CN109234927A

CN109234927A - A kind of thread cutting mechanism and sewing machine

Info

Publication number: CN109234927A
Application number: CN201811350761.4A
Authority: CN
Inventors: 万义明; 林晓晓
Original assignee: Jack Sewing Machine Co Ltd
Current assignee: Jack Technology Co Ltd
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2019-01-18
Anticipated expiration: 2038-11-14
Also published as: CN109234927B

Abstract

The present invention provides a kind of thread cutting mechanism, including trimming component and separated time component, trimming component includes cutter, separated time component includes movable distributor plate, distributor plate is respectively equipped with separated time groove and suture clamping part at the both ends of its direction of motion, the cutter head and distributor plate of cutter are all disposed between the needle plate and rotating shuttle in sewing machine, and the entrance of baseline and upper thread or upper thread the end of a thread is allowed in the separated time groove of distributor plate.Upper thread and baseline can be cut when trimming after sewing and cut upper thread the end of a thread when playing seam by the application, solves the problems, such as seam Bird's Nest, particularly, by cutter and clamping of the distributor plate to suture and the cutter head by cutter cuts off the different suture of thickness, and tangent line is stablized；Also, the lower section of needle plate is arranged in the application, does not influence the operating space at head, has good applicability.

Description

A kind of thread cutting mechanism and sewing machine

Technical field

The present invention relates to a kind of thread cutting mechanisms.

The invention further relates to it is a kind of include above-mentioned thread cutting mechanism sewing machine.

Background technique

Currently, being equipped with thread cutting mechanism in sewing machine, it is used for suture (including upper thread and baseline) after sewing It cuts.As shown in Figure 1, existing thread cutting mechanism includes the moving knife 100 and stationary knife 200 being oppositely arranged, moving knife 100 and stationary knife 200 It is all disposed within the top of rotating shuttle 400 in the lower section of needle plate 300 in sewing machine and sewing machine, wherein stationary knife 200 is fixed on seam It threads on machine matrix, moving knife 100 can rotate under the action of driving assembly around the lower axle in sewing machine.Trimming after sewing When, driving assembly drives moving knife 100 to rotate to the direction close to stationary knife 200, and the point of a knife of moving knife 100 is with suture together to close The direction of stationary knife 200 is mobile, until the side moving knife 100 and stationary knife 200 in eedle carry out the mechanical snap of high pressure, cutting seam Line.

Further, the stitching of sewing machine is formed by eedle 500 and the mutually movement of rotating shuttle 400, in normally sewing shape Under state, suture cannot encounter moving knife blade and stationary knife blade, while in order to not influence the movement of eedle 500 and rotating shuttle 400, therefore Moving knife 100 and stationary knife 200 must just avoid the motion range of eedle 500 and rotating shuttle 400 under normal sewing state.Therefore, just Under normal sewing state, moving knife 100 eedle 500 side and there are a distances with the center of eedle 500, stationary knife 200 is in machine The other side of needle 500 and there are a distances with the center of eedle 500.

But the thread cutting mechanism with above structure, in trimming, due to mechanical snap trimming and suture is in and tightens shape State, so that remaining the end of a thread is too long on sewed product after trimming, remaining stub is unstable, stays in the residual face of eedle side The problems such as stub of line is unstable.In addition, the occlusion friction for a long time of moving knife 100 and stationary knife 200, will lead to tangent line and stablizes Property it is poor, moving knife 100 and 200 service life of stationary knife are short, be difficult to cut compared with tailor-tacking line, cutting mechanics noise is big, is by cutting the end of a thread The defects of hardness is pulled open under the powerful pressure of cutter, the end of a thread notch is irregular, the wire drawing of the end of a thread notch, the end of a thread scatter.Sewed product The process that upper longer the end of a thread of residual needs to increase artificial trimming the end of a thread, it is time-consuming and laborious；The unstable upper thread the end of a thread of length is under The bad stitching that Bird's Nest class is easily formed when secondary sewing starts, influences the quality of sewed product.

In order to solve the problems, such as seam Bird's Nest, have following way in industry at present: installation is for by upper thread thread end clamp on head Sliding wire-clamping device firmly, is arranged blade on presser feet, makes upper thread line by sliding wire-clamping device and pullling for suture when playing seam Blade on head rest on presser feet, and then upper thread the end of a thread is cut off, solve the problems, such as " Bird's Nest ".Although above-mentioned way has been able to solve seam The problem of Bird's Nest, but it is not general, thick to influence operating space, the presser feet with blade after causing head to install sliding wire-clamping device additional Upper thread blade cuts upper thread the end of a thread that is continuous, cutting off and needs air draught collection processing, air draught that gas source, presser feet secant is needed to lead to upper thread line Head remains in the appearance for a series of problems, such as sewing positive influences are beautiful.

Summary of the invention

It in view of the foregoing deficiencies of prior art, can be the purpose of the present invention is to provide a kind of thread cutting mechanism Upper thread and baseline are cut when trimming after sewing and cut upper thread the end of a thread when playing seam.

To achieve the above object, the present invention provides a kind of thread cutting mechanism, including trimming component and separated time component, the trimming Component includes cutter, and the separated time component includes movable distributor plate, and the distributor plate is at the both ends of its direction of motion point Not She You separated time groove and suture clamping part, the cutter head and distributor plate of the cutter be all disposed within needle plate and rotation in sewing machine Between shuttle；Baseline and upper thread is allowed to enter after sewing when trimming, in the separated time groove of the distributor plate, and distributor plate can Baseline and upper thread is driven to move to the direction close to cutter, until the suture clamping part of distributor plate end and the cutter head of cutter Baseline and upper thread are clamped, is cut off baseline and upper thread by the cutter head of cutter；When playing seam, in the separated time groove of the distributor plate Upper thread the end of a thread is allowed to enter, and distributor plate is able to drive upper thread the end of a thread and moves to the direction close to cutter, until distributor plate end The suture clamping part in portion and the cutter head of cutter clamp upper thread the end of a thread, are cut off upper thread the end of a thread by the cutter head of cutter.

Further, the cutter are ultrasonic cutting knife；The trimming component further includes supersonic generator, fixation In sewing machine insole board mounting bracket, be fixed on the ultrasonic transducer of mounting bracket and defeated with ultrasonic transducer The input terminal of the ultrasonic variable amplitude bar that outlet is connected, the ultrasonic transducer passes through ultrasonic wire and supersonic generator It is connected, the ultrasonic cutting knife is connected to the output end of ultrasonic variable amplitude bar.

