CN109267251B

CN109267251B - Control method of thread trimming device of sewing machine

Info

Publication number: CN109267251B
Application number: CN201811475090.4A
Authority: CN
Inventors: 田国兵; 张建波
Original assignee: Jack Sewing Machine Co Ltd
Current assignee: Jack Technology Co Ltd
Priority date: 2018-12-04
Filing date: 2018-12-04
Publication date: 2020-10-09
Anticipated expiration: 2038-12-04
Also published as: CN109267251A

Abstract

The invention provides a control method of a thread trimming device of a sewing machine, belonging to the technical field of clothing manufacturing. The thread trimming device solves the technical problems of poor stability and reliability and the like of the thread trimming device of the existing sewing machine. The thread cutting device comprises an upper tool rest arranged on the base, a movable cutter fixedly arranged at one end of the upper tool rest, a lower tool rest arranged on the base and a fixed cutter fixedly arranged at one end of the lower tool rest and corresponding to the movable cutter; the movable knife is provided with a thread hooking groove, a base of the sewing machine is provided with a swing rod capable of driving the upper knife rest to do reciprocating linear movement, an adjusting connecting rod capable of driving the upper knife rest to swing along the width direction of the upper knife rest, a first driving source for driving the swing rod to swing and a second driving source for driving the swing rod to move, the first driving source is provided with a first sensor and a third sensor which can respectively detect that the first driving source moves to two different limit positions, and the second driving source is provided with a second sensor which can detect that the second driving source moves to the limit positions. According to the invention, by controlling the thread trimming device, the stability and the reliability during sewing and trimming are high.

Description

Control method of thread trimming device of sewing machine

Technical Field

The invention belongs to the technical field of garment manufacturing equipment, relates to a sewing machine, and particularly relates to a control method of a thread trimming device of the sewing machine.

Background

A sewing machine is a machine that uses one or more sewing threads to form one or more stitches in a material to be sewn, thereby interweaving or stitching one or more layers of material. The sewing machine can sew fabrics such as cotton, hemp, silk, wool, artificial fiber and the like and products such as leather, plastic, paper and the like, and the sewed stitches are neat, beautiful, flat and firm, the sewing speed is high, and the use is simple and convenient. The sewing machine is generally composed of four parts, namely a feeding device, a machine base, a transmission part and an accessory part, and sewing materials are sewn through reasonable cooperation and circular work of the movement of each mechanism. The sewing machine can use the automatic thread trimming function in the sewing process, and the moving knife goes out the knife and colludes the suture during thread trimming, then moves the knife and returns and cuts off the suture to press from both sides tight bottom line, move the knife and do straight reciprocating motion along left and right directions through the spacing groove on the moving knife rest usually.

Chinese patent (publication No. CN207031720U, published as 2018-02-23) discloses a single thread and pressure foot lifting drive device for sewing machine thread trimming, which comprises a stepping motor, a first main shaft connected with the thread and pressure foot lifting device, a thread trimming device and a second main shaft connected with the thread trimming device, wherein the first main shaft is connected with the thread and pressure foot lifting device through a linkage rod assembly, and an output shaft of the stepping motor is provided with a crank mechanism of the thread and pressure foot lifting device connected with the first main shaft and a crank mechanism of the thread and pressure foot lifting device connected with the second main shaft. The presser foot lifting device crank mechanism comprises a first cam and a first crank, one end of the first crank is fixed on the first main shaft, and the other end of the first crank is rotationally connected with the first cam; the wire shearing device crank mechanism comprises a second cam and a second crank, one end of the second crank is fixed on the second main shaft, and the other end of the second crank is connected with the second cam in a sliding manner; the second cam is provided with a sliding block, and the second crank is provided with a sliding groove in sliding fit with the sliding block. The linkage rod assembly comprises a pull rod arranged above the first main shaft and a top rod respectively connected with the pull rod and the first main shaft; the first main shaft is provided with a third crank for driving the ejector rod to lift, and the third crank is provided with a transverse through hole for mounting the first main shaft and a connecting part for driving the ejector rod to lift.

