JP2013022362A - Sewing machine and method for controlling sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewing machine and a method for controlling a sewing machine, which can reduce the switching frequency of the rotational direction of a fabric feed motor and can maintain the synchronization between the driving of a main shaft and the driving of a fabric feed mechanism.SOLUTION: The sewing machine includes a main motor for driving a main shaft which vertically moves a sewing needle, and a fabric feed motor for driving a fabric feed mechanism feeding a fabric. A power transmission mechanism provided in the sewing machine converts the rotational movement of an output shaft of the fabric feed motor in one direction and in the opposite direction to one reciprocating swing movement of the fabric feed mechanism in the horizontal direction so as to transmit the power of the fabric feed motor to the fabric feed mechanism. A CPU of the sewing machine detects a main rotational angle which is a rotational angle of an output shaft of the main motor (S11). The CPU detects a fabric feed rotational angle which is a rotational angle of the output shaft of the fabric feed motor (S13 and S19). The CPU uses the main rotational angle and the fabric feed rotational angle to calculate a rotational speed on which the fabric feed motor is instructed (S16 and S22).

Description

  The present invention relates to a sewing machine that drives a main shaft and a cloth feed mechanism with separate motors, and a method for controlling the sewing machine.

  There is a sewing machine in which the main shaft and the cloth feed mechanism are driven by different motors. Since the sewing machine can freely control the cloth feed amount, various patterns can be easily sewn. The sewing machine disclosed in Patent Document 1 connects a feed dog to an output shaft of a cloth feed motor that is a step motor. When the cloth feed motor reciprocates the output shaft once within a range of a predetermined angle, the feed dog reciprocates once in the horizontal direction.

  When the main shaft and the cloth feed mechanism are driven by different motors, the sewing machine needs to keep the drive of the main shaft and the cloth feed mechanism synchronized. The sewing machine disclosed in Patent Document 2 determines the timing for starting cloth feeding based on the rotation speed and rotation phase of the main shaft. Further, the sewing machine corrects the timing for starting the cloth feed based on the cloth feed amount and the acceleration of the spindle. Therefore, the cloth feed is started at an appropriate timing and is finished by the time when the sewing needle comes in contact with the cloth.

JP 54-92444 A JP-A-5-228276

  The conventional sewing machine reciprocates the output shaft of the cloth feed motor once in a predetermined angle range every time the feed dog reciprocates in the horizontal direction. Therefore, the rotation direction of the cloth feed motor must be frequently switched, and the load on the cloth feed motor is large. Further, in the conventional sewing machine, when the operator operates the pedal or the like to change the rotation speed of the spindle during the cloth feeding operation, the cloth feeding speed cannot follow the change in the rotation speed of the spindle, and the driving of the spindle and the cloth The drive mechanism is out of synchronization. If the driving of the main shaft and the driving of the cloth feed mechanism are out of synchronization, the quality of sewing deteriorates. Therefore, the conventional sewing machine cannot reduce the switching frequency of the rotation direction of the cloth feed motor and cannot maintain the synchronization of the drive of the main shaft and the drive of the cloth feed mechanism.

  An object of the present invention is to provide a sewing machine and a sewing machine control method capable of reducing the switching frequency of the rotation direction of the cloth feed motor and maintaining the synchronization of the drive of the main shaft and the drive of the cloth feed mechanism.

  The sewing machine according to the first aspect of the present invention has a main output shaft, a main motor that drives the main shaft that moves the sewing needle up and down by rotating the main output shaft, and a cloth feed output shaft, In a sewing machine including a cloth feed motor that rotates a cloth feed output shaft within a range of a predetermined angle and a cloth feed mechanism that feeds cloth in a horizontal direction, the cloth feed output shaft rotates in one direction and in the opposite direction. A power transmission mechanism that converts the movement operation into a swinging motion in which the cloth feed mechanism swings one reciprocating motion horizontally, and transmits the power of the cloth feed motor to the cloth feed mechanism; and a rotation angle of the main output shaft A main rotation angle detection unit that detects a main rotation angle, a cloth feed rotation angle detection unit that detects a cloth feed rotation angle that is a rotation angle of the cloth feed output shaft, and the main rotation angle detection unit that detects the main rotation angle Using the main rotation angle and the cloth feed rotation angle detected by the cloth feed rotation angle detector A speed calculation unit that calculates a rotation speed instructed to the cloth feed motor, and the cloth feed motor is driven and controlled at the rotation speed calculated by the speed calculation unit, and the cloth feed mechanism is shaken via the power transmission mechanism. A drive control unit that moves.

  The sewing machine according to the first aspect can horizontally drive the cloth feed mechanism twice each time the cloth feed output shaft is reciprocated once. The frequency of switching the rotation direction of the cloth feed motor is reduced as compared with the case where the cloth feed mechanism is driven to reciprocate once every time the cloth feed output shaft is reciprocated. Therefore, the load applied to the cloth feed motor is reduced. The sewing machine can maintain the synchronization between the driving of the main shaft and the driving of the cloth feeding mechanism by calculating the rotation speed using the main rotation angle and the cloth feeding rotation angle. That is, the sewing machine can reduce the switching frequency of the rotation direction of the cloth feed motor, and can appropriately maintain the synchronization of the drive of the main shaft and the drive of the cloth feed mechanism.

  The sewing machine includes a period during which the power transmission mechanism converts one rotation operation in one direction and in the opposite direction of the cloth feed output shaft into one reciprocating swing motion in the cloth feed mechanism. A period determining unit that determines whether the period before the reversal is a period before the swinging direction of the cloth feeding mechanism is reversed and the period after the reversing is a period after the reversing; A change amount determination unit that determines whether or not a change amount of the speed change of the rotation speed calculated by the speed calculation unit is greater than a threshold value when it is determined that it is a period after inversion; A change amount limiting unit configured to calculate a rotation speed at which the change amount is equal to or less than the threshold when the change amount determination unit determines that the change amount is large, and to set the rotation speed after the speed change of the cloth feed motor; May be. In the present invention, the swinging direction of the cloth feed mechanism is reversed while the cloth feed output shaft is rotating in one direction and in the opposite direction at high speed. Therefore, the speed calculation unit may calculate a greatly different speed before and after reversing the swing direction of the cloth feed mechanism. The cloth feed motor receives a large load when a rapid speed change occurs during rotation. The sewing machine of the present invention can set the rotation speed of the cloth feed motor so that the amount of change in the rotation speed is less than or equal to the threshold value. Therefore, the sewing machine can prevent a large load from being applied to the cloth feed motor due to a sudden change in the rotational speed.

  The speed calculation unit, when the period determination unit determines that it is the period before reversal, the main rotation angle detected by the main rotation angle detection unit and the cloth detected by the cloth feed rotation angle detection unit A pre-reverse speed calculation unit that calculates a rotational speed instructed to the cloth feed motor using a feed rotation angle, and the main rotation angle detection unit when the period determination unit determines that the post-reverse period is A reverse rotation speed calculation unit that calculates a rotation speed instructed to the cloth feed motor using the main rotation angle detected by the machine and the cloth feed rotation angle detected by the cloth feed rotation angle detection unit. Also good. The sewing machine calculates the rotation speed of the cloth feed motor separately using the main rotation angle and the cloth feed rotation angle before and after the swing direction of the cloth feed mechanism is reversed. Therefore, the sewing machine calculates the appropriate rotation speed according to each situation (cloth feed amount, cloth feed timing, etc.) before and after the swinging direction of the cloth feed mechanism is reversed, and keeps the two motors synchronized. it can. Since the sewing machine keeps the synchronization of the two motors in both the forward path and the return path of the cloth feeding mechanism, the synchronization of the two motors can be held more reliably.

  The sewing machine sets a target rotation angle at which the cloth feed output shaft should be positioned corresponding to a main rotation angle from the main rotation angle detected by the main rotation angle detector, and The apparatus may further include the target rotation angle set by the cloth feed target angle setting section and the cloth feed deviation calculating section that calculates a deviation between the cloth feed rotation angle detected by the cloth feed rotation angle detecting section. The speed calculation unit may include a first speed calculation unit that calculates the rotation speed based on the deviation. In this case, even if the rotational speed of the main shaft changes, the cloth feed motor rotates in synchronization with the main motor. Therefore, even if the sewing speed changes, the sewing machine can appropriately maintain the synchronization between the driving of the main shaft and the driving of the cloth feeding mechanism. In particular, the sewing machine can properly keep the cloth feed motor and the main motor synchronized even when the main motor stops or when the operator manually rotates the main shaft.

  The sewing machine sets a target rotation angle at which the main output shaft should be positioned corresponding to a cloth feed rotation angle based on the cloth feed rotation angle detected by the cloth feed rotation angle detection unit; and The apparatus may further include a target rotation angle set by the main target angle setting unit and a main deviation calculation unit that calculates a deviation between the main rotation angles detected by the main rotation angle detection unit. The speed calculation unit may include a first speed calculation unit that calculates the rotation speed based on the deviation. In this case, even when the rotational speed of the main shaft changes, the cloth feed motor rotates while maintaining synchronization with the main motor. Therefore, even if the sewing speed changes, the sewing machine can appropriately maintain the synchronization between the driving of the main shaft and the driving of the cloth feeding mechanism. In particular, the sewing machine can properly keep the cloth feed motor and the main motor synchronized even when the main motor stops or when the operator manually rotates the main shaft.

  The sewing machine includes an inversion angle acquisition unit that acquires an inversion angle that is a main rotation angle at which the main output shaft should be positioned when the cloth feed mechanism reaches the inversion position in the swing direction next time, and the inversion angle acquisition unit includes A main rotation angle remaining amount calculation unit that calculates a remaining rotation angle until the main output shaft reaches the inversion angle based on the acquired reversal angle and the main rotation angle detected by the main rotation angle detection unit; A speed acquisition unit that acquires a main rotation speed that is a rotation speed of the main motor, the remaining rotation angle calculated by the main rotation angle remaining amount calculation unit, and the main rotation speed acquired by the speed acquisition unit. Based on the time calculation unit that calculates the time required for the main output shaft to reach the reversal angle, and the cloth feed rotation angle detected by the cloth feed rotation angle detection unit, the cloth feed mechanism is in the reversal position. The remaining number of times of the cloth feed motor until it reaches Corners may further comprise a cloth feed rotation angle remaining amount calculating section for calculating a. The speed calculation unit calculates the rotation speed necessary for the cloth feed motor to rotate in the required time calculated by the time calculation unit based on the remaining rotation angle calculated by the cloth feed rotation angle remaining amount calculation unit. You may provide the 2nd speed calculation part to calculate. In this case, the time when the cloth feed mechanism reaches the reverse position coincides with the time when the output shaft of the main motor reaches the reverse angle. Therefore, even if the sewing speed changes, the sewing machine can appropriately maintain the synchronization between the driving of the main shaft and the driving of the cloth feeding mechanism. In particular, even when the speed of the main shaft is increasing, the sewing machine can accurately keep the two motors synchronized.

  The sewing machine includes an inversion angle acquisition unit that acquires an inversion angle that is a main rotation angle at which the main output shaft should be positioned when the cloth feed mechanism reaches the inversion position in the swing direction next time, and the inversion angle acquisition unit includes A main rotation angle remaining amount calculation unit that calculates a remaining rotation angle until the main output shaft reaches the inversion angle based on the acquired reversal angle and the main rotation angle detected by the main rotation angle detection unit; A speed acquisition unit that acquires a main rotation speed that is a rotation speed of the main motor, the remaining rotation angle calculated by the main rotation angle remaining amount calculation unit, and the main rotation speed acquired by the speed acquisition unit. Based on the time calculation unit that calculates the time required for the main output shaft to reach the reversal angle, and the cloth feed rotation angle detected by the cloth feed rotation angle detection unit, the cloth feed mechanism is in the reversal position. The remaining number of times of the cloth feed motor until it reaches Corners may further comprise a cloth feed rotation angle remaining amount calculating section for calculating a. The speed calculation unit calculates the rotation speed necessary for the cloth feed motor to rotate in the required time calculated by the time calculation unit based on the remaining rotation angle calculated by the cloth feed rotation angle remaining amount calculation unit. You may further provide the 2nd speed calculation part to calculate. The drive control unit includes a speed determination unit that determines whether or not the main rotation speed acquired by the speed acquisition unit is equal to or less than a predetermined value, and the speed determination unit that determines that the main rotation speed is equal to or less than the predetermined value. Is determined, the low speed driving unit that drives the cloth feed motor at the rotation speed calculated by the first speed calculation unit, and the speed determination unit determines that the main rotation speed is greater than the predetermined value. In this case, a high-speed drive unit that drives the cloth feed motor based on at least the rotation speed calculated by the second speed calculation unit may be further provided.

