JP2010068913A - Welting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To favorably and intermittently feed a cloth. <P>SOLUTION: The welting machine includes: a pair of right and left needle bars vertically moved by a sewing machine motor 16; a needle vertical movement mechanism vertically moving the respective needle bars; a clamp foot 41 for retaining a body section cloth C and a binding cloth on a placement base 11, and a clamp foot feed mechanism 40 moving the clamp foot along the cloth feed direction by a pulse motor 45; and sews the cloth while intermittently feeding the clamp foot. The clamp foot feed mechanism has a servomotor 46 for assisting the intermittent drive of the pulse motor, and the servomotor has a servo control means 60 which applies an acceleration torque when accelerating in rising of the intermittent drive of the pulse motor and applying a deceleration torque when decelerating before a stop. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an edge stitch sewing machine that performs intermittent feeding.

The bead stitch sewing machine is a sewing machine for sewing the opening of a clothing pocket, and forms a square slit-shaped pocket opening and a seam with two needles on both sides along the opening. In this way, the bag is sewn in a bag shape along the edge of the pocket opening.
In order to perform the above-described ball stitching, the ball stitching sewing machine includes a pair of large pressers that hold the cloth from above, a binder that holds the bead in a predetermined shape between each large presser, and a pocket opening. The knife mechanism to be formed, the needle vertical movement mechanism to form two seams along the pocket opening, and the large presser in the predetermined feed direction so that the body cloth and the cloth pass through the needle drop point of the sewing needle It is equipped with a large press feed mechanism to be moved, and while the pocket opening is formed by the female mechanism, the body cloth and the ball cloth are fed and the edge stitch is performed (for example, see Patent Document 1).
JP 2007-259934 A

By the way, some conventional edge stitch sewing machines perform an intermittent feed stitching operation by adopting a method in which a large press feed mechanism is used to feed a large press by a belt drive using a pulse motor as a drive source.
In such a ball stitch sewing machine, the motor is driven in synchronization with the vertical movement of the sewing needle, and the cloth is fed intermittently only during the period when the sewing needle is not stuck in the cloth.

On the other hand, the large presser is large because of the structure for pressing the whole body cloth from above, and the large presser is equipped with a holding mechanism such as a ball cloth, so that the total weight is considerably heavy. For this reason, there is a problem that the inertia of the large presser feed mechanism is increased due to the weight of the large presser, and the timing belt is easily expanded and contracted. Even if a pulse motor having a large static torque and suitable for intermittent feed is used. However, the operation of repeating the stop and drive in a short cycle cannot be stably performed, and there is a problem that it is not possible to cope with high speed.
In particular, even if the output of the pulse motor is increased, the control accuracy (vibration, etc.) at the time of acceleration / stop is not always improved, and the overshoot may increase and the vibration, etc. may increase.

  An object of the present invention is to perform good intermittent feeding.

  According to the first aspect of the present invention, a pair of left and right needle bars that individually hold sewing needles and move up and down by a sewing machine motor, a needle up-and-down movement mechanism that moves the needle bars up and down, and a body cloth on a mounting table A pair of left and right large pressers that hold the belt together with the ball cloth, a large presser feed mechanism that moves the pair of large pressers along a predetermined cloth feed direction by driving a pulse motor, and the large presser for moving the sewing needle up and down. In an edge stitch sewing machine that performs sewing while intermittently feeding in synchronization, the large presser feed mechanism has a servo motor that assists intermittent driving of the pulse motor, and the servo motor is connected to the pulse motor. Servo control means is provided for controlling the acceleration torque to be applied at the time of acceleration of rising in the intermittent drive, and to apply the deceleration torque at the time of deceleration before the stop.

  The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the servo control means starts applying the acceleration torque immediately before acceleration of the rise of the pulse motor, and before stopping. Control is performed so that the application of deceleration torque is started immediately before the deceleration.

  According to the first aspect of the present invention, the large presser feed mechanism includes a servo motor that assists the pulse motor, and applies acceleration assist torque and deceleration assist torque when the pulse motor is intermittently driven up and down. Therefore, it is possible to suppress overshoot caused by driving the pulse motor, effectively reduce vibrations such as damping, and realize stable intermittent feeding. As a result, even during high-speed intermittent feed, vibration can be similarly prevented and the operation can be stabilized, so that high-speed intermittent feed drive can also be realized.