The moving blade of the thread trimming device in the above patent document can only do linear reciprocating motion under the driving of the stepping motor. If the stitch length of the sewing machine is adjusted or the needle stop position is inaccurate, the position of the bottom thread of the sewing machine is changed, the motion track of the movable knife cannot be changed correspondingly, and the phenomenon of continuous sewing thread cutting caused by the fact that the bottom thread cannot be hooked is likely to occur. For example, when a small stitch length can be used for hooking a thread and cutting the thread, the cutting is not continuous due to different positions of the looper thread after the stitch length is adjusted to be the large stitch length. If the movable knife is adjusted upwards, the large needle pitch can cut off the thread, and then the small needle pitch can cause the knife point of the movable knife to be positioned above the curved needle thread when the knife is discharged due to the upward adjustment of the knife point of the movable knife, so that the curved needle thread is cut continuously.

In the prior art, the movable knife can be adjusted to a proper position, the position range is usually small, the movable knife is greatly changed even if the movable knife is finely adjusted after an adjusting screw is loosened due to the fact that the lever proportion is enlarged in the conventional adjusting mode, the movable knife is difficult to adjust, and a non-professional person cannot adjust to the proper position.

Disclosure of Invention

The invention provides a control method of a thread cutting device of a sewing machine aiming at the problems in the prior art, and the technical problems to be solved by the invention are as follows: how to improve the stability and reliability of the thread cutting of the sewing machine.

The purpose of the invention can be realized by the following technical scheme:

a control method of a thread trimming device of a sewing machine comprises an upper tool rest arranged on a machine base, a movable cutter fixedly arranged at one end of the upper tool rest, a lower tool rest arranged on the machine base and a fixed cutter fixedly arranged at one end of the lower tool rest and corresponding to the movable cutter; the movable knife is provided with a thread hooking groove, and the sewing machine is characterized in that a base of the sewing machine is provided with a swing rod capable of driving an upper knife rest to do reciprocating linear movement, an adjusting connecting rod capable of driving the upper knife rest to swing along the width direction of the upper knife rest, a first driving source for driving the swing rod to swing and a second driving source for driving the swing rod to move, the first driving source is provided with a first sensor and a third sensor which can respectively detect that the first driving source moves to two different limit positions, and the second driving source is provided with a second sensor which can detect that the second driving source moves to the limit positions; the control method comprises the following steps:

step a, triggering a thread trimming signal, enabling a driving source to start to act to drive an upper knife rest to move towards a target thread until the upper knife rest reaches a limit position and a sensor detects a signal, and enabling the driving source to enter a holding state;

step b, the second driving source acts to drive the upper knife rest and the moving knife on the upper knife rest to rotate for a certain angle towards the target suture line until the second driving source acts completely and the second sensor detects a signal and enters a holding state;

c, finishing the action keeping state of the first driving source, starting resetting until the third sensor detects a signal, cutting off the target suture in the process, and then completely resetting;

and d, the driving source II is stopped keeping the state, resetting is started until the driving source II is completely reset, the upper tool rest and the movable tool on the upper tool rest are restored to the initial state, and thread trimming is finished.

The principle is as follows: when the sewing is finished and the thread needs to be cut, the first driving source and the second driving source receive a thread cutting signal of the main controller, the first driving source drives the swing rod to swing, the swing rod drives the upper knife rest and the moving knife on the upper knife rest to move linearly to the maximum displacement, the swing rod keeps unchanged after the first sensor detects the signal, the second driving source drives the adjusting connecting rod to move, the adjusting connecting rod drives the upper knife rest and the upper knife to swing for a certain angle, at the moment, the moving knife and the curved needle are staggered in the vertical direction, after the second sensor detects the signal, the first driving source drives the swing rod to return, the swing rod drives the moving knife on the upper knife rest and the upper knife rest to return, a thread hooking groove on the moving knife hooks a thread and is matched with the fixed knife to cut the thread, after the third sensor detects the signal, the second driving source drives the. The thread trimming device in the technical scheme enables the moving blade to move in two directions, the moving track of the moving blade is changed in a moving mode, the thread hooking range is wider due to the nonlinear motion track of the blade component, thread trimming can be achieved without special precision of the moving blade position, the thread trimming stability and reliability are high, the requirement on the initial position of the moving blade is low, and the thread trimming device is convenient to install and adjust.

