakage processing and returns to the sewing failure processing (see FIG. 10). When the number of detection times J is equal to or greater than the disconnection threshold (S114: "YES"), the CPU91 stops the driving of the drive motor (S115). The sewing machine 1 stops the sewing operation. The CPU91 notifies the occurrence of a disconnection via the notification section (S116). Specifically, the CPU91 displays a message on the first display unit 25, turns on the disconnection LED200A, and emits a buzzer sound from the speaker 223. The CPU91 ends the thread breakage processing and returns to the sewing failure processing (see fig. 10).

As shown in fig. 10, after the process of the CPU91 at the time of the thread breakage (S101), it is determined whether or not the sewing operation is stopped based on S115 (see fig. 11) (S102). When the sewing operation is judged to be stopped (S102: YES), the CPU91 turns on the stop flag (S108), ends the sewing failure processing, and returns to the sewing processing (see FIG. 8). When determining that the sewing operation is not stopped (NO in S102), the CPU91 executes a stitch skipping process (see FIG. 12) (S103).

As shown in fig. 12, the CPU91 determines whether or not a stitch skipping has occurred based on the sewing failure determined in S46 (see fig. 8) (S121). When it is determined that stitch skipping has not occurred (NO in S121), the CPU91 ends the stitch skipping processing and returns to the sewing failure processing (see FIG. 10). When the skip stitch is determined to have occurred (S121: "YES"), the CPU91 determines whether or not the skip stitch flag is on without notifying it (S122). When it is determined that the skip stitch non-notification flag is on (S122: YES), the CPU91 ends the skip stitch processing and returns to the sewing failure processing (see FIG. 10).

When it is determined that the skip stitch non-notification flag is off (S122: NO), the CPU91 adds 1 to the number of detection times K of the skip stitch (S123). The CPU91 determines whether the updated detection number K is equal to or greater than the stitch skipping threshold (S124). When the detection frequency K is smaller than the stitch skipping threshold (S124: NO), the CPU91 ends the stitch skipping processing and returns to the sewing failure processing (see FIG. 10). When the number of detection times K is equal to or greater than the stitch skipping threshold (S124: "YES"), the CPU91 stops the driving of the drive motor (S125). The sewing machine 1 stops the sewing operation. The CPU91 notifies the occurrence of a stitch jump by the notification section (S126). Specifically, the CPU91 displays a message on the first display unit 25, turns on the jumper LED200B, and sounds a buzzer sound from the speaker 223. The CPU91 ends the stitch skipping processing and returns to the sewing failure processing (see fig. 10).

As shown in fig. 10, after the skip stitch processing (S103), the CPU91 determines whether or not the sewing operation is stopped based on S125 (see fig. 12) (S104). When the sewing operation is judged to be stopped (YES in S104), the CPU91 turns on a stop flag (S108). The CPU91 ends the sewing failure processing and returns to the sewing processing (see fig. 8). When the sewing operation is determined not to be stopped (NO in S104), the CPU91 executes the processing (refer to FIG. 13) of poor thread take-up (S105).

As shown in fig. 13, the CPU91 determines whether a defective take-up occurs based on the sewing failure determined in S46 (see fig. 8) (S131). When it is determined that the thread take-up failure has not occurred (NO in S131), the CPU91 ends the thread take-up failure processing and returns to the sewing failure processing (see FIG. 10). When it is determined that the wire rewinding failure has occurred (YES in S131), the CPU91 determines whether the wire rewinding non-notification flag is on (S132). When the thread take-up non-notification flag is turned on (S132: "YES"), the CPU91 ends the thread take-up failure processing and returns to the sewing failure processing (see FIG. 10).

When the wire rewinding non-notification flag is determined to be off (S132: "NO"), the CPU91 adds 1 to the number L of times of detection of a wire rewinding failure (S133). The CPU91 determines whether the updated detection count L is equal to or greater than the wire-rewinding threshold (S134). When the number of times of detection L is smaller than the thread take-up threshold (S134: NO), the CPU91 ends the thread take-up failure processing and returns to the sewing failure processing (see FIG. 10). When the number of times L of detection is equal to or greater than the wire-rewinding threshold (S134: "YES"), the CPU91 stops the driving of the drive motor (S135). The sewing machine 1 stops the sewing operation. The CPU91 notifies the occurrence of a wire-rewinding failure by the notification section (S136). Specifically, the CPU91 displays a message on the first display unit 25, lights the take-up LED200C, lights the needle bar LED210A, and sounds a buzzer sound from the speaker 223. The CPU91 ends the take-up failure processing and returns to the sewing failure processing (see fig. 10).