  The “servo motor” here refers to a brushless DC motor, an AC motor (synchronous motor, induction motor), a DC motor (brush type), etc. capable of servo control, and shaft angle detection is performed. Pulse motors are not included.

  According to the second aspect of the present invention, the application of the auxiliary torque for acceleration and deceleration by the servo motor is started prior to the acceleration or deceleration of the rise of the pulse motor, so that the torque fluctuation by the pulse motor at the start of acceleration / deceleration is reduced. Therefore, it is possible to further suppress overshoot and reduce vibration.

(Overall configuration of the embodiment of the invention)
Hereinafter, a bead stitch sewing machine 10 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an overall schematic configuration of the edge stitch sewing machine 10, and FIG. 2 is a front view of the edge stitch sewing machine 10. In the present embodiment, the direction of each part of the sewing machine 10 is determined based on the XYZ axes shown in the drawings. In the state where the sewing machine 10 is installed on the horizontal plane, the Z-axis direction indicates the vertical direction, the X-axis direction indicates the horizontal and the direction corresponding to the cloth feeding direction E, the Y-axis direction is horizontal and orthogonal to the X-axis direction. Indicates the direction to do.

The bead stitch sewing machine 10 overlaps the body cloth C and the ball cloth and sews them at a predetermined length with two sewing needles 13 and 13, and linearly extends between the two stitches along the sewing direction. The sewing machine further forms a V-shaped cut at both ends of the cut.
The bead stitch sewing machine 10 includes a body 11 on the table 11 by means of a table 11 serving as a work table for sewing and a pair of left and right large pressers 41, 41 extending in the cloth feeding direction of the body cloth C. Is held together with the ball cloth from above, and the large presser 41, 41 is moved in the cloth feed direction E so that the body cloth C and the large cloth are conveyed. Two binders are sewn on the body cloth C and the ball cloth which are fed along the X-axis direction by the binder mechanism that folds the both side edges of the ball cloth by applying the binder 12 to the ball cloth to be sewn on and the large press feed mechanism 40. A needle up-and-down moving mechanism as a sewing means for performing sewing with the needles 13 and 13, and a moving knife 14 is moved up and down downstream of the sewing needles 13 and 13 to form a cut L in the body cloth C and the ball cloth. Female And a sewing machine frame 80 which is installed on the table 11 and stores and holds the needle up-and-down moving mechanism and the knife mechanism, and corners where substantially V-shaped cuts V and V are formed at positions corresponding to both ends of the straight cut. A knife mechanism 90 and operation control means 60 as sewing control means for performing operation control of each of the above-described configurations are provided.
Each part is described in detail below.

(Table and sewing frame)
The table 11 has an upper surface parallel to the XY plane and is used in a horizontal state. A needle plate 15 is mounted at a needle drop position by the sewing needles 13 and 13 on the table 11. The needle plate 15 is formed with a needle hole into which the two sewing needles 13 and 13 are individually inserted and a slit through which the moving knife 14 of the knife mechanism is inserted.
Further, a recess for storing the bed portion 81 of the sewing machine frame 80 is formed on the table 11, and the sewing machine frame 80 is installed in the recess. Further, the table 11 is provided with a large press feed mechanism 40 and a corner knife mechanism 90 on the downstream side in the cloth feed direction of the sewing machine frame 80, and a binder mechanism (not shown except for the binder 12) on the upstream side in the cloth feed direction. Is arranged.

The sewing machine frame 80 mainly includes a bed portion 81 installed on the table 11, a vertical trunk portion 82 erected therefrom, and an arm portion 83 extending horizontally from the upper portion thereof.
A sewing machine motor 16 is disposed below the sewing machine frame 80, and a rotating drive force transmitted from the sewing machine motor 16 to the sewing machine frame 80 via a belt (not shown) is transmitted to the hook mechanism inside the bed portion 81. The shaft is supported in a state along the Y-axis direction, and an upper shaft that transmits the vertical movement driving force of the needle vertical movement mechanism 70 from the sewing machine motor 16 is provided in the arm portion 83 along the Y-axis direction. It is supported.
Pulleys are fixedly mounted on the upper shaft and the lower shaft, respectively, and are connected by a timing belt passed through the vertical body portion 82 of the sewing machine frame 80.