Whether the action of the first driving source and the second driving source is finished or the resetting is finished is judged through the three sensors, the whole process is accurately and reliably controlled, the manufacturing cost and the use cost of equipment are low, and the working efficiency is high.

In the control method of the thread trimming device of the sewing machine, the sewing machine comprises a base and a looper arranged on the base; the other end of the upper tool rest is provided with a limiting groove along the length direction of the upper tool rest, the machine base is connected with a limiting connecting rod, and the end part of the limiting connecting rod is fixedly provided with a limiting screw inserted in the limiting groove; one end of the swing rod is movably connected with the middle part of the upper tool rest, and the other end of the swing rod is connected with the first driving source; the upper knife rest is provided with a strip-shaped hole along the length direction, the strip-shaped hole is positioned between the middle part of the upper knife rest and the movable knife, one end of the adjusting connecting rod is fixedly provided with an adjusting screw inserted in the strip-shaped hole, the other end of the adjusting connecting rod is connected with an eccentric adjusting plate, and the eccentric adjusting plate is connected with the driving source two phase.

In the control method of the thread trimming device of the sewing machine, the eccentric adjusting plate is L-shaped, the middle part of the eccentric adjusting plate is connected with the end part of the adjusting connecting rod through the eccentric disc, and the reset torsion spring is arranged between one end of the eccentric adjusting plate and the base.

In the control method of the thread trimming device of the sewing machine, the first driving source is an electromagnet, the second driving source is an electromagnet, an output shaft of the electromagnet is connected with a guide shaft capable of linearly reciprocating through a connecting plate, a fixed block is fixedly arranged on the guide shaft, and the fixed block is hinged with the end part of the oscillating rod through a connecting rod; the output shaft of the second electromagnet is connected with a connecting rod capable of linearly reciprocating through a pin screw, a connecting convex column is arranged at the end of the connecting rod, a waist-shaped hole is formed in the end of the eccentric adjusting plate, and the connecting convex column is movably inserted in the waist-shaped hole.

Compared with the prior art, the thread cutting device provided by the invention has the advantages that the movable cutter moves in two directions, the thread hooking range is wider due to the non-linear movement track of the movable cutter part, the thread cutting stability and reliability are high, the requirement on the initial position of the movable cutter is low, and the thread cutting device is convenient to mount and adjust; meanwhile, whether the action or the reset of the first driving source and the second driving source is finished or not is judged through the three sensors, the whole process is accurately and reliably controlled, the manufacturing cost and the using cost of equipment are low, and the working efficiency is high.

Drawings

Fig. 1 is a schematic view of the installation structure of the thread trimming apparatus.

Fig. 2 is a schematic perspective view of the thread trimming device.

Fig. 3 is a schematic view of a partially exploded structure of the thread trimming apparatus.

Fig. 4 is a partially enlarged schematic view of fig. 3.

Fig. 5 is a time course diagram in the present control method.

Fig. 6 is a control flow diagram in the present control method.

