JP2011115258A - Binding sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a binding sewing machine for stably performing a cloth cutting operation while evading or reducing the damage of a cloth and the decline of sewing quality. <P>SOLUTION: The binding sewing machine includes a needle vertically moving mechanism whose driving source is a sewing machine motor, a cloth feeding mechanism whose driving source is a feed motor, a knife mechanism for vertically moving a center knife by a knife motor relative to a fixed knife and forming a straight cut, an operation control means for controlling the knife motor according the vertical movement frequency of the center knife determined corresponding to the carrying speed of an object to be sewn, and a detection means for detecting the operation speed of the knife motor. When the operation speed detected by the detection means has declined by a stipulated value or more relative to the command value of the knife motor, the operation control means executes the control of decelerating the sewing machine motor and the feed motor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sewing machine that forms a cut in a workpiece while performing sewing.

The hem-sewn sewing machine is a sewing machine suitable for forming a pocket by sewing a garment on a garment body fabric and forming a cut in the garment fabric and the garment (hereinafter referred to as a stacked body body). The fabric and the drape are simply referred to as the fabric).
A conventional edge stitch sewing machine includes a cloth feed mechanism that transports a fabric along a binder, a needle up-and-down movement mechanism that moves the fabric to be transported by two needles, and a fabric that is transported by the cloth feed mechanism. On the other hand, a scalpel mechanism that forms a cut between two seams of the fabric by cooperation of a fixed scalpel fixed on the needle plate and a center scalpel that moves up and down is provided.
The ball stitching sewing machine includes a cloth feed mechanism, a needle up-and-down movement mechanism, and a knife mechanism, each having a motor as a driving source, and each of these motors is driven at an appropriate rotational speed to be appropriate. Sewing was done.
That is, the motor that feeds the cloth so that the feed speed is obtained by multiplying the preset sewing pitch by the rotation speed of the sewing machine motor with respect to the set rotation speed (rotation speed) of the sewing machine motor that moves the sewing needle up and down. Was driving. In addition, the knife motor that drives the knife mechanism is driven at a rotational speed that is proportional to the value obtained by dividing the effective cutting length for cutting with a single vertical movement of the center knife relative to the cloth feed speed (for example, , See Patent Document 1).

JP 2006-218189 A

As described above, the conventional stitching machine for the ball edge sewing determines the rotational speed of the female motor on the premise that the center knife is cut with substantially the effective cutting length by one vertical movement.
However, when the fabric is thick or hard, a large resistance is generated when the center knife cuts, causing a reduction in speed of the knife motor and poor cutting. Further, when the fabric is thin or soft, the fabric enters between the fixed knife and the center knife to cause resistance due to pinching, resulting in a reduction in the speed of the knife motor and cutting failure.
If sewing is performed according to the setting in such a state of cutting failure, cutting cannot catch up with the cloth feed speed, and the sewing quality is reduced by damaging the cloth or performing sewing while the cloth is crushed. There was a problem that.

  An object of the present invention is to avoid or reduce damage to fabric and deterioration of sewing quality.

  According to the first aspect of the present invention, there is provided a needle up-and-down movement mechanism that moves the sewing needle up and down by a sewing motor, a cloth feed mechanism that conveys a workpiece along a cloth feed direction on a needle plate by a feed motor, and a fixed knife. On the other hand, according to a knife mechanism that forms a linear cut along the cloth feed direction in the fabric workpiece by moving the center knife up and down by a knife motor, and according to the vertical movement frequency of the center knife determined according to the conveyance speed of the workpiece. An edge stitch sewing machine comprising an operation control means for controlling the female motor is provided with a detection means for detecting the operation speed of the female motor, and the operation control means detects the command value of the female motor by the detection means. Control is performed to decelerate the sewing machine motor and the feed motor when the operating speed drops below a specified value.

  The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the deceleration control by the operation control means is such that once the sewing machine motor and the feed motor are decelerated, sewing of one sewing pattern is performed. The decelerating state is continued until is completed.

  The invention according to claim 3 has the same configuration as that of the invention according to claim 1 or 2, and in the deceleration control by the operation control means, the sewing machine motor and the sewing motor at a ratio equal to the ratio of the speed reduction generated in the female motor. Control for decelerating the feed motor is performed.

In the first aspect of the invention, the speed of the scalpel motor is monitored by the detecting means, and a state where cutting is not performed well (hereinafter referred to as cutting failure) due to a constant speed reduction is detected. The main cause of these cutting failures is a reduction in the speed of the female motor, and a reduction in cutting length can be detected by monitoring the speed reduction.
When a decrease in the cutting length is detected, the sewing motor and the feed motor are controlled to decelerate, thereby avoiding or reducing the occurrence of a state where cutting cannot catch up with the cloth feeding, It becomes possible to avoid or reduce deterioration of the sewing quality.
In addition, when a cutting failure is detected, the sewing machine motor and feed motor are decelerated rather than accelerating the knife motor, reducing the sliding contact between the center knife and the fixed knife and avoiding a decrease in the life of the center knife. However, it is possible to avoid or reduce the breakage of the fabric and the deterioration of the sewing quality.