(Needle vertical movement mechanism)
The needle up-and-down movement mechanism includes two needle bars that individually hold the sewing needles 13 and 13 at the lower end, a needle bar holding that can be switched between holding and releasing the two needle bars, and a sewing machine motor 16. It has a crank mechanism that converts the rotational drive to vertical drive and applies it to the needle bar holder, and can switch between sewing with both the left and right sewing needles 13 and sewing with only one needle It is said.

(Female mechanism)
The knife mechanism includes a moving knife 14 that forms a linear cut, a knife motor 17 that moves the moving knife 14 up and down, and an air cylinder 14 a that switches between power transmission and power cutting by the knife motor 17.
The moving knife 14 is disposed adjacent to the two needles 13 and 13 and downstream of the two needles 13 and 13 in the cloth feeding direction (left side in FIG. 2).
The knife motor 17 is driven to rotate together with the body cloth C feeding operation, and the moving knife 14 is moved up and down by the transmission mechanism to repeatedly form a cut according to the knife width to form a linear cut.

(Binder mechanism)
The binder mechanism has an inverted T-shaped cross section, a binder 12 that is set so as to wind a ball and is sent out along the longitudinal direction, and a support mechanism (not shown) that supports the binder 12 so as to be movable up and down. is doing.
The support mechanism includes an air cylinder (not shown) that serves as a drive source for the lifting and lowering operation of the binder 12, an electromagnetic valve 18 that drives the air cylinder (see FIG. 3), and the driving force of the air cylinder is changed to a moving force in the vertical direction. And a plurality of link bodies to be applied to the binder 12. At the time of sewing, the binder mechanism lowers the binder 12 by the air cylinder so that the tip of the binder 12 is between the needle drop positions of the two needles 13 and 13. And, in a state where the ball cloth is held around the binder 12 so as to have a cross-sectional shape of the binder 12 in cooperation with a pair of large pressing members 41, 41 of the large pressing feed mechanism 40 described later, The sewing is performed on the body cloth C.

(Large press feed mechanism)
The large presser feed mechanism 40 is individually disposed below the large pressers 41, 41 and a pair of large pressers 41, 41 that press the body cloth C from above at positions on both sides of the sewing needles 13, 13. Two laying plates 47 (see FIG. 1) on which the body cloth C is placed during cloth feeding, a support body 42 that supports the two large pressers 41, 41 so as to be movable up and down, and a large press against the support body 42 The air cylinder 43 that moves 41 and 41 up and down, the electromagnetic valve 44 that controls the driving of the air cylinder 43 (see FIG. 3), and the body cloth C pressed by the large pressers 41 and 41 are moved in the cloth feed direction E. A pulse motor 45 (see FIG. 2) as a driving means, a servo motor 46 that assists in driving the pulse motor 45, a pulley 48 that rotates by the output of the pulse motor 45, and a servo motor 46 It includes a pulley 49 which rotates, and a timing belt 50 stretched between the pulleys 48 and 49 by.

  Each of the large pressers 41, 41 is a rectangular flat plate, and is arranged side by side in the Y-axis direction with the two needles 13, 13 interposed therebetween, and the support 42 has a longitudinal direction along the X-axis direction. It is supported. In each of the large pressers 41, 41, a presser plate of a ball cloth operated by an air cylinder (not shown) is stored. Each presser plate can be folded so that both ends of the ball are wrapped around the binder 12 and can be maintained in this state.

The timing belt 50 is provided along the X-axis direction. One end of the timing belt 50 is stretched over the pulley 48 and the other end is stretched over the pulley 49. Further, the timing belt 50 is connected to the support body 42, and by driving the pulse motor 45, it is possible to arbitrarily position the two large pressers 41, 41 in the X-axis direction.
Further, as described above, one pulley 48 is rotationally driven by the pulse motor 45, and the other pulley 49 is rotationally driven by the servo motor 46. Therefore, the servo motor 46 is driven in the same rotational direction as the pulse motor 45. Thus, the servo motor 46 can assist the application of torque when the large presser 41 is moved by the pulse motor 45.
In the non-assist state where only the pulse motor 45 is driven, the servo motor 46 is deenergized so that no torque load is generated from the servo motor 46.