In the figure, 1, a machine base; 2. bending a needle; 3. an upper tool rest; 31. a limiting groove; 32. a strip-shaped hole; 33. a connecting groove; 4. moving a knife; 41. a wire hooking groove; 5. a lower tool rest; 6. fixing a cutter; 7. a swing rod; 71. a connecting portion; 72. a thin neck portion; 8. a limit screw; 9. a limiting connecting rod; 10. adjusting the connecting rod; 11. an adjusting screw; 12. an eccentric adjusting plate; 12a, a kidney-shaped hole; 13. a return torsion spring; 14. an electromagnet I; 15. an electromagnet II; 16. a connecting plate; 17. a guide shaft; 18. a fixed block; 19. a pin screw; 20. a connecting rod; 20a, connecting the convex columns; a. the needle line position is bent at a large needle pitch; b. and (5) bending the needle line position with a small needle pitch.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1 to 4, the sewing machine includes a bed 1 and a looper 2 provided on the bed 1; the thread trimming device comprises an upper tool rest 3 arranged on the machine base 1, a movable tool 4 fixedly arranged at one end of the upper tool rest 3, a lower tool rest 5 arranged on the machine base 1 and a fixed tool 6 fixedly arranged at one end of the lower tool rest 5 and corresponding to the movable tool 4; the movable knife 4 is provided with a line hooking groove 41, the base 1 is provided with a swing rod 7, the end part of the swing rod 7 is connected with the middle part of the upper knife rest 3 and can drive the upper knife rest 3 to linearly reciprocate on the base 1, the other end of the upper knife rest 3 is provided with a limiting groove 31 along the length direction of the upper knife rest, the base 1 is connected with a limiting connecting rod 9, and the end part of the limiting connecting rod 9 is fixedly provided with a limiting screw 8 inserted in the limiting groove 31; the upper tool rest 3 is also provided with an adjusting connecting rod 10 connected between the middle part of the upper tool rest 3 and the movable blade 4, and the adjusting connecting rod 10 can drive the upper tool rest 3 to swing along the width direction of the upper tool rest 3; the thread cutting device also comprises a first driving source for driving the swing rod 7 to swing and a second driving source for driving the adjusting connecting rod 10 to move. A first sensor and a third sensor which can respectively detect that the first driving source moves to two different limit positions are arranged at the first driving source, and a second sensor which can detect that the second driving source moves to the limit positions is arranged at the second driving source; further, a strip-shaped hole 32 is formed in the upper tool rest 3 along the length direction of the upper tool rest, the strip-shaped hole 32 is located between the middle of the upper tool rest 3 and the movable blade 4, an adjusting screw 11 inserted into the strip-shaped hole 32 is fixedly arranged at one end of the adjusting connecting rod 10, and an eccentric adjusting plate 12 is connected to the other end of the adjusting connecting rod 10; the eccentric adjusting plate 12 is in an L shape, the middle part of the eccentric adjusting plate 12 is connected with the end part of the adjusting connecting rod 10 through an eccentric disc, a reset torsion spring 13 is arranged between one end of the eccentric adjusting plate 12 and the machine base 1, and the other end of the eccentric adjusting plate 12 is connected with a driving source; a connecting groove 33 is formed in one side of the middle of the upper tool rest 3, the middle of the swing rod 7 is hinged to the base 1, and one end part of the swing rod 7 is inserted into the connecting groove 33; the end part of the swing rod 7 is provided with a connecting part 71 with a circular arc-shaped peripheral surface, a thin neck part 72 formed by a yielding groove is arranged between the connecting part 71 and the middle part of the swing rod 7, the connecting part 71 is inserted in the connecting groove 33, and the depth of the connecting groove 33 is larger than the radial size of the connecting part 71.

The control method in this embodiment includes the steps of:

step a, triggering a thread trimming signal, enabling a driving source to start to act to drive an upper knife rest 3 to move towards a target thread until the upper knife rest 3 reaches a limit position and a sensor detects a signal, and enabling the driving source to enter a holding state;

step b, the second driving source acts to drive the upper knife rest 3 and the movable knife 4 on the upper knife rest 3 to rotate for a certain angle towards the target suture line until the second driving source acts completely and the second sensor detects a signal and enters a holding state;

and d, finishing the holding state of the second driving source, starting resetting until the second driving source is completely reset, restoring the upper tool rest 3 and the movable tool 4 on the upper tool rest 3 to the initial state, and finishing thread trimming.