  In the invention according to claim 2, after the deceleration, the deceleration state is continued until the sewing of one sewing pattern is completed. As described above, because the cause of the cutting failure is due to the characteristics of the fabric, it is normal for a fabric where a cutting failure is detected to continue until the sewing is completed. Even if it recovers, it is often temporary. Therefore, if the control for returning the speeds of the sewing machine motor and the feed motor is performed every time the speed recovery of the knife motor is detected, there is a possibility that the deceleration and the return may be continuously repeated, and the cutting cannot be stably performed. Therefore, as in the present invention, after the deceleration, by performing the control to continue the deceleration state until the sewing of one sewing pattern is completed, stable sewing can be performed, and the sewing quality can be improved even when a cutting defect occurs. It is possible to avoid or reduce the decrease.

  In the invention of claim 3, since the sewing machine motor and the feed motor are decelerated at the same rate as the rate of reduction in the speed of the female motor, the sewing machine motor and the feed motor can be set at speeds appropriate to the cutting speed of the female motor. It is possible to avoid or reduce the deterioration of sewing quality effectively.

It is a perspective view which shows the schematic structure of the whole edge stitch sewing machine. It is explanatory drawing which shows the relationship of the linear cut | interruption by a center knife, the cut | interruption by a corner knife, and the arrangement | positioning of the seam by two needles. It is a perspective view of a needle up-and-down movement mechanism. It is a perspective view of the state which can cut | disconnect a knife mechanism and a needle | hook up-and-down moving mechanism. It is a perspective view of the cutting regulation state of a knife mechanism and a needle up-and-down movement mechanism. FIG. 5 is a perspective view of a knife mechanism viewed from a direction different from that in FIGS. 3 and 4. It is the figure which looked at the center knife from the Y-axis direction, FIG. 7 (A) shows the state in the top dead center in the cutting possible state mentioned above, and FIG. 7 (B) shows the state in the bottom dead center. It is a block diagram which shows the control system containing the operation control means of a bead stitch sewing machine. It is a flowchart which shows the whole flow of operation | movement control of a bead stitch. It is a flowchart which shows control of the setting operation | movement in the operation control of a bead stitch. It is a flowchart which shows control of the sewing operation | movement in the operation control of a bead stitch. It is a flowchart which shows the sewing deceleration control performed during sewing.

(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 a bead stitch sewing machine 10. In the present embodiment, the respective directions are determined with reference to the XYZ axes shown in the drawings, and the Z-axis direction coincides with the vertical movement direction of the center knife, which will be described later, and is a plane for performing the sewing work. Is perpendicular to the Z-axis direction and is parallel to the work plane and the direction in which the cloth is fed is the X-axis direction, and the direction parallel to the work plane and perpendicular to the X-axis direction is the Y-axis direction.

The edge stitch sewing machine 10 sews a ball cloth B to a body cloth M by two parallel straight seams T formed by two needles 41 and 41 and follows a feeding direction F of these cloths. The sewing machine forms a straight cut (straight cut) S and substantially V-shaped cuts V (see FIG. 2) at both ends of the cut S.
Then, the edge stitch sewing machine 10 serves as a cloth feed mechanism that feeds a cloth made up of a table 11 serving as a sewing work table, a sewing machine frame 12 disposed on the table 11, a body cloth M and a ball cloth B. Large presser feed mechanism 20, binder 30 that presses the cloth B from the upper side of the body material M, and needle up and down movement that is in the vicinity of the downstream side in the fabric feed direction F of the binder 30 and performs needle drop on both sides of the binder 30 A mechanism 40, a knife mechanism 50 for raising and lowering the center knife 51 on the downstream side in the cloth feeding direction of each sewing needle 41 to form a cut in each of the fabrics B and M, and a position approximately V at both ends of the linear cut S A corner knife mechanism 90 that forms a letter-shaped break V and an operation control means 80 that controls each of the above parts 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 the bead stitch sewing machine 10 is used in a state where the table upper surface is horizontal. The upper surface of the table 11 is formed in a long rectangular shape along the cloth feeding direction F, that is, the X-axis direction. A large press feed mechanism 20 and a binder 30 are arranged on the table 11, and a corner knife mechanism (not shown) is arranged below the table 11.
A needle plate 13 is provided at a position below the two sewing needles 41, 41 in the table 11. The needle plate 13 is provided with a needle hole corresponding to each of the two needles 41 and 41, and a horizontal hook (not shown) is provided below each needle hole. That is, the sewing thread inserted into each of the sewing needles 41, 41 is captured by the corresponding horizontal hook at the lower side of the needle plate 13, and is entangled with the lower thread fed from the horizontal hook so that the sewing is performed. It has become.
Furthermore, a slit into which the center knife 51 is inserted is formed in the middle of the two needle holes of the needle plate 13 and on the front side in the cloth feeding direction F, and in cooperation with the center knife 51 inside the slit. A fixed knife (not shown) for cutting the fabric is disposed.

  The sewing machine frame 12 extends along the Y-axis direction from the bed portion 12a disposed immediately next to the intermediate position in the longitudinal direction of the table 11, the vertical body portion 12b erected from the bed portion, and the upper end portion of the vertical body portion 12b. The arm portion 12c is provided, and the main components of the needle vertical movement mechanism 40 and the knife mechanism 50 are stored in the arm portion 12c. Further, the two needles 41 and 41 and the center knife 51 are supported in a suspended manner from the lower end portion on the distal end side of the arm portion 12c.