Further, the separated time component further includes the separated time driving assembly that distributor plate can be driven to move, trimming drive Dynamic component and reset drives component；Under original state, the distributor plate and cutter are located at the same of eedle in sewing machine Side, the suture clamping part of the distributor plate end and the cutter head of cutter are in clamping shape and all neighbour is pressed from both sides in eedle, the suture The portion of holding is located at front end of the distributor plate close to eedle, and the separated time groove is located at the rear side of suture clamping part；It is cut after sewing When line and when playing seam, the separated time driving assembly and trimming driving assembly drive distributor plate to the direction far from cutter to Preceding movement, makes distributor plate move to extreme position, the underface side that the separated time groove on distributor plate is located at eedle, and the reset is driven Dynamic component finally drives distributor plate to move backward to the direction close to cutter, make separated time sheet reset.

Further, the separated time driving assembly includes separated time driving source, first connecting rod, is parallel to lower axle in sewing machine Drive shaft, fixed driving crank on the driving shaft, second connecting rod, third connecting rod and it is installed in rotation on lower axle periphery Mounting base, the separated time driving source has telescopic separated time driving portion, is extended with separated time crank arm on the driving crank Portion, the both ends of the first connecting rod are hinged with separated time driving portion and separated time crank arm respectively, one end of the second connecting rod The one end for being fixed on drive shaft, the other end and third connecting rod is hinged, and the other end and mounting base of the third connecting rod are hinged, described There is plate mounting portion, the plate mounting portion is fixed on mounting base on distributor plate.

Further, the trimming driving assembly includes the trimming crank arm extended from the driving crank, puts down Row in drive shaft sliding pin, be rotatably installed on sliding pin ball, all be fixed on lower axle first driving cam part and second The switching driving assembly for driving cam part and driving sliding pin mobile, the sliding pin are movably mounted at trimming crank arm In, it is described switching driving assembly driving sliding pin axial movement, make ball with first driving cam part outer peripheral surface abut against or with The outer peripheral surface of second driving cam part abuts against；After sewing when trimming, the periphery of the ball and the first driving cam part Face abuts against；When playing seam, the ball and the outer peripheral surface of the second driving cam part are abutted against.

Further, the first driving cam part and the second driving cam part are integrated into a driving cam.

Further, there is the outer peripheral surface of the first driving cam part the first highest reduction point and the first minimum trimming to rise Initial point, the outer peripheral surface of the second driving cam part have the second highest reduction point and a second minimum trimming starting point, and described the The radius of one highest reduction point and the second highest reduction point is identical, and the first minimum trimming starting point and the second minimum trimming rise The radius of initial point is identical；When ball is abutted with the first highest reduction point or the second highest reduction point, the distributor plate is located at just Beginning position；When ball is abutted with the first minimum trimming starting point or the second minimum trimming starting point, the distributor plate is located at pole Extreme position；The first highest reduction point and the second highest reduction point constitute a part of the reset drives component.

Further, the outer peripheral surface of the second driving cam part in the second minimum trimming starting point there is one section to be waited half The stop section of diameter.

Further, the switching driving assembly includes the installation base plate for being fixed on sewing machine insole board, is fixed on installation Substrate switching driving source, the switching driving swing arm for being articulated with installation base plate, the ejector pin extended up and down, the limiting card for being fixed on sliding pin Spring and the first back-moving spring being set on sliding pin, the switching driving source has can be along the switching of sliding pin axial stretching Driving portion, the ejector pin are fixedly connected with switching driving portion, and the ejector pin can be abutted with switching driving swing arm, and the switching is driven On movable pendulum arm have can with the pushing part of sliding pin end abutment, the both ends of the first back-moving spring respectively with trimming crank arm Portion and limit circlip abut against.

Further, the guide groove extended along ejector pin moving direction, the end of the ejector pin are offered on the installation base plate Portion is threaded through in guide groove and is in contact with the cell wall of guide groove.

Further, the installation base plate is equipped with the limit otic placode portion upwardly extended, the switching of the switching driving source Be installed on driving portion positioned at ejector pin two sides initial limited block and terminate limited block, the initial limited block can and position-limiting ear Plate portion abuts, and the limited block that terminates can be abutted with the shell of switching driving source.

Further, the reset drives component further includes being fixed on the fixed pin of separated time driving portion end and being arranged Second back-moving spring on separated time driving portion, the both ends of the second back-moving spring respectively with fixed pin and separated time driving source Shell abuts.

Further, the distributor plate offers the line of fall hole of perforation, the upper table of the distributor plate at suture clamping part Offer the appearance line trenches being downwardly concaved on face, described one end for holding line trenches extends at line of fall hole, the other end extends to point At line trenches.

Further, the cutter are hot knife；The trimming component further includes electrothermal generator and is fixed on electricity The input terminal of the cutting knife mounting seat of heater, the electrothermal generator is controlled to a power supply by electric wire, and the electric heating occurs The output end of device is connected with hot knife.

The present invention also provides a kind of sewing machine, thread cutting mechanism as described above is installed in the sewing machine.

As described above, thread cutting mechanism of the present invention and sewing machine, have the advantages that

Upper thread and baseline can be cut when trimming after sewing and cut upper thread the end of a thread when playing seam by the application It is disconnected, solve the problems, such as seam Bird's Nest, particularly, the clamping to suture and the knife by cutter by cutter and distributor plate Head cuts off the different suture of thickness, and tangent line is stablized；Also, the lower section of needle plate is arranged in the application, does not influence at head Operating space has good applicability.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of thread cutting mechanism in the prior art.

Fig. 2 and Fig. 3 is structural schematic diagram of the thread cutting mechanism under different perspectives in the application.

Fig. 4 and Fig. 5 be Fig. 2 omit sewing machine insole board after and the structural schematic diagram under different perspectives.

Fig. 6 is the structural schematic diagram of trimming assembly embodiment one in the application.

Fig. 7 is the structural schematic diagram of the application middle separated time driving assembly a part.

Fig. 8 is the structural schematic diagram of trimming driving assembly in the application.

Fig. 9 is the structural schematic diagram for switching driving assembly in the application.

Figure 10 is the structural schematic diagram of switching driving swing arm in the application.

Figure 11 is the structural schematic diagram that cam is driven in the application.

Figure 12 is the structural schematic diagram of the application middle separated time plate.

Figure 13 is the structural schematic diagram of thread cutting mechanism in the initial state in the application.

Figure 14 is structure of thread cutting mechanism after sewing when trimming, when distributor plate moves to extreme position in the application Schematic diagram.

Figure 15 is structural schematic diagram of the Figure 14 under trimming final state.

Figure 16 is thread cutting mechanism in the application when playing seam, structural schematic diagram when distributor plate moves to extreme position.

Figure 17 is structural schematic diagram of the Figure 16 under trimming final state.

Figure 18 is the structural schematic diagram of trimming assembly embodiment two in the application.