As shown in fig. 10, after the processing (S105) of the defective thread take-up, the CPU91 determines whether or not the sewing operation is stopped based on S135 (see fig. 13) (S106). When the sewing operation is judged to be stopped (YES in S106), the CPU91 turns on a stop flag (S108). The CPU91 ends the sewing failure processing and returns to the sewing processing (see fig. 8). When the sewing operation is determined not to be stopped (S106: NO), the CPU91 turns off the stop flag (S107). The CPU91 ends the sewing failure processing and returns to the sewing processing (see fig. 8). As shown in fig. 8, the CPU91 performs a sewing failure processing (S47), and then proceeds to S48.

The CPU91 determines whether the stop flag is on (S48). When determining that the stop flag is on (S48: YES), the CPU91 shifts the process to S63 (refer to FIG. 9). When determining that the stop flag is off (S48: NO), the CPU91 determines whether sewing is finished based on the detection result of the pedal 38 (S49). As the operator continues to step into the pedal 38, the CPU91 continues to receive turn-on signals from the pedal 38. At this time, the CPU91 judges that the sewing operation is not ended (S49: NO). At this time, the CPU91 shifts the process to S44 and executes the tension acquisition process (S44). When the operator releases the pedal 38, the CPU91 receives a close signal from the pedal 38. At this time, the CPU91 determines that the sewing operation is ended (S49: yes), and the process proceeds to S51 (see fig. 9).

As shown in fig. 9, the CPU91 determines whether a tangent signal is received (S51). When the operator instructs to perform the thread cutting by operating the pedal 38, the CPU91 receives a thread cutting signal from the pedal 38. Upon determining that the tangent signal is not received from the pedal 38 (S51: NO), the CPU91 shifts the process to S62. Upon determining that the thread cutting signal is received from the pedal 38 (S51: YES), the CPU91 controls the thread cutting solenoid 17A of the thread cutting mechanism 17 to perform thread cutting (S52).

When the disconnection non-notification flag is off, the CPU91 displays the number of times of detection of disconnection J (1) on the first screen 221A, when the jumper non-notification flag is off, the CPU91 displays the number of times of detection of jumper K (1) on the second screen 221B, and when the take-up non-notification flag is off, the CPU91 displays the number of times of detection of poor take-up L (1) on the third screen 221C (S53). When the disconnection non-notification flag is on, the CPU91 does not display the number of times of detection of disconnection J (1) on the first screen 221A. When the skip stitch non-notification flag is on, the CPU91 does not display the number of times of detection K (1) of skip stitches on the second screen 221B. When the wire rewinding non-notification flag is on, the CPU91 does not display the number of times L (1) of detection of poor wire rewinding on the third screen 221C.

When the operation on the second input unit 222 is accepted, the CPU91 displays the variable N on the second display unit 221 as the number of needles (S53). That is, the CPU91 notifies the operator of the number of times J (1) of broken stitches, the number of times K (1) of skip stitches, and the number of times L (1) of defective take-up stitches in association with the number of stitches. The CPU91 sets the number of detections J (1), the number of detections K (1), and the number of detections L (1) to 0, initializes them (S54), and advances the process to S62.

The CPU91 stops driving of the drive motor (S62). The CPU91 stops the update process of the variable N started in S42 (S63). The CPU91 determines whether there is an operation to turn off the power of the sewing machine 1 (S65). When the operator does not perform the operation of turning off the power of the sewing machine 1 (S65: no), the CPU91 determines whether the initialization signal is received (S66). When the operator performs an operation of designating at least one of a wire breakage, a skip stitch, and a wire rewinding failure to initialize the number of detections through the input unit, the CPU91 receives an initialization signal. Upon determining that the initialization signal has not been received (S66: NO), the CPU91 shifts the process to S69.