(Needle vertical movement mechanism)
FIG. 3 is a perspective view of the needle vertical movement mechanism 40. The needle up-and-down moving mechanism 40 includes two sewing needles 41 and 41 constituting two needles, two needle bars 42 holding the respective sewing needles 41 of the two needles at the lower end, and each needle bar 42. A support frame 43 that is slidably supported along the longitudinal direction, a needle bar holder 44 that simultaneously holds the two needle bars 42, a sewing machine spindle motor 45 that is a drive source for the sewing needle vertical movement, and a sewing machine spindle motor 45 (FIG. 8), the sewing machine main shaft 46 that is rotationally driven, a rotary weight 47 that is fixedly connected to one end portion of the sewing machine main shaft 46, and one end portion is connected to a position eccentric from the rotation center of the rotary weight 47. And a crank rod 48 having the other end connected to the needle bar holder 44, and a rotation shaft 49 having one end connected to the support frame 43 and applied with a rotation driving force by a rotation driving source (not shown). have.

The support frame 43 is pivotally supported by a rotation shaft 49, and the rotation shaft 49 is rotatably supported along the Y-axis direction inside the arm portion 12c. On the other hand, each needle bar 42 is supported by the support frame 43 in parallel with each other along the direction orthogonal to the rotation shaft 49. Further, the support frame 43 is arranged so that each needle bar 42 is generally along the Z-axis direction. When turning force is applied within a predetermined angle range from the rotation shaft 49, the support frame 43 is arranged at the lower end of each needle bar 42. The positioned sewing needles 41 and 41 are moved in parallel with the X-axis direction, that is, the cloth feeding direction.
The rotary shaft 49 performs a so-called back tack sewing that prevents the sewing thread at the sewing start and the sewing end from being unwound by performing sewing with a short stroke in the direction opposite to the cloth feeding direction and performing sewing so as to overlap from above. In order to perform this, a driving force is applied from a rotational driving source (not shown). Therefore, at the time of normal sewing, the rotation shaft 49 is held in a state where each needle bar 42 is parallel to the Z-axis direction.

  The sewing machine main shaft 46 is also rotatably supported along the Y-axis direction inside the arm portion 12 c, and a rotational driving force of full rotation is applied by the sewing machine main shaft motor 45. When the sewing machine main shaft 46 is rotated, the rotary weight 47 rotates in the same manner, and one end portion of the crank rod 48 performs a circular motion around the sewing machine main shaft 46, and the other end portion has a circular motion Z on one end side. Only the axial movement component is transmitted to the needle bar holder 44 so that each needle bar 42 reciprocates up and down. With this structure, the frequency of the vertical movement of the needle bar 42 matches the number of rotations of the sewing machine spindle motor 45.

(Female mechanism)
4 is a perspective view of the knife mechanism 50 and the needle up-and-down movement mechanism 40 in a state where cutting is possible, FIG. 5 is a perspective view of the knife mechanism 50 and the needle up-and-down movement mechanism 40 in a cutting restriction state, and FIG. 6 is different from FIGS. It is the perspective view of the knife mechanism 50 seen from the direction.
The knife mechanism 50 includes a center knife 51 that forms a linear cut by vertical movement, and a fixed knife (not shown) that is fixed below the needle plate 13 and slidably contacts the center knife 51 to promote cutting of the fabrics B and M. A female knife 52 provided with a center knife 51 at its lower end and supported so as to be slidable along the Z-axis direction in the arm 12c, and a knife bar 52 fixed to the sewing machine frame so as to be slidable along its longitudinal direction. A metal bearing 53 to be supported, a female bar holder 54 fixedly installed at an intermediate position in the longitudinal direction of the female bar 52, a piece 55 provided on the female bar holder 54, and fixedly supported by the sewing machine frame 12. A guide frame 56 that guides movement in the vertical direction without rotating the knife rod 52, a knife motor 57 that is a stepping motor that is a drive source for the vertical movement of the center knife 51, A crank rod 59 having one end connected via an eccentric cam 58 mounted eccentric to the output shaft 57b of the motor 57, and an input arm 60 having a swing end connected to the other end of the crank rod 59. A rotation shaft 61 that rotates by being supported by a bearing 69 that is connected to the input arm 60 and fixed to the sewing machine frame, and a rotation shaft 61 at the other end of the rotation shaft 61. An output arm 62 that is integrally formed orthogonally and swings, a first link body 63 having one end connected to the swing end of the output arm 62, and the other end of the first link body 63 A second link body 64 that connects the head and the scalpel bar 54, an air cylinder 65 that serves as a drive source for switching the cutting state of the center knife 51 between the cuttable state and the cutting restricted state, and one end of the plunger of the air cylinder 65. Oscillating motion is performed by connecting the parts A bell crank 66, a connecting link body 67 connecting the connecting point J of the first link body 63 and the second link body 64 and the other end of the bell crank 66, and a plunger when the air cylinder 65 protrudes. And a stopper 68 for stopping at a predetermined position.

  When the air cylinder 65 is in the retracted position (the state shown in FIG. 4), the knife mechanism 50 is in a severable state in which the rotational driving force of the knife motor 57 is converted into a vertical reciprocating motion to the center knife 51 and transmitted. When the cylinder 65 is in the forward position (the state shown in FIG. 5), it is possible to switch to a cutting restriction state in which the rotational driving force of the knife motor 57 is not transmitted to the center knife 51.

