KR100962886B1 - Sewing machine - Google Patents

Abstract

In the sewing machine, by shortening the time taken from cutting the thread at the end of sewing to raising the presser foot, the cycle time can be shortened to improve productivity.

The thread cutting cam portion 63 for converting the rotational driving force of the pulse motor 60 into the driving force corresponding to the thread cutting mechanism 40 and the presser foot cam portion 64 for converting the driving force corresponding to the presser foot raising mechanism 10 to each other. The presser foot thread cutting cam member 62 which has, the thread cutting link 41 which slides the cam groove 63a of the thread cutting cam part 63, and transmits the said driving force to the thread cutting mechanism 40, and the presser foot cam part 64 And a presser foot lifting link 11 for sliding the cam face 64a of the step C) to transmit the driving force to the presser foot lifting mechanism 10, and a presser foot thread cutting cam member 62, a thread cutting link 41, and a presser foot lifting link. 11 is an idle running which does not transmit a driving force to any of the two mechanisms even when the presser foot thread cutting cam member 62 is operated by the pulse motor 60 from the end of the thread cutting until the start of the presser foot lifting. It is configured to set an idle running interval. .

Description

Sewing machine {SEWING MACHINE}

1 is a perspective view illustrating a thread cutting mechanism and a presser foot raising mechanism installed in a sewing machine according to the present invention.

It is a top view which shows the operation | movement at the time of the thread cutting of the fixed blade member and the movable blade member which comprise a thread cutting mechanism.

(A) is a perspective view seen from the back surface of a presser foot thread cutting cam member, (b) is a top view which shows the thread cutting cam part of a presser foot thread cutting cam member, and FIG. It is the top view shown.

(A), (b), (c) is a top view centering on a presser foot thread cutting cam member, in order to demonstrate the thread cutting and presser foot raising operation in order.

FIG. 5 is a plan view sequentially showing an operation following FIG. 4C.

It is a figure which shows typically the variety of thread cutting and presser foot raising operation | movement.

It is a figure for demonstrating the change of the operation speed at the time of a thread cutting operation.

8 is a graph showing the timing of the pulse motor and the thread cutting operation with respect to the operation of the needle bar.

Description of the main parts of the drawing

10: presser foot raising mechanism 11: presser foot raising link                 

12: presser foot drive link 13: linkage arm

16: presser foot drive leg 23: roller

40: thread cutting mechanism 41: thread cutting link

43: thread cutting connecting rod 44: fixed scalpel member

45: movable blade member 60: pulse motor (drive motor)

62: presser foot thread cutting cam member (cam means) 63: thread cutting cam portion (first cam)

63a: cam groove (sliding surface) 64: presser foot cam portion (second cam)

64a: cam surface (sliding surface) X1: circular arc portion (idle running portion)

X2: bending part (actual cutting operation part) Y1: arc part

Y2: ellipse part

The present invention relates to a sewing machine provided with a thread cutting mechanism and a presser foot raising mechanism for raising the presser foot.

Conventionally, a sewing machine including a thread cutting mechanism for cutting a thread after sewing, a presser foot raising mechanism for raising the presser foot, and a drive motor for driving both mechanisms, and controlling the rotation of the drive motor to drive both mechanisms. Known.

However, when the thread cutting and the presser foot raising are operated continuously, sufficient time lag is required until the start of the operation of the presser foot raising mechanism after the thread cutting mechanism is stopped in order to raise the presser foot after the thread cutting is finished. In the conventional sewing machine, in order to appropriately set this time lag, it was necessary to control the rotational speed of the above-described driving motor after deceleration after thread cutting. Such control not only complicates the control, but also requires the acceleration of the drive speed once decelerated again to improve the cycle time when driving the presser foot lifting mechanism. Since a load for driving the presser foot raising mechanism is simultaneously applied to the drive motor, the acceleration time of the drive motor is further required, and the cycle time cannot be improved, and as a result, the productivity cannot be improved. In addition, the use of a motor having a large output capacity to shorten the acceleration time, the motor is expensive, resulting in an increase in the cost of the sewing machine.

Further, even when the thread sewing mechanism is driven, the conventional sewing machine drives the presser foot raising mechanism because acceleration and the load for driving the thread cutting mechanism are simultaneously applied to the drive motor even when the thread cutting mechanism is driven. There was the same problem as the case.

In the conventional sewing machine described above, when only one of the thread cutting mechanism and the presser foot raising mechanism is repeatedly driven, a complicated mechanism such as disconnecting the motor of one of the mechanisms is required. One caused a rise in costs.

SUMMARY OF THE INVENTION An object of the present invention is a sewing machine equipped with a thread cutting mechanism and a presser foot raising mechanism that raises a presser foot. By shortening the time, the cycle time can be shortened and the productivity is improved.

In order to solve the above problems, the invention described in claim 1 is, for example, as shown in Figs.

In the sewing machine provided with the thread cutting mechanism 40, the presser foot raising mechanism 10 for raising the presser foot, and a single drive motor (pulse motor) 60 for driving these two mechanisms,

A first cam (thread cutting cam portion) 63 for converting the rotational driving force of the drive motor into a driving force corresponding to the thread cutting mechanism, and a second cam (presser foot cam portion) 64 for converting the driving force corresponding to the presser foot raising mechanism; Cam means having a presser foot thread cutting cam member 62,

A thread cutting connecting member (thread cutting link 41) connected to the sliding surface (cam groove; 63a) of the first cam and the thread cutting mechanism to transfer the driving force of the drive motor to the thread cutting mechanism;

A presser foot lifter connecting member (presser foot lifter link) 11 connected to the sliding surface (cam face; 64a) of the second cam and the presser foot lifter to transfer the driving force of the drive motor to the presser foot lifter;

The drive cam member, the thread cutting connecting member, and the presser foot raising coupling member start to raise the presser foot from the end of the thread cutting when the presser foot is continuously raised by the presser foot raising mechanism after the cutting of the thread by the thread cutting mechanism. Until now, it is characterized in that it is configured to set an idle running section which does not transmit the driving force of the drive motor to either of the two mechanisms even if the cam means is operated by the drive motor.