Upon determining that the initialization signal is received (S66: YES), the CPU91 shifts the process to S67. When the initialization signal of the number of times J (3) of detection of disconnection is received and the disconnection non-notification flag is off, the CPU91 displays the number of times J (3) of detection of disconnection on the first screen 221A (S67). When the initialization signal of the number of detection times K (3) of the skip pins is received and the skip pin non-notification flag is off, the CPU91 displays the number of detection times K (3) of the skip pins on the second screen 221B (S67). When the initialization signal of the number L (3) of times of defective wire rewinding detection is received and the wire rewinding non-notification flag is off, the CPU91 displays the number L (3) of times of defective wire rewinding detection on the third screen 221C (S67). When the disconnection non-notification flag is on, the CPU91 does not display the number of times of detection of disconnection J (3) on the first screen 221A. When the skip stitch non-notification flag is on, the CPU91 does not display the number of times of detection K (3) of skip stitches on the second screen 221B. When the wire rewinding non-notification flag is on, the CPU91 does not display the number of times L (3) of detection of poor wire rewinding on the third screen 221C. When the operation on the second input unit 222 is accepted, the CPU91 displays the variable N on the second display unit 221 as the number of needles (S67). The CPU91 sets the number of detections J (3), the number of detections K (3), and the number of detections L (3) specified by the initialization signal to 0 to initialize the signals (S68), and the process proceeds to S69.

The CPU91 determines whether the second period signal is received (S69). The second period corresponds to a period in which the number of detections J (2), the number of detections K (2), and the number of detections L (2) are counted. As a specific example of the second period, there is a period of n (n is an integer) sewing operations. When the operator performs an operation for setting the second period through the input unit, the CPU91 receives the second period signal. Upon determining that the second period signal has not been received (S69: NO), the CPU91 shifts the process to S71. When determining that the second period signal has been received (S69: YES), the CPU91 sets a second period in accordance with the operation result of the operator operating the input unit (S70), and the process proceeds to S71.

The CPU91 determines whether the second period set by S70 has elapsed (S71). When determining that the second period has not elapsed (S71: NO), the CPU91 returns the process to S1 (refer to FIG. 6). When determining that the second period has elapsed (S71: "YES"), the CPU91 shifts the process to S72. When the disconnection non-notification flag is off, the CPU91 displays the number of times of detection of disconnection J (2) on the first screen 221A (S72). When the skip-stitch non-notification flag is off, the CPU91 displays the detection frequency K (2) of the skip-stitch on the second screen 221B (S72). When the wire rewinding non-notification flag is off, the CPU91 displays the number of times L (2) of detection of a wire rewinding failure on the third screen 221C (S72). When the disconnection non-notification flag is on, the CPU91 does not display the number of times of detection of disconnection J (2) on the first screen 221A. When the skip stitch non-notification flag is on, the CPU91 does not display the number of times of detection K (2) of skip stitches on the second screen 221B. When the wire rewinding non-notification flag is on, the CPU91 does not display the number of times L (2) of detection of poor wire rewinding on the third screen 221C. When the operation on the second input unit 222 is accepted, the CPU91 displays the variable N on the second display unit 221 as the number of needles (S72). That is, the CPU91 notifies the operator of the number of times J (2) of broken stitches, the number of times K (2) of skip stitches, and the number of times L (2) of defective take-up stitches in association with the number of stitches. The CPU91 sets the number of detections J (2), the number of detections K (2), and the number of detections L (2) to 0, initializes them (S73), and shifts the process to S1 (see fig. 6).

When the operator turns off the power of the sewing machine 1 (S65: "yes"), the CPU91 ends the sewing process.

As described above, the sewing machine 1 can count the number of times of detection of a sewing failure for each type of a sewing failure, that is, a broken thread, a skip stitch, and a take-up failure, and notify the operator of the detection. Therefore, the operator can appropriately handle the sewing machine 1 according to the type of the sewing failure notified by the sewing machine 1.

The sewing machine 1 notifies the operator of the number of times of detection when a sewing failure is detected within a predetermined period (a first period, a second period, and a third period). Therefore, the operator can grasp the number of occurrences of the sewing failure in the predetermined period for each sewing failure category.