Component label instructions

1 trimming component

101 cutter

102 mounting brackets

103 ultrasonic transducers

104 ultrasonic variable amplitude bars

105 ultrasonic wires

106 electrothermal generators

107 cutting knife mounting seats

108 electric wires

The 109 hot knife edges of a knife

2 distributor plates

21 separated time grooves

22 suture clamping parts

23 plate mounting portions

24 line of fall holes

25 hold line trenches

3 separated time driving assemblies

31 separated time driving sources

311 separated time driving portions

32 first connecting rods

33 drive shafts

34 driving cranks

341 separated time crank arms

342 trimming crank arms

35 second connecting rods

36 third connecting rods

37 mounting bases

4 trimming driving assemblies

41 sliding pins

42 balls

43 first driving cam parts

431 first highest reduction points

432 first minimum trimming starting points

433 first arc sections

434 second arc sections

44 second driving cam parts

441 second highest reduction points

442 second minimum trimming starting points

443 stop sections

444 third arc sections

445 the 4th arc sections

5 reset drives components

51 fixed pins

52 second back-moving springs

6 switching driving assemblies

61 installation base plates

611 guide grooves

612 limit otic placode portions

62 switching driving sources

621 switching driving portions

63 switching driving swing arms

631 pushing parts

64 ejector pins

65 limit circlips

66 first back-moving springs

67 initial limited blocks

68 terminate limited block

7 needle plates

8 rotating shuttles

81 rotating shuttle off-line tail portions

9 baselines

10 upper threads

11 upper thread the end of a thread

12 lower axles

13 bottom plates

14 eedles

Specific embodiment

Embodiments of the present invention are illustrated by particular specific embodiment below, those skilled in the art can be by this explanation Content disclosed by book is understood other advantages and efficacy of the present invention easily.

It should be clear that structure, ratio, size etc. that this specification attached drawing is drawn, only to cooperate specification revealed interior Hold, so that those skilled in the art understands and reads, is not intended to limit the invention enforceable qualifications, therefore does not have skill Essential meaning in art, the modification of any structure, the change of proportionate relationship or the adjustment of size can be produced not influencing the present invention Under raw effect and the purpose that can reach, should all still it fall in the range of disclosed technology contents can cover.Together When, cited such as "upper" in this specification, "lower", "left", "right", " centre " and " one " term, be merely convenient to chat It states clearly, rather than to limit the scope of the invention, relativeness is altered or modified, and is changing technology without essence It inside holds, when being also considered as the enforceable scope of the present invention.

This application involves a kind of sewing machine, in particular in the thread cutting mechanism and the thread cutting mechanism in a kind of sewing machine Trimming driving assembly 4, wherein thread cutting mechanism for realizing upper thread 10 and baseline 9 are cut when trimming after sewing, with And cut upper thread the end of a thread 11 when playing seam, trimming driving assembly 4 after sewing for realizing driving distributor plate 2 when trimming Movement and driving distributor plate 2 movement when playing seam.For convenient for describing, in following embodiments, all directions are defined as follows: will The length direction of sewing machine is defined as left and right directions, and towards the direction of head of sewing machine be left direction, towards sewing machine tail Direction be right direction；Feed dog drives cloth in sewing machine when the width direction of sewing machine being defined as front-rear direction, and being sewed The mobile direction of material is front direction；The short transverse of sewing machine is defined as up and down direction.

As shown in Figures 2 to 5, this application involves thread cutting mechanism include trimming component 1 and separated time component, trimming component 1 Including cutter 101, separated time component includes movable distributor plate 2, in the present embodiment, the motion mode of distributor plate 2 be around with The parallel axis oscillating of lower axle 12 in sewing machine, therefore distributor plate 2 can mainly move, with separate or close in the longitudinal direction Cutter 101, the cutter head and distributor plate 2 of cutter 101 are all disposed between the needle plate 7 in sewing machine and rotating shuttle 8, therefore, cut The cutter head and distributor plate 2 of cutter 101 are all located at the lower side of sewing machine insole board 13；As shown in figure 11,2 left sections of parts of distributor plate Rear end and front end be respectively equipped with separated time groove 21 and suture clamping part 22.After sewing when trimming, the separated time ditch of distributor plate 2 Baseline 9 and upper thread 10 is allowed to enter in slot 21, and distributor plate 2 is able to drive baseline 9 and upper thread 10 to the side close to cutter 101 To swing backward, until the suture clamping part 22 and the cutter heads of cutter 101 of 2 end of distributor plate clamp baseline 9 and upper thread 10, Baseline 9 and upper thread 10 are cut off by the cutter head of cutter 101 again.When playing seam, upper thread line is allowed in the separated time groove 21 of distributor plate 2 First 11 enter, and distributor plate 2 is able to drive upper thread the end of a thread 11 and swings backward to the direction close to cutter 101, until distributor plate 2 The suture clamping part 22 of end and the cutter head of cutter 101 clamp upper thread the end of a thread 11, then by cutter 101 cutter head by upper thread The end of a thread 11 is cut off.Therefore, above-mentioned thread cutting mechanism upper thread 10 and baseline 9 can be cut when trimming after sewing, Yi Ji Upper thread 10 is cut when playing seam.Preferably, the cutter 101 are ultrasonic cutting knife or hot knife；With ultrasonic cutting knife For, due to using ultrasonic cutting knife and distributor plate 2 to the clamping of suture and using by the way of ultrasonic cutting by upper thread 10 It is cut with baseline 9 or by upper thread the end of a thread 11, ultrasonic wave tangent line is mechanical wave tangent line, therefore the cutter head of ultrasonic cutting knife does not need Equally there is sharp cutting edge to mechanical trimming blade, therefore the cutter head of ultrasonic cutting knife will not hang up suture, it can be by thickness Different suture cuttings, and cutting noise is small, suture notch is neat, suture notch is not in wire drawing and opens scattered phenomenon, significantly Improve thread cutting stability.Meanwhile the cutter head of ultrasonic cutting knife can be away from needle plate 7 for mechanical trimming blade Needle falling hole it is closer, therefore remaining the end of a thread is very short after trimming and remaining stub is stablized, and does not need subsequent artefacts' trimming The end of a thread greatly improves sewing efficiency and quality.Similarly, hot knife equally has that cutting noise is small, suture notch is neat, suture is cut The advantages that mouth is not in wire drawing and opens scattered phenomenon.Particularly, after the application realizes sewing simultaneously using same group of mechanism Automatic shearing and rise seam when trim upper thread the end of a thread 11 automatically, has solved the problems, such as stitch Bird's Nest under the premise of, do not influence at head Operating space, have good applicability.