According to the invention as set forth in claim 1, since the two operations are mechanically configured so as not to overlap, the time difference between the two operations is minimized without the need to control the time lag. This can shorten the cycle time and improve the productivity.

In addition, since the motor is operating from the end of the thread cutting until the start of the presser foot ascending, there is an idle running section in which the driving force is not transmitted to either of the mechanisms. In addition, the presser foot raising can be started without slowing down the speed of the motor, and the cycle time can be shortened in that the presser foot can be raised while the driving force of the motor is sufficiently large.

Here, the cam means may be one member including the first cam and the second cam, and although they are independent members, they may be configured to operate substantially in one unit.

The invention described in claim 2 is, for example, as shown in Figs.

In the invention according to claim 1, the first cam converts the driving force corresponding to the idle cutting part (arc part X1) that does not transmit the driving force of the drive motor to the driving force corresponding to the thread cutting mechanism. It has a sliding surface (cam groove; 63a) consisting of a thread cutting operation portion (bending portion; X2)                     

A thread cutting connecting member (thread cutting link) 41 which slides the thread cutting operation part and transmits a driving force to the thread cutting mechanism,

At the time of thread cutting, the drive motor runs up before the timing at which thread cutting is possible so that the thread cutting connection member slides the idle running portion and then the thread cutting operation portion slides to perform thread cutting. It is characterized by.

According to the invention as claimed in claim 2, the thread cutting connection member slides the idle running portion, and then the thread cutting operation is performed before the timing at which the thread can be cut so that the thread is cut by sliding the thread cutting operation portion. By driving the motor up, the driving force of the yarn cutting motor is sufficiently large at the time when the yarn cutting operation is started, so that the yarn cutting operation proceeds smoothly and the operation is faster, and further, the cycle time can be shortened.

The invention described in claim 3 is, for example, as shown in Figs.

In the sewing machine according to claim 1,

The drive motor is configured to be capable of forward / reverse rotation,

The sliding surface of at least one of the first cam and the second cam is symmetrically configured such that the corresponding connecting member draws the same drive trajectory regardless of the rotational direction of the drive motor.

According to the invention as claimed in claim 3, the sliding surface of at least one of the first cam and the second cam is symmetric such that the corresponding connecting member draws the same drive trajectory regardless of the rotational direction of the drive motor. Since the motor can be driven in either the forward direction or the reverse direction, the same operation can be performed, so that the control convenience is high.

The invention according to claim 4, in the sewing machine according to claim 3,

At least one of the seal cutting connecting member and the presser foot raising connecting member changes the rotational speed of the driving motor while transmitting the rotational driving force of the driving motor while sliding the cam means.

According to the invention as claimed in claim 4, the speed of the motor can be changed during thread cutting or presser foot lifting. For example, when capturing or cutting a thread at the time of thread cutting, the speed is slower, otherwise, the speed is increased. It is useful because the speed of the operation can be changed according to a specific situation such as slowing down at the moment of increasing load.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described in detail based on drawing.

In this embodiment, as an example of the sewing machine which concerns on this invention, the stitching machine which forms a zigzag rod etc. by a main rod is mentioned. The sewing machine is sewn by cooperation of a sewing needle and a bobbin according to a predetermined sewing pattern stored in a memory (not shown), and after sewing, a thread cutting command or a presser foot raising command included in the sewing pattern As a result, the thread cutting and the presser foot raising operation are started at a predetermined timing.

1 shows a presser foot raising mechanism 10 for raising the presser foot in such a stitching machine, and a thread cutting mechanism 40 for cutting the lower thread.

The presser foot raising mechanism 10 drives the presser foot (not shown) up and down before and after sewing, and is mainly a presser foot raising link 11, a presser foot driving link 12, a presser foot driving arm 15, and a presser foot driving leg 16. ) And the like.

The presser foot lifting link 11 as the presser foot lifting connecting member is formed in a substantially "L" shape, and is rotatably attached to the frame inside the sewing machine, not shown by the support pin 22 at its bend portion 11b. have. A roller 23 (see FIGS. 4 and 5) is fixed to the lower end portion 11c of the presser foot raising link 11 so as to protrude toward the rear surface side, and the roller 23 is a presser foot cam portion of the presser foot thread cutting cam member 62 described later. It is in contact with the outer circumferential surface 64a (see FIGS. 3A and 3C) of 64. In addition, a coil spring (not shown) is hung on the small pin 24 protruding toward the surface side of the presser foot raising link 11, and the presser foot raising link 11 has a roller 23 formed by the coil spring. 64 is always being added.

One end portion 12a of the presser foot drive link 12 is rotatably connected to the upper end portion 11a of the presser foot raising link 11.

The presser foot drive link 12 is a long, thin flat rod-shaped member, and the other end portion 12b is rotatably connected to the lower end portion of the linkage arm 13.

The light shielding member 21 which has the light shielding plate 21a bent in the horizontal direction is being fixed to the side surface of the presser foot drive link 12 near one end 12a. On the other hand, in the vicinity of the light blocking member 21, a photointerrupter 20 made of a light emitting element and a light receiving element is fixed to a frame (not shown). The photointerrupter 20 detects the home position of the presser foot raising mechanism 10 and is located at the home position when the light shielding plate 21a is positioned between the light emitting element and the light receiving element of the photointerrupter 20. The signal is output to a control circuit (not shown).