  The sewing machine can calculate the rotation speed (first speed) of the cloth feed motor in accordance with the deviation between the rotation angle at which the output shaft should be positioned and the rotation angle at which the output shaft is actually positioned. Further, the sewing machine can calculate the rotation speed (second speed) of the cloth feed motor based on the rotation speed of the main motor. According to the first speed, the sewing machine can appropriately keep the cloth feed motor and the main motor synchronized even when the main motor is stopped or the operator manually rotates the main shaft. Considering the second speed, the sewing machine can accurately keep the two motors synchronized even when the speed of the spindle is increased. The sewing machine can drive the cloth feed mechanism more appropriately by changing the control method of the cloth feed motor according to the rotation speed of the main motor.

  The speed calculation unit calculates a rotation speed instructed to the cloth feed motor by a specific ratio from the rotation speed calculated by the first speed calculation unit and the rotation speed calculated by the second speed calculation unit. A third speed calculation unit may be further provided. The third speed calculation unit may calculate a rotation speed for driving the cloth feed motor by changing the specific ratio according to the main rotation speed. The high-speed drive unit may drive the cloth feed motor at the rotation speed calculated by the third speed calculation unit when the speed determination unit determines that the main rotation speed is greater than the predetermined value. Good. The sewing machine can calculate the rotational speed of the cloth feed motor by changing the ratio of the first speed suitable for low speed and the second speed suitable for high speed according to the main rotational speed. Therefore, the cloth feed motor can be driven at a rotation speed more suitable for the rotation speed of the main motor.

  The sewing machine may further include a setting unit capable of setting a cloth feed end position in the cloth feed mechanism. The operator can freely set the cloth feed amount. The sewing machine can appropriately control the operation of the cloth feed mechanism according to the cloth feed amount set by the operator.

  The sewing machine control method according to the second aspect of the present invention includes a main motor that has a main output shaft and rotates the main output shaft to drive the main shaft that moves the sewing needle up and down, and a cloth feed output shaft. A cloth feed motor that rotates the cloth feed output shaft within a predetermined angle range, a cloth feed mechanism that feeds the cloth in a horizontal direction, and a power transmission mechanism that transmits the power of the cloth feed motor to the cloth feed mechanism. A main rotation angle detecting step for detecting a main rotation angle that is a rotation angle of the main output shaft, and a cloth feed rotation angle that is a rotation angle of the cloth feed output shaft. The cloth feed rotation angle detecting step to detect, and the power transmission mechanism performs a reciprocating swinging motion in the horizontal direction of the cloth feed mechanism in the one direction and the reverse direction of the cloth feed output shaft. Of the cloth feed mechanism A period determining step for determining whether the period before the reversal is a period before the flat rocking direction is reversed, or a period after the reversing is a period after the reversal; and the period before the reversal in the period determining step Is determined using the main rotation angle detected in the main rotation angle detection step and the cloth feed rotation angle detected in the cloth feed rotation angle detection step, the cloth feed motor is instructed. The main rotation angle detected in the main rotation angle detection step and the cloth feed rotation angle detection when it is determined in the pre-reverse speed calculation step for calculating the rotation speed and the post-reverse period in the period determination step A post-reverse speed calculation step of calculating a rotational speed instructed to the cloth feed motor using the cloth feed rotation angle detected in the step.

  According to the sewing machine control method of the second aspect, the sewing machine can horizontally reciprocate the cloth feed mechanism every time the cloth feed output shaft reciprocates once. The frequency of switching the rotation direction of the cloth feed motor is reduced as compared with the case where the cloth feed mechanism is driven to reciprocate once every time the cloth feed output shaft is reciprocated. Therefore, the load applied to the cloth feed motor is reduced. The sewing machine calculates the rotation speed of the cloth feed motor separately using the main rotation angle and the cloth feed rotation angle before and after the swing direction of the cloth feed mechanism is reversed. Therefore, the sewing machine can calculate an appropriate rotation speed in accordance with each situation (cloth feed amount, cloth feed timing, etc.) before and after the swing direction of the cloth feed mechanism is reversed. The sewing machine can maintain the synchronization between the driving of the main shaft and the driving of the cloth feeding mechanism by calculating the rotation speed using the main rotation angle and the cloth feeding rotation angle. That is, the sewing machine can reduce the switching frequency of the rotation direction of the cloth feed motor, and can appropriately maintain the synchronization of the drive of the main shaft and the drive of the cloth feed mechanism.

The perspective view of the sewing machine 1. FIG. FIG. 3 is an enlarged perspective view in the vicinity of a sewing needle 8 and a needle plate 15. The perspective view which looked at the cloth feed motor 23, the cloth feed mechanism 32, and the power transmission mechanism 35 from diagonally left rear. FIG. 6 is a perspective view of the cloth feed motor 23, the cloth feed mechanism 32, and the power transmission mechanism 35 in a state where the cloth feed output shaft 24 is at an intermediate position in the rotation range. FIG. 6 is a perspective view of the cloth feed motor 23, the cloth feed mechanism 32, and the power transmission mechanism 35 in a state where the cloth feed output shaft 24 is at the front end of the rotation range. FIG. 6 is a perspective view of the cloth feed motor 23, the cloth feed mechanism 32, and the power transmission mechanism 35 in a state where the cloth feed output shaft 24 (see FIGS. 3 to 5) is at the rear end of the rotation range. FIG. 2 is a block diagram showing an electrical configuration of the sewing machine 1. 6 is a flowchart of a cloth feed amount setting process executed by the sewing machine 1; The flowchart of the 1st speed control process which the sewing machine 1 of 1st embodiment performs. 6 is a flowchart of an operation confirmation process executed by the sewing machine 1; The flowchart of the 2nd speed control process which the sewing machine 1 of 2nd embodiment performs. The flowchart of the 3rd speed control process which the sewing machine 1 of 3rd embodiment performs. The flowchart of the 4th speed control process which the sewing machine 1 of 4th embodiment performs. The flowchart of the 1st speed calculation process performed during a 4th speed control process. The flowchart of the 2nd speed calculation process performed during a 4th speed control process.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The configuration of the sewing machine 1 will be described with reference to FIGS. The upper side, lower side, right side, left side, front side, and rear side of FIG. 1 are the upper side, lower side, right side, left side, front side, and rear side of the sewing machine 1, respectively.

  The sewing machine 1 includes a bed 2, a pedestal 3, and an arm 4. The bed part 2 is a foundation of the sewing machine 1. The bed 2 is mounted from above on a recess (not shown) on the upper surface of the table 20. The pedestal 3 extends vertically upward from the right end of the bed 2. The arm portion 4 extends leftward from the upper end of the pedestal column portion 3. The arm part 4 faces the upper surface of the bed part 2. The arm portion 4 is provided with a presser foot 17 below the left end portion. The arm portion 4 holds a needle bar 7 therein. The needle bar 7 has a sewing needle 8 (see FIG. 2) attached to the lower end. The needle bar 7 and the sewing needle 8 reciprocate up and down as the main motor 13 is driven. The arm portion 4 includes a balance 9 in front of the left end portion. The balance 9 moves up and down in conjunction with the needle bar 7. The arm unit 4 includes an operation unit 10 at the top. The operation unit 10 includes a liquid crystal panel 11 on the front surface. The operator operates the operation unit 10 while looking at the liquid crystal panel 11 and inputs various instructions to the sewing machine 1.

  The sewing machine 1 includes a control device 30 on the lower surface of the table 20. The control device 30 is connected to a stepping pedal 22 via a rod 21. The operator operates the pedal 22 to the toe side or the heel side. The control device 30 controls the operation of the sewing machine 1 according to the operation direction and the operation amount of the pedal 22.

  The pedestal 3 has a main motor 13 at the upper right side. The arm portion 4 includes a main shaft 14 inside. The main shaft 14 extends in the left-right direction inside the arm portion 4 in a rotatable state. The right end of the main shaft 14 is connected to the main motor 13. The left end of the main shaft 14 is connected to a needle bar vertical movement mechanism (not shown). The main motor 13 drives the main shaft 14 to move the needle bar 7 and the balance 9 up and down.

  As shown in FIG. 2, the bed portion 2 includes a needle plate 15 at the upper left end. The needle plate 15 has a needle hole 18 in a substantially central portion. The lower end of the sewing needle 8 passes through the needle hole 18 when lowered. The needle plate 15 is provided with a feed dog hole 19 on each of the left, rear and right sides of the needle hole 18. The feed dog hole 19 is a rectangular hole that is long in the front-rear direction. The bed 2 has a hook mechanism (not shown), a cloth feed motor 23 (see FIGS. 3 to 7), a cloth feed mechanism 32 (see FIGS. 3 to 6), and a power transmission mechanism 35 (see FIG. 3) below the needle plate 15. To FIG. 6).

  The cloth feed motor 23, the cloth feed mechanism 32, and the power transmission mechanism 35 will be described with reference to FIG. The upper side, the lower side, the left rear side, the right front side, the right rear side, and the left front side of FIG. 3 are the upper side, the lower side, the right side, the left side, the front side, and the rear side of the sewing machine 1, respectively. As shown in FIG. 3, the cloth feed motor 23 is arranged on the right side of the cloth feed mechanism 32. A cloth feed output shaft 24 of the cloth feed motor 23 extends leftward from the motor body. The cloth feed motor 23 is a step motor, and can rotate the cloth feed output shaft 24 within a range of a predetermined angle. The cloth feed motor 23 moves the cloth feed mechanism 32 in the front-rear direction.

  The cloth feed mechanism 32 includes a feed base 34 and a feed dog 33. The feed base 34 is located below the needle plate 15 (see FIG. 2) and is parallel to the needle plate 15. The feed base 34 includes a feed dog 33 near the center of the upper surface. The feed dog 33 corresponds to the position of the feed dog hole 19 (see FIG. 2). The feed dog 33 is long in the front-rear direction. The length of the feed dog 33 in the front-rear direction is shorter than the length of the feed dog hole 19. The feed dog 33 is provided with irregularities on the upper part for sandwiching the cloth with the presser foot 17 (see FIG. 2).

  The power transmission mechanism 35 includes a horizontal feed shaft 36, a first arm portion 37, a working arm portion 38, a second arm portion 39, and a connection portion 40. The horizontal feed shaft 36 is rotatably held at the upper left of the cloth feed motor 23. The horizontal feed shaft 36 extends in the left-right direction. The first arm portion 37 is connected perpendicularly to the cloth feed output shaft 24. The working arm portion 38 is orthogonally connected to the vicinity of the right end of the horizontal feed shaft 36. The horizontal feed shaft 36 rotates as the working arm portion 38 rotates. The second arm portion 39 is connected to the tip of the first arm portion 37 and the tip of the working arm portion 38 in a rotatable state. The connecting portion 40 extends upward from the vicinity of the left end of the horizontal feed shaft 36. The connection part 40 is rotatably connected to the front end part of the feed base 34 of the cloth feed mechanism 32.

  The operation of the power transmission mechanism 35 will be described with reference to FIGS. In the following description, the axis of the cloth feed output shaft 24 is L, the axis of the connecting shaft of the first arm portion 37 and the second arm portion 39 is M, and the connecting shaft of the second arm portion 39 and the working arm portion 38 is Let N be the axis. Each of W <b> 1 to W <b> 3 in FIGS. 4 to 6 indicates the vicinity of the feed dog 33. As described above, the cloth feed motor 23 can rotate the cloth feed output shaft 24 within a range of a predetermined angle. As shown in FIG. 4, the cloth feed output shaft 24 is located at an intermediate position in the rotation range at the time when the cloth feed is started. When the cloth feed output shaft 24 is positioned at an intermediate position in the rotation range, the straight line connecting L and M (straight line LM) and the straight line connecting M and N (straight line MN) are straight in the vertical direction in a side view. Become. Therefore, the distal end portion of the working arm portion 38 (portion connected to the second arm portion 39) is located at the upper end of the movable range. When the distal end portion of the working arm portion 38 is located at the upper end, the upper end portion of the connection portion 40 is located at the front end (the right end portion in FIG. 4) of the movable range. Therefore, the cloth feed mechanism 32 is located at the front end of the movable range.