When the sewing is finished and the thread needs to be cut, a driving source receives a thread cutting signal of a main controller, the driving source drives a swing rod 7 to swing, the swing rod 7 drives an upper knife rest 3 and a moving knife 4 on the upper knife rest 3 to linearly move to the maximum displacement, a sensor senses the signal, the swing rod 7 keeps the position unchanged, the driving source drives an adjusting connecting rod 10 to move, the adjusting connecting rod 10 drives the upper knife rest 3 and the moving knife to swing by a certain angle until a sensor senses the signal, at the moment, the moving knife 4 and a curved needle 2 are staggered in the vertical direction, then the driving source drives the swing rod 7 to return, the swing rod 7 drives the moving knife 4 on the upper knife rest 3 and the moving knife 4 on the upper knife rest 3 to return, a thread hooking groove 41 on the moving knife 4 hooks. After the third sensor senses a signal, the driving source drives the adjusting connecting rod 10 to reset, and the adjusting connecting rod 10 drives the upper tool rest 3 and the upper tool to reset. This thread trimming device makes and moves the motion that sword 4 has two directions, moves the motion trail that moves sword 4 and changes, and the non-linear motion trail of sword part makes the line scope of colluding wider, no matter is big gauge needle position a, still little gauge needle position b, moves sword 4 homoenergetic and catches on the suture, moves sword 4 position and need not be accurate very much also can realize the trimming, and the stability and the reliability of trimming are high, require lowly to the initial position that moves sword 4, be convenient for installation and regulation.

As shown in fig. 2 and 4, in this embodiment, the first driving source is an electromagnet 14, the second driving source is an electromagnet 15, an output shaft of the electromagnet 14 is connected to a guide shaft 17 capable of linearly reciprocating through a connecting plate 16, a fixed block 18 is fixedly arranged on the guide shaft 17, and the fixed block 18 is hinged to an end portion of the oscillating bar 7 through a connecting rod; the output shaft of the second electromagnet 15 is connected with a connecting rod 20 capable of linearly reciprocating through a pin screw, the end part of the connecting rod 20 is provided with a connecting convex column 20a, the end part of the eccentric adjusting plate 12 is provided with a waist-shaped hole 12a, and the connecting convex column 20a is movably inserted in the waist-shaped hole 12 a; the first electromagnet 14 and the second electromagnet 15 are fixed on the machine base 1 through the mounting assembly, the second electromagnet 15 drives the connecting rod 20 to move and limit through a shaft position screw, the connecting rod 20 comprises a connecting convex column 20a, and the connecting convex column 20a is matched with the eccentric adjusting plate 12 to achieve movable connection.

The trimming device in this embodiment mainly improves the driving and limiting structure of the driving knife 4, the adjusting connecting rod 10 on the upper knife rest 3 is specially designed, the eccentric adjusting plate 12 contains an eccentric disc feature, the adjusting connecting rod 10 is hinged with the eccentric adjusting plate, the fixing screw is an axial position screw, the axial position part of the axial position screw is hinged with an inner hole of the eccentric adjusting plate 12, the fixing screw is fixed on the cover plate, the reset torsion spring 13 is fixed on the cover plate through a spring fixing screw, one end of the reset torsion spring 13 is in contact with the cover plate, the other end of the reset torsion spring is in contact with the eccentric adjusting plate 12, and an anticlockwise reset torque is provided for the eccentric adjusting plate 12. Through the structure, the second electromagnet 15 drives the eccentric adjusting plate 12 and the adjusting connecting rod 10 to move, and further drives the upper tool rest 3 to swing.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Although 1, stand is used more herein; 2. bending a needle; 3. an upper tool rest; 31. a limiting groove; 32. a strip-shaped hole; 33. a connecting groove; 4. moving a knife; 41. a wire hooking groove; 5. a lower tool rest; 6. fixing a cutter; 7. a swing rod; 71. a connecting portion; 72. a thin neck portion; 8. a limit screw; 9. a limiting connecting rod; 10. adjusting the connecting rod; 11. an adjusting screw; 12. an eccentric adjusting plate; 12a, a kidney-shaped hole; 13. a return torsion spring; 14. an electromagnet I; 15. an electromagnet II; 16. a connecting plate; 17. a guide shaft; 18. a fixed block; 19. a pin screw; 20. a connecting rod; 20a, connecting the convex columns; a. the needle line position is bent at a large needle pitch; b. small gauge curved needle position, etc., but does not exclude the possibility of using other terms. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