That is, the bell crank 66 is supported by the sewing machine frame 12 so that the middle position in the longitudinal direction becomes the fulcrum of oscillating and the oscillating axis of the fulcrum is directed in the Y-axis direction. When the air cylinder 65 is in the retracted state, the bell crank 66 swings the output arm 62 at the connection point J between the first link body 63 and the second link body 64 via the connection link body 67. The position is maintained at a position lower than the center line.
When the female motor 57 rotates in this state, one end of the crank rod 59 is moved circularly by the eccentric cam 58 mounted on the output shaft 57b oriented in the Y-axis direction. The crank rod 59 moves back and forth at the other end by a circular motion at one end thereof, and swings the input arm 60. As a result, the rotation shaft 61 rotates and swings the output arm 62.
The connection point J between the first link body 63 and the second link body 64 has a radius of the connection link body 67 centering on one end of the connection link body 67 (connection end with the bell crank 66). It is restricted to a state where only arc motion is possible. Then, the connecting point J performs the arc motion, so that the swinging motion of the output arm 62 moves the knife bar 52 and the center knife 51 up and down via the first link body 63 and the second link body 64. A cutting operation is performed.

On the other hand, when the air cylinder 65 is in the advanced state (the state of FIG. 5), the plunger of the air cylinder 65 is stopped at the position where it abuts against the stopper 68, and the bell crank 66 is The connection point J between the first link body 63 and the second link body 64 is pulled up and maintained at a position on the center line of the swing of the output arm 62.
The distance between the centers of rotation at both ends of the first link body 63 is set to a length that matches the swing radius of the output arm 62. When the output arm 62 starts to swing by driving the knife motor 57 in a state where the connection point J is located on the center line of the swing of the output arm 62, the first link body 63 is also centered on the connection point J. As a result, the second link body 64 is not applied with any driving force. Accordingly, the center knife 51 does not move up and down and remains stopped.
Accordingly, the air knife 65 is driven so that the center knife 51 can be switched between the cutting-capable state and the cutting restriction state.

FIG. 7 is a view of the center knife 51 as viewed from the Y-axis direction. FIG. 7A shows the state at the top dead center in the above-described cuttable state, and FIG. 7B shows the state at the bottom dead center. Indicates.
The center knife 51 has a pointed portion 51a that protrudes downward and a portion that is inclined downward from the upstream side to the downstream side in the cloth feeding direction F by the large presser 2 and moves up and down. And a cutting blade portion 51b that is in sliding contact with the fixed knife and forms a cut in the sewing product. The center knife 51 is set so that the lower end portion of the pointed portion 51 a is positioned higher than the upper surface of the needle plate 13 in the cutting restricted state. Further, the center knife 51 is lowered when the cutting restriction state is switched to the cuttable state, whereby the pointed portion 51a is pierced by the cloths B and M on the needle plate 13, and the knife motor 57 in the cuttable state The height is set so that the fabrics B and M are cut almost only by the cutting edge portion 51b by the vertical movement by rotation. That is, the cutting length in the X-axis direction (start cutting length) by the portion where the center knife 51 is pierced by the fabrics B and M at the top dead center in the cuttable state is E1, and the center knife at the bottom dead center. When the cutting length in the X-axis direction by the portion where 51 is pierced by the fabrics B and M is E2, the effective cutting length E which is the length along the cloth feeding direction of the cutting edge portion 51b is E2-E1 It becomes.

(binder)
The binder 30 includes a bottom plate portion 31 that is a long flat plate, a standing plate portion 32 that is erected vertically on the upper surface along the longitudinal direction of the bottom plate portion 31, and a downstream end in the cloth feeding direction of the standing plate portion 32. A guide member 33 that guides the ball cloth B while avoiding the center knife 51 and a longitudinal guide that guides the both ends in the width direction of the ball cloth B so as to be fed along both surfaces of the standing plate portion 32 respectively. (Not shown).
The binder 30 is supported by a support mechanism (not shown) including an air cylinder, and is retracted away from the position below the needles 41 and 41 when not in use, as shown in FIG. And in use, it is set to the needle plate position by driving the air cylinder.

The bottom plate portion 31 is formed in a rectangular shape, and is supported so that, when in use, the longitudinal direction thereof is parallel to the X-axis direction and the bottom surface thereof is placed facing the top surface of the table 11. Yes. In addition, a substantially U-shaped notch (not shown) is formed at the front end portion of the bottom plate portion 31 in the cloth feeding direction so that the two sewing needles 41 and 41 respectively perform needle dropping.
The standing plate portion 32 is entirely flat except for a portion in the vicinity of the guide member 33, and on the upper surface of the bottom plate portion 31, the bottom plate portion is located at an intermediate position in the width direction (Y-axis direction) of the bottom plate portion 31. It is erected vertically with the longitudinal direction aligned with 31. That is, the binder 30 is integrally formed so that the bottom plate portion 31 and the upright plate portion 32 have an inverted T shape when viewed from the longitudinal direction.

Then, when the ball cloth B is set on the needle plate 13 so as to overlap the upper side of the body cloth M, the binder 30 is placed from above, and both ends in the width direction of the ball cloth B (Y-axis direction in FIG. 6). The large presser to be described later is formed by folding the portion up from both ends in the width direction of the bottom plate portion 31 and further extending both ends in the width direction of the ball cloth B along the side surfaces on both sides of the standing plate portion 32, respectively. 21 and 21 are held by folding plates. In other words, the ball cloth B is in a state of being lined from one side surface of the standing plate portion 32 to the other side surface 32 through the bottom plate portion 31. In this way, while the ball cloth B and the body cloth M are being set so as to wind the ball cloth B around the binder 30, sewing is performed with the two needles 41 and 41 on both sides of the standing plate portion 32 and the center knife. A straight cut line S is formed by the vertical movement of 51.
Further, a guide member 33 is provided immediately downstream in the cloth feeding direction F of the binder 30 so as not to be torn by the center knife 51. The guide member 33 is bifurcated in the same direction F so that the shape in plan view is substantially V-shaped. With this shape, both ends in the width direction of the ball cloth B are guided in a direction away from the upright plate portion 32 and are guided in a direction to avoid the center knife 51 when the cloth is fed.