The interlocking arm 13 is held and fixed with respect to the rotatable shaft member 14 at its upper end, and swings together with the shaft member 14 as a support point.

Moreover, the presser foot drive arm 15 formed horizontally long on the back surface side of the interlocking arm 13 with respect to the shaft member 14 is hold | maintained, and it oscillates together with the shaft member 14 as a support point.

The presser foot drive leg 16 which is long up and down is connected to the front-end part 15a of this presser foot drive arm 15 so that rotation is possible. The presser foot drive leg 16 is formed in a substantially 'co'-shaped cross section in the horizontal direction, and the lower edge portion 16a is in contact with the presser foot drive member (not shown) that drives the presser foot when lowered. One end of the horizontally long support rod 17 is rotatably supported by the intermediate part of the presser foot drive leg 16. The other end of the supporting rod 17 is rotatably attached to the frame (not shown) via the pin 18, and the direction at the time of the lowering of the presser foot drive leg 16 is regulated by the supporting rod 17. .

In addition, a gap of a predetermined length is provided between the presser foot drive leg 16 and the presser foot drive member positioned below it, so that when the presser foot drive leg 16 descends, the gap after the start of the lowering starts. Delayed in contact with the presser foot drive member. Moreover, when the presser foot drive leg 16 descends, the presser foot is configured to rise.

The rear end 31a of the wiper coupling link 31 of the wiper mechanism 30 is connected to the intermediate portion of the interlocking arm 13. After the upper thread is cut by the upper thread cutting mechanism (not shown), the wiper mechanism 30 removes the upper thread leading to the fabric from the sewing needle and pulls the thread end on the sewing needle side onto the fabric before the presser foot is raised. will be.

In the front end portion 31b of the wiper connecting link 31, a horizontal hole 31c which is formed to extend horizontally is formed. In the vicinity of the front end portion 31b, a wiper L-shaped link 32 formed in an approximately 'L' shape and attached to the sewing machine frame so as to be rotatable through the attachment screw 35 at the bent portion is installed, and at the upper end thereof. The fixed coupling pin 32a is inserted through the horizontal hole 31c. Moreover, the coil spring 33 in which one end is hanged on the sewing machine frame is provided in the back surface side of the wiper connection link 31. As shown in FIG. The other end of the coil spring 33 is engaged with the engagement pin 32a, so that the wiper L-shaped link 32 is always biased backward in FIG.

However, in the vicinity of the wiper L-shaped link 32, even if the stopper pin 34 is fixed to the sewing machine frame and protrudes, the wiper L-shaped link 32 moves backward by the force of the coil spring 33. It stops at the part which contact | connects the stopper pin 34. As shown in FIG.

In addition, when the presser foot raising mechanism 10 does not operate (when the roller 23 is in contact with an arc portion Y1 to be described later on the outer circumferential surface 64a), the rotation position of the presser foot raising link 11 is determined. have. Thereby, the position of each member which comprises the presser foot raising mechanism 10 and the wiper mechanism 30 is determined, and the position of the wiper connection link 31 is also determined. The coil spring 33 has no spring force for pulling the wiper L-shaped link 32 against the presser foot raising mechanism 10 with the wiper connecting link 31. Therefore, only when the presser foot raising mechanism 10 is operated so that the wiper connecting link 31 moves backward, the coil spring 33 is adapted to pull the wiper L-shaped link 32 through the engaging pin 32a. .

The wiper connecting plate 36 which is formed long in the vertical direction is connected to the front end of the wiper L-shaped link 32 so as to be rotatable. An extension portion 36a extending rearward is formed at the lower end of the wiper connecting plate 36. On the other hand, in the vicinity of the wiper connecting plate 36, a supporting plate 37 fixed to the sewing machine frame is fixed. In the planar view, the wiper 38 formed in substantially L shape is connected to this support plate 37 by the attachment screw 39 so that rotation is possible.

One end portion 38a of the wiper 38 is rotatably connected to the extension portion 36a. The lower end of the wiper 38 is provided with a wiper portion 38b formed to protrude forward, and the upper thread is removed by the wiper portion 38b.

Presser foot raising mechanism 10 and wiper mechanism 30 having the above-described configuration are presser foot when the presser foot raising link 11 rotates in the counterclockwise direction (arrow A direction) of FIG. 1 after cutting the upper thread and the lower thread. Drive link 12 is pulled back. By this operation, the interlocking arm 13 swings backward with the shaft member 14 and around the shaft member 14, so that the presser foot drive arm 15 also rotates clockwise around the shaft member 14. Rotate to As the presser foot drive arm 15 rotates, the presser foot drive leg 16 is lowered while being restricted to the support rod 17.

On the other hand, since the wiper connecting link 31 moves backward by the swing of the interlocking arm 13 to the rear, the horizontal hole 31c and the engaging pin 32a are also rearward by the force of the coil spring 33. , The wiper L-link 32 rotates counterclockwise about the attachment screw 35. With the rotation, the wiper connecting plate 36 rises, and the rise of the end 38a of the wiper 38 causes the wiper 38 to move counterclockwise in FIG. 1 around the attachment screw 39. By rotating in the direction, the upper thread is removed by the wiper portion 38b, and the upper thread is pulled out of the cloth.

In addition, the wiper L-shaped link 32 stops rotation in contact with the stopper pin 34, and the coupling pin 32a is formed in the horizontal hole 31c as long as the wiper connecting link 31 is moved further backward. It slides along this, and it does not affect the operation | movement of the wiper L-shaped link 32. As shown in FIG.

As described above, since a gap is provided between the presser foot driving leg 16 and the presser foot driving member, the presser foot driving leg 16 is delayed by a predetermined time after starting the lowering, and after the upper thread is removed, The presser foot drive leg 16 pushes down the presser foot drive member, and the presser foot is raised.