Claims

1. A control method of a thread trimming device of a sewing machine comprises a base (1), wherein the thread trimming device comprises an upper tool rest (3) arranged on the base (1), a movable tool (4) fixedly arranged at one end of the upper tool rest (3), a lower tool rest arranged on the base (1) and a fixed tool (6) fixedly arranged at one end of the lower tool rest (5) and corresponding to the movable tool (4); the movable knife (4) is provided with a line hooking groove (41), and the sewing machine is characterized in that a machine base (1) of the sewing machine is provided with a swing rod (7) capable of driving an upper knife rest (3) to do reciprocating linear movement, an adjusting connecting rod (10) capable of driving the upper knife rest (3) to swing along the width direction of the upper knife rest, a first driving source for driving the swing rod (7) to swing and a second driving source for driving the swing rod (7) to move, the first driving source is provided with a first sensor and a third sensor which can respectively detect that the first driving source moves to two different limit positions, and the second driving source is provided with a second sensor which can detect that the second driving source moves to the limit positions; the control method comprises the following steps:

step a, triggering a thread trimming signal, enabling a driving source to start to act to drive an upper knife rest (3) to move towards a target thread until the upper knife rest (3) reaches a limit position and a sensor detects a signal, and enabling the driving source to enter a holding state;

step b, the second driving source acts to drive the upper knife rest (3) and the movable knife (4) on the upper knife rest (3) to rotate for a certain angle towards the target suture line until the second driving source acts completely and the second sensor detects a signal and enters a holding state;

and d, the driving source II is stopped keeping the state, resetting is started until the driving source II is completely reset, the upper tool rest (3) and the movable tool (4) on the upper tool rest (3) are restored to the initial state, and thread trimming is finished.

2. The control method of the thread trimming device of a sewing machine according to claim 1, wherein the sewing machine comprises a looper (2) provided on the bed (1); the other end of the upper tool rest (3) is provided with a limiting groove (31) along the length direction of the upper tool rest, the base (1) is connected with a limiting connecting rod (9), and the end part of the limiting connecting rod (9) is fixedly provided with a limiting screw (8) inserted in the limiting groove (31); one end of the swing rod (7) is movably connected with the middle part of the upper tool rest (3), and the other end of the swing rod (7) is connected with the first driving source; the utility model discloses a knife rest, including last knife rest (3), last knife rest (3) is last to be seted up along its length direction's bar hole (32), bar hole (32) are located the middle part of last knife rest (3) with move between sword (4), the one end of adjusting connecting rod (10) sets firmly and is established adjusting screw (11) in bar hole (32), the other end of adjusting connecting rod (10) is connected with eccentric adjusting plate (12), eccentric adjusting plate (12) with the driving source is two-phase to be connected.

3. The control method of the thread trimming device of the sewing machine according to claim 2, wherein the eccentric adjusting plate (12) is in an "L" shape, the middle part of the eccentric adjusting plate (12) is connected with the end part of the adjusting connecting rod (10) through an eccentric disc, and a reset torsion spring (13) is arranged between one end of the eccentric adjusting plate (12) and the machine base (1).

4. The control method of the thread trimming device of the sewing machine according to claim 3, characterized in that the first driving source is an electromagnet (14), the second driving source is an electromagnet (15), the output shaft of the electromagnet (14) is connected with a guide shaft (17) capable of linearly reciprocating through a connecting plate (16), a fixed block (18) is fixedly arranged on the guide shaft (17), and the fixed block (18) is hinged with the end part of the swing rod (7) through a connecting rod; the output shaft of the second electromagnet (15) is connected with a connecting rod (20) capable of moving linearly in a reciprocating mode through a pin screw (19), the end portion of the connecting rod (20) is provided with a connecting convex column (20a), the end portion of the eccentric adjusting plate (12) is provided with a waist-shaped hole (12a), and the connecting convex column (20a) is movably inserted into the waist-shaped hole (12 a).