As shown in fig. 6, trimming component 1 further includes supersonic generator, consolidates when cutter 101 are ultrasonic cutting knife Due to sewing machine insole board 13 mounting bracket 102, be fixed on mounting bracket 102 ultrasonic transducer 103 and with ultrasound The ultrasonic variable amplitude bar 104 that the output end of wave transducer 103 is connected, the input terminal of ultrasonic transducer 103 pass through ultrasonic wave Electric wire 105 is connected with supersonic generator, and ultrasonic cutting knife is connected to the output end of ultrasonic variable amplitude bar 104, ultrasonic wave Generator is also connected in the control system of sewing machine.Control system can control the opening and closing of supersonic generator, into And the trimming time of ultrasonic cutting knife is controlled, be conducive to the anti-Bird's Nest control of seam.After supersonic generator is opened, ultrasonic wave hair Alternating current is converted into high-frequency and high-voltage alternating current by raw device, passes through the connection of ultrasonic wire 105 and ultrasonic transducer 103, ultrasound The electric energy that supersonic generator inputs is converted into mechanical energy (i.e. ultrasonic wave) by wave transducer 103, and ultrasonic variable amplitude bar 104 will surpass The Amplitude amplification that acoustic wave transducer 103 exports passes to ultrasonic cutting knife, and amplitude is further amplified in ultrasonic cutting knife, focuses By cutting part, i.e., ultrasonic energy concentration is input to by ultrasonic wave and output ultrasonic wave using the cutter head of ultrasonic cutting knife The holding position of both cutter heads of suture clamping part 22 and ultrasonic cutting knife for being input to 2 front end of distributor plate is concentrated, and then will folder The suture held between suture clamping part 22 and the cutter head of ultrasonic cutting knife is cut.In the trimming component 1, since ultrasonic wave is cut Cutter is doing ultrasonic activation, does not need very big cutting force, and the energy of ultrasonic wave, which can be concentrated, to be input to by cutting material Cutting part makes the softening of cutting part moment, fusing under the action of huge ultrasonic energy, realizes cutting by cutting material It is disconnected, so that remaining the end of a thread is shorter after making trimming, and can realize perfect edge sealing to the end of a thread notch, prevent suture in the end of a thread notch Locate material wire drawing, loose, greatly improves sewed product quality.Simultaneously as ultrasonic cutting knife is mechanical wave trimming and on-mechanical It is engaged trimming, therefore the friction of ultrasonic cutting knife is very small, long service life, and can shear thicker suture, it will not be because of seam Line is thicker and needs replacing ultrasonic cutting knife, uses and operates and is all very simple.

As shown in figure 18, when cutter 101 are hot knife, trimming component 1 further includes electrothermal generator 106, Yi Jigu Input terminal due to the cutting knife mounting seat 107 of electrothermal generator 106, electrothermal generator 106 is connected by electric wire 108 with power supply It connects, the output end of electrothermal generator 106 is connected with hot knife, and electrothermal generator 106 is also connected in the control system of sewing machine It connects.Control system can control the opening and closing of electrothermal generator 106, and then control the trimming time of hot knife, be conducive to Play the anti-Bird's Nest control of seam.After electrothermal generator 106 is opened, the hot knife edge of a knife 109 of hot knife heating power, hot knife front end makes The softening of cutting part moment, fusing, realize the cutting of suture, and it is shorter to make remaining the end of a thread after trimming, and can cut to the end of a thread The existing perfect edge sealing of cause for gossip, prevents suture in the wire drawing of the end of a thread incision material, loosely, greatly improves sewed product quality.In addition, earnestly The surface of knife has insulation and thermal insulation layer.

As shown in Figures 2 to 5, separated time component further includes the separated time driving assembly 3 that distributor plate 2 can be driven to swing, cuts Line driving assembly 4 and reset drives component 5.Thread cutting mechanism in the initial state, i.e., in the normal sewing process of sewing machine, And under sewing machine shutdown status, as shown in figure 13, in the longitudinal direction, distributor plate 2 and ultrasonic cutting knife be all located at seam It threads the rear side of eedle 14 in machine, in other words, in the longitudinal direction, distributor plate 2 and ultrasonic cutting knife be all located on needle plate 7 and fall The rear side of pin hole；The cutter head of the suture clamping part 22 of 2 front end of distributor plate and ultrasonic cutting knife in clamping shape and all neighbour in Eedle 14 (i.e. neighbours are in the needle falling hole on needle plate 7)；Suture clamping part 22 is located at distributor plate 2 close to the front end of eedle 14, divides Line trenches 21 are located at the middle position of distributor plate 2, positioned at the rear side of suture clamping part 22.After sewing when trimming, with And when playing seam, such as Figure 14 or as shown in figure 16, separated time driving assembly 3 and trimming driving assembly 4 drive distributor plate 2 to separate together The direction of ultrasonic cutting knife is swung forward, and distributor plate 2 is made to be rocked to extreme position forward, at this point, the separated time ditch on distributor plate 2 Slot 21 is located at the underface side of eedle 14.Reset drives component 5 finally drives distributor plate 2 to the direction close to ultrasonic cutting knife It swings backward, reset distributor plate 2.Below to separated time driving assembly 3, trimming driving assembly 4 and reset drives component 5 Preferred embodiment expansion narration.

As shown in Fig. 4 and Fig. 5 and Fig. 7, separated time driving assembly 3 includes the first company of separated time driving source 31, front and back extension Bar 32, the driving crank 34 for being fixed on 33 left end of drive shaft, is arranged in lower axle the drive shaft 33 for being parallel to lower axle 12 in sewing machine The second connecting rod 35 of 12 peripheries, the third connecting rod 36 that 12 periphery of lower axle is set and it is installed in rotation on 12 periphery of lower axle Mounting base 37.Electromagnet or cylinder or linear motor etc., separated time driving source 31 and control system can be selected in separated time driving source 31 It is connected, by control system control action；Separated time driving source 31 is fixed on mounting plate, which is fixed on the lower end of bottom plate 13 Face, and then separated time driving source 31 is fixed on to the lower end surface of bottom plate 13；There is separated time driving source 31 separated time that can be elastic to drive Dynamic portion 311；Separated time crank arm 341 is extended on driving crank 34；Before the rear end of first connecting rod 32 and separated time driving portion 311 End is hinged, and the front end of first connecting rod 32 and the outer end of separated time crank arm 341 are hinged；One end of second connecting rod 35 is fixed on One end of the left end of drive shaft 33, the other end and third connecting rod 36 is hinged；The other end and mounting base 37 of third connecting rod 36 are hinged； Right section of part of distributor plate 2 has plate mounting portion 23, and plate mounting portion 23 is fixed on mounting base 37 by screw.Second connecting rod 35, Third connecting rod 36 and 37 three of mounting base constitute the transmission mechanism being connected between drive shaft 33 and distributor plate 2.It is driven with separated time Source 31 is for electromagnet, in the initial state, separated time driving source 31 is in off-position, the separated time driving of separated time driving source 31 The state that portion 311 is stretched out forwardly；Upper thread the end of a thread 11 is trimmed automatically when automatic shearing and after playing seam after sewing When, control system controls separated time driving source 31 and is powered, then the separated time driving portion 311 of separated time driving source 31 is backward indent, by the One connecting rod 32 drives driving crank 34 to turn over an angle, then passes through drive shaft 33, second connecting rod 35, third connecting rod 36 and installation Seat 37 drives distributor plate 2 to rotate forward over an angle around lower axle 12, then distributor plate 2 is swung forward relative to cutter 101.