(Corner knife mechanism)
The corner knife mechanism 90 is arranged below the table 11 and on the downstream side (left side in FIG. 2) in the cloth feeding direction with respect to the moving knife 14 in the passage path of the large pressers 41 and 41 by the large press feed mechanism 40. The body cloth C conveyed to the work position of the corner knife 91 by the large press feed mechanism 40 is penetrated through the corner knife 91 from below to form substantially V-shaped cuts V at positions that are both ends of the straight cut. .
That is, the corner knife mechanism 90 includes a corner knife unit including a corner knife 91 and an air cylinder 92 that moves the corner knife 91 up and down, one on each of the sewing start end side and the sewing end end side. And a drive motor 94 for moving and positioning the corner knife unit on the sewing start end side along the X-axis direction with respect to the fixed corner knife unit on the sewing end side, and an electromagnetic valve 93 for driving each air cylinder 92. ing.
The corner knife 91 has a V-shaped cross section viewed from above, and forms a V-shaped cut V by penetrating each fabric from below.

(Control system for hem stitch machine)
FIG. 3 is a block diagram showing a control system of the edge stitch sewing machine 10. As shown in this figure, the operation control means 60 has a display panel 64 for displaying various control status information, a setting switch 65 for inputting various settings relating to sewing, and an activation switch 66 for inputting the start of sewing. Are connected via an input / output circuit (not shown).

The operation control means 60 includes a sewing machine motor 16, a pulse motor 45, a servo motor 46, a female motor 17, and a corner knife driving motor 94 to be controlled via drivers 16 a, 45 a, 46 a, 17 a, and 94 a, respectively. Connected.
The operation control means 60 includes an air cylinder that moves the binder 12 up and down, an air cylinder 43 that raises and lowers the large pressers 41 and 41, an air cylinder 92 that raises and lowers the corner knife 91, and a standby state of the moving knife 14. Solenoid valves 18, 44, 93, 20 that control the respective operations of the air cylinder to be switched to the usable state are connected via drivers 18 a, 44 a, 93 a, 20 a.
Further, a spindle sensor 67 for detecting the axis angle of the spindle that is rotationally driven by the sewing machine motor 16 is connected to the operation control means 60 via an interface 67a.

  The operation control means 60 includes a CPU 61 that performs various controls, a ROM 62 that stores a control program, a RAM 63 that stores various data relating to processing of the CPU 61 in a work area, and various setting data for sewing (for example, And EEPROM 69 as storage means for storing rewritable feed pitch, spindle rotation speed (rotation speed, etc.).

(Intermittent feed and assist control)
In the sewing machine 10, the sewing needle 13 comes out of the body cloth C in synchronization with the continuous feed for continuously dropping the needle while moving the large presser 41 at a constant speed and the vertical movement of the sewing needle 13. It is possible to perform intermittent feeding for moving the large presser 41 during the period. Since continuous feed is well known, intermittent feed will be described here.
FIG. 4 is a diagram showing the relationship between the change in the angle of the main shaft that is rotationally driven by the sewing machine motor 16 and the drive timing of the pulse motor 45 that sends the large presser 41. G1 indicates the change in the main shaft angle, and G2 indicates the pulse. The drive timing of the motor 45 is shown. In FIG. 4, the horizontal axis represents time, and the band B represents a period during which the sewing needle 13 is stuck in the body cloth C. In the intermittent feed, as shown in the figure, the pulse motor 45 is driven in a predetermined spindle angle period that avoids the period of sticking into the body cloth C with respect to the spindle that rotates continuously.

  FIG. 5A is a diagram showing a speed command V1 in a single drive of the pulse motor 45 in intermittent feed and a speed command V2 of the servo motor 46 that assists this, and FIG. 5B is a pulse in intermittent feed. FIG. 5 is a diagram showing a necessary torque T1 for a single drive of a motor 45 and an auxiliary torque T2 of a servo motor 46 that assists the motor 45.