When the presser foot is lowered, the presser foot raising link 11 rotates in the clockwise direction in FIG. 1 so that when the presser foot drive leg 16 is raised, the presser foot is lowered by its own weight. Moreover, by returning the interlocking arm 13 as it was, the wiper connection link 31 returns to the front, and the wiper mechanism 30 as a whole returns to the state of FIG.

The thread cutting mechanism 40 cuts the lower thread which connected to the cloth placed on the needle board 70 from the bobbin (not shown) provided below the needle board 70 immediately after completion of sewing, and is mainly a thread cutting link 41 ), A thread cutting connecting rod 43, a fixed blade member 44, a movable blade member 45, and the like.

The thread cutting link 41 as the thread cutting connecting member is formed in an elongated rod-shaped shape in which the middle part is slightly bent, and is attached to the frame (not shown) by the support pin 42 so as to be rotatable at the bent portion 41b. have. On the surface side of the upper end part of the thread cutting link 41, as shown in FIG. 4 and FIG. 5, the engaging pin 41a which fits and engages with the thread cutting cam part 63 of the presser foot thread cutting cam member 62 is provided.

The lower end portion 41c of the thread cutting link 41 is attached to the attachment plate 46 with a screw 47 in a state capable of being rotated together with the rear end of the thread cutting connecting rod 43. The light shielding member 48 which has the light shielding plate 48a is being fixed to the edge part of the attachment plate 46 similarly to the said light shielding member 21. On the other hand, in the vicinity of the light blocking member 48, a photointerrupter 49 similar to the photointerrupter 20 is fixed to a frame (not shown). The photointerrupter 49 detects the home position of the thread cutting mechanism 40 and is located at the home position when the light shielding plate 48a is positioned between the light emitting element of the photointerrupter 49 and the light receiving element. A signal is output to the control circuit.

The thread cutting connecting rod 43 is an elongated rod-shaped member that is bent at a predetermined portion to face upward slightly, and the tip portion 43a reaches the lower side of the needle plate 70. As shown in FIG. 2, the movable female connecting member 50 is rotatably connected to the distal end portion 43a via a screw 51. In addition, the thread cutting lever 53 is fixed on the movable knife connecting member 50. The connecting pin 52 fixed to the needle plate 70 is inserted through the movable scalpel connecting member 50 and the thread cutting lever 53, and the movable scalpel connecting member 50 and the thread cutting lever 53 are inserted. The rotation is centered around the connecting pin 52. One end portion 54a of the movable female link 54 is rotatably connected to the tip of the thread cutting lever 53.

The center portion of the movable scalpel member 45 is connected to the other end 54b of the movable scalpel 54 so as to be rotatable. The end portion 45a of the movable scalpel member 45 is rotatably attached to the fixing screw 55. The fixing screw 55 is fixed to the needle plate 70. At the distal end of the movable scalpel member 45, a wiper portion 45b for removing the lower thread without cutting the lower thread during the cutting operation, and a thread trapping portion curved inward by capturing the yarn removed from the wiper portion 45b ( 45c) and the movable blade 45d for cutting a thread are formed.

In the vicinity of the movable scalpel member 45, a fixed scalpel member 44 which is screwed to the needle plate 70 is provided, and a lower thread is provided at the tip of the fixed scalpel member 44 with the movable blade 45d. The fixed blade 44a which clamps and cut | disconnects is formed.

The thread cutting mechanism 40 of the above-mentioned structure is in the state of FIG.2 (a) during sewing, and when sewing is complete | finished, before operation of the presser foot raising mechanism 10, the presser foot thread cutting cam is mentioned later. The thread cutting link 41 rotates around the support pin 42 in the counterclockwise direction (arrow B direction) of FIG. 1 by the member 62, and the lower end part moves forward. Thereby, as shown in FIG.2 (b), the thread cutting connecting rod 43 moves forward, the movable female connecting member 50 is pressed through the screw 51, and centers the connecting screw 52. As shown in FIG. Thus, the movable knife connecting member 50 and the thread cutting lever 53 rotate. By the operation of this thread cutting lever 53, the movable meslink 54 connected to the front end is pressed back, and the movable mestem member 45 rotates clockwise around the fixing screw 55. As shown in FIG. According to this rotation operation, the lower thread (not shown) which leads to cloth and bobbin is loosened by the wiper part 45b, and the lower thread is located between the thread capture part 45c and the fixed blade 44a.

Subsequently, when the thread cutting link 41 rotates clockwise about the support pin 42 and the lower end part returns to the rear, each member which comprises the thread cutting mechanism 40 performs the opposite operation. That is, the movable scalpel member 45 rotates to return to its original state in the state of FIG. 2 (b), and rotates while capturing the thread by the thread capturing unit 45c, thereby pulling the lower thread out of the bobbin. The lower thread approaches the fixed blade 44a, and as shown in FIG.2 (c), the movable blade 45d and the fixed blade 44a are matched, and a thread is cut | disconnected. The movable scalpel 45 continues to be reversed as it is, and returns to the state of FIG.

As described above, the presser foot raising link 11 in the presser foot raising mechanism 10 and the thread cutting link 41 in the thread cutting mechanism 40 are operated as starting points, respectively. The presser foot raising link 11 and the thread cutting link 41 are configured to transmit the driving force of the pulse motor 60 at a predetermined timing through the presser foot thread cutting cam member 62 to operate.