As shown in Fig. 5, Fig. 8 and Fig. 9, trimming driving assembly 4 includes the trimming crank arm extended from driving crank 34 Lower axle 12, the ball 42 for being rotatably installed on 41 left end of sliding pin, is all fixed at the sliding pin 41 for being parallel to drive shaft 33 in portion 342 The first driving cam part 43 and the second driving cam part 44 and drive the switching driving assembly 6 that moves left and right of sliding pin 41, it is sliding Pin 41 can be movably mounted in the outer end of trimming crank arm 342, and switching driving assembly 6 drives sliding pin 41 is axial to move It moves, ball 42 is made to drive the outer peripheral surface of cam part 43 to abut against or offset with the outer peripheral surface of the second driving cam part 44 with first It connects.In the present embodiment, after sewing when trimming, the ball 42 that switching driving assembly 6 makes to be fixed on 41 left end of sliding pin is located at the The peripheral side of one driving cam part 43, then ball 42 and the outer peripheral surface of the first driving cam part 43 abut against；During trimming, Lower axle 12 drives the first driving cam part 43 to rotate, and passes through the variable diameter property driving trimming of the outer peripheral surface of the first driving cam part 43 Crank arm 342 turns over an angle, it may be assumed that makes that crank 34 is driven to turn over an angle, then passes through drive shaft 33, second connecting rod 35, third connecting rod 36 and mounting base 37 drive distributor plate 2 to rotate forward over an angle around lower axle 12, it is final drive distributor plate 2 to Preceding swing extremely extreme position, to allow upper thread 10 and baseline 9 to enter in the separated time groove 21 of distributor plate 2.When playing seam, switching driving Component 6 makes the ball 42 for being fixed on 41 left end of sliding pin be located at the peripheral side of the second driving cam part 44, then ball 42 and second drives The outer peripheral surface in moving cam portion 44 abuts against；During playing seam, lower axle 12 drives the second driving cam part 44 to rotate, and passes through second The variable diameter property driving trimming crank arm 342 of the outer peripheral surface of cam part 44 is driven to turn over an angle, it may be assumed that make to drive crank 34 An angle is turned over, then drives distributor plate 2 around lower axle by drive shaft 33, second connecting rod 35, third connecting rod 36 and mounting base 37 12 rotate forward over an angle, final that distributor plate 2 is driven to be rocked to extreme position forward, to allow upper thread the end of a thread 11 to enter separated time In the separated time groove 21 of plate 2.

The preferred structure of first driving cam part 43 and the second driving cam part 44 are as follows: as shown in Figure 10, the first driving is convex Wheel portion 43 and the second driving cam part 44 are integrated into a driving cam, and the first driving cam part 43 is to drive the left side of cam Point, the second driving cam part 44 is the right half part for driving cam.The outer peripheral surface of first driving cam part 43 has the first highest The outer peripheral surface of reduction point 431 and the first minimum trimming starting point 432, the second driving cam part 44 has the second highest reduction point 441 and the second minimum trimming starting point 442, the first highest reduction point 431 is identical with the radius of the second highest reduction point 441, and One minimum trimming starting point 432 is identical with the radius of the second minimum trimming starting point 442, the first highest reduction point 431 and second Highest reduction point 441 shifts to install, and the first minimum trimming starting point 432 and the second minimum trimming starting point 442 shift to install；When When ball 42 is abutted with the first highest reduction point 431 or the second highest reduction point 441, distributor plate 2 is located at initial position；Work as ball 42 with the first minimum trimming starting point 442 of minimum trimming starting point 432 or the second when abutting, and distributor plate 2 is located at extreme position；Cause This, drives the first highest reduction point 431 and the second highest reduction point 441 on cam to constitute a part of reset drives component 5. In addition, the outer peripheral surface of the second driving cam part 44 waits the stop section of radiuses at the second minimum trimming starting point 442 with one section 443；When playing seam, stop section 443 can make distributor plate 2 rest on extreme position for a period of time.Certainly, in other embodiments, First driving cam part 43 and the second driving cam part 44 can be two mutually independent cams, and installation site can also be mutual It changes.

Further, as shown in Figure 10, the direction for driving the outer peripheral surface of cam part 43 and ball 42 to be in contact along first, the Two section circles of the outer peripheral surface of one driving cam part 43 between the first highest reduction point 431 and the first minimum trimming starting point 432 Segmental arc is followed successively by the first arc section 433 and the second arc section 434, and the radius of the first arc section 433 is by the first highest reduction point 431 The radius value at place is gradually decreased as the radius value at the first minimum trimming starting point 432, and the radius of the second arc section 434 is by first Radius value at minimum trimming starting point 432 gradually increases as the radius value at the first highest reduction point 431.Therefore, sewing knot When cutting upper thread 10 and baseline 9 after beam, first highest reduction point 431 of the ball 42 first with the first driving cam part 43 is abutted against, As lower axle 12 drives the first driving cam part 43 to rotate, ball 42 successively rises with the first arc section 433, the first minimum trimming again Initial point 432 and the contact of the second arc section 434, finally abut against with the first highest reduction point 431 again.

Further, as shown in Figure 10, the direction for driving the outer peripheral surface of cam part 44 and ball 42 to be in contact along second, the Two section arc sections of the outer peripheral surface between the first highest reduction point 431 and stop section 443 of two driving cam parts 44 are followed successively by the Three-arc section 444 and the 4th arc section 445, the radius of third arc section 444 by the second highest reduction point 441 radius value by The radius of the radius value being gradually reduced at the second minimum trimming starting point 442, the 4th arc section 445 is originated by the second minimum trimming Radius value at point 442 gradually increases as the radius value at the second highest reduction point 441.Therefore, seam trimming upper thread the end of a thread 11 is played When, second highest reduction point 441 of the ball 42 first with the second driving cam part 44 abuts against, as lower axle 12 drives the second driving Cam part 44 rotates, ball 42 again successively with third arc section 444, the second minimum trimming starting point 442 (i.e. stop section 443 Starting point), stop section 443 and the 4th arc section 445 contact, finally abutted against again with the second highest reduction point 441.