The sewing machine 1 notifies the operator of the number of detections counted in any one of a first period after the upper thread 6 and the lower thread are cut by the thread cutting mechanism 17 until the upper thread 6 and the lower thread are cut by the thread cutting mechanism 17 next time, a second period set by the operator via the input unit, and a third period after the operator initializes the number of detections via the input unit until the next operator initializes the number of detections. Therefore, the operator can grasp the number of occurrences of sewing defects in various periods for each type of sewing defect.

The CPU91 turns on the disconnection notification flag, the jumper notification flag, and the take-up notification flag in response to an operation of the input unit by the operator (S4, S6, S8). When the non-notification flag is off, the CPU91 updates the corresponding detection times J, K, and L (S113, S123, and S133). Therefore, the operator can efficiently grasp the number of occurrences of the desired type of sewing failure.

When the number of times of detection of sewing failure is equal to or greater than the corresponding threshold value, the CPU91 stops the sewing operation (S115, S125, S135). In this case, the sewing machine 1 can suppress continuation of sewing in a state where a sewing failure has occurred, and therefore can suppress an influence of the occurrence of the sewing failure on quality degradation. When stopping the sewing operation, the CPU91 notifies the type of the sewing failure (S116, S126, S136). Therefore, the operator can grasp the type of the sewing failure which is a main cause of stopping the sewing operation.

The CPU91 can set corresponding thresholds (S23, S25, S27) corresponding to the number of detections J, the number of detections K, and the number of detections L in accordance with an input operation performed by an operator to the input unit. Therefore, the operator can adjust the condition under which the sewing machine 1 stops the sewing operation according to the number of times of detection of the sewing failure for each type of sewing failure.

When the CPU91 receives an operation on the second input unit 222 with the detection count J, the detection count K, and the detection count L displayed on the second display unit 221, it displays a variable N indicating the number of stitches from the start of sewing. In this case, the operator can grasp the number of occurrences of the sewing failure and the number of stitches for each sewing failure category in association with each other.

The present invention is not limited to the above-described embodiments. As for the method of detecting the sewing failure (thread breakage, stitch skipping, and thread take-up failure) based on the tension of the upper thread 6 in the sewing machine 1, various well-known methods can be applied. The CPU91 may detect sewing defects of other types than broken thread, skip stitch, and take-up defect based on the acquired tension of the upper thread 6. The sewing machine 1 may notify the operator of the number of detections by a method other than the method of displaying the number of detections on the second display unit 221. For example, the sewing machine 1 may display the number of times of detection on the first display unit 25, may continuously flash the thread breakage LED200A, the stitch skipping LED200B, and the thread take-up LED200C of the head amplifier 200, may change the color according to the number of times of detection, or may flash the number of times of detection.

The period in which the CPU91 counts the number of detections is not limited to the first period, the second period, and the third period. The CPU91 may count the number of detection times of a sewing failure detected during a period from the start of the sewing operation to the end of the sewing operation for each type of the sewing failure, or count the number of detection times of the sewing failure detected during a period from the power-on of the sewing machine 1 to the power-off of the sewing machine 1 for each type of the sewing failure.

The CPU91 may not notify that the flag is on when the sewing process is started. The operator may operate the input unit when the count of the number of times of detection of sewing failure is valid. At this time, the CPU91 may turn off the non-notification flag based on a signal received from the input unit. The CPU91 may be configured not to display the number of times of detection on the second display unit 221 when the flag is not turned on, or may be configured to count the number of times of detection of defective sewing.

The manner of notifying the number of detection of defective sewing is not limited to the above embodiment. When the number of times of detection of a sewing failure is equal to or greater than the corresponding threshold value, the CPU91 may notify the type of the corresponding sewing failure without stopping the sewing operation. When the number of times of detection of a sewing failure is equal to or greater than the corresponding threshold value, the CPU91 may stop the sewing operation and not notify the type of the corresponding sewing failure. The sewing machine 1 may store the corresponding threshold value in the storage device 94 in advance. In this case, the corresponding threshold value may not be set by the operator.