The pulse motor 60 which is the drive motor of this invention is fixed to the wall 61 which is a part of the sewing machine frame, The output shaft 60a protrudes from the wall 61, and the presser foot thread cutting cam member 62 is attached to the output shaft. The central portion of the is fixed, and the presser foot thread cutting cam member 62 is rotated at a predetermined angle by the pulse motor 60. The pulse motor 60 is drive-controlled by the said control circuit. Each operation of the thread cutting mechanism 40 and the presser foot raising mechanism 10 is performed by the control circuit, while counting the rotational direction of the pulse motor 60 and the number of pulses in operation. It is to perform by controlling the operation of.

The presser foot thread cutting cam member 62 which is a cam means, as shown in FIG. 1 and FIG. 3A, is a substantially circular box chain thread in which the outer shape includes some straight portions when viewed from the front of FIG. 1. It consists of the cutting cam part 63 and the presser foot cam part 64 integrally provided in the front side.

As the thread cutting cam part (first cam) 63, as shown to Fig.3 (a), the cam groove 63a which is substantially heart shape is formed in the back surface side. The engagement pin 41a of the thread cutting link 41 is fitted into the cam groove 63a to be engaged and slides along the surface thereof. That is, each surface which forms the said cam groove 63a becomes the sliding surface of this invention.

The shape of the cam groove 63a is shown in FIG.3 (b). P1-P7 conveniently showed the angular position which becomes a point in the circumference. The cam groove 63a is formed so as to draw an arc having the same distance to the rotation center C1 between P2 and P3 through P7. On the other hand, between P2 and P7 centering on P1, it is formed symmetrically so that the distance to a rotation center may become short toward P1. The inflection part X2 is defined between P2 and P7 centering on the arc part X1 and P1 between P2 and P3 through P3.

As shown in Fig. 3B, the coupling pin 41a relatively moves in the cam groove 63a in accordance with the rotation of the presser foot thread cutting cam member 62. Therefore, for example, when the pulse motor 60 is moving between P2 which is the arc part X1 to P7 via P3 which rotates to a predetermined direction (it makes it the positive direction), the engagement pin 41a and the rotation center The distance from C1 does not change, and the thread cutting link 41 does not rotate. That is, arc part X1 is the idle running part of this invention.

However, when the coupling pin 41a moves from P7 to P1, it gradually approaches the rotation center C1. Thereby, the thread cutting link 41 rotates counterclockwise of FIG. 1, and the movable scalpel member 45 moves beyond the fixed blade 44a as mentioned above.

Subsequently, when the coupling pin 41a moves from P1 to P2, it gradually moves away from the rotation center C1, and the thread cutting link 41 rotates in the clockwise direction of FIG. The thread is cut between the blade 44a. The same is true when the pulse motor 60 rotates in the reverse direction and passes from P2 to P1. That is, the inflection section X2 is the thread cutting operation section of the present invention.

The presser foot cam portion (second cam; 64) is integrally fixed to the front side of the thread cutting cam portion 63, and as shown in Fig. 3C, an approximately stepped shape is formed, and the cam surface 64a thereof. ), The roller 23 of the presser foot lifting link 11 is in contact with each other. Q1 to Q7 in FIG. 3C conveniently show the angular position of the point in the circumference. The cam surface 64a is formed so that the distance to the rotation center C1 may draw the circular arc between Q6 through Q1 and Q3. On the other hand, between Q3 to Q4 and Q6 to Q5 are formed symmetrically so that the distance from a rotation center may become long toward Q4 and Q5, respectively. Moreover, between Q4 and Q5, it is formed so that the distance to rotation center C1 may draw the same circular arc. The period from Q6 to Q1 through Q3 is defined as the ellipse part Y2 between the arc part Y1, Q3 to Q4, and Q6 up to Q6.

As shown typically in FIG.3 (c), the said roller 23 moves relatively along the cam surface 64a which is a sliding surface according to rotation of the presser foot thread cutting cam member 62. As shown in FIG. Thus, for example, when the pulse motor 60 rotates in the forward direction and moves from Q6 to Q1 through Q3, the distance between the roller 23 and the rotation center C1 does not change, so that the presser foot lifting link 11 does not rotate.

However, when the roller 23 moves between Q3 and Q4, it gradually moves away from the rotation center C1. As a result, the presser foot raising link 11 rotates in the counterclockwise direction in FIG. 1, and the presser foot drive link 12 moves forward as described above, so that the presser foot is raised. When the pulse motor 60 rotates in the reverse direction and the roller 23 returns from Q4 to Q3, the roller 23 gradually approaches the rotation center C1, and the presser foot raising link 11 rotates clockwise in FIG. 1, and the presser foot drive link ( 12) returns to the rear, and the presser foot goes down.                     

Similarly, between Q6-Q5, the presser foot drive link 11 rotates counterclockwise in FIG. 1 through the roller 23 when heading to Q5, and clockwise when heading to Q6.

The reason why the presser foot cam portion 64 is formed in an arc shape between Q4-Q5 is for the following reason. In the case of the presser foot, basically, the lifting and lowering operations are rarely continuously performed. For example, the presser foot is a flow of operation such as sewing and raising after lowering. Even if the pulse motor 60 stops in the state where the roller 23 reaches Q4 or Q5 and the presser foot is raised, mechanical deviation occurs in the stop of rotation of the presser foot thread cutting cam member 62 therewith. Or you might go past Q5. By forming the arc between Q4-Q5 in an arc shape, the stop is delayed, and even if it rotates more than Q4 or Q5, it can prevent that a fall operation is started.

As described above, the thread cutting cam portion 63 and the presser foot cam portion 64 are each angularly related to each other, and the coupling pins 41a and the roller 23 are considered in such a manner that the operation of cutting and then pushing up the yarn is performed. The contact position of is set. Specifically, the angles between P1-P7, P1-P2, Q1-Q7, and Q1-Q2 are all the same (angle m1), and when the coupling pin 41a is directed from P7 to P2, In accordance with this, the roller 23 is also directed from Q7 to Q2. That is, during the thread cutting operation, the presser foot raising mechanism 10 does not operate.