As shown in Figure 9 and Figure 10, switching driving assembly 6 includes the installation base plate for being fixed on 13 lower end surface of sewing machine insole board 61, it is fixed on installation base plate 61 switches driving source 62, front and back extends switching driving swing arm 63, is the ejector pin 64 that extends up and down, solid The first back-moving spring 66 for being scheduled on the limit circlip 65 of 41 right end of sliding pin and being set on sliding pin 41, switching driving swing arm 63 Front end be articulated with installation base plate 61, constitute switching driving swing arm 63 fixation swing pivot O1, switching driving source 62 have energy Enough switching driving portions 621 flexible along the axial left and right of sliding pin 41, the lower end of ejector pin 64 are fixedly connected with switching driving portion 621, push up Pin 64, which is located at the right side of switching driving swing arm 63 and the middle part of ejector pin 64, to abut with the right side wall of switching driving swing arm 63, The rear end of switching driving swing arm 63 has the pushing part 631 that can be abutted with 41 right end of sliding pin, the left and right of first back-moving spring 66 Both ends are abutted against with trimming crank arm 342 and limit circlip 65 respectively.Switching driving source 62 can be selected electromagnet or cylinder or Linear motor etc., switching driving source 62 are connected to the control system, and for switching driving source 62 and be electromagnet, play seam trimming face When line the end of a thread 11, control system control switching driving source 62 is in off-position, then switches the switching driving portion 621 of driving source 62 In the state stretched out to the right, at this point, first back-moving spring 66 is uncompressed, the ball 42 of 41 left end of sliding pin is located at the second driving The peripheral side of cam part 44.When cutting upper thread 10 and baseline 9 after sewing, control system control switching driving source 62 is in logical Electricity condition, then the switching driving portion 621 for switching driving source 62 is in be retracted to the left, and switching driving portion 621 drives ejector pin 64 together It is moved to the left, and then pushes switching driving swing arm 63 to swing to the left by ejector pin 64, by the passage of switching driving 63 rear end of swing arm Portion 631 pushes sliding pin 41 to be moved to the left, at this point, first back-moving spring 66 is compressed, the ball 42 of 41 left end of sliding pin is located at first Drive the peripheral side of cam part 43；After the completion of trimming, control system control switching driving source 62 is powered off, and switching driving source 62 is cut It changes driving portion 621 to stretch out to the right, reset, then so that sliding pin 41 moved right, resetted under the action of first back-moving spring 66, in turn Switching driving swing arm 63 is set to swing to the right, reset, at this point, the ball 42 of 41 left end of sliding pin is located at the outer of the second driving cam part 44 Side.

Further, as shown in figure 9, offering the guide groove extended along 64 moving direction of ejector pin or so on installation base plate 61 611, the upper end of ejector pin 64 is threaded through in guide groove 611 and is in contact with the cell wall of guide groove 611, can be improved 64 edge of ejector pin The mobile stability of left and right directions.Installation base plate 61 is equipped with the limit otic placode portion 612 upwardly extended, and switching driving source 62 is cut It changes on driving portion 621 and is installed with initial limited block 67 and terminates limited block 68, initial limited block 67 and termination limited block 68 are distinguished Positioned at the right side and left side of ejector pin 64, when switching the power-off of driving source 62, initial limited block 67 and limit otic placode portion 612 are abutted, and are risen To position-limiting action；When switching the energization of driving source 62, the shell for terminating limited block 68 and switching driving source 62 is abutted, and is played to limit and be made With.

As shown in figure 3, reset drives component 5 is in addition to including that the first highest on the first driving 43 outer peripheral surface of cam part resets Outside the second highest reduction point 441 on point 431 and the second driving 44 outer peripheral surface of cam part, reset drives component 5 further includes fixing Fixed pin 51 in 311 front end of separated time driving portion and the second back-moving spring 52 that is set on separated time driving portion 311, second The rear and front end of reset spring 52 is abutted with the shell of fixed pin 51 and separated time driving source 31 respectively.The upper thread 10 at the end of sewing When upper thread the end of a thread 11 is cut when cutting with baseline 9 and when playing seam, control system controls separated time driving source 31 and powers off, the Two reset springs 52 and the first highest reduction point 431 or in 441 collective effect of second back-moving spring 52 and the second highest reduction point Under, so that distributor plate 2 swung backward, resetted around lower axle 12.

As shown in figure 11, distributor plate 2 offers the line of fall hole 24 of perforation, the upper table of distributor plate 2 at suture clamping part 22 Offer the appearance line trenches 25 being downwardly concaved on face, the front end for holding line trenches 25 extends at line of fall hole 24, rear end extends to point At line trenches 21, the left end of separated time groove 21 extends to the left edge of distributor plate 2 to the left.

By taking cutter 101 are ultrasonic cutting knife as an example, the working principle of the thread cutting mechanism with above structure is as follows:

It in the initial state, is also separated time driving source 31 and switching driving source under the normal sewing state of sewing machine 62 all in off-position, and ball 42 is located at the peripheral side of the second driving cam part 44 but not and outside the second driving cam part 44 Circumferential surface is in contact, and distributor plate 2 and ultrasonic cutting knife are all located at the rear side of needle falling hole on needle plate 7, the suture of 2 front end of distributor plate The cutter head of clamping part 22 and ultrasonic cutting knife is in clamping shape and all neighbour is in needle falling hole on needle plate 7, as shown in figure 13.

The embodiment of automatic shearing after sewing are as follows: when sewing machine, which is sewed, completes to carry out trimming, the control of sewing machine System processed receives trimming signal, then control system first controls switching driving source 62 and is powered, and sliding pin 41 is made to drive ball 42 to the left Mobile, ball 42 is located at the peripheral side of the first driving cam part 43 but is not in contact with the first driving 43 outer peripheral surface of cam part.It Afterwards, control system control separated time driving source 31 is powered, and makes that crank 34 is driven to turn over an angle by first connecting rod 32, then ball 42 are in contact with the first highest reduction point 431 on the first driving 43 outer peripheral surface of cam part, meanwhile, distributor plate 2 rotates forward over one A angle but distributor plate 2 is not rocked to forward extreme position.The main motor of sewing machine drives 12 rotary motion of lower axle, and first drives Moving cam portion 43 is mounted on the also rotary motion together of rotating shuttle 8 of 12 left end of lower axle with 12 rotary motion of lower axle；Such as Figure 14 institute Show, after rotating shuttle off-line tail portion 81 moves to immediately below eedle 14, with the continuation rotary motion of rotating shuttle 8,14 side of eedle Upper thread 10 is deviate from from rotating shuttle off-line tail portion 81 around rotating shuttle 8, and upper thread 10 is divided into "eight" shape by rotating shuttle 8 below eedle 14, At the same time, ball 42 enters the first minimum trimming by the first highest reduction point 431 on the first driving 43 outer peripheral surface of cam part Starting point 432 drives cam part 43, second connecting rod 35 and third connecting rod 36 under the action ofs to make point in separated time driving source 31, first Line plate 2 turns to forward extreme position, at this point, upper thread 10 and baseline 9 are entered together in the separated time groove 21 on distributor plate 2, Upper thread 10 is divided into the " u "-shaped wire loop that line point is punished around separated time groove 21 by distributor plate 2.The main motor of sewing machine continues to drive lower axle 12 rotations, control system control separated time driving source 31 and power off, in second back-moving spring 52 and the first driving 43 outer peripheral surface of cam part Distributor plate 2 is set to swing backward, reset under the collective effect of upper first highest reduction point 431；In the reseting procedure of distributor plate 2, It pulls back into the appearance line trenches 25 of upper thread 10 and baseline 9 on 2 upper surface of distributor plate in separated time groove 21, finally by distributor plate 2 suture clamping part 22 and the cutter head of ultrasonic cutting knife form clamping shape to upper thread 10 and baseline 9, as shown in figure 15, at this time The movement of lower shaft of sewing machine 12 draws to an end, and control system control switching driving source 62 powers off, in the work of first back-moving spring 66 Sliding pin 41 is set to move right, reset under, meanwhile, control system connects the power supply of supersonic generator, and ultrasonic cutting knife exists High-frequency ultrasonic is formed at cutter head, and upper thread 10 and baseline 9 are cut off.Finally, the power supply of control system cutting supersonic generator, Shorter the end of a thread of cutting remains on fabric, and then completes the automatic shearing movement after sewing.