When the intermittent feed is executed, the speed pattern of the pulse motor 45 as shown in the speed command V1 of FIG. 5A is calculated according to the set rotational speed (set spindle speed) of the sewing motor 16 and the set feed pitch. The That is, when the CPU 61 described above receives the spindle rotation speed and feed pitch setting input from the setting switch 65, the CPU 61 sets a spindle angle section in which intermittent feed is possible based on this, and operates within the section for the feed pitch. A speed pattern for driving the pulse motor 45 by the amount is calculated. Such a speed pattern determination method is well known, for example, the amount of movement corresponding to the feed pitch within the time determined by the spindle speed within the acceleration period, constant speed period, deceleration period length and constant speed period speed. The process of determining so as to satisfy the condition of driving only is performed.
At the time of sewing, the CPU 61 monitors the spindle angle with the spindle sensor 67, and when the sewing needle 13 reaches the spindle angle that has come out of the body cloth C, it sequentially outputs a command value according to the speed pattern to the driver 45a at a predetermined cycle. Operation control is performed so that the pulse motor 45 is driven according to the speed pattern. Such operation control is performed for each needle.

Next, assist control of the pulse motor 45 by the servo motor 46 will be described.
In order for the pulse motor 45 to operate in accordance with the speed command V1, the torque of the necessary torque T1 shown in FIG. That is, high torque in the positive direction is required in the acceleration period P1, moderate torque in the positive direction is required in the constant speed period, and high torque in the direction of deceleration is required in the deceleration period P2. In FIG. 5B, the required torque is shown to be zero during the stop period, but in actuality, the pulse motor 45 applies a static torque to maintain the large presser 41 in the stop state. Is in a state of being.
The servo motor 46 is controlled to start applying torque prior to the start of the acceleration period P1 of the pulse motor 45 and end applying torque after the end of the acceleration period P1. Similarly, the servo motor 46 starts to apply torque prior to the start of the deceleration period P2 of the pulse motor 45, and performs operation control so as to end the application of torque after the end of the deceleration period P2. Is called. In addition, in the case of acceleration, the extent to which the assist torque application is started is determined by, for example, always ensuring that the assist torque is already applied at the moment when the acceleration or deceleration torque application of the pulse motor 45 is started. If this is done, the start timing difference may be slight. The same applies to deceleration.
In the acceleration period P1, the assist torque applied by the servo motor 46 is applied so as to have a uniform torque value throughout the application period as shown in FIG. 5B, and the torque value is a pulse. It is set to be less than the static torque of the motor 45. That is, the servo motor 46 starts applying assist torque ahead of the pulse motor 45. However, since the torque value is less than the static torque, the large presser 41 does not move unless the pulse motor 45 starts acceleration. ing.
The deceleration period P2 is also applied so that the assist torque of the servo motor 46 is uniform throughout the application period.

  FIG. 6A is a diagram showing a command value (solid line) of the pulse motor 45 when no assist torque is applied at the start of acceleration and a torque value actually applied to the timing belt 50 (dotted line). B) is a diagram showing a command value (solid line) of the pulse motor 45 and an actual torque value (dotted line) applied to the timing belt 50 when assist torque is applied at the start of acceleration. When the assist torque is not applied, as shown in FIG. 6 (A), it is necessary to increase the command value for rising, so that a large overshoot occurs. However, when the assist torque is applied, FIG. 6 (B ), It is possible to reduce the rise command value and suppress overshoot.

FIG. 7 shows a control block diagram of the servo motor 46 for realizing the application of the assist torque shown in FIG.
The servo motor 46 is provided with an encoder 46b that detects the shaft angle (position detection) of its output shaft. The control system of the servo motor 46 differentiates the detection position of the encoder 46b at a predetermined period to obtain a detection speed. 51, a speed amplifier 52 that obtains a deviation between the speed command from the CPU 61 and the detected speed and outputs a torque command, a driver 46a that controls torque by current control of the servo motor 46, a torque command and feedback from the driver 46a And a current amplifier 53 that outputs a command to the motor driver 46a in accordance with the deviation from the current.