In addition, during the presser foot raising operation from which the roller 23 goes from Q3 to Q4, the engagement pin 41a moves between P3-P4, and the thread cutting mechanism 40 does not operate. Even when the roller 23 moves between Q5-Q6 and the presser foot raising mechanism 10 operates, the thread cutting mechanism 40 does not operate because the engaging pin 41a is moving between P5-P6.

In addition, when the roller 23 is located between Q4-Q5, the engagement pin 41a is located between P4-P5.

In addition, even if the presser foot thread cutting cam member 62 rotates together by the rotation of the pulse motor 60, the presser foot thread cutting cam member 62 has a rotational force to the presser foot raising mechanism 10 and the thread cutting mechanism 40. In other words, it is designed so that a "run up section" exists so that a thread cutting or a presser foot raising operation can be started at the time when the rotation speed of the pulse motor 40 fully rises so that there exists an "idle running section" which is not transmitted.

That is, when the engagement pin 41a is between P2-P3 and the roller 23 is between Q2-Q3, or the engagement pin 41a is between P6-P7 and the roller 23 is between Q6-Q7. In any case, the presser foot raising mechanism 10 and the thread cutting mechanism 40 do not operate.

Next, the operation of the presser foot raising mechanism 10 and the thread cutting mechanism 40 around the presser foot thread cutting cam member 62 will be described with reference to FIGS. 4 to 8. 4 and 5 are views showing the operation around the presser foot thread cutting cam member 62, and FIGS. 6 and 7 are images showing the operating states of the presser foot raising mechanism 10 and the thread cutting mechanism 40. FIG. 8 is a graph showing the timing of the thread cutting operation with respect to the movement of the needle bar. 6, a plurality of operation patterns are shown. Hereinafter, first, the operation of the pattern 1 will be described in detail.

First, the thread cutting operation is started from the start of FIG. At this time, it is in the I state of FIG. That is, the engaging pin 41a is located in the arc part X1 of the cam groove 63a of the thread cutting cam part 63, and the roller 23 contacts the arc part Y1 of the cam surface 64a of the presser foot cam part 64, have.

In this state, the presser foot thread cutting cam member 62 rotates counterclockwise in FIG. 4 (clockwise in FIG. 1) by the pulse motor 60 rotating in the forward direction. The engaging pin 41a moves relative to the arc portion X1, and the roller 23 moves relatively to the arc portion Y1. The coupling pin 41a is positioned at the boundary between the arc portion X1 and the inflection portion X2 (Fig. 3 (b)). ) Is in the state of P7) II.

From this time, the engagement pin 41a starts to move in the inflection portion X2, and the thread cutting mechanism 40 starts to operate. And when the engagement pin 41a reaches the state III which reaches | attains the center part (P1 of FIG.3 (b)) of the inflexion part X2, the movable scalpel member 45 is the most in FIG.2 (b) mentioned above. It is in a much moved state.

In both II and III states, the roller 23 is moving the arc portion Y1, and the presser foot raising mechanism 10 does not operate.

Subsequently, the coupling pin 41a advances the inside of the inflection portion X2 from P1 to P2. In this process, the movable scalpel member 45 operates to return to its original position. Cut the thread in accordance with 44). Then, the coupling pin 41a reaches the end position (the above-mentioned P2) of the inflection portion X2 and becomes the state of IV shown in Fig. 5A. At this time, the operation | movement of the thread cutting mechanism 40 is complete | finished.

In addition, the presser foot thread cutting cam member 62 rotates in the same direction so that the engagement pin 41a is positioned between P2-P3 in FIG. 3B, and the roller 23 is Q2- in FIG. 3C. "Relay time" is moved between Q3, and neither the presser foot raising mechanism 10 nor the thread cutting mechanism 40 operate at this time.

And when the roller 23 reaches the ellipse part Y2 (position Q3 of FIG.3 (c)) of the cam surface 64a (V state) like FIG.5 (b), from this time, a presser foot raising link 11 starts to rotate clockwise (counterclockwise in FIG. 1). Then, as shown in Fig. 5C, when the roller 23 reaches the above Q4-Q5 and reaches the state of VI, the presser foot raising operation is terminated, and the pulse motor 60 is stopped at this point. Let's do it. In the state of V and the state of VI, since the engagement pin 41a moves along the arc part X1, the thread cutting mechanism 40 does not operate.

The above is "pattern 1" which is a typical operation after sewing.

In addition, the presser foot thread cutting cam member 62 can rotate in the forward / reverse direction of the pulse motor 62 according to the rotational motion, and both the thread cutting cam portion 63 and the presser foot cam portion 64 are formed symmetrically. Although various operation patterns are possible, the patterns 2-4 of FIG. 6 are mentioned, for example.

In the pattern 2, the yarn is cut from the above-described state of I to the state of V and the thread is cut, and then the pulse motor 60 is rotated in the reverse direction without proceeding until the presser foot is raised, and after the predetermined sewing is finished, the thread is unloaded again. By cutting, the thread cutting mechanism 40 is returned to the initial state I. Then, the roller 23 moves from Q6 to Q5 in FIG. 3C as it continues to rotate in the reverse direction. In this process, the presser foot raising operation is performed so that the roller 23 reaches Q5-Q4. At one time point, the pulse motor 60 is stopped.

In the pattern 3, the pulse motor 60 is driven from the start to the reverse direction, only the presser foot raising operation is performed, and the pulse motor 60 is rotated in the forward direction to return to the start state. That is, the presser foot is lowered to terminate the operation. Similarly to the pattern 3, the pattern 4 drives the pulse motor in the reverse direction from the start, performs the presser foot raising operation, continues to rotate in the reverse direction as it is, and lowers the presser foot again.