Play the embodiment of anti-Bird's Nest when seam are as follows: when sewing machine plays seam again, eedle 14 passes through cloth with upper thread 10 Into 7 lower section of needle plate, during eedle 14 by moving upwards below needle plate 7, control system controls separated time driving source 31 It is powered, makes that crank 34 is driven to turn over an angle by first connecting rod 32, then ball 42 and the second driving 44 outer peripheral surface of cam part On the second highest reduction point 441 be in contact, meanwhile, distributor plate 2 rotates forward over an angle but distributor plate 2 is not swung forward To extreme position.The main motor of sewing machine drives 12 rotary motion of lower axle, and the second driving cam part 44 is rotated with lower axle 12 Movement, ball 42 enter the second minimum trimming by the second highest reduction point 441 on the second driving 44 outer peripheral surface of cam part and originate Point 442 makes distributor plate 2 under the action of separated time driving source 31, second drives cam part 44, second connecting rod 35 and third connecting rod 36 Extreme position is turned to forward, as shown in figure 16.The main motor of sewing machine continues to drive 12 rotary motion of lower axle, ball 42 and the Stop section 443 on two driving 44 outer peripheral surfaces of cam part is in contact, then distributor plate 2 rests on always extreme position, at this point, stitching Thread 14 side of machine eedle upper thread the end of a thread 11 around deviating from after rotating shuttle 8 from rotating shuttle off-line tail portion 81, upper thread the end of a thread 11 enters In separated time groove 21 on distributor plate 2.The main motor of sewing machine continues that lower axle 12 is driven to rotate, and control system controls separated time driving Source 31 powers off, the common work of the second highest reduction point 441 in second back-moving spring 52 and the second driving 44 outer peripheral surface of cam part Distributor plate 2 is set to swing backward, reset under；In the reseting procedure of distributor plate 2, into upper thread the end of a thread 11 in separated time groove 21 Appearance line trenches 25 on 2 upper surface of distributor plate are pulled back, finally by the suture clamping part 22 of distributor plate 2 and ultrasonic cutting knife Cutter head forms clamping shape to upper thread the end of a thread 11.Sewing machine main motor remains in operation, and the second needle thorn material, take-up is carried out, to complete Second needle locking wire, at this point, control system connects the power supply of supersonic generator, it is super that ultrasonic cutting knife forms high frequency at cutter head Sound wave cuts off upper thread the end of a thread 11, then the shorter upper thread the end of a thread 11 cut off remains on fabric, and cut-off residual the end of a thread falls It falls, as shown in figure 17.Finally, sewing machine remains in operation until completing to sew.14 side of eedle when can will play seam in this way Upper thread the end of a thread 11 cut off, effectively prevent the end of a thread to be wound " Bird's Nest " ball of string.

In conclusion the application has the following advantages:

1, since ultrasonic cutting knife is high frequency machinery wave trimming, the edge of a knife of ultrasonic cutting knife can be located at eedle 14, needle The side of plate 7, the cutting position closer apart from eedle 14 keep remaining the end of a thread after trimming shorter；Meanwhile ultrasonic cutting knife pair The end of a thread thickness rubs very small, long service life, part exchanging is few, and cutting noise is small without limitation.

2, suture moment under the action of huge ultrasonic energy is softened, melts, and realizes perfect envelope to the end of a thread notch Side prevents suture in the wire drawing of the end of a thread incision material, loose, the stable sewing of realization sewing machine high-quality.

3, supersonic generator is directly controlled by control system, can realize anti-Bird's Nest function during playing seam.

4, sew after trimming when distributor plate 2 separated time time point and rise seam when distributor plate 2 separated time time point by driving The first minimum trimming starting point 432 and the second minimum 442 independent control of trimming starting point, separated time on moving cam is more stable.

So the present invention effectively overcomes various shortcoming in the prior art and has high industrial utilization value.

The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe The personage for knowing this technology all without departing from the spirit and scope of the present invention, carries out modifications and changes to above-described embodiment.Cause This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as At all equivalent modifications or change, should be covered by the claims of the present invention.

Claims

1. a kind of thread cutting mechanism, it is characterised in that: including trimming component (1) and separated time component, the trimming component (1) includes cutting Cutter (101), the separated time component include movable distributor plate (2), and the distributor plate (2) is at the both ends of its direction of motion point Not She You separated time groove (21) and suture clamping part (22), the cutter head and distributor plate (2) of the cutter (101) be all disposed within seam Between the needle plate (7) and rotating shuttle (8) threaded in machine；After sewing when trimming, permit in the separated time groove (21) of the distributor plate (2) Perhaps baseline (9) and upper thread (10) enter, and distributor plate (2) is able to drive baseline (9) and upper thread (10) to close to cutter (101) Direction movement, until the suture clamping part (22) and the cutter heads of cutter (101) of distributor plate (2) end clamp baseline (9) With upper thread (10), baseline (9) and upper thread (10) are cut off by the cutter head of cutter (101)；When playing seam, the distributor plate (2) Upper thread the end of a thread (11) are allowed to enter in separated time groove (21), and distributor plate (2) is able to drive upper thread the end of a thread (11) to close to cutting The direction of knife (101) moves, until the suture clamping part (22) of distributor plate (2) end and the cutter head of cutter (101) clamp Upper thread the end of a thread (11) is cut off upper thread the end of a thread (11) by the cutter head of cutter (101).

2. thread cutting mechanism according to claim 1, it is characterised in that: the cutter (101) are ultrasonic cutting knife；Institute Trimming component (1) is stated to further include supersonic generator, the mounting bracket (102) for being fixed on sewing machine insole board (13), be fixed on The ultrasonic transducer (103) of mounting bracket (102) and the ultrasound being connected with the output end of ultrasonic transducer (103) The input terminal of wave amplitude transformer (104), the ultrasonic transducer (103) passes through ultrasonic wire (105) and supersonic generator It is connected, the ultrasonic cutting knife is connected to the output end of ultrasonic variable amplitude bar (104).