(Large press feed mechanism)
The large presser feed mechanism 20 stores a pair of folding plates (not shown) that press each of the both ends in the width direction of the ball cloth B set on the binder 30, and stores each folding plate and both sides of the binder 30 in the width direction. Large pressers 21 and 21 that hold the body cloth from above, a support 22 that supports these large pressers 21 and 21, and an air cylinder (not shown) that moves the large pressers 21 and 21 up and down via the support 22 And a feed motor 23 (FIG. 8) for moving the cloth B and the body cloth M pressed by the large pressers 21 and 21 in the cloth feed direction F via the support 22.
Each of the large pressers 21 and 21 is a rectangular flat plate, and each of the large pressers 21 and 21 is supported by the support body 22 in a state where the longitudinal direction is along the X-axis direction. The large pressers 21 and 21 are supported so that the flat plate surfaces thereof are parallel to the XY plane. Then, it can be switched to two upper and lower positions by driving the air cylinder. When the air cylinder is in the upper position, it is separated from the upper surface of the table 11, and the upper surface of the table 11 is at the lower position. The two large pressers 21 and 21 are supported in a state of being separated from each other in the Y-axis direction so that at least the standing plate portion 32 of the binder 30 can pass between them.
The support body 22 is supported on the table 11 so as to be movable along the X-axis direction, and the two large pressers 21 and 21 supported by the support body 22 are disposed on both sides of the vertical movement path of the two needles 41 and 41. It is arranged to pass. The support 22 is driven by the feed motor 23 via a ball screw mechanism (or belt mechanism) (not shown).

(Corner knife mechanism)
The corner knife mechanism 90 is disposed below the table 11 and in the passage path of the large pressers 21 and 21 by the large press feed mechanism 20, and the ball cloth B and the body cloth M conveyed by the large press feed mechanism 20. Is cut through the corner knife 91 from below to form substantially V-shaped cuts V at the positions corresponding to both ends of the linear cut S.
That is, the corner knife mechanism 90 includes two corner knives 91 and 91 arranged at intervals along the cloth feeding direction F, and a vertical movement motor (not shown) that moves the corner knives 91 and 91 up and down, respectively. ing.
Each corner knife 91 is composed of a pair of triangular knives arranged so that the shape seen from the distal end side is V-shaped, and is supported with the distal end portion facing upward. Then, the V-shaped cut V can be formed in the fabrics B and M by moving from below to above the upper surface of the table 11 by the vertical movement motor. Each corner knife 91 can adjust the angle between the pair of triangular knifes, and can correspond to the interval between the two seams T by the two needles 41 and 41.
The two corner knives 91 are supported so that the openings of the V-shaped cuts formed by the two corner knives 91 are opposite to each other. Further, the corner knife 91 on the downstream side in the cloth feeding direction is provided with a drive source for adjusting the movement position on the downstream side in the cloth feeding direction with respect to the other corner knife 91, and can adjust the interval between the corner knife.
In the corner knife mechanism 90, when the fabrics B and M in which the two seams T and the linear cut S are formed are conveyed by the large press feed mechanism 20 to a position directly above the corner knife mechanism 90. The two V-shaped cuts V are formed in the fabrics B and M by moving the two corner knives 91 and 91 up and down at the respective end positions of the cut S. That is, by the corner knife mechanism 90, as shown in FIG. 2, one of the cuts V extending from one end of the straight cut S to the close end of each of the two seams T, and the straight cut S Another cut V is formed from the other end to the closest end of each of the two seams T.

(Control system for hem stitch machine)
FIG. 8 is a block diagram showing a control system including the operation control means 80 of the edge stitch sewing machine 10.
The operation control means 80 includes a display panel 84 for displaying predetermined characters or image information, a setting switch 85 for performing screen selection and command input for making various settings provided in the display panel 84, various types A numeric keypad 86 for inputting numerical values and the determination and cancellation of the setting and a start switch 87 for inputting the start of sewing are connected via an input / output circuit (not shown).
Each of the sewing machine spindle motor 45, the feed motor 23, and the female motor 57 is provided with encoders 101, 102, 103 as detection means for detecting the number of rotations. The encoders 101, 102, 103 are input circuits 101a. , 102a, 103a are connected to the operation control means 80. Thereby, it is possible to detect the rotation angle and rotation speed from a predetermined origin.
The operation control means 80 is connected to a sewing machine spindle motor 45, a feed motor 23, and a female motor 57 to be controlled through drivers 45a, 23a, and 57a, respectively. In addition, an electromagnetic valve (not shown) that drives an air cylinder that moves the binder 30 up and down, an air cylinder that raises and lowers the large pressers 21 and 21, and an air cylinder that raises and lowers the corner knife is an operation control unit via a driver. 80. Similarly, an electromagnetic valve 69 of the air cylinder 65 that switches between an operating state and a non-operating state of the center knife 51 is connected via a driver 69a.
Furthermore, a solenoid valve 89 for driving a knife drive cylinder (not shown) for driving a knife for cutting a sewing thread is connected to the operation control means 80 via a driver 89a.