These patterns 3 and 4 are used when an operator adjusts the position of the cloth on the needle plate 70, for example.

In addition, when the present invention is applied to an automatic sewing machine that cuts a thread by driving the thread cutting mechanism according to a thread cutting command included in the sewing pattern while performing sewing according to a predetermined sewing pattern, pattern 1 Alternatively, as shown in the pattern 2, at the time of thread cutting by the thread cutting command, the thread cutting link 41 slides the idle running portion (arc portion X1) of the thread cutting cam portion 63, and then the thread cutting operation portion ( Since the yarn cutting motor can be run up before the timing at which the yarn is cut so that the yarn is cut by sliding the inflection portion X2), the cycle time can be improved more effectively.

Since the presser foot raising mechanism 10 and the thread cutting mechanism 40 use the pulse motor 60 as a drive source, the operation speed can also be controlled to a desired magnitude | size.

For example, the operation from (a) to (b) of FIG. 2 by the thread cutting mechanism 40 should be as quick as possible to shorten the cycle time, but returns to (c) from (b) of FIG. 2. It is preferable that the reverse operation is slower than when moving forward in order to capture the lower thread and then pull out the lower thread connected to the bobbin and reliably cut it. If the speed is too high at the time of reversing, it is not preferable because the operation of capturing and cutting the lower thread becomes uncertain, or the bobbin may revolve and entangle the lower thread when withdrawing the lower thread from the bobbin.

For this reason, as shown in FIG. 7, when cutting a thread using the forward rotation of a motor similarly to the above-mentioned pattern 1, it speeds up to the state of I-III mentioned above, and slows it to the state of III-V. (Control D1). In addition, when the thread is cut by using the reverse direction of the pulse motor 60, that is, when the coupling pin 41a performs the thread cutting operation in the path from P2 to P7 through P2 in FIG. Operation from V to III is made faster, and operation from III to I is made slow (control D2).

8 is a graph of the movement of the control D1. The horizontal axis | shaft of FIG. 8 shows the 1 time distribution of the shanghai-dong of the needle bar of a sewing machine, and evenly divides the angle. The two-point dashed lines 1 and 2 both show the operation of the pulse motor 60. The rotational speed (speed) of the starting point of the left end is zero, and is floating to the negative side as the rotational speed increases.

At the end of sewing, as indicated by the needle bar curve, the needle bar starts to rise from the bottom dead center F1 at 180 degrees and finally stops near the top dead center (360 degrees) not shown. At this time, for example, as in the line ②, the pulse motor 60 starts to operate when the needle bar becomes 260 degrees, and the rotation speed gradually increases. When the needle bar reaches 270 degrees, the thread cutting operation is started, and the operation proceeds as shown by the thread cutting curve. The thread cutting curve is a relative position of the presser foot thread cutting cam member 62 with respect to the needle bar angle, and indicates that the faster the inclination, the faster the movement of the thread cutting mechanism 40 side with respect to the movement of the needle bar. The point F2 is a state in which the movable scalpel member 45 shown in FIG.

Comparing the inclination indicated by b1 / a1 with the point F2 and the inclination represented by b2 / a2 (where a1 = a2), the electron certainly has a steep inclination and the speed is large.

In addition, not only the speed control during the thread cutting operation but also the "runup section" can be appropriately controlled. That is, the operation of the pulse motor 60 is not limited to starting the operation of the pulse motor 60 at the time when the needle bar becomes 260 degrees as shown by the line ② in FIG. 8. May be started. In this case, the speed of the pulse motor is sufficiently raised at the point of 270 degrees at which the thread cutting starts, compared with the line ②, and the thread cutting operation can be performed more smoothly, and the time can be shortened.

According to the sewing machine provided with the presser foot raising mechanism 10 and the thread cutting mechanism 40 mentioned above, the presser foot thread cutting cam member 62 which has the presser foot cam surface 64a and the thread cutting cam groove 63a is provided. Further, each cam is shifted so that the timing at which the engagement pin 41a moves on the inflection portion X2 of the cam groove 63a and the timing at which the roller 23 contacts the ellipse portion Y2 of the cam surface 64a are shifted. Shape and the engagement position of the engagement pin 41a and the roller 23 are set. That is, since one cam member 62 is configured so that the two motions are mechanically shifted, it is not necessary to control the time lag, and the time difference between the two motions can be minimized. In addition, productivity can be improved by shortening the cycle time.

In addition, although the pulse motor 60 and the presser foot thread cutting cam member 62 rotate before the thread cutting operation, a run-up section in which the operation is not transmitted to the thread cutting mechanism 40 is set, so that the thread cutting operation starts. The driving force of the motor is in a sufficiently large state. Therefore, the coupling pin 41a can easily move the inflection portion X2 of the cam groove 63a, so that the thread cutting operation proceeds smoothly, and accordingly, the cycle time can be shortened.

Further, even when the presser foot raising operation is performed in succession to the thread cutting operation, there is an idle running section therebetween, and after the thread cutting is reliably terminated, the presser foot raising operation can be shifted to the presser foot raising operation as well. By continuously operating 60, the presser foot raising can be started without slowing down, and the roller 23 can ride over the ellipse portion Y2 of the cam face 64a while the driving force of the motor is sufficiently large. Also in this respect, the cycle time can be shortened.

In addition, at what stage after sewing, the operation of the pulse motor 60 can be appropriately selected as shown in 1 and 2 of FIG. 8 or can be set according to the actual situation.

In addition, the fact that there is a run up section or an idle running section, on the contrary, means that the output torque of the pulse motor 60 can be reduced, and miniaturization is possible.

In addition, since the pulse motor 60 is used, the forward operation at the time of cutting the thread is shortened, and the cycle time is shortened. In the reverse operation, the thread is cut reliably and the slow operation is performed to prevent idle of the bobbin. Etc. control is possible.