3. thread cutting mechanism according to claim 1, it is characterised in that: the separated time component further includes that can drive separated time Separated time driving assembly (3), trimming driving assembly (4) and the reset drives component (5) of plate (2) movement；Under original state, institute It states distributor plate (2) and cutter (101) is located at the same side of eedle (14) in sewing machine, the suture of distributor plate (2) end The cutter head of clamping part (22) and cutter (101) is in clamping shape and all neighbour sets in eedle (14), the suture clamping part (22) In distributor plate (2) close to the front end of eedle (14), the separated time groove (21) is located at the rear side of suture clamping part (22)；Sewing After trimming when and when playing seam, the separated time driving assembly (3) and trimming driving assembly (4) drive distributor plate (2) to remote Direction from cutter (101) travels forward, and distributor plate (2) is made to move to extreme position, the separated time groove on distributor plate (2) (21) it is located at the underface side of eedle (14), the reset drives component (5) finally drives distributor plate (2) to close to cutter (101) direction moves backward, resets distributor plate (2).

4. thread cutting mechanism according to claim 3, it is characterised in that: the separated time driving assembly (3) includes separated time driving Source (31), first connecting rod (32), the drive shaft (33) for being parallel to lower axle in sewing machine (12), the drive being fixed on drive shaft (33) Dynamic crank (34), second connecting rod (35), third connecting rod (36) and the mounting base for being installed in rotation on lower axle (12) periphery (37), the separated time driving source (31) has telescopic separated time driving portion (311), is extended on the driving crank (34) point Line crank arm (341), the both ends of the first connecting rod (32) respectively with separated time driving portion (311) and separated time crank arm (341) it is hinged, one end of drive shaft (33), the other end and third connecting rod (36) is fixed in one end of the second connecting rod (35) Hingedly, the other end of the third connecting rod (36) and mounting base (37) hingedly, have plate mounting portion on the distributor plate (2) (23), the plate mounting portion (23) is fixed on mounting base (37).

5. thread cutting mechanism according to claim 4, it is characterised in that: the trimming driving assembly (4) includes from the drive It moves the trimming crank arm (342) extended on crank (34), the sliding pin (41) for being parallel to drive shaft (33), be rotatably mounted In sliding pin (41) ball (42), all be fixed on lower axle (12) first driving cam part (43) and second drive cam part (44) and the switching driving assembly (6) of driving sliding pin (41) movement, the sliding pin (41) are movably mounted at trimming crank In arm (342), switching driving assembly (6) driving sliding pin (41) axial movement makes ball (42) to drive cam with first The outer peripheral surface in portion (43) is abutted against or is abutted against with the outer peripheral surface of the second driving cam part (44)；After sewing when trimming, institute It states ball (42) and the outer peripheral surface of the first driving cam part (43) abuts against；When playing seam, the ball (42) and the second driving are convex The outer peripheral surface of wheel portion (44) abuts against.

6. thread cutting mechanism according to claim 5, it is characterised in that: first driving cam part (43) and the second driving Cam part (44) is integrated into a driving cam.

7. thread cutting mechanism according to claim 5 or 6, it is characterised in that: the periphery of first driving cam part (43) Face has the first highest reduction point (431) and the first minimum trimming starting point (432), and described second drives the outer of cam part (44) Circumferential surface has the second highest reduction point (441) and the second minimum trimming starting point (442), the first highest reduction point (431) It is identical with the radius of the second highest reduction point (441), the first minimum trimming starting point (432) and the second minimum trimming starting The radius of point (442) is identical；When ball (42) is abutted with the first highest reduction point (431) or the second highest reduction point (441), The distributor plate (2) is located at initial position；When ball (42) and the first minimum trimming starting point (432) or the second minimum trimming are risen When initial point (442) abuts, the distributor plate (2) is located at extreme position；The first highest reduction point (431) and the second highest are multiple Site (441) constitutes a part of the reset drives component (5).

8. thread cutting mechanism according to claim 5 or 6, it is characterised in that: the periphery of second driving cam part (44) Face has the stop section (443) of one section of equal radius at the second minimum trimming starting point (442).

9. thread cutting mechanism according to claim 5, it is characterised in that: the switching driving assembly (6) includes being fixed on seam Thread machine insole board (13) installation base plate (61), be fixed on installation base plate (61) switching driving source (62), be articulated with installation base Plate (61) switching driving swing arm (63), extend up and down ejector pin (64), be fixed on sliding pin (41) limit circlip (65) and The first back-moving spring (66) being set on sliding pin (41), the switching driving source (62) have and can axially stretch along sliding pin (41) The switching driving portion (621) of contracting, the ejector pin (64) are fixedly connected with switching driving portion (621), and the ejector pin (64) can be with Switching driving swing arm (63) abuts, and having on switching driving swing arm (63) can be with the pushing part of sliding pin (41) end abutment (631), the both ends of the first back-moving spring (66) are abutted against with trimming crank arm (342) and limit circlip (65) respectively.

10. thread cutting mechanism according to claim 9, it is characterised in that: offer on the installation base plate (61) along ejector pin (64) moving direction extend guide groove (611), the end of the ejector pin (64) be threaded through in guide groove (611) and with guiding The cell wall of slot (611) is in contact.

11. thread cutting mechanism according to claim 9, it is characterised in that: the installation base plate (61) is equipped with and upwardly extends Limit otic placode portion (612), it is described switching driving source (62) switching driving portion (621) on be installed with positioned at ejector pin (64) two sides Initial limited block (67) and terminate limited block (68), the initial limited block (67) can with limit otic placode portion (612) abut, Terminate limited block (68) can be abutted with the shell of switching driving source (62).

12. thread cutting mechanism according to claim 4, it is characterised in that: the reset drives component (5) further includes being fixed on The fixed pin (51) of separated time driving portion (311) end and the second back-moving spring being set on separated time driving portion (311) (52), the both ends of the second back-moving spring (52) are abutted with the shell of fixed pin (51) and separated time driving source (31) respectively.

13. thread cutting mechanism according to claim 1, it is characterised in that: the distributor plate (2) is at suture clamping part (22) The line of fall hole (24) of perforation is offered, the appearance line trenches (25) being downwardly concaved, institute are offered on the upper surface of the distributor plate (2) State hold line trenches (25) one end extend at line of fall hole (24), the other end extends at separated time groove (21).

14. thread cutting mechanism according to claim 1, it is characterised in that: the cutter (101) are hot knife；It is described to cut Line component (1) further includes electrothermal generator (106) and the cutting knife mounting seat (107) for being fixed on electrothermal generator (106), institute The input terminal for stating electrothermal generator (106) is controlled to a power supply by electric wire (108), the output of the electrothermal generator (106) End is connected with hot knife.

15. a kind of sewing machine, it is characterised in that: be equipped with the described in any item thread trimmers of claim 1-14 in the sewing machine Structure.