  The operation control means 80 includes a CPU 81 for performing various controls, a control program for executing various functions and operations described later of the edge stitch sewing machine 10, a ROM 82 storing control data, and an EEPROM 88 storing various sewing data. And a RAM 83 for storing various data related to the processing of the CPU 81 in the work area.

The setting switch 85 and the numeric keypad 86 are connected to the operation control means 80 by a sewing pitch P, which is a needle drop interval for each needle of the edge stitch sewing machine 10, and a sewing machine spindle 46 based on the sewing machine spindle motor 45 at the time of sewing. Speed N, knife speed adjustment value (adjustment value of knife drive frequency increase) A, effective cutting length E of center knife 51, sewing length of straight seam T, cutting length of straight seam S, sewing deceleration control to be described later It is possible to perform setting input of a deceleration rate indicating the degree of deceleration of the sewing machine spindle motor 45 and the feed motor 23. That is, an input item is selected by the setting switch 85, and a set numerical value is input by the ten key 86.
The rotation speed N (rpm) of the sewing machine main shaft 46 indicates the rotation speed maintained during sewing by the operation control of the sewing machine main shaft motor 45.
For the knife speed adjustment value A, the ratio to be adjusted is set as a percentage with the reference value as 100 percent (%).
The deceleration rate of the rotational speed of the sewing machine spindle motor 45 and the feed motor 23 in the sewing deceleration control is a value common to each of the motors 45 and 23, and the multiplication factor of the rotational speed of the knife motor 57 in the normal cutting speed control described later is Set as a percentage. It should be noted that it is possible to set not the magnification but the value of the rotation speed itself of the sewing machine spindle motor 45 or the feed motor 23 in the sewing deceleration control.

  The ROM 82 also includes a sewing control program 82a for controlling the operation of the entire edge stitch, a normal cutting speed control program 82b for determining and controlling the overall cutting speed, and a cloth feed speed when a defective cutting state is detected. A sewing deceleration control program 82c for controlling the sewing speed to decelerate according to the above-described deceleration rate is stored.

(Normal cutting speed control by normal cutting speed control program)
At the time of sewing, the CPU 81 calculates the cloth feed speed P × N of the fabrics B and M from the multiplication value of the preset sewing pitch P and the set rotational speed N of the sewing machine spindle 46 according to the normal cutting speed control program 82b. The rotational speed control of the feed motor 23 is executed so that the fabrics B and M are continuously performed at the cloth feed speed.
The feed motor 23 is driven so that the fabrics B and M are continuously moved regardless of the vertical movement position of the center knife 51 when the fabrics B and M are cut by the center knife 51. That is, so-called intermittent feeding is performed in which the fabric is intermittently fed in synchronization with the vertical movement of the sewing needle.
Further, at the time of sewing, the CPU 81 calculates an appropriate rotation speed R [rpm] of the knife motor from the calculated feed speed P × N of the fabrics B and M and the effective cutting length E of the center knife 51 according to a predetermined processing program. Execute the process. At this time, if the knife speed adjustment value A is set, the value is multiplied.

Since the knife mechanism 50 is cut by sliding contact between the center knife 51 and the fixed knife, deterioration due to wear progresses quickly, so it is necessary to cut efficiently. Further, it is desirable that the entire range of the effective cutting length E contributes to cutting. For this purpose, it is desirable that the length of the center knife cut during the descent period of the center knife matches the feed amount of the cloth conveyed by the feed motor 23 during the rise period.
For this purpose, it is desirable to feed the center knife 51 by a distance equal to the effective cutting length E when the stroke of the center knife 51 is descending and ascending. That is, 2E feed is performed for each rotation of the knife motor 57. If the feed speed is faster than this, the cloth conveyed to the center knife 51 catches up while rising, and if it is slower than this, a part of the range of the effective cutting length E of the center knife 52 does not contribute to cutting. .
Accordingly, the rotational speed R of the female motor 57 is controlled so as to satisfy the following condition.
R = P × N / 2E
Accordingly, the rotational speed R of the knife motor 57 in the predetermined time of the center knife 51 is a speed obtained by dividing the cloth feed speed G by twice the effective cutting length E of the center knife 51, and the cloth feed pitch P and the rotation speed N Can be obtained by dividing the value by the value obtained by doubling the effective cutting length E of the center knife 51.

The rotational speed R of the knife motor 57 obtained above is an ideal value obtained on the assumption that the center knife 51 moves up and down at a constant speed and the fabrics B and M have a thickness of 0. In fact, the vertical movement of the center knife 51 is performed by a cam, so that it is a sine wave-like non-uniform motion, and the fabrics B and M are also thick.
Therefore, it is necessary to set the number of vertical movements obtained by adding a slight increment to the number of vertical movements obtained above. For this reason, the calculated value of R is adjusted by the knife speed adjustment value A under conditions such as the types and thicknesses of the fabrics B and M.
That is, the CPU 81 calculates R = (P × N / 2E) · (1 + 0.01 × A) [rpm], and the CPU 81 controls the rotational speed of the female motor 57 so that the rotational speed R [rpm]. I do.