In addition, in relation to the rise of the presser foot, by controlling the rotation of the pulse motor 60, it is also possible to stop the presser foot at a predetermined height, thereby improving the functionality for the user.

In addition, since the inflection portion X2 and the ellipse portion Y2 are formed in a symmetrical shape, even if the pulse motor 60 is rotated in any of the forward and reverse directions, the thread cutting and the presser foot raising operation can be performed. Since various operations are possible, it is easy to control and has high utility.

In addition, since the presser foot raising mechanism 10 and the thread cutting mechanism 40 are driven by one pulse motor 60, the cost for the actuator can be reduced.

Incidentally, the present invention is not limited to the above-described embodiments, and of course, can be modified as appropriate.

According to the invention as set forth in claim 1, since the two operations are mechanically configured so as not to overlap, there is no need to control the time lag and control the time difference between the two operations to the minimum. Since the cycle time can be shortened, productivity can be improved.

Also, from the end of the thread cutting until the presser foot lifting is started, there is an idle running section in which the driving force is not transmitted to any of the mechanisms. In addition, it is possible to start the presser foot lifting without decreasing the speed of the motor in the meantime, and it is possible to raise the presser foot while the driving force of the motor is sufficiently large. In this respect, the cycle time can be shortened.

According to the invention according to claim 2, the thread cutting motor is operated before the timing at which thread cutting is possible so that the thread cutting connection member slides the idle running portion and then the thread cutting operation portion slides to perform thread cutting. Since the run-up driving is performed, the driving force of the thread cutting motor is sufficiently large when the thread cutting operation is started, so that the thread cutting operation proceeds smoothly, the operation is accelerated, and the cycle time can be shortened.

According to the invention described in claim 3, the sliding surface of at least one of the first cam and the second cam is configured such that the corresponding connecting member draws the same drive trajectory regardless of the rotational direction of the drive motor. Since the configuration is symmetrical, the motor can be operated in the same direction regardless of whether the motor is driven in the forward or reverse direction. Therefore, for at least one of the thread cutting mechanism and the presser foot raising mechanism, only the thread cutting operation or the presser foot raising operation can be repeated simply by repeating the forward / reverse rotation of the motor, thus requiring no complicated control or mechanism. It is possible to simply repeat the operation without the convenience, high convenience.

In addition, according to the invention of claim 4, the speed of the motor can be changed during the cutting of the thread or during the presser foot lifting, so that, for example, when capturing or cutting the thread at the time of cutting the thread, When the presser foot is raised, the operation speed can be changed according to the specific situation, such as slowing down when the load increases.

Claims (4)

A sewing machine comprising a thread cutting mechanism driven at different timings, a presser foot raising mechanism, and a driving device for driving the driving of both mechanisms with the same driving motor, The drive motor is configured to be capable of forward rotation and reverse rotation, The drive device, Drive cam means having a first cam for converting the rotational drive force of the drive motor into a drive force corresponding to a seal cutting mechanism, a second cam for converting the drive force corresponding to a presser foot lifting mechanism; A thread cutting connecting member which slides a predetermined sliding surface of the first cam, the other end of which is connected to a thread cutting mechanism to transmit a driving force of the driving motor to the thread cutting mechanism; A presser foot lifter connecting member which slides a predetermined sliding surface of the second cam, the other end of which is connected to the presser foot lifter to transfer the driving force of the drive motor to the presser foot lifter, The drive cam means, the thread cutting connecting member and the presser foot raising connecting member, Sewing machine characterized in that it can repeat only the thread cutting operation or only the presser foot raising operation by simply rotating the drive motor forward and reverse.  A sewing machine comprising a thread cutting mechanism driven at different timings, a presser foot raising mechanism, and a driving device for driving the driving of both mechanisms with the same driving motor, The drive motor is configured to be forward rotation and reverse rotation, The drive device, Drive cam means having a first cam for converting the rotational drive force of the drive motor into a drive force corresponding to a seal cutting mechanism, a second cam for converting the drive force corresponding to a presser foot lifting mechanism; A thread cutting connecting member which slides the sliding surface of the first cam, the other end of which is connected to a thread cutting mechanism to transfer the driving force of the driving motor to the thread cutting mechanism; A presser foot lifting connecting member for sliding the sliding surface of the second cam, the other end of which is connected to the presser foot lifting mechanism to transfer the driving force of the drive motor to the presser foot lifting mechanism, The drive cam means, the thread cutting connecting member and the presser foot raising connecting member, After cutting the thread by rotating the drive motor forward, the sewing machine characterized in that the reverse rotation without cutting to the presser foot raising, and again cut the thread, as it is rotated in the reverse direction to raise the presser foot. By sewing according to a predetermined sewing pattern, and having a thread cutting mechanism driven by a thread cutting motor different from the sewing motor, and driving the thread cutting mechanism in accordance with the thread cutting commands included in the sewing pattern. As an automatic sewing machine for cutting thread, A thread cutting cam having a sliding surface comprising an idle running portion that does not transmit the driving force of the thread cutting motor, and a thread cutting operation portion for converting the driving force into a driving force corresponding to a thread cutting mechanism; , And a thread cutting connecting member for sliding the idle running portion and the thread cutting operation part at the same time, and for transmitting the driving force to the thread cutting mechanism by sliding the thread cutting operation part. At the time of thread cutting by a thread cutting command, the thread cutting connecting member starts the thread cutting motor at the rotational speed 0 at the idle running portion, gradually raises the rotational speed to slide, and then slides the thread cutting operation portion to seal the yarn. And the thread cutting motor is run up before the timing at which thread cutting is possible so that cutting is performed. delete

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