On the other hand, when the CPU 61 calculates the speed command V1 in the single drive of the pulse motor 45 in the intermittent feed described above, the speed command V2 of the servo motor 46 for realizing the torque application of the auxiliary torque T2 in FIG. Is calculated. As shown in FIG. 5A, the servo motor speed command V2 corresponding to the acceleration period of the pulse motor 45 is set to be equal to the acceleration of the pulse motor 45 and started before the start of acceleration of the pulse motor 45. A pattern is calculated in which the speed is maintained at a point at which a predetermined speed slightly higher than the speed of the constant speed period of the pulse motor 45 is reached and the predetermined period elapses from the end of the acceleration period of the pulse motor 45. The speed command V2 of the servo motor 46 at the time of acceleration calculates a command for accelerating to a speed higher than the speed of the constant speed period of the pulse motor 45, but is not limited to this, and the constant speed period of the pulse motor 45 is calculated. It is only necessary to accelerate to a speed that is equal to or somewhat slower than
Further, as shown in FIG. 5A, the speed command V2 corresponding to the deceleration period of the pulse motor 45 is pulsed by making the acceleration equal to that of the pulse motor 45 and starting before the start of deceleration of the pulse motor 45. When the motor 45 is always kept at a lower speed and reaches the stop speed (speed 0), the reverse rotation speed command is issued, the predetermined reverse rotation speed is maintained, and the predetermined period elapses from the end of the deceleration period of the pulse motor 45. The pattern that ends is calculated.

With this speed command V2, the spindle sensor 67 is monitored during intermittent feeding, and the speed command V2 is output from the CPU 61 when the output start phase of the speed command V2 preceding the speed command V1 of the pulse motor 45 is reached. Is done. As a result, the servo motor 46 is driven and an auxiliary torque is applied to the pulley 49. However, since the auxiliary torque is less than the static torque of the pulse motor 45, tension is applied to the timing belt 50, but the pulley 49 hardly rotates. For this reason, although the position detection of the encoder 46b is fed back and the torque command value increases, the motor driver 46a has a built-in torque limiter, and a predetermined auxiliary torque (a predetermined value less than the static torque of the pulse motor 45). The servomotor 46 is energized so that the upper limit 41 is not exceeded, and only the auxiliary torque is applied to the timing belt 50 while the large presser 41 is stopped.
When the output start phase of the speed command V1 of the pulse motor 45 is detected, the speed command V1 is output and the driving of the pulse motor 45 is started. At this time, since the auxiliary torque has already been applied to the timing belt 50, as shown in FIG. 6B, the fluctuation range of the applied torque to the belt due to the start of driving of the pulse motor 45 is reduced, and the overshoot is also reduced. .
Then, during the acceleration period, the command output is performed so that the speed command V2 is always higher than V1, so the auxiliary torque T2 becomes constant as shown in FIG. The operation up to the constant speed is performed stably.
As described above, the configuration of the control system of the operation control means 60 and the servo motor 46 functions as the servo control means.

Next, in the deceleration period, the speed command V2 is output again from the CPU 61 when the output start phase of the speed command V2 preceding the speed command V1 of the pulse motor 45 is reached. As a result, the servo motor 46 is driven and an auxiliary torque is applied to the pulley 49. At this time, since the pulse motor 45 is driven in accordance with a speed command V1 that is faster than the speed command V2, a deceleration torque acts on the pulley 49 against it. Also in this case, the position detection of the encoder 46b is fed back and the torque command value increases to the reverse rotation side. In this case also, the servo does not exceed the reverse rotation side auxiliary torque determined by the torque limiter of the motor driver 46a. The motor 46 is energized and controlled.
When the speed command V1 of the pulse motor 45 reaches the deceleration period, the pulse motor 45 starts to decelerate. At this time, since the auxiliary torque has already been applied to the timing belt 50, the fluctuation range of the applied torque to the belt due to the start of deceleration of the pulse motor 45 is reduced. In the deceleration period, the command output is performed so that the speed command V2 is always lower than V1. Therefore, as shown in FIG. 5 (B), the auxiliary torque T2 is constant and the deceleration of the large presser 41 starts. The operation up to the stop is performed stably.

(Intermittent feed operation in the edge stitch sewing machine)
FIG. 8 is a control flowchart of the intermittent feeding operation of the edge stitch sewing machine 10. The intermittent feed operation by the operation control means 60 will be described according to this.
First, when the start switch 66 is pressed (step S1), the large presser 41 is conveyed to the set position toward the upstream side in the sewing feed direction by driving the pulse motor 45 (step S2).
When the body cloth C and the ball cloth are set on the large presser 41, the driving of the sewing machine motor 16 is started. Then, the drive of the servo motor 46 is started by the speed command V2 in a predetermined main shaft phase, and acceleration assist torque is applied (step S4). Subsequently, the pulse motor 45 is driven by the speed command V1 at a predetermined needle up phase (step S5). Next, prior to the deceleration period of the pulse motor 45, the auxiliary torque for deceleration is applied by the servo motor 46 (step S6).
Then, the large press is stopped by stopping the pulse motor 45 (step S7). Then, stitch formation by needle drop, linear cut formation by driving of a moving knife, and the like are performed, and if the needle vertical movement mechanism has a needle swing function such as back tack sewing, needle swing is also performed (step S8). ) Waiting for the sewing needle 13 to rise (step S9), it is determined whether the sewing end position has been reached by counting the spindle speed (step S10). If not reached, the process returns to step S4 to send The formation of the seam is repeated, and if the sewing end position has been reached, the pulse motor 45 is driven to move the large presser 41 to the cutting position of the corner knife (step S11). Then, cuts by the corner knife are formed on both sides of the straight cut, the pulse motor 45 is driven again, the large presser 41 is moved to the stop position, and the sewing work is finished (step S12).