(Sewing deceleration control by sewing deceleration control program)
The CPU 81 performs sewing deceleration control by executing a sewing deceleration control program. In this sewing deceleration control, the CPU 81 monitors the encoder 103 of the female motor 57 during sewing. The rotational speed of the knife motor 57 is controlled to the rotational speed based on the sewing pitch P and the set rotational speed N of the sewing machine main shaft 46 by the above-described normal cutting speed control. Some cases are harder or thicker than usual, or on the other hand, they are difficult to cut depending on whether they are excessively thin or soft, and the cutting length scheduled for one stroke of the center knife 51 (= 2E (knife speed adjustment) The case where the value A = 0) may not be satisfied. In a state where such a cutting failure has occurred, the load on the female motor 57 is usually large, and a decrease in speed is detected.
Accordingly, the EEPROM 88 has a threshold value for speed reduction (also referred to as a prescribed value) with respect to the rotational speed of the female motor 57 determined by the normal cutting speed control. Then, control is performed to decelerate the sewing machine spindle motor 45 and the feed motor 23 at the same rate as the speed reduction rate of the female motor 57. The “speed reduction rate of the female motor 57” is a value obtained by dividing the measured rotational speed detected by the encoder 103 of the female motor 57 by the rotational speed (command value) of the female motor 57 determined by the normal cutting speed control. is there.
This sewing deceleration control is applied with priority over the normal cutting speed control, and even when the rotational speeds of the sewing machine spindle motor 45 and the feed motor 23 are reduced by the sewing deceleration control, the rotational speed command of the female motor 57 is commanded. The value is kept as it is without decelerating.

(Ball stitching operation control)
The operation control of the edge stitching will be described with reference to the flowcharts of FIGS. The processing according to these flowcharts is processing performed by the CPU 81 by executing various programs 82a to 82c.
FIG. 9 is a flowchart showing an overall flow of operation control of the edge stitch, FIG. 10 is a flowchart showing control of the set operation in the operation control of the bead stitch, and FIG. 11 is a sewing operation (seam stitch) in the operation control of the bead stitching. FIG. 12 is a flowchart showing the sewing deceleration control.

First, the overall flow of the sewing operation will be described with reference to FIG.
When the sewing is started, first, the setting operation process of the body cloth M and the ball cloth B is performed (step S20), and then the formation operation control of the straight seam T and the straight cut S is performed (step S50). As a sewing end operation process, corner cut forming operation control is performed (step S70), and a series of edge stitches is completed. The processes in steps S20 to S70 are repeatedly executed, whereby the plurality of body cloths and the ball cloth B are sewn.

Next, processing of the set operation in the sewing operation will be described with reference to FIG.
First, the feed motor 23 is driven to move the large presser 21 from the origin position to a predetermined sewing start position (step S21).
Next, when the cloth M is set in accordance with the reference position on the upper surface of the table 11 and the ball cloth B is set on the large presser 21, the large presser 21 is lowered and the cloth M is held by the large presser 21. (Step S22). Further, the binder 30 is lowered between the large pressers 21 and 21 (step S23). At this time, the corner knife mechanism 90 moves to a predetermined origin position and stands by (step S24).
Further, each large presser 21 is provided with a folding plate for folding both sides of the ball cloth B to the upper surface side of the binder 30, which is moved inward by driving of the air cylinder, and the ball cloth B is moved to the binder 30. (Step S25).
Further, when the flap cloth is sewn on the upper surface of the ball cloth T, the flap cloth is set, and then the cloth pressing mechanism is operated so as to press the flap cloth (step S26).
Thereby, the set operation is completed. Note that the sewing of the flap cloth is not essential and may not be performed.

Next, control of the sewing operation in the sewing operation will be described with reference to FIG.
First, in the control of the sewing operation, sewing data creation processing in which various settings for sewing are performed is executed (step S51).
That is, when creating data required for sewing, the sewing pitch P, the rotational speed N of the sewing machine spindle motor 45 during sewing, the length of the straight seam T, the effective cutting length E of the center knife, the knife speed adjustment value A, etc. are set or input. Then, these are stored in the EEPROM 71.

Next, the large presser 21 starts to move, and the position that is the front end of the straight seam T in the fabrics M and B is conveyed below the sewing needle 41 (step S52). At this time, the sewing machine spindle motor 45 starts to drive, and the feed motor 23 starts to be driven based on the sewing pitch P and the set rotational speed of the sewing machine spindle motor 45, and the formation of the seam is started (step S53). .
Further, the number of stitches is counted from the start of driving of the sewing machine spindle motor 45, and it is determined whether the number of stitches until the sewing is completed is reached (step S54). If the number of stitches has reached the completion number, the sewing is finished.
If not reached, the sewing deceleration control is executed (step S55).
Next, it is determined from the accumulated rotation amount of the feed motor 23 whether the center knife descending position (front end of the straight line break S) determined based on the end position reference of the stitch end has been reached (step S56). In this case, the center knife 51 is lowered by the air cylinder 65, the vertical movement is started, and the formation of the straight cut S is started (step S57).
At this time, the rotational speed of the female motor 57 is determined based on the normal cutting speed control described above.

On the other hand, if it is determined in step S56 that the straight cut S has already been formed past the lower position of the center knife, the process proceeds to step S58.
Next, it is determined from the accumulated rotation amount of the feed motor 23 whether the center knife ascending position (rear end portion of the straight line break S) determined by the end position reference of the stitch end has been reached (step S58). In this case, the rising and vertical movement of the center knife 51 are stopped, and the formation of the straight cut S is completed (step S59). On the other hand, if it is determined in step S56 that the straight cut S has already been formed past the lower position of the center knife, the process proceeds to step S58. Thereafter, the process is returned to step S54, and it is determined whether or not the rear end position of each straight stitch TL, TR has been reached. And when it reaches | attains, the formation operation | movement of the straight seams TL and TR and the straight cut S is complete | finished.

