CN102535039A

CN102535039A - Sewing machine

Info

Publication number: CN102535039A
Application number: CN2011103748542A
Authority: CN
Inventors: 洼田义彦
Original assignee: Juki Corp
Current assignee: Juki Corp
Priority date: 2010-11-19
Filing date: 2011-11-18
Publication date: 2012-07-04
Anticipated expiration: 2031-11-18
Also published as: TW201241260A; CN102535039B; JP2012105896A; KR20120054529A

Abstract

Provided is a sewing machine (10) capable of reducing take-up faults, comprising a wire-cutting unit, a take-up mechanism (70), and a control unit (100) for controlling the wire-cutting unit and the take-up mechanism (70). The sewing machine (10) is characterized by comprising a detection unit (22) for detecting the rotating angle of a drive shaft that rotates in a period equal to the up-and-down moving period of the stitch (11). The control unit controls a drive unit (13) based on the detection of the detecting unit, thereby making a take-up device carry out the forwarding movement from the initial position to the movement position before utilizing the wire-cutting unit to cut off the up wire.

Description

Sewing machines

Technical field

The present invention relates to a kind of Sewing machines with spudger that reaching the standard grade after cutting off chosen.

Background technology

Current, shown in for example patent documentation 1 discloses, known a kind of Sewing machines, it has: thread cutting device, it is positioned at the needle plate below, cuts off reaching the standard grade; And the spudger device, it is choosing reaching the standard grade between suture needle and the cloth above needle plate, pull out from the cloth top with the end of reaching the standard grade that will link to each other with suture needle after will cutting off.

Thread cutting device mainly is made up of following part: grooved cam, and it is through being rotated as the sewing machine electromotor of making drive source; Movable cutting knife, it engages back and forth with grooved cam and rotates through cutting off the transmission mechanism that moves; And the tangent line solenoid, the snap action of its applying groove cam and transmission mechanism.The movable cutting knife of thread cutting device carries out the action that the suture that will cut off and the suture that does not cut off are separated advancing when rotating, and cuts off at the suture of only retreating when rotating the conduct cut-out object after separately.

This spudger device has: spudger, and its front end has hook-shaped bend; And as the take-up solenoid of the drive source of take-up action, through above suture needle is positioned at needle plate the time, the bend of spudger carries out reciprocating action with the mode that moves up and down the path of crossing suture needle, thereby the bend of spudger is caught and reached the standard grade and pull out.

The take-up solenoid bears spring pressure usually and pushes the maintenance plunger along certain orientation, if electric current flows through, plunger antagonistic spring pressure is moved, and makes spudger begin to advance from its initial position and turns to operating position.Spudger advance through suture needle move up and down the path time, reaching the standard grade slips over (skimming over suture) from the side of bend, does not catch reaching the standard grade but it is passed through.And if electric current stops, then the take-up solenoid utilizes spring pressure to make plunger return initial position, and thus, spudger is retreated rotation and returned initial initial position from operating position.When return action, said bend is caught when moving up and down the path through suture needle and is reached the standard grade, and will reach the standard grade and extract from cloth.That is, the shape of the bend of spudger has directionality, being formed on to make to reach the standard grade when advancing rotation to slip over and do not catch from the side of bend, is retreating the shape that can catch when rotating.

Continuation regularly describes the action of above-mentioned spudger and thread cutting device.

The main shaft of Sewing machines is provided with lower position detector and top position detector, and they detect the suitable timing that the transmission mechanism that is used to make thread cutting device engages with grooved cam.And if according to the detection signal drives tangent line solenoid of lower position detector, then transmission mechanism engages with grooved cam.Thus, according to the groove shape of grooved cam, the action that movable cutting knife back and forth rotates and cut off and reach the standard grade.

In addition, the top position detector produces the detection signal of stipulating in the timing that thread cutting device cuts off after accomplishing, and the take-up solenoid begins to drive and spudger is back and forth rotated, and carries out the take-up action.

Patent documentation 1: japanese kokai publication sho 56-151089 communique

Summary of the invention

But in above-mentioned Sewing machines, after accomplishing the suture cut-out by thread cutting device, spudger begins to drive and carries out take-up and move.Therefore, when spudger advanced, reaching the standard grade to become was cut off and does not produce the state of thread tension, reached the standard grade to be skimmed over by spudger and remain the state of lateral shift.Therefore, when spudger was retreated, the bend of generation spudger can't be caught and reached the standard grade and the problem of take-up baulk.Especially, under the situation of thin cloth or the cloth that is easy to slide, less being difficult to of resistance that reaching the standard grade after the cut-out produces owing to cloth keeps, so is easy to generate the problems referred to above.

In addition; Because above-mentioned Sewing machines makes spudger carry out reciprocating action after accomplishing the suture cut-out by thread cutting device; So after carrying out tangent line; Need waiting for connecting through the solenoidal action current of take-up makes spudger advance and the take-up solenoid stops to make spudger to retreat beginning to make after these two actions are accomplished next time again, produce the problem that operating efficiency reduces.

The objective of the invention is to, carry out the take-up action of spudger more reliably, and improve operating efficiency.

The invention that technical scheme 1 is put down in writing is a kind of Sewing machines, and it has: the tangent line unit, and it moves in prescribed period of time according to the generation of tangent line signal, utilizes the co-operating of movable cutting knife and fixed cutting tool to cut off and reaches the standard grade; Operating unit, it produces said tangent line signal to said tangent line unit; Thread take-up mechanism; It has spudger and driver element; This spudger carries out from the reciprocating action of initial position to operating position, and this driver element makes said spudger carry out reciprocating action, and this thread take-up mechanism is at said spudger during from said operating position to the homing action of said initial position; Choose from the reaching the standard grade of suture needle to sewn object, extract said cut-out end of reaching the standard grade from said sewn object; Control module, it controls the said driver element of said thread take-up mechanism; And detecting unit; It detects the regulation anglec of rotation that moves up and down the driving shaft that synchronously is rotated with said suture needle, and this Sewing machines is characterised in that said control module is controlled said driver element; After producing at said tangent line signal; Based on the detection of said detecting unit, before cutting off said reaching the standard grade, make said spudger carry out forward motion to said operating position from said initial position by said tangent line unit.

The invention that technical scheme 2 is put down in writing is characterised in that; Has the identical structure of being put down in writing with technical scheme 1 of invention; And said control module is controlled said driver element; With become said spudger can be through the regulation anglec of rotation between said suture needle and the needle plate after, make said spudger carry out forward motion to said operating position from said initial position.

The invention that technical scheme 3 is put down in writing is characterised in that; Has the identical structure of being put down in writing with technical scheme 1 or 2 of invention; And said detecting unit has: the suture needle position detector; It is at the anglec of rotation place of the Sewing machines driving shaft suitable with the lower position of said suture needle, and the lower position signal that begins moves in the said tangent line of output regulation unit; And the timing unit that the angle of said driving shaft is changed the angle detector that detects or carried out timing the time; If begin from the said lower position signal that detects said suture needle position detector; The angle that said angle detector detects regulation changes, or said timing unit timing the elapsed time of regulation; Then said control module is controlled, so that said spudger carries out forward motion.

The effect of invention

The invention that technical scheme 1 is put down in writing; Owing to before reaching the standard grade, carry out the rotation action of advancing of spudger by the cut-out of tangent line unit; Even so when this spudger advances rotation, under the bend of spudger and the situation that slips over and pass through of reaching the standard grade, also owing to be in the state of reaching the standard grade and rolling off the production line and twining; Feasible reaching the standard grade from the state that slips over returned the home position so can utilize thread tension; When retreating rotation, the bend of spudger can be caught