(Effect of embodiment)
In the edge stitch sewing machine 10, the large presser feed mechanism 40 includes a servo motor 46 that assists a pulse motor 45 that is a drive source, and an auxiliary torque for acceleration and a deceleration when the pulse motor 45 is intermittently driven up and down, respectively. Therefore, it is possible to suppress overshoot due to driving of the pulse motor 45, effectively reduce vibration such as damping, and realize stable intermittent feeding. As a result, even during high-speed intermittent feed, vibration can be similarly prevented and the operation can be stabilized, so that high-speed intermittent feed drive can also be realized.

Further, the edge stitch sewing machine 10 starts the application of the acceleration and deceleration auxiliary torque by the servo motor 46 prior to the acceleration or deceleration of the rise of the pulse motor 45, and therefore the torque fluctuation of the pulse motor at the start of acceleration / deceleration. Thus, it is possible to further suppress overshoot and reduce vibrations such as damping.
Further, by applying the acceleration and deceleration auxiliary torque by the servo motor 46 until after the acceleration period or the deceleration period of the pulse motor 45 is completed, vibrations such as damping at the completion of the period are more effectively suppressed. It becomes possible.

The perspective view which shows the schematic structure of the whole bead stitch sewing machine concerning embodiment to invention is shown. The front view of a bead stitch sewing machine is shown. It is a block diagram which shows the control system of a bead stitch sewing machine. It is a diagram which shows the relationship between the angle change of a main axis | shaft, and the drive timing of the pulse motor which sends large press. FIG. 5A is a diagram showing a speed command and a servo motor speed command in a single intermittent feed of the pulse motor, and FIG. 5B is a torque required for a single drive of the pulse motor and a servo motor. It is a diagram which shows the auxiliary | assistant torque. FIG. 6A is a diagram showing the command value of the pulse motor when the auxiliary torque is not applied during acceleration and the torque value applied to the timing belt, and FIG. 6B is the case where the auxiliary torque is applied during acceleration. It is a diagram which shows the command value of a pulse motor, and the torque value concerning a timing belt. It is a control block diagram of a servo motor for realizing provision of auxiliary torque. It is a control flowchart of the intermittent feeding operation | movement of a bead stitch sewing machine.

Explanation of symbols

10 Sewing machine 11 Table (mounting table)
13 Sewing needle 16 Sewing machine motor 40 Large presser feed mechanism 41 Large presser 45 Pulse motor 46 Servo motor 60 Operation control means (servo control means)
61 CPU
62 ROM
C Body material

Claims (2)

A pair of left and right needle bars that hold the sewing needles individually and move up and down by the sewing machine motor;
A needle up-and-down movement mechanism for moving up and down each needle bar;
A pair of left and right large pressers that hold the body fabric on the mounting table together with the ball cloth,
A large press feed mechanism that moves the pair of large presses along a predetermined cloth feed direction by driving a pulse motor;
In an edge stitch sewing machine that performs sewing while intermittently feeding the large presser in synchronization with the vertical movement of the sewing needle,
The large press feed mechanism has a servo motor that assists intermittent driving of the pulse motor,
An edge stitch sewing machine comprising: servo control means for controlling the servo motor to apply acceleration torque during acceleration of rising during intermittent drive of the pulse motor and to apply deceleration torque during deceleration before stopping. .   The servo control means controls the servo motor to start applying acceleration torque immediately before acceleration of rising of the pulse motor and to start applying deceleration torque immediately before deceleration before stopping. The rim stitch sewing machine described.

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