Next, the sewing deceleration control executed during the sewing operation will be described with reference to FIG.
In such sewing deceleration control, the CPU 81 detects the rotational speed of the knife motor 57 with the encoder 103, and the detected rotational speed of the knife motor 57 is delayed by a predetermined threshold or more with respect to the rotational speed determined by the normal cutting speed control. It is determined whether or not (step S71).
If there is a delay in the knife motor 57, a ratio of the delay obtained by dividing the detected rotation speed by the command value is calculated, and the rotation speed is obtained by multiplying the ratio by the current rotation speed of the sewing machine spindle motor 45. Next, deceleration control of the sewing machine spindle motor 45 is executed (step S72).
At the same time, the feed motor 23 also performs deceleration control so that the calculated speed ratio of the female motor 57 is multiplied by the current rotational speed of the feed motor 23 (step S73). And sewing deceleration control is complete | finished and it progresses to control (step S56) of sewing operation | movement.
On the other hand, if it is determined in step S71 that there is no delay in the rotational speed of the knife motor 57, the sewing deceleration control is terminated as it is, and the process proceeds to the sewing operation control (step S56).

(Effect of embodiment)
In the edge stitch sewing machine 10, the speed is monitored by the encoder 103 of the knife motor 57, and when a constant speed decrease is detected by a predetermined threshold, it is assumed that a cutting failure has occurred, By performing the sewing deceleration control for decelerating the feed motor 23, it is possible to avoid or reduce the occurrence of a state where cutting cannot catch up with the feed of the fabric, and to avoid or reduce the breakage of the fabric and the deterioration of the sewing quality. It becomes.
At this time, when a cutting failure is detected, the knife motor 57 is not accelerated, but the sewing machine spindle motor 45 and the feed motor 23 are decelerated, so that the sliding contact between the center knife 51 and the fixed knife is reduced, and the center knife While avoiding the 51 life reduction, it is possible to avoid or reduce the breakage of the fabric and the deterioration of the sewing quality.
In particular, the edge stitch sewing machine 10 performs normal cutting speed control when no cutting failure occurs, and focuses on extending the life by using the center knife 51 efficiently. Even when a cutting failure occurs, the life of the center knife 51 can be extended, the center knife 51 can be protected synergistically, and further life extension can be realized.

Further, at the beginning of sewing, the edge stitch sewing machine 10 is set to a rotational speed corresponding to the set rotational speed of the sewing machine spindle motor 45 by normal cutting speed control, and the feed motor 23 corresponds to the rotational speed of the sewing machine spindle motor 45. However, if the sewing speed is reduced by the sewing deceleration control during sewing, the speed is not returned until the sewing is completed.
On the other hand, because the cause of the cutting failure is due to the characteristics of the fabric, even if the speed of the female motor 57 is temporarily recovered during the cutting, cutting failures frequently occur thereafter. Therefore, if the feed motor 23 and the sewing machine spindle motor 45 are controlled so as to return their speeds, there is a possibility that deceleration and return may be repeated constantly, and cutting cannot be performed stably. Therefore, by performing control to continue the deceleration state until the sewing of one sewing pattern is completed after deceleration, stable sewing can be performed, and deterioration of the sewing quality can be suppressed.
In the sewing deceleration control, the CPU 81 decelerates the sewing machine spindle motor 45 and the feed motor 23 at the same rate as the speed reduction rate of the knife motor 57. Therefore, the speed can be set to an appropriate speed, and the deterioration of the sewing quality can be suppressed more effectively.

(Other)
In the above example, the case where the sewing machine continuously feeds is illustrated, but the present invention is not limited to this, and intermittent feeding may be performed.

10 Sewing stitch machine 13 Needle plate 20 Large presser feed mechanism (cloth feed mechanism)
23 Feed motor 40 Needle up / down movement mechanism 41 Sewing needle 45 Sewing spindle motor (sewing motor)
50 Female mechanism 51 Center knife 57 Female motor (female drive source)
80 Operation control means 81 CPU
82a Sewing control program 82b Normal cutting speed control program 82c Sewing deceleration control program 101, 102, 103 Encoder (detection means)
B. Tampo (Sewing product)
E Effective cutting length of center knife F Cloth feed direction M Body material (sewing material)
N Number of rotations of sewing machine spindle P Sewing pitch P x N Conveying speed S Straight cut T Straight stitch

Claims (3)

A needle up-and-down movement mechanism that moves the sewing needle up and down with a sewing machine motor;
A cloth feed mechanism that conveys the workpiece along the cloth feed direction on the needle plate by a feed motor;
A knife mechanism that forms a straight cut along the cloth feed direction on the sewing product by moving the center knife up and down with a knife motor relative to the fixed knife,
In a stitched sewing machine comprising an operation control means for controlling the knife motor in accordance with the vertical movement frequency of a center knife determined according to the conveyance speed of the sewing product,
Comprising detection means for detecting the operating speed of the female motor;
The operation control means performs control to decelerate the sewing machine motor and the feed motor when the operation speed detected by the detection means with respect to the command value of the female motor is reduced by a predetermined value or more. A beaded sewing machine.   2. The edge stitching according to claim 1, wherein the deceleration control by the operation control means is such that once the sewing motor and the feed motor are decelerated, the deceleration state is continued until the sewing of one sewing pattern is completed. sewing machine.   3. The edge stitching according to claim 1, wherein in the deceleration control by the operation control means, the sewing machine motor and the feed motor are controlled to decelerate at a rate equal to a rate of reduction in speed generated in the female motor. sewing machine.

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