  When the cloth feed output shaft 24 rotates clockwise from the state shown in FIG. 4, the straight line LM and the straight line MN are bent. The smaller one of the angles formed by the straight line LM and the straight line MN (hereinafter referred to as “inner angle”) gradually decreases. Therefore, the tip of the working arm 38 is lowered. The horizontal feed shaft 36 rotates counterclockwise when viewed from the left side. The cloth feed mechanism 32 moves backward. As shown in FIG. 5, when the cloth feed output shaft 24 reaches one of the two end portions (front end portion) of the rotation range, the inner angles of the straight line LM and the straight line MN become minimum. The tip of the working arm 38 is located at the lower end of the movable range. Therefore, the cloth feed mechanism 32 is located at the rear end of the movable range.

  When the cloth feed output shaft 24 is reversed from the state shown in FIG. 5 and rotated counterclockwise when viewed from the left side, the inner angles of the straight line LM and the straight line MN gradually increase. Therefore, the tip part of the action arm part 38 rises. The cloth feed mechanism 32 moves forward. When the cloth feed output shaft 24 reaches an intermediate position in the rotation range, the cloth feed mechanism 32 returns to the state shown in FIG. 4 and is positioned at the front end of the movable range. When the cloth feed output shaft 24 is further rotated counterclockwise as viewed from the left side from the state shown in FIG. 4, the straight angle LM and the inner angle of the straight line LM decrease again, and the cloth feed mechanism 32 moves rearward. As shown in FIG. 6, when the cloth feed output shaft 24 reaches the rear end of the rotation range, the cloth feed mechanism 32 is located at the rear end of the movable range. As described above, every time the cloth feed output shaft 24 rotates from one end of the rotation range to the other end, the cloth feed mechanism 32 swings back and forth horizontally.

  The power of the cloth feed motor 23 is more easily transmitted to the working arm 38 when the straight line LM and the straight line MN are in a straight line. That is, the load received by the cloth feed motor 23 is smaller when the cloth feed output shaft 24 is rotating in one direction than when the rotation direction is reversed. Therefore, the sewing machine 1 according to the present embodiment smoothly feeds the cloth if the cloth feed output shaft 24 starts the cloth feed at an intermediate position (position shown in FIG. 4) in the middle of the rotation operation in one direction. be able to.

  As shown in FIGS. 3 to 6, the sewing machine 1 includes a vertical feed shaft 27 behind the cloth feed mechanism 32. The vertical feed shaft 27 extends in the left-right direction in a rotatable state. The vertical feed shaft 27 is positioned parallel to the horizontal feed shaft 36. The vertical feed shaft 27 includes a pulley 25 at the right end. The pulley 25 is connected to the main shaft 14 via a timing belt (not shown). The main shaft 14 and the vertical feed shaft 27 rotate while maintaining synchronization. The vertical feed shaft 27 includes an eccentric cam 28 at the left end. The eccentric cam 28 moves the cloth feed mechanism 32 up and down as the vertical feed shaft 27 rotates. In the sewing machine 1, the feed dog 33 and the feed base 34 reciprocate up and down once while the needle bar 7 and the sewing needle 8 reciprocate up and down once. That is, in the sewing machine 1, the vertical movement of the sewing needle 8 and the vertical movement of the feed dog 33 are mechanically synchronized.

  When the feed base 34 is raised, the feed dog 33 protrudes above the needle plate 15 from the feed dog hole 19 (see FIG. 2) and sandwiches the cloth with the presser foot 17. If the cloth has a predetermined thickness or less, the sewing needle 8 does not pierce the cloth while the feed dog 33 is positioned above the needle plate 15. During the execution of sewing, the sewing machine 1 monitors the rotation angle phases of the main motor 13 and the cloth feed motor 23. As will be described in detail later, the sewing machine 1 synchronizes the main motor 13 and the cloth feed motor 23, and while the feed dog 33 is positioned above the needle plate 15, the cloth feed by an amount specified by the sewing program. The motor 23 is driven. Therefore, the cloth moves in the front-rear direction with the sewing needle 8 not pierced. When the feed base 34 is lowered, the feed dog 33 is positioned below the needle plate 15. If the feed dog 33 is positioned below the needle plate 15, the cloth does not move even if the feed dog 33 moves in the front-rear direction. The sewing needle 8 forms a seam on the cloth while the feed dog 33 is positioned below the needle plate 15. As described above, the sewing machine 1 executes the driving of the cloth feeding mechanism 32 in the horizontal direction (in the present embodiment, the front-rear direction) and the driving of the sewing needle 8 with different motors. Therefore, the sewing machine 1 can freely control the amount of horizontal movement of the feed dog 33 during sewing.

  An electrical configuration of the sewing machine 1 will be described with reference to FIG. The control device 30 of the sewing machine 1 includes a CPU 44. The CPU 44 controls the sewing machine 1. The CPU 44 is connected to a ROM 45, a RAM 46, an EEPROM (registered trademark) 47, and an I / O interface (hereinafter referred to as I / O) 48 via a bus. The ROM 45 stores a program for executing a cloth feed amount setting process (see FIG. 8), a speed control process (see FIGS. 9, 11, 12, and 13) and an operation confirmation process (see FIG. 10), which will be described later. The RAM 46 temporarily stores various values necessary for executing the program. The EEPROM 47 is a non-volatile storage device that stores various values.

  The I / O 48 is connected to the pedal 22 and the operation unit 10. The CPU 44 inputs the operation direction and operation amount of the pedal 22. The CPU 44 inputs an operation instruction from the operator from the operation unit 10. The operator can set a cloth feed start position, a cloth feed end position, and a cloth feed return position, which will be described later, by operating the operation unit 10. The I / O 48 is connected to the drive circuits 51-53. The drive circuit 51 drives the liquid crystal panel 11. The drive circuit 52 drives the main motor 13 in accordance with a torque command signal input from the CPU 44. The sewing machine 1 includes a main encoder 55 for detecting a rotation angle phase and a rotation speed of the main motor 13. The main encoder 55 outputs the detection result of the rotation angle phase and rotation speed of the main motor 13 to the I / O 48. The drive circuit 53 drives the cloth feed motor 23 according to the cloth feed drive signal input from the CPU 44. The cloth feed drive signal of the cloth feed motor 23 is a pulse signal. The sewing machine 1 includes a cloth feed encoder 56 for detecting the rotation angle phase and the rotation speed of the cloth feed motor 23. The cloth feed encoder 56 outputs the detection result of the rotation angle phase and the rotation speed of the cloth feed motor 23 to the I / O 48.

  With reference to FIGS. 8-10, the process which the sewing machine 1 of 1st embodiment performs is demonstrated. The CPU 44 of the sewing machine 1 executes the cloth feed amount setting process shown in FIG. 8, the first speed control process shown in FIG. 9, and the operation confirmation process shown in FIG. 10 according to the program stored in the ROM 45. The sewing machine 1 can execute the above three processes in parallel.

  The cloth feed setting process will be described with reference to FIG. In the cloth feed setting process, the sewing machine 1 sets the cloth feed start position, the cloth feed end position, and the cloth feed return position of the cloth feed mechanism 32 (specifically, the feed dog 33) according to the operation of the operation unit 10 by the operator. The cloth feed start position is a position where the cloth feed mechanism 32 is reversed after the cloth feed return is completed and comes into contact with the cloth to start the cloth feed. The cloth feed end position is a position where the cloth feed mechanism 32 ends the cloth feed. The cloth feed return position is a position where the cloth feed mechanism 32 starts to return the cloth feed below the needle plate 15. The cloth feed amount that is the amount of movement of the feed dog 33 in the front-rear direction is determined by setting the cloth feed start position and the cloth feed end position. In the sewing machine 1, the operator sets the cloth feed start position, the cloth feed end position, and the cloth feed return position, respectively, so that the cloth feed motor drive intermediate position, the cloth feed motor drive end position, and the cloth feed position of the cloth feed output shaft 24 are set. The motor drive start position can be obtained respectively. Further, the sewing machine 1 can set the rotation angle of the main motor 13 at the start of driving of the cloth feed motor 23, the rotation angle of the main motor 13 at the intermediate position of driving, and the rotation angle of the main motor 13 at the end position of driving. When the power of the sewing machine 1 is turned on, the CPU 44 starts the cloth feed amount setting process.

  The CPU 44 determines whether or not the operator has input setting values for the cloth feed start position, the cloth feed end position, and the cloth feed return position from the operation unit 10 (S1). If not input (S1: NO), the CPU 44 proceeds to the determination of S9. When the operator operates the operation unit 10 to input each set value (S1: YES), the CPU 44 converts the input value into an angle of the cloth feed output shaft 24. The CPU 44 stores the converted values in the EEPROM 47 to set the cloth feed motor drive start position “STPos”, the cloth feed motor drive intermediate position “CTPos”, and the cloth feed motor drive end position “ENPos” (S2 to S4). . As described above, the cloth feed mechanism 32 starts the cloth feed when the cloth feed output shaft 24 is at the cloth feed motor drive intermediate position “CTPos” (state shown in FIG. 4). When the cloth feed output shaft 24 is at the cloth feed motor drive start position “STPos” and the cloth feed motor drive end position “ENPos”, the cloth feed mechanism 32 is in the state shown in FIG. The CPU 44 sets a cloth feed amount “Pitch” which is a distance from the cloth feed motor drive intermediate position “CTPos” to the cloth feed motor drive end position “ENPos” (S5). In this embodiment, the cloth feed motor drive start position, the cloth feed motor drive intermediate position, the cloth feed motor drive end position, and the cloth feed amount are represented by the angle of the cloth feed output shaft 24. As described above, in this embodiment, every time the cloth feed output shaft 24 rotates once in one way, the cloth feed mechanism 32 swings back and forth horizontally once. Therefore, the sewing machine 1 separately has the cloth feed motor drive start position “STPos”, the cloth feed motor drive intermediate position “CTPos”, and the cloth feed motor drive end position “ENPos” for each of the two rotational directions of the output shaft 24. Set to. The cloth feed motor drive start position, the cloth feed motor drive intermediate position, the cloth feed motor drive end position, and the cloth feed amount may be expressed by other values such as the number of pulses of the cloth feed motor 23. The cloth feed amount may be expressed by an actual movement amount of the cloth feed mechanism 32. A table set in advance based on the sewing program may be used as the cloth feed amount.

  The CPU 44 sets the rotation speed of the output shaft of the main motor 13 (hereinafter referred to as “main output shaft”) (hereinafter referred to as “main rotation angle”) at the time of starting the cloth feed motor drive uniquely determined from the cloth feed motor drive start position. A start angle “FeedStart” which is the main rotation angle is set (S6). The CPU 44 sets an intermediate angle “FeedCenter” which is a main rotation angle uniquely determined from the cloth feed motor drive intermediate position (S7). The CPU 44 sets an end angle “FeedEnd” that is a main rotation angle uniquely determined from the cloth feed motor drive end position (S8). If the operator has not input an instruction to end the process (S9: NO), the CPU 44 returns the process to the determination of S1. When the operator inputs an end instruction (S9: YES), the CPU 44 ends the cloth feed amount setting process.

  The first speed control process will be described with reference to FIG. In the first speed control process, the sewing machine 1 calculates the deviation between the target rotation angle of the cloth feed output shaft 24 and the actual rotation angle. The sewing machine 1 calculates the rotation speed of the cloth feed motor 23 based on the calculated deviation. Therefore, in the sewing machine 1, the rotation speed of the cloth feed motor 23 can follow the change in the rotation speed of the main motor 13. When the power of the sewing machine 1 is turned on, the CPU 44 starts the first speed control process.

  The CPU 44 obtains the current main rotation angle “DDPOS” of the main motor 13 from the main encoder 55 (S11). The CPU 44 determines whether or not the main rotation angle “DDPOS” acquired in S11 is before the intermediate angle “FeedCenter” (S12). In other words, the CPU 44 determines whether or not the main rotation angle “DDPOS” is between the start angle “FeedStart” and the intermediate angle “FeedCenter”.