The CPU91 may display the number of detections J, K, and L on the second display unit 221, and display a variable N indicating the number of needles from the start of sewing on a separate display unit (e.g., the first display unit 25, a separate display unit provided on the panel unit 220). The CPU91 may alternately display the detection frequency J, the detection frequency K, the detection frequency L, and the variable N on the second display unit 221. The CPU91 may count the variable N for each of the first to third periods. The CPU91 may display the variable N corresponding to the period in which the number of detections J, the number of detections K, and the number of detections L are counted, on the second display unit 221 in association with the number of detections J, the number of detections K, and the number of detections L.

In the thread breakage processing (see fig. 11), when the CPU91 determines that the sewing failure includes thread breakage (S111: yes), the sewing operation may be stopped every time regardless of the number of times of detection J.

The CPU91 when performing the process of S44 is an example of the acquisition unit of the present invention. The CPU91 that performs the process of S45 is an example of the detection unit of the present invention. The CPU91 when performing the processing of S113, S123, and S133 is an example of the first counter unit of the present invention. The number of detection times J is an example of the first time of the present invention. The number of detection times K is an example of the second time of the present invention. The number of detections L is an example of the third number of the present invention. The CPU91 when performing the processing of S53, S67, and S72 is an example of the first notification unit of the present invention. The CPU91 when performing the processing of S4, S6, and S8 is an example of the first setting unit of the present invention. The CPU91 when performing the processing of S112, S122, and S132 is an example of the determination unit of the present invention. The CPU91 for performing the processing of S115, S125, and S135 is an example of the stop unit of the present invention. The CPU91 when performing the processing of S116, S126, and S136 is an example of the second notification unit of the present invention. The CPU91 when performing the processing of S23, S25, and S27 is an example of the second setting unit of the present invention.

Claims

1. A sewing machine is characterized by comprising:

an acquisition unit (91) which acquires the tension of the upper thread;

a detection unit that detects a defective sewing including at least a broken thread, a skip stitch, and a defective take-up thread based on the tension acquired by the acquisition unit;

a first counting unit that counts the number of times the detection unit detects the defective sewing, the first counting unit counting a first number of times the detection unit detects the thread breakage, a second number of times the detection unit detects the stitch skipping, and a third number of times the detection unit detects the defective thread take-up; and

a first notification unit that notifies the first count, the second count, and the third count obtained by the counting by the first counting unit.

2. The sewing machine of claim 1,

the first counting unit counts the number of times of the sewing failure detected by the detecting unit within a predetermined period.

3. The sewing machine of claim 2,

further comprises a cutting mechanism for cutting the upper thread and the lower thread,

the predetermined period is any one of a first period, a second period and a third period,

wherein the first period is a period after the upper thread and the lower thread are cut by the cutting mechanism until the upper thread and the lower thread are cut by the cutting mechanism next time,

the second period is set by the operator via the input unit,

the third period is a period after the operator initializes the number of times via the input unit until the next time the operator initializes the number of times.

4. Sewing machine as in any of claims 1 to 3,

further comprising a first setting unit for setting validity or invalidity of the count of the first count unit for each of the first count, the second count, and the third count,

the first counting unit counts the number of times set to be valid by the first setting unit among the first number of times, the second number of times, and the third number of times,

the first notification unit notifies the number of times the first setting unit has set to be valid, of the first number of times, the second number of times, and the third number of times.

5. The sewing machine according to any one of claims 1 to 4, further comprising:

a determination unit that determines whether or not the first count, the second count, and the third count counted by the first counting unit are equal to or greater than corresponding thresholds;

a stopping section that stops the sewing operation when the determining section determines that at least one of the first frequency, the second frequency, and the third frequency is equal to or greater than the corresponding threshold; and

a second notifying section that notifies the sewing failure corresponding to the first frequency, the second frequency, and the third frequency which are determined by the determining section to be equal to or greater than the corresponding threshold value when the stopping section stops the sewing operation.

6. Sewing machine as in claim 5,

further comprising a second setting unit that sets the corresponding threshold values corresponding to the first number of times, the second number of times, and the third number of times,

the determination unit determines whether or not the first count, the second count, and the third count counted by the first counting unit are equal to or greater than the corresponding thresholds set by the second setting unit.

7. The sewing machine according to any one of claims 1 to 6,

further comprises a second counting part for counting the number of needles from the beginning of the sewing operation,

the first notification unit notifies the first count, the second count, and the third count, which are counted by the first counting unit, in association with the number of needles counted by the second counting unit.