  If the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” (S12: YES), the CPU 44 calculates the rotation speed of the cloth feed motor 23 in the period before reversal in one cloth feed period (S13). To S17). The one-time cloth feed period is a period in which the power transmission mechanism 35 converts the rotational movement of the cloth feed output shaft 24 in one direction and the opposite direction into one reciprocating swing motion of the cloth feed mechanism 32. The period before reversal is a period before the oscillating direction of the cloth feeding mechanism 32 is reversed in one cloth feeding period. In the cloth feed mechanism 32, the feed dog 33 returns from the cloth feed return position to the cloth feed start position in the period before reversal.

  Specifically, the CPU 44 acquires the current cloth feed rotation angle “RELPOS” of the cloth feed motor 23 from the cloth feed encoder 56 (S13). The CPU 44 sets a target rotation angle “POS1a” that is a cloth feed rotation angle at which the cloth feed output shaft 24 corresponding to the main rotation angle “DDPOS” acquired in S11 is to be positioned (S14). As described above, in the sewing machine 1, the main motor 13 and the cloth feed motor 23 are synchronized. Therefore, the target rotation angle of the cloth feed motor 23 is uniquely determined from the main rotation angle “DDPOS”.

A method for setting the target rotation angle “POS1a” will be described in detail. The CPU 44 calculates an angle “FeedDeg <a>” at which the main output shaft rotates from when the feed dog 33 starts to reverse the cloth feed to when the feed dog 33 reverses by the following equation.
FeedDeg <a> = FeedCenter-FeedStart
Of “FeedDeg <a>”, the percentage of the angle that has already been turned is
(DDPOS-FeedStart) / FeedDeg <a>
It becomes. Therefore, the CPU 44 can calculate the target rotation angle “POS1a” by the following equation.
POS1a = STPos + (CTPos−STPos) (DDPOS−FeedStart) / FeedDeg <a>

  The CPU 44 calculates a deviation between the set target rotation angle “POS1a” and the cloth feed rotation angle “RELPOS” acquired from the cloth feed encoder 56 (S15). Based on the calculated deviation, the CPU 44 calculates the rotational speed “SP1a” instructed to the cloth feed motor 23 (S16). Specifically, the CPU 44 calculates the rotation speed “SP1a” by multiplying the deviation by a preset fixed value count N1a. The CPU 44 outputs a cloth feed driving signal for driving the cloth feed motor 23 at the rotational speed “SP1a” to the drive circuit 53 to drive the cloth feed motor 23 (S17). The CPU 44 returns the process to S11.

  If the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter” (S12: NO), the CPU 44 calculates the rotation speed of the cloth feed motor 23 in the post-reversal period in one cloth feed period (S19 to S19). S28). The period after inversion is a period after the swing direction of the cloth feeding mechanism 32 is reversed in one cloth feeding period. In the cloth feed mechanism 32, the feed dog 33 moves from the cloth feed start position to the cloth feed end position and feeds the cloth in the post-inversion period. The CPU 44 acquires the current cloth feed rotation angle “RELPOS” of the cloth feed motor 23 from the cloth feed encoder 56 (S19). The CPU 44 sets a target rotation angle “POS1b” that is a cloth feed rotation angle at which the cloth feed output shaft 24 corresponding to the main rotation angle “DDPOS” acquired in S11 is to be positioned (S20).

A method for setting the target rotation angle “POS1b” will be described in detail. The CPU 44 calculates an angle “FeedDeg <b>” by which the main output shaft rotates from the time when the feed dog 33 is reversed and starts to feed the cloth to the cloth feed end position by the following formula. .
FeedDeg <b> = FeedEnd-FeedCenter
Of “FeedDeg <b>”, the ratio of the angles that have already been turned is
(DDPOS-FeedCenter) / FeedDeg <b>
It becomes. Therefore, the CPU 44 can calculate the target rotation angle “POS1b” by the following equation.
POS1b = CTPos + Pitch (DDPOS-FeedCenter) / FeedDeg <b>

  The CPU 44 calculates a deviation between the set target rotation angle “POS1b” and the cloth feed rotation angle “RELPOS” acquired from the cloth feed encoder 56 (S21). The CPU 44 calculates the rotational speed “SP1b” by multiplying the calculated deviation by a fixed value count N1b (S22). The fixed value N1b is set in advance according to the characteristics of the cloth feed mechanism 32 and the like. N1a and N1b are set separately.

  The CPU 44 determines whether or not the change amount of the rotational speed “SP1b” calculated in S22 with respect to the speed instructed to the cloth feed motor 23 in any of the previous S17, S25, and S28 is 10% or less of the previous instructed speed. Is determined (S24). The sewing machine 1 may acquire the current rotation speed of the cloth feed motor 23 and determine whether or not the amount of change in “SP1b” with respect to the acquired current rotation speed is 10% or less. The amount of change to be determined is not limited to 10%, and may be a predetermined fixed value. If the amount of change is 10% or less (S24: YES), the CPU 44 drives the cloth feed motor 23 at the rotational speed “SP1b” calculated in S22 (S25). The CPU 44 returns the process to S11. When the change amount is larger than 10% (S24: NO), the CPU 44 calculates the rotation speed “SP1c” so that the change amount is 10% or less (S27). Specifically, when the rotation speed “SP1b” is decelerated from the previous instruction speed, the CPU 44 calculates the rotation speed “SP1c” by multiplying the previous instruction speed by 0.9. When the rotation speed “SP1b” accelerates from the previous instruction speed, the CPU 44 calculates the rotation speed “SP1c” by multiplying the previous instruction speed by 1.1. The CPU 44 drives the cloth feed motor 23 at the rotational speed “SP1c” calculated in S27 (S28). Therefore, the sewing machine 1 can appropriately prevent the instruction speed from changing suddenly before and after the swinging direction of the cloth feed mechanism 32 is reversed. When the swinging direction of the cloth feed mechanism 32 is reversed, the feed dog 33 of the cloth feed mechanism 32 protrudes above the needle plate 15 and starts to move from the cloth feed start position to the cloth feed end position. Accordingly, the sewing machine 1 can prevent the rotational speed of the cloth feed motor 23 from changing suddenly when starting the cloth feed. The CPU 44 returns the process to S11. The first speed control process ends when the power of the sewing machine 1 is turned off.

  The operation confirmation process will be described with reference to FIG. In the operation confirmation processing, the sewing machine 1 confirms whether or not the main motor 13 and the cloth feed motor 23 are synchronized, and performs error processing if they are not synchronized. When the power of the sewing machine 1 is turned on, the CPU 44 starts an operation confirmation process.

  The CPU 44 acquires the current main rotation angle “DDPOS” of the main motor 13 from the main encoder 55 (S31). CPU44 judges the setting content of the operation confirmation timing which the operator performed beforehand (S32, S33).

  In the sewing machine 1 of the present embodiment, the operator can set the operation confirmation timing by operating the operation unit 10. The operation confirmation timing includes a constant confirmation and a predetermined position confirmation. In the constant confirmation, the operation is confirmed at every predetermined interval (for example, the interval at which the CPU 44 performs the processing of S31 to S44 or the predetermined time according to the number of clocks of the CPU 44). In the constant check, the sewing machine 1 can check the operation more accurately. The predetermined position confirmation is performed when the feed dog 33 of the cloth feed mechanism 32 reaches a predetermined operation confirmation position. In the predetermined position confirmation, the sewing machine 1 can efficiently confirm the operation at a necessary timing, and the processing load on the CPU 44 is reduced.

  When the operator confirms the predetermined position, the operator can set an operation confirmation position of either a default position or an arbitrary position. When the predetermined confirmation position is set to the default position, the operation confirmation position is a position where the feed dog 33 of the cloth feed mechanism 32 is raised and lowered from the plate surface of the needle plate 15. The cloth feed mechanism 32 feeds the cloth in a state where the feed dog 33 is above the needle plate 15. Therefore, the synchronization of the two motors 13 and 23 is particularly important at the position where the feed dog 33 is raised and lowered from the needle plate 15. By setting the predetermined confirmation position to the default position, the sewing machine 1 can efficiently confirm the operation at a particularly important timing.

  When the predetermined confirmation position is set to an arbitrary position, the operator operates the operation unit 10 to arbitrarily set the operation confirmation position. The position that can be arbitrarily set by the operator is a position between the cloth feed motor drive intermediate position “CTPos” and the cloth feed motor drive end position “ENPos”. For example, when the cloth is thick, the sewing needle 8 pierces the cloth at an earlier timing than when the cloth is thin. If the predetermined confirmation position is set to the default position when the cloth is thick, the sewing needle 8 may pierce the cloth before reaching the position where the feed dog 33 of the cloth feed mechanism 32 descends from the plate surface of the needle plate 15. Therefore, when the two motors 13 and 23 are out of synchronization and the lowering of the feed dog 33 is delayed, the cloth moves with the sewing needle 8 stuck. When the cloth moves while the sewing needle 8 is stuck in the cloth, the sewing needle 8 bends. The bent sewing needle 8 does not pass through the needle hole 18 and may contact the upper surface of the needle plate 15 and be damaged. By arbitrarily setting the operation check position at a position that is earlier than the position at which the feed dog 33 descends from the needle plate 15, the sewing machine 1 can check the operation by changing the timing according to the cloth thickness. By setting the predetermined confirmation position to an arbitrary position, the operator can confirm the operation of the sewing machine 1 at a desired confirmation position.

  If the operation confirmation timing is not always confirmed (S32: NO), the CPU 44 determines from the main rotation angle “DDPOS” of the main motor 13 whether the position of the cloth feed mechanism 32 is a predetermined operation confirmation position. (S33). As described above, the sewing machine 1 drives the cloth feed motor 23 so that the cloth feed rotation angle “RELPOS” of the cloth feed motor 23 is synchronized with the main rotation angle “DDPOS” of the main motor 13 (see FIG. 9). The position of the cloth feed mechanism 32 is determined from the cloth feed rotation angle “RELPOS”. Therefore, the sewing machine 1 can determine the position where the cloth feed mechanism 32 should be present from the main rotation angle “DDPOS” of the main motor 13. If the cloth feed mechanism 32 is not at the predetermined operation confirmation position (S33: NO), the CPU 44 returns the process to S31.

  When the setting of the operation confirmation timing is always confirmation (S32: YES), or when the cloth feed mechanism 32 is at the predetermined operation confirmation position (S33: YES), the CPU 44 acquires the current main rotation angle “ It is determined whether or not “DDPOS” is before the intermediate angle “FeedCenter” (S34). If it is before the intermediate angle “FeedCenter” (S34: YES), the CPU 44 acquires the cloth feed rotation angle “RELPOS” from the cloth feed encoder 56 (S36). The CPU 44 sets the target rotation angle “POS1a” of the cloth feed output shaft 24 corresponding to the main rotation angle “DDPOS” acquired in S31 (S37). The setting method of “POS1a” is the same as S14 (see FIG. 6) described above. The CPU 44 calculates a deviation between the set target rotation angle “POS1a” and the cloth feed rotation angle “RELPOS” acquired in S36 (S38).

  The CPU 44 determines whether or not the calculated deviation is equal to or less than a threshold value (S39). The threshold can be set arbitrarily. The threshold value may be a value that can be changed by the operator operating the operation unit 10. If the deviation is equal to or smaller than the threshold (S39: YES), the CPU 44 determines that the main motor 13 and the cloth feed motor 23 are synchronized, and returns the process to S31. If the deviation is larger than the threshold value (S39: NO), the CPU 44 displays on the liquid crystal panel 11 an error screen indicating that the two motors 13, 23 are out of synchronization (S46). Therefore, the operator can easily grasp that the two motors 13 and 23 are out of synchronization and take appropriate measures. In S46, the CPU 44 may output an error sound from the speaker to notify the error. The CPU 44 stops driving the main motor 13 and the cloth feed motor 23 (S47) and ends the operation confirmation process.

  When the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter” (S34: NO), the CPU 44 acquires the cloth feed rotation angle “RELPOS” (S41). The CPU 44 sets the target rotation angle “POS1b” of the cloth feed output shaft 24 corresponding to the main rotation angle “DDPOS” acquired in S31 (S42). The setting method of “POS1b” is the same as S20 (see FIG. 9) described above. The CPU 44 calculates a deviation between the set target rotation angle “POS1b” and the cloth feed rotation angle “RELPOS” acquired in S41 (S43).

  The CPU 44 determines whether or not the calculated deviation is equal to or less than a threshold value (S44). The threshold can be set arbitrarily. When the cloth feeding mechanism 32 is in contact with the cloth and performs cloth feeding, the sewing machine 1 is synchronized more strictly than when the cloth feeding is finished and the cloth feeding mechanism 32 is moved from the cloth feeding return position to the cloth feeding start position. Should be retained. Therefore, it is desirable to set the threshold value when the cloth feed mechanism 32 performs the cloth feed to a value smaller than the threshold value when the cloth feed mechanism 32 moves from the cloth feed return position to the cloth feed start position. If the deviation is less than or equal to the threshold (S44: YES), the CPU 44 returns the process to S31. If the deviation is larger than the threshold (S44: NO), the CPU 44 displays an error screen (S46), stops driving the two motors 13 and 23 (S47), and ends the process. The cloth feed amount setting process (see FIG. 8), the first speed control process (see FIG. 9), and the operation confirmation process (see FIG. 10) are finished when the power of the sewing machine 1 is turned off.

  As described above, the sewing machine 1 of the first embodiment can horizontally drive the cloth feed mechanism 32 twice each time the cloth feed output shaft 24 is reciprocated once. The frequency of switching the rotation direction of the cloth feed motor 23 is reduced as compared with the case where the cloth feed mechanism 32 is driven to reciprocate once every time the cloth feed output shaft 24 is reciprocated. Therefore, the load applied to the cloth feed motor 23 is reduced. The sewing machine 1 can maintain the synchronization of the drive of the main shaft 14 and the drive of the cloth feed mechanism 32 by calculating the rotation speed using the main rotation angle and the cloth feed rotation angle. The sewing machine 1 can reduce the switching frequency of the rotation direction of the cloth feed motor 23 and can appropriately maintain the drive synchronization of the main shaft 14 and the cloth feed mechanism 32.

  In the present invention, the swinging direction of the cloth feed mechanism 32 is reversed while the cloth feed output shaft 24 is rotating in one direction and in the opposite direction at high speed. The sewing machine 1 may calculate different speeds before and after reversing the swing direction of the cloth feed mechanism 32. The cloth feed motor 23 receives a large load when a rapid speed change occurs during rotation. The sewing machine 1 of the present embodiment can set the rotation speed of the cloth feed motor 23 so that the amount of change in the rotation speed is equal to or less than the threshold value. Therefore, the sewing machine 1 can prevent a large load from being applied to the cloth feed motor 23 due to a sudden change in the rotational speed.

  The sewing machine 1 calculates the rotation speed instructed to the cloth feed motor 23 by using the main rotation angle “DDPOS” and the cloth feed rotation angle “RELPOS” before and after the swinging direction of the cloth feed mechanism 32 is reversed. . Therefore, the sewing machine 1 can calculate an appropriate rotation speed according to each situation (cloth feed amount, cloth feed timing, etc.) before and after the swing direction of the cloth feed mechanism 32 is reversed. Since the sewing machine keeps the synchronization of the two motors 13 and 23 both in the forward path and the return path of the cloth feed mechanism 32, the synchronization of the two motors 13 and 23 can be held more reliably.

  The sewing machine 1 of the first embodiment sets a target rotation angle “POS1a / POS1b” at which the cloth feed output shaft 24 should be positioned from the main rotation angle “DDPOS” of the main motor 13. The sewing machine 1 calculates a deviation between the set target rotation angle “POS1 / POS1b” and the actual cloth feed rotation angle “RELPOS” of the cloth feed motor 23. The sewing machine 1 calculates the rotation speed of the cloth feed motor 23 based on the calculated deviation. Even when the rotation speeds of the main motor 13 and the main shaft 14 are changed, the cloth feed motor 23 is driven in synchronization with the main motor 13. Therefore, the sewing machine 1 can maintain the synchronization of the driving of the main shaft 14 and the driving of the cloth feeding mechanism 32 even if the sewing speed changes.

  The sewing machine 1 of the first embodiment can calculate the rotation speed of the cloth feed motor 23 without using the rotation speed of the main motor 13. Therefore, the sewing machine 1 of the first embodiment can appropriately keep the cloth feed motor 23 and the main motor 13 synchronized even when the main motor 13 is stopped or when the operator manually rotates the main shaft 14. In the sewing machine 1, the operator can freely set the cloth feed motor drive start position, the cloth feed motor drive intermediate position, the cloth feed motor drive end position, and the cloth feed amount. The sewing machine 1 can drive the cloth feed motor 23 at an appropriate speed according to the set value.

  In the first embodiment, the CPU 44 that acquires the main rotation angle in S11 of FIG. 9 functions as a main rotation angle detection unit. The CPU 44 that acquires the cloth feed rotation angle in S13 and S19 of FIG. 9 functions as a cloth feed rotation angle detection unit. The CPU 44 that calculates the rotation speed of the cloth feed motor 23 in S16 and S22 of FIG. 9 functions as a speed calculation unit. The CPU 44 that drives and controls the cloth feed motor in S17, S25, and S28 of FIG. 9 functions as a drive control unit.

  The CPU 44 that determines whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” in S12 of FIG. 9 functions as a period determination unit. The CPU 44 that determines the amount of change in rotational speed in S24 of FIG. 9 functions as a change amount determination unit. The CPU 44 that sets the rotation speed whose change amount is equal to or less than the threshold value in S27 of FIG. 9 as the rotation speed of the cloth feed motor 23 functions as a change amount limiting unit. The CPU 44 that calculates the rotation speed of the cloth feed motor 23 in S16 of FIG. 9 functions as a pre-reverse speed calculation unit. The CPU 44 that calculates the rotation speed of the cloth feed motor 23 in S22 of FIG. 9 functions as a post-reverse speed calculation unit. The CPU 44 that sets the target rotation angle in S14 and S20 of FIG. 9 functions as a cloth feed target angle setting unit. The CPU 44 that calculates the deviation in S15 and S21 in FIG. 9 functions as a cloth feed deviation calculation unit. The CPU 44 that performs the cloth feed amount setting process of FIG. 8 functions as a setting unit. The CPU 44 that calculates the rotation speed of the cloth feed motor 23 based on the deviation in S16 and S22 of FIG. 9 functions as a first speed calculation unit.

  The process of acquiring the main rotation angle in S11 of FIG. 9 corresponds to a main rotation angle detection step. The process of acquiring the cloth feed rotation angle in S13 and S19 of FIG. 9 corresponds to the cloth feed rotation angle detection step. The process of determining whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” in S12 of FIG. 9 corresponds to a period determination step. The process of calculating the rotation speed of the cloth feed motor 23 in S13 to S16 in FIG. 9 corresponds to a pre-reverse speed calculation step. The process of calculating the rotation speed of the cloth feed motor 23 in S19 to S22 of FIG. 9 corresponds to a post-reverse speed calculation step.

  The second embodiment of the present invention will be described with reference to FIG. The sewing machine 1 of the second embodiment sets the target rotation angle of the main output shaft of the main motor 13 from the current cloth feed rotation angle of the cloth feed output shaft 24. The sewing machine 1 calculates the deviation between the set target rotation angle of the main output shaft and the actual main rotation angle, and calculates the rotation speed of the cloth feed motor 23. The sewing machine 1 according to the first embodiment described above sets the target rotation angle of the cloth feed output shaft 24 and calculates the rotation speed. The sewing machine 1 of the second embodiment is different from the sewing machine 1 of the first embodiment only in that the target rotation angle of the main output shaft is used. The mechanical configuration, the electrical configuration, and the cloth feed amount setting process (see FIG. 8). ), The operation confirmation process (see FIG. 10) and the like are the same as those in the first embodiment. Therefore, in description of 2nd embodiment, the same number is attached | subjected to the same structure and process as the sewing machine 1 of 1st embodiment, and description is abbreviate | omitted or simplified.

  When the power of the sewing machine 1 is turned on, the CPU 44 starts the second speed control process. The CPU 44 acquires the main rotation angle “DDPOS” of the main output shaft (S11). The CPU 44 determines whether or not the main rotation angle “DDPOS” acquired in S11 is before the intermediate angle “FeedCenter” (S12). If “DDPOS” is earlier than “FeedCenter” (S12: YES), the CPU 44 acquires the cloth feed rotation angle “RELPOS” (S13).

The CPU 44 sets a target rotation angle “POS2a” that is a main rotation angle at which the main output shaft of the main motor 13 corresponding to the cloth feed rotation angle “RELPOS” acquired in S13 is to be positioned (S114). A method for setting the target rotation angle “POS2a” will be described in detail. The angle at which the cloth feed output shaft 24 rotates while the feed dog 33 moves in the front-rear direction is (CTPos-STPos). Of (CTPos-STPos), the ratio of the angles at which the rotation has already ended is (RELPOS-STPos) / (CTPos-STPos). The CPU 44 can calculate the target rotation angle “POS2a” by the following equation.
POS2a = FeedStart + (FeedCenter-FeedStart) (RELPOS-STPos) / (CTPos-STPos)

  The CPU 44 calculates a deviation between the set target rotation angle “POS2a” and the main rotation angle “DDPOS” acquired from the main encoder 55 (S115). The CPU 44 calculates a conversion value for calculating the rotation speed instructed to the cloth feed motor 23 based on the deviation calculated in S115 (S116). Specifically, the CPU 44 multiplies the deviation by (FeedCenter-FeedStart) / (CTPos-STPos), which corresponds to the deviation between the target rotation angle at which the cloth feed output shaft 24 should be positioned and the cloth feed rotation angle “RELPOS”. The deviation calculated in S115 is converted into a value to be processed. The CPU 44 calculates the rotational speed “SP1a” instructed to the cloth feed motor 23 based on the conversion value calculated in S116 (S16). Specifically, the CPU 44 calculates the rotation speed “SP1a” by multiplying the converted value by the count N1a. The CPU 44 drives the cloth feed motor 23 at the calculated rotation speed “SP1a” (S17). The CPU 44 returns the process to S11.

If the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter” (S12: NO), the CPU 44 acquires the current cloth feed rotation angle “RELPOS” (S19). The CPU 44 calculates and sets the target rotation angle “POS2b” of the main output shaft corresponding to the cloth feed rotation angle “RELPOS” acquired in S19 using the following equation (S120).
POS2b = FeedCenter + (FeedEnd−FeedCenter) (RELPOS−CTPos) / Pitch

  The CPU 44 calculates a deviation between the set target rotation angle “POS2b” and the main rotation angle “DDPOS” (S121). The CPU 44 converts the deviation by multiplying the deviation calculated in S121 by (FeedEnd−FeedCenter) / Pitch (S122). The CPU 44 calculates the rotation speed “SP1b” by multiplying the converted value by the count N1b (S22).

  The CPU 44 determines whether or not the amount of change in the rotational speed “SP1b” with respect to the speed previously instructed to the cloth feed motor 23 is 10% or less of the previous instructed speed (S24). If the amount of change is 10% or less (S24: YES), the CPU 44 drives the cloth feed motor 23 at the rotational speed “SP1b” (S25). The CPU 44 returns the process to S11. When the amount of change is greater than 10% (S24: NO), the CPU 44 calculates the rotational speed “SP1c” at which the amount of change is 10% or less (S27). The CPU 44 drives the cloth feed motor 23 with “SP1c” (S28), and returns the process to S11. The second speed control process ends when the power of the sewing machine 1 is turned off.

  As described above, the sewing machine 1 according to the second embodiment sets the target rotation angle “POS2a / POS2b” of the main output shaft from the cloth feed rotation angle “RELPOS”. The sewing machine 1 calculates a deviation between the set target rotation angle and the actual main rotation angle “DDPOS”. The sewing machine 1 calculates the rotation speed of the cloth feed motor 23 based on the calculated deviation. Even when the rotation speeds of the main motor 13 and the main shaft 14 change, the cloth feed motor 23 rotates while maintaining synchronization with the main motor 13. Therefore, the sewing machine 1 can maintain the synchronization of the driving of the main shaft 14 and the driving of the cloth feeding mechanism 32 even if the sewing speed changes. In particular, the sewing machine 1 according to the second embodiment can appropriately keep the cloth feed motor 23 and the main motor 13 synchronized even when the main motor 13 is stopped or when the operator manually rotates the main shaft 14.

  In the second embodiment, the CPU 44 that sets the target rotation angle in S114 and S120 of FIG. 11 functions as a main target angle setting unit. The CPU 44 that calculates the deviation in S115 and S121 in FIG. 11 functions as a main deviation calculation unit. The CPU 44 that calculates the rotation speed of the cloth feed motor 23 based on the deviation in S16 and S22 of FIG. 11 functions as a first speed calculation unit.

  A third embodiment of the present invention will be described with reference to FIG. The sewing machine 1 of the third embodiment calculates the time required until the main output shaft of the main motor 13 reaches the intermediate angle “FeedCenter” or the terminal angle “FeedEnd” (corresponding to the reversal angle of the present invention). The intermediate angle “FeedCenter” is a main rotation angle at which the main output shaft should be positioned when the cloth feed mechanism 32 is reversed at the cloth feed start position and starts the cloth feed. The end angle “FeedEnd” is a main rotation angle at which the main output shaft should be positioned when the cloth feed mechanism 32 reaches the position where the cloth feed mechanism 32 finishes the cloth feed and reverses the swinging direction (cloth feed return position). The sewing machine 1 calculates the remaining rotation angle of the cloth feed output shaft 24 until the cloth feed mechanism 32 next reaches the cloth feed start position or the cloth feed return position. The sewing machine 1 calculates the rotation speed for the cloth feed motor 23 to rotate the remaining rotation angle in the calculated required time. The sewing machine 1 of the third embodiment is different from the first and second embodiments only in that the third speed control process is executed instead of the first speed control process and the second speed control process. Therefore, in description of 3rd embodiment, the same number is attached | subjected to the structure and process same as the sewing machine 1 of 1st, 2nd embodiment, and description is abbreviate | omitted or simplified.

  When the power of the sewing machine 1 is turned on, the CPU 44 starts the third speed control process. The CPU 44 acquires the main rotation angle “DDPOS” of the main motor 13 from the main encoder 55 (S51). The CPU 44 determines whether or not the main rotation angle “DDPOS” acquired in S51 is before the intermediate angle “FeedCenter” (S52). That is, the CPU 44 determines whether or not the main rotation angle “DDPOS” is between the start angle “FeedStart” and the intermediate angle “FeedCenter”.

  When it is before the intermediate angle “FeedCenter” (S52: YES), the CPU 44 calculates the rotation speed of the cloth feed motor 23 in the period before reversal (S53 to S59). Specifically, the CPU 44 acquires an intermediate angle “FeedCenter”, which is the main rotation angle when the cloth feed mechanism 32 reaches the cloth feed start position, from the EEPROM 47 (S53). The CPU 44 subtracts the current main rotation angle “DDPOS” from the intermediate angle “FeedCenter” to calculate the remaining rotation angle “RemMa” until the main output shaft reaches the intermediate angle “FeedCenter” (S54).

The CPU 44 acquires the rotational speed “DDSspeed (unit: rpm)” of the main motor 13 (S55). The rotation speed is a rotation speed detection process (not shown) executed in parallel with the third speed control process, and the change amount (unit: rotation speed) of the main rotation angle acquired from the main encoder 55 is sampled (unit: minute). ). The CPU 44 calculates a required time Ta (unit: minute) until the main output shaft of the main motor 13 reaches the intermediate angle “FeedCenter” by the following formula (S56).
Ta = RemMa / (360 · DDSspeed)

The CPU 44 acquires the current cloth feed rotation angle “RELPOS” of the cloth feed motor 23 from the cloth feed encoder 56 (S57). The CPU 44 subtracts the current cloth feed rotation angle “RELPOS” from the cloth feed motor drive intermediate position “CTPos”, thereby remaining rotation angle “RemFa” until the cloth feed output shaft 24 reaches the cloth feed motor drive intermediate position. Is calculated (S58). The CPU 44 calculates the rotational speed “SP2a” necessary for the cloth feed motor 23 to rotate the remaining rotational angle “RemFa” by the required time Ta using the following equation (S59).
SP2a = RemFa / (360 · Ta)
The CPU 44 drives the cloth feed motor 23 at the calculated rotation speed “SP2a” (S60). The CPU 44 returns the process to S51.

  If the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter” (S52: NO), the CPU 44 calculates the rotation speed of the cloth feed motor in the post-reversal period (S62 to S72). Specifically, the CPU 44 acquires the end angle “FeedEnd”, which is the main rotation angle at the time when the cloth feed mechanism 32 reaches the cloth feed end position, from the EEPROM 47 (S62). The CPU 44 subtracts the current main rotation angle “DDPOS” from the end angle “FeedEnd” to calculate the remaining rotation angle “RemMb” until the main output shaft reaches the end angle “FeedEnd” (S63).

The CPU 44 acquires the rotational speed “DDSspeed” of the main motor (S64). The CPU 44 calculates a required time Tb until the main output shaft reaches the terminal angle “FeedEnd” by the following formula (S65).
Tb = RemMb / (360 · DDSspeed)
The CPU 44 acquires the current cloth feed rotation angle “RELPOS” (S66). The CPU 44 subtracts the current cloth feed rotation angle “RELPOS” from the cloth feed motor drive end position “ENPos”, thereby remaining rotation angle until the cloth feed output shaft 24 reaches the cloth feed motor drive end position “ENPos”. “RemFb” is calculated (S67). The CPU 44 calculates the rotational speed “SP2b” necessary for the cloth feed motor 23 to rotate the remaining rotational angle “RemFb” within the required time Tb by the following formula (S68).
SP2b = RemFb / (360 · Tb)

  The CPU 44 determines whether or not the change amount of the rotational speed “SP2b” calculated in S68 with respect to the speed instructed to the cloth feed motor 23 in any of the previous S60, S71, and S73 is 10% or less of the previous instructed speed. Is determined (S69). If the amount of change is 10% or less (S69: YES), the CPU 44 drives the cloth feed motor 23 at the rotational speed “SP2b” calculated in S68 (S71). The CPU 44 returns the process to S51. When the amount of change is greater than 10% (S69: NO), the CPU 44 calculates the rotational speed “SP2c” at which the amount of change is 10% or less (S72). For example, when the rotation speed “SP2b” is decelerated from the previous instruction speed, the CPU 44 may calculate “SP2c” by multiplying the previous instruction speed by a value of 0.9 or more and less than 1.0. When the rotation speed “SP2b” accelerates from the previous command speed, the CPU 44 may calculate “SP2c” by multiplying the previous command speed by a value greater than 1.0 and 1.1 or less. The CPU 44 may calculate “SP2c” by other methods. The CPU 44 drives the cloth feed motor 23 at the rotation speed “SP2c” calculated in S72 (S73). The CPU 44 returns the process to S51. The third speed control process ends when the power of the sewing machine 1 is turned off.

  As described above, the sewing machine 1 of the third embodiment calculates the required time “Ta / Tb” until the main output shaft of the main motor 13 reaches the intermediate angle or the terminal angle. The sewing machine 1 calculates the remaining rotation angle “RemFa / RemFb” of the cloth feed motor 23 until the cloth feed mechanism 32 reaches the cloth feed start position or the cloth feed end position next time. The sewing machine 1 calculates the rotation speed “SP2a / SP2b” for the cloth feed motor 23 to rotate the remaining rotation angle “RemFa / RemFb” for the required time “Ta / Tb”. The cloth feed motor 23 is synchronized with the main motor 13 by driving the cloth feed motor 23 at the rotation speed “SP2a / SP2b”. When the cloth feed output shaft 24 reaches the cloth feed motor drive intermediate position “CTPos” or the cloth feed motor drive end position “ENPos”, the main output shaft of the main motor 13 is turned at an inversion angle (intermediate angle “FeedCenter” or end angle “ It coincides with the time when “FeedEnd”) is reached. Therefore, the sewing machine 1 can maintain the synchronization of the driving of the main shaft 14 and the driving of the cloth feeding mechanism 32 even if the sewing speed changes. The sewing machine 1 of the third embodiment does not use the deviation between the positions of the output shafts of the two motors 13 and 23 and the target position. The sewing machine 1 of the third embodiment can appropriately control the two motors 13 and 23 without using a deviation when the rotation speed of the main motor 13 is increasing.

  In the third embodiment, the CPU 44 that acquires the main rotation angle in S51 of FIG. 12 functions as the main rotation angle detection unit of the present invention. The CPU 44 that acquires the cloth feed rotation angle in S57 and S66 of FIG. 12 functions as a cloth feed rotation angle detection unit. The CPU 44 that drives and controls the cloth feed motor 23 in S60 and S71 of FIG. 12 functions as a drive control unit.

  The CPU 44 that determines whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” in S52 of FIG. 12 functions as a period determination unit. The CPU 44 that determines the change amount in S69 of FIG. 12 functions as a change amount determination unit. The CPU 44 that calculates and sets the rotation speed at which the change amount is equal to or less than the threshold value in S72 and S73 of FIG. The CPU 44 that calculates the rotation speed in S59 of FIG. 12 functions as a pre-inversion speed calculation unit. The CPU 44 that calculates the rotation speed in S68 of FIG. 12 functions as a post-inversion speed calculation unit.

  The CPU 44 that acquires the intermediate angle “FeedCenter” and the terminal angle “FeedEnd” in S53 and S62 in FIG. 12 functions as an inversion angle acquisition unit. The CPU 44 that calculates the remaining rotation angle “RemMa / RemMb” in S54 and S63 in FIG. 12 functions as a main rotation angle remaining amount calculation unit. The CPU 44 that acquires the rotational speed “DDSspeed” in S55 and S64 of FIG. 12 functions as a speed acquisition unit. The CPU 44 that calculates the required time “Ta / Tb” in S56 and S65 in FIG. 12 functions as a time calculation unit. The CPU 44 that calculates the remaining rotation angle “RemFa / RemFb” in S58 and S67 of FIG. 12 functions as a cloth feed rotation angle remaining amount calculation unit. The CPU 44 that calculates the rotation speed “SP2a / SP2b” in S59 and S68 of FIG. 12 functions as a second speed calculation unit.

  The process of acquiring the main rotation angle in S51 of FIG. 12 corresponds to the main rotation angle detection step of the present invention. The process of acquiring the cloth feed rotation angle in S57 and S66 in FIG. 12 corresponds to the cloth feed rotation angle detection step. The process of determining whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” in S52 of FIG. 12 corresponds to a period determination step. The process of calculating the rotation speed in S53 to S59 in FIG. 12 corresponds to a speed calculation step before inversion. The process of calculating the rotation speed in S62 to S68 in FIG. 12 corresponds to a post-inversion speed calculation step.

  A fourth embodiment of the present invention will be described with reference to FIGS. The sewing machine 1 of the fourth embodiment calculates the rotation speed “SP1a / SP1b” according to the deviation between the target rotation angle and the actual rotation angle. The sewing machine 1 calculates the rotation speed “SP2a / SP2b” based on the rotation speed of the main motor 13. The sewing machine 1 changes the control method of the cloth feed motor 23 according to the rotation speed of the main motor 13. The sewing machine 1 of the fourth embodiment is different from the first to third embodiments only in that the fourth speed control process is executed instead of the first to third speed control processes. Therefore, in description of 4th embodiment, the same number is attached | subjected to the structure and process same as the sewing machine 1 of 1st-3rd embodiment, and description is abbreviate | omitted or simplified.

  When the power of the sewing machine 1 is turned on, the CPU 44 starts the fourth speed control process shown in FIG. The CPU 44 acquires the main rotation angle “DDPOS” of the main motor 13 from the main encoder 55 (S81). The CPU 44 executes a first speed calculation process (S82). The first speed calculation process is a process for calculating the rotation speed according to the deviation between the target rotation angle and the actual rotation angle. The contents of the first speed calculation process are substantially the same as the contents of the first speed control process (see FIG. 9) in the first embodiment.

  As shown in FIG. 14, the CPU 44 determines whether or not the main rotation angle “DDPOS” acquired in S81 (see FIG. 13) is before the intermediate angle “FeedCenter” (S12). If the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” (S12: YES), the CPU 44 acquires the current cloth feed rotation angle “RELPOS” of the cloth feed motor 23 from the cloth feed encoder 56 (S13). ). The CPU 44 sets a target rotation angle “POS1a” that is a cloth feed rotation angle at which the cloth feed output shaft 24 corresponding to the main rotation angle “DDPOS” acquired in S81 is to be positioned (S14). The CPU 44 calculates a deviation between the set target rotation angle “POS1a” and the cloth feed rotation angle “RELPOS” acquired from the cloth feed encoder 56 (S15). The CPU 44 calculates the rotational speed “SP1a” by multiplying the deviation by a preset fixed value count N1a (S16). The CPU 44 returns the process to the fourth speed control process.

  If the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter” (S12: NO), the CPU 44 acquires the current cloth feed rotation angle “RELPOS” of the cloth feed motor 23 from the cloth feed encoder 56 (S19). . The CPU 44 sets a target rotation angle “POS1b” that is a cloth feed rotation angle at which the cloth feed output shaft 24 corresponding to the main rotation angle “DDPOS” acquired in S81 is to be positioned (S20). The CPU 44 calculates a deviation between the set target rotation angle “POS1b” and the cloth feed rotation angle “RELPOS” acquired from the cloth feed encoder 56 (S21). The CPU 44 calculates the rotational speed “SP1b” by multiplying the calculated deviation by a fixed value count N1b (S22). The CPU 44 returns the process to the fourth speed control process.

  Returning to the description of FIG. The CPU 44 acquires the rotational speed “DDSspeed” of the main motor 13 (S83). The CPU 44 determines whether or not the rotation speed “DDSspeed” is equal to or less than a threshold value of 300 (rpm) (S84). The threshold value is not limited to 300. The threshold value may be changed by the operator operating the operation unit 10. If the rotation speed “DDSspeed” is 300 or less (S84: YES), the CPU 44 determines SP1a or SP1b calculated in the first speed calculation process of S82 as the primary calculation speed (S85). The primary calculation speed is a speed that is directly adopted as the rotation speed of the cloth feed motor 23 when the amount of change with respect to the previous instruction speed is equal to or less than a threshold value. The CPU 44 moves the process to S95. If the rotation speed “DDSspeed” is greater than 300 (S84: NO), the CPU 44 executes a second speed calculation process (S87). The second speed calculation process is a process for calculating the rotation speed of the cloth feed motor 23 based on the rotation speed of the main motor 13. The content of the second speed calculation process is substantially the same as the content of the third speed control process (see FIG. 12) in the third embodiment.

  As shown in FIG. 15, the CPU 44 determines whether or not the main rotation angle “DDPOS” acquired in S81 (see FIG. 13) is before the intermediate angle “FeedCenter” (S52). If it is before the intermediate angle “FeedCenter” (S52: YES), the CPU 44 acquires from the EEPROM 47 the intermediate angle “FeedCenter” that is the main rotation angle when the cloth feed mechanism 32 reaches the cloth feed start position (S53). ). The CPU 44 subtracts the current main rotation angle “DDPOS” from the intermediate angle “FeedCenter” to calculate the remaining rotation angle “RemMa” until the main output shaft reaches the intermediate angle “FeedCenter” (S54). The CPU 44 calculates a required time Ta (unit: minute) until the main output shaft of the main motor 13 reaches the intermediate angle “FeedCenter” (S56).

  The CPU 44 subtracts the current cloth feed rotation angle “RELPOS” from the cloth feed motor drive intermediate position “CTPos”, thereby remaining rotation angle until the cloth feed output shaft 24 reaches the cloth feed motor drive intermediate position “CTPos”. “RemFa” is calculated (S58). The CPU 44 calculates the rotational speed “SP2a” necessary for the cloth feed motor 23 to rotate the remaining rotational angle “RemFa” by the required time Ta (S59). The CPU 44 returns the process to the fourth speed control process.

  If the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter” (S52: NO), the CPU 44 sets the end angle “FeedEnd”, which is the main rotation angle when the cloth feed mechanism 32 reaches the cloth feed end position, to the EEPROM 47. (S62). The CPU 44 subtracts the current main rotation angle “DDPOS” from the end angle “FeedEnd” to calculate the remaining rotation angle “RemMb” until the main output shaft reaches the end angle “FeedEnd” (S63). The CPU 44 calculates a required time Tb until the main output shaft reaches the terminal angle “FeedEnd” (S65). The CPU 44 subtracts the current cloth feed rotation angle “RELPOS” from the cloth feed motor drive end position “ENPos”, thereby remaining rotation angle “RemFb” until the cloth feed output shaft 24 reaches the cloth feed motor drive end position. Is calculated (S67). The CPU 44 calculates the rotational speed “SP2b” necessary for the cloth feed motor 23 to rotate the remaining rotational angle “RemFb” for the required time Tb (S68). The CPU 44 returns the process to the fourth speed control process.

Returning to the description of FIG. The CPU 44 determines whether or not the rotational speed “DDSspeed” is smaller than a threshold value of 3000 (rpm) (S88). The threshold value is not limited to 3000, but needs to be larger than the threshold value used in the determination in S84. If the rotation speed “DDSspeed” is 3000 or more (S88: NO), the CPU 44 determines SP2a or SP2b calculated in the second speed calculation process of S87 as the primary calculation speed (S89). If the rotational speed “DDSspeed” is larger than 300 and smaller than 3000 (S88: YES), the CPU 44 calculates the rotational speeds “SP1a or SP1b (hereinafter referred to as SP1)” and “SP2a or SP2b (hereinafter referred to as SP2) calculated in S82 and S87. The rotation speed “SP3” of the cloth feed motor 23 is calculated from a specific ratio (S91, S92). Specifically, the CPU 44 calculates the ratio “rt” of SP1 occupying SP3 by the following formula (S91).
rt = (3000−DDSspeed) / 2700
The CPU 44 calculates the rotation speed “SP3” by the following formula (S92).
SP3 = rt.SP1 + (1-rt) .SP2
As for the rotational speed “SP3”, as the rotational speed “DDSspeed” approaches 3000, the proportion of SP1 in SP3 decreases and the proportion of SP2 increases. The CPU 44 determines the calculated rotation speed “SP3” as the primary calculation speed (S93), and the process proceeds to S95.

  The CPU 44 determines whether or not the change amount of the primary calculation speed with respect to the speed instructed to the cloth feed motor 23 in the previous S96 or S98 is 10% or less of the previous instructed speed (S95). If the change amount is 10% or less (S95: YES), the CPU 44 drives the cloth feed motor 23 as it is at the primary calculation speed (S96), and returns the process to S81. When the amount of change is greater than 10% (S95: NO), the CPU 44 calculates a secondary calculation speed at which the amount of change is 10% or less (S97). For example, the CPU 44 may calculate the secondary calculation speed by multiplying the previous instruction speed by a value of 0.9 or 1.1. The CPU 44 drives the cloth feed motor 23 at the secondary calculation speed calculated in S97 (S98), and returns the process to S81. The fourth speed control process ends when the power of the sewing machine 1 is turned off.

  As described above, the sewing machine 1 according to the fourth embodiment calculates the rotation speed “SP1a / SP1b” according to the deviation between the target rotation angle and the actual rotation angle. The sewing machine 1 calculates the rotation speed “SP2a / SP2b” based on the rotation speed of the main motor 13. According to the rotational speed “SP1a / SP1b”, the sewing machine 1 properly keeps the cloth feed motor 23 and the main motor 13 synchronized even when the main motor 13 is stopped or the operator manually rotates the main shaft 14. Can do. Considering the rotational speed “SP2a / SP2b”, even when the rotational speed of the main shaft 14 is increased, the sewing machine 1 instructs the cloth feed motor 23 to provide an appropriate rotational speed to synchronize the two motors 13 and 23. Can keep. The sewing machine 1 can drive the cloth feed mechanism 32 more appropriately by changing the control method of the cloth feed motor 23 according to the rotational speed “DDSspeed” of the main motor 13. More specifically, the sewing machine 1 changes the ratio of the rotational speed “SP1a / SP1b” suitable for the low speed and the rotational speed “SP2a / SP2b” suitable for the high speed in accordance with the rotational speed “DDSspeed”. The rotational speed “SP3” can be calculated. When the rotational speed “DDSspeed” is an intermediate speed (300 to 3000 in this embodiment), the sewing machine 1 appropriately considers the rotational speed “SP1a / SP1b” and the rotational speed “SP2a / SP2b”. SP3 "can be calculated. Therefore, the sewing machine 1 can drive the cloth feed motor 23 at a rotation speed more suitable for the rotation speed “DDSspeed”.

  In the fourth embodiment, the CPU 44 that acquires the main rotation angle in S81 of FIG. 13 functions as a main rotation angle detection unit of the present invention. The CPU 44 that acquires the cloth feed rotation angle in S13 and S19 in FIG. 14 functions as a cloth feed rotation angle detection unit. The CPU 44 that calculates the rotation speed in S91 to S93 in FIG. 13, S16 and S22 in FIG. 14, and S59 and S68 in FIG. 15 functions as a speed calculation unit. The CPU 44 that drives and controls the cloth feed motor 23 in S96 and S98 in FIG. 13 functions as a drive control unit.

  The CPU 44 that determines whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” in S12 of FIG. 14 and S52 of FIG. 15 functions as a period determination unit. The CPU 44 that calculates the rotation speed in S16 of FIG. 14 and S59 of FIG. 15 functions as a pre-reverse speed calculation unit. The CPU 44 that calculates the rotation speed at SS22 in FIG. 14 and S68 in FIG. 15 functions as a post-inversion speed calculation unit.

  The CPU 44 that calculates the rotation speed in S16 and S22 of FIG. 14 functions as a first speed calculation unit. The CPU 44 that acquires the intermediate angle “FeedCenter” and the terminal angle “FeedEnd” in S53 and S62 in FIG. 15 functions as an inversion angle acquisition unit. The CPU 44 that calculates the remaining rotation angle “RemMa / RemMb” in S54 and S63 in FIG. 15 functions as a main rotation angle remaining amount calculation unit. The CPU 44 that acquires the rotation speed “DDSspeed” in S83 of FIG. 13 functions as a speed acquisition unit. The CPU 44 that calculates the required time “Ta / Tb” in S56 and S65 in FIG. 15 functions as a time calculation unit. The CPU 44 that calculates the remaining rotation angle “RemFa / RemFb” in S58 and S67 of FIG. 15 functions as a “cloth feed rotation angle remaining amount calculation unit”. The CPU 44 that calculates the rotation speed “SP2a / SP2b” in S59 and S68 of FIG. 15 functions as a second speed calculation unit. The CPU 44 that determines whether or not “DDSspeed” is equal to or less than a predetermined value in S84 of FIG. 13 functions as a speed determination unit. The CPU 44 that drives the cloth feed motor 23 at the rotational speed “SP1a / SP1b” in S85, S96, and S98 of FIG. 13 functions as a low-speed drive unit. The CPU 44 that drives the cloth feed motor 23 at the rotational speed “SP2a / SP2b” or “SP3” in S89, S93, S96, and S98 in FIG. 13 functions as a high-speed driving unit. The CPU 44 that calculates the rotation speed “SP3” in S91 and S92 in FIG. 13 functions as a third speed calculation unit.

  The process of acquiring the main rotation angle in S81 of FIG. 13 corresponds to the main rotation angle detection step of the present invention. The process of acquiring the cloth feed rotation angle in S13 and S19 in FIG. 14 corresponds to the cloth feed rotation angle detection step. The process of determining whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” in S12 of FIG. 14 and S52 of FIG. 15 corresponds to a period determination step. The process of calculating the rotation speed in S13 to S16 in FIG. 14 and S53 to S59 in FIG. 15 corresponds to a speed calculation step before inversion. The process of calculating the rotation speed in S19 to S22 of FIG. 14 and S62 to S68 of FIG. 15 corresponds to a post-reverse speed calculation step.

  The above embodiment can be variously modified. The sewing machine 1 according to the first to third embodiments determines the amount of change between the calculated rotational speed and the previous designated speed only when the main rotational angle “DDPOS” is after the intermediate angle “FeedCenter”. Therefore, the sewing machine 1 can suppress the influence of a rapid change in the rotation speed while the cloth feed output shaft 24 is rotating in one direction. However, even when the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter”, the sewing machine 1 determines whether or not the change amount is equal to or less than the threshold value, and performs processing according to the determination result. Good. On the other hand, the sewing machine 1 according to the fourth embodiment determines whether or not the change amount is equal to or less than the threshold value regardless of whether or not the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter”. Processing is performed according to the results. However, the sewing machine 1 of the fourth embodiment may perform the above determination and processing only when the main rotation angle “DDPOS” is after the intermediate angle “FeedCenter”, similarly to the sewing machine 1 of the first to third embodiments. .

  In the sewing machine 1 of the above embodiment, the main rotation angle and the cloth feed rotation angle are respectively set when the main rotation angle “DDPOS” is before the intermediate angle “FeedCenter” and after the intermediate angle “FeedCenter”. To calculate the rotation speed. Therefore, the main motor 13 and the cloth feed motor 23 are synchronized in both the forward path and the return path of the cloth feed mechanism 32. However, the sewing machine 1 can maintain the synchronization of the two motors 13 and 23 only while the feed dog 33 moves over the needle plate 15 and feeds the cloth.

  In the sewing machine 1 of the above-described embodiment, the cloth feed rotation angle “RELPOS” is set in each of the case where the main rotation angle “DDPOS” is before and after the intermediate angle “FeedCenter” (before and after inversion). Perform the acquisition process. However, common processes before and after inversion may be performed together. For example, S13 to S15 and S19 to S21 in FIG. 9 may be performed together before the process of S12.

  The sewing machine 1 of the above embodiment moves the cloth feed mechanism 32 up and down by the main motor 13. Therefore, the vertical movement of the cloth feed mechanism 32 and the vertical movement of the sewing needle 8 are mechanically synchronized. However, the present invention can also be applied to a sewing machine provided with a motor that moves the cloth feed mechanism 32 up and down (specifically, a motor that rotates the vertical feed shaft 27 in FIG. 3) separately from the main motor 13.

  The specific calculation method of the rotation speed may be changed. For example, the sewing machine 1 of the fourth embodiment calculates SP3 so that the proportion of SP2 increases in proportion to the value of the rotational speed “DDSspeed” (see S91 and S92 in FIG. 13). The value of the rotational speed “DDSspeed” and the ratio of SP2 may not be proportional. The sewing machine 1 stores a table associating the value of the rotational speed “DDSspeed” with the ratios of SP1 and SP2 in the ROM 45 or the like, acquires the ratio corresponding to the value of the rotational speed “DDSspeed” from the table, and calculates SP3. Also good. The method of calculating “SP1a / SP1b” from the deviation in S16 and S22 in FIG. 9, S16 and S22 in FIG. 11, and S16 and S22 in FIG. 14 can be changed. The sewing machine 1 may calculate “SP1a / SP1b” using a table that associates the deviation with the value of “SP1a / SP1b”.

  The processing order of the fourth speed control process shown in FIG. 13 can be changed. For example, the sewing machine 1 acquires the rotational speed “DDSspeed” of the main motor 13 immediately after the start of the fourth speed control process, and determines which of SP1, SP2, and SP3 is used to drive the cloth feed motor 23. Also good. The sewing machine 1 may calculate the rotational speed determined to be used in subsequent processing and drive the cloth feed motor 23. In the fourth speed control process, the CPU 44 calculates the rotational speed of the cloth feed motor 23 using the deviation between the target rotation angle of the cloth feed output shaft 24 and the actual cloth feed rotation angle (S13 to S16). The CPU 44 may calculate the rotation speed using the deviation between the target rotation angle of the main output shaft and the actual main rotation angle.

  The configuration of the power transmission mechanism 35 can be changed. For example, instead of the first arm portion 37 and the second arm portion 39, a cam mechanism or the like that reciprocates the acting arm portion 38 twice in one reciprocating motion (reciprocates the acting arm portion 38 once in each of the forward path and the return path). It may be used.

DESCRIPTION OF SYMBOLS 1 Sewing machine 7 Needle bar 8 Sewing needle 10 Operation part 13 Main motor 14 Main shaft 15 Needle plate 22 Pedal 23 Cloth feed motor 24 Cloth feed output shaft 32 Cloth feed mechanism 33 Feed dog 35 Power transmission mechanism 44 CPU
45 ROM
47 EEPROM
55 Main encoder 56 Cloth feed encoder

Claims (10)

A main motor that has a main output shaft and drives the main shaft to move the sewing needle up and down by rotating the main output shaft;
A cloth feed motor having a cloth feed output shaft and rotating the cloth feed output shaft within a range of a predetermined angle;
In a sewing machine equipped with a cloth feeding mechanism for feeding cloth in a horizontal direction,
The rotational movement of the cloth feed output shaft in one direction and the opposite direction is converted into a swinging motion in which the cloth feed mechanism swings back and forth horizontally, and the power of the cloth feed motor is converted into the cloth feed motor. A power transmission mechanism that transmits to the mechanism;
A main rotation angle detector that detects a main rotation angle that is the rotation angle of the main output shaft;
A cloth feed rotation angle detecting unit for detecting a cloth feed rotation angle which is a rotation angle of the cloth feed output shaft;
Using the main rotation angle detected by the main rotation angle detection unit and the cloth feed rotation angle detected by the cloth feed rotation angle detection unit, a speed calculation unit that calculates a rotation speed instructed to the cloth feed motor. When,
A sewing machine comprising: a drive control unit that drives and controls the cloth feed motor at the rotation speed calculated by the speed calculation unit, and swings the cloth feed mechanism via the power transmission mechanism. During the period in which the power transmission mechanism converts one rotation operation in one direction and in the opposite direction of the cloth feed output shaft into one reciprocating swing motion of the cloth feed mechanism, the cloth feed mechanism A period determination unit that determines which of the period before inversion that is a period before the oscillation direction of the inversion and the period after inversion that is the period after the inversion is reversed;
A change amount determination unit that determines whether or not a change amount of the speed change of the rotation speed calculated by the speed calculation unit is greater than a threshold when the period determination unit determines that it is the period after inversion;
When the change amount determination unit determines that the change amount is greater than the threshold value, a change in which the change amount is equal to or less than the threshold value is calculated and set to the rotation speed after the change in the speed of the cloth feed motor. The sewing machine according to claim 1, further comprising: a quantity limiting unit. The speed calculator is
When the period determination unit determines that it is the period before inversion, the main rotation angle detected by the main rotation angle detection unit and the cloth feed rotation angle detected by the cloth feed rotation angle detection unit are used. A pre-reverse speed calculation unit that calculates a rotational speed instructed to the cloth feed motor;
When the period determination unit determines that it is the period after inversion, the main rotation angle detected by the main rotation angle detection unit and the cloth feed rotation angle detected by the cloth feed rotation angle detection unit are used. The sewing machine according to claim 2, further comprising: a reverse speed calculation unit that calculates a rotational speed instructed to the cloth feed motor. A cloth feed target angle setting unit for setting a target rotation angle at which the cloth feed output shaft should be positioned corresponding to the main rotation angle from the main rotation angle detected by the main rotation angle detector;
The target rotation angle set by the cloth feed target angle setting unit, and a cloth feed deviation calculating unit that calculates a deviation of the cloth feed rotation angle detected by the cloth feed rotation angle detecting unit,
The sewing machine according to any one of claims 1 to 3, wherein the speed calculation unit includes a first speed calculation unit that calculates the rotation speed based on the deviation. A main target angle setting unit that sets a target rotation angle at which the main output shaft should be positioned corresponding to a cloth feed rotation angle from the cloth feed rotation angle detected by the cloth feed rotation angle detection unit;
The target rotation angle set by the main target angle setting unit, and a main deviation calculation unit that calculates a deviation of the main rotation angle detected by the main rotation angle detection unit,
The sewing machine according to any one of claims 1 to 3, wherein the speed calculation unit includes a first speed calculation unit that calculates the rotation speed based on the deviation. A reversal angle acquisition unit that acquires a reversal angle that is a main rotation angle at which the main output shaft should be positioned when the cloth feed mechanism reaches the reversal position in the swinging direction next time;
Main rotation for calculating a remaining rotation angle until the main output shaft reaches the inversion angle based on the inversion angle acquired by the inversion angle acquisition unit and the main rotation angle detected by the main rotation angle detection unit A remaining corner calculation unit;
A speed acquisition unit that acquires a main rotation speed that is a rotation speed of the main motor;
Based on the remaining rotation angle calculated by the main rotation angle remaining amount calculation unit and the main rotation speed acquired by the speed acquisition unit, a time required until the main output shaft reaches the inversion angle is calculated. A time calculator,
A cloth feed rotation angle remaining amount calculating section for calculating a remaining rotation angle of the cloth feed motor until the cloth feed mechanism reaches the reverse position from the cloth feed rotation angle detected by the cloth feed rotation angle detecting section; In addition,
The speed calculation unit calculates the rotation speed necessary for the cloth feed motor to rotate in the required time calculated by the time calculation unit based on the remaining rotation angle calculated by the cloth feed rotation angle remaining amount calculation unit. The sewing machine according to any one of claims 1 to 3, further comprising a second speed calculation unit for calculating. A reversal angle acquisition unit that acquires a reversal angle that is a main rotation angle at which the main output shaft should be positioned when the cloth feed mechanism reaches the reversal position in the swinging direction next time;
Main rotation for calculating a remaining rotation angle until the main output shaft reaches the inversion angle based on the inversion angle acquired by the inversion angle acquisition unit and the main rotation angle detected by the main rotation angle detection unit A remaining corner calculation unit;
A speed acquisition unit that acquires a main rotation speed that is a rotation speed of the main motor;
Based on the remaining rotation angle calculated by the main rotation angle remaining amount calculation unit and the main rotation speed acquired by the speed acquisition unit, a time required until the main output shaft reaches the inversion angle is calculated. A time calculator,
A cloth feed rotation angle remaining amount calculating section for calculating a remaining rotation angle of the cloth feed motor until the cloth feed mechanism reaches the reverse position from the cloth feed rotation angle detected by the cloth feed rotation angle detecting section; In addition,
The speed calculation unit calculates the rotation speed necessary for the cloth feed motor to rotate in the required time calculated by the time calculation unit based on the remaining rotation angle calculated by the cloth feed rotation angle remaining amount calculation unit. A second speed calculation unit for calculating,
The drive control unit
A speed determination unit that determines whether or not the main rotation speed acquired by the speed acquisition unit is a predetermined value or less;
A low-speed driving unit that drives the cloth feed motor at the rotation speed calculated by the first speed calculation unit when the speed determination unit determines that the main rotation speed is equal to or less than the predetermined value;
A high-speed driving unit that drives the cloth feed motor based on at least the rotation speed calculated by the second speed calculation unit when the speed determination unit determines that the main rotation speed is greater than the predetermined value; The sewing machine according to claim 4 or 5, further comprising: The speed calculator is
A third speed calculation unit that calculates a rotation speed instructed to the cloth feed motor by a specific ratio from the rotation speed calculated by the first speed calculation unit and the rotation speed calculated by the second speed calculation unit. Further comprising
The third speed calculation unit calculates a rotation speed for driving the cloth feed motor by changing the specific ratio according to the main rotation speed,
The high-speed drive unit drives the cloth feed motor at the rotation speed calculated by the third speed calculation unit when the speed determination unit determines that the main rotation speed is greater than the predetermined value. 7. The sewing machine according to 7.   The sewing machine according to any one of claims 1 to 8, further comprising a setting section capable of setting a cloth feed end position in the cloth feed mechanism. A main motor that has a main output shaft and drives the main shaft to move the sewing needle up and down by rotating the main output shaft;
A cloth feed motor having a cloth feed output shaft and rotating the cloth feed output shaft within a range of a predetermined angle;
A cloth feed mechanism for feeding the cloth in a horizontal direction;
In a sewing machine control method executed by a sewing machine comprising: a power transmission mechanism that transmits power of the cloth feed motor to the cloth feed mechanism;
A main rotation angle detecting step of detecting a main rotation angle which is a rotation angle of the main output shaft;
A cloth feed rotation angle detecting step for detecting a cloth feed rotation angle which is a rotation angle of the cloth feed output shaft;
During the period in which the power transmission mechanism converts the rotational movement of the cloth feed output shaft in one direction and the opposite direction into one reciprocating swinging motion in the horizontal direction of the cloth feed mechanism. A period determining step for determining which is a period before inversion, which is a period before the horizontal swing direction of the mechanism is inverted, and a period after inversion, which is a period after inversion;
When it is determined in the period determination step that the period is before reversal, the main rotation angle detected in the main rotation angle detection step and the cloth feed rotation angle detected in the cloth feed rotation angle detection step are used. A pre-reverse speed calculation step for calculating a rotational speed instructed to the cloth feed motor;
When it is determined in the period determination step that the period is after the reversal, the main rotation angle detected in the main rotation angle detection step and the cloth feed rotation angle detected in the cloth feed rotation angle detection step are used. And a post-reverse speed calculation step of calculating a rotational speed instructed to the cloth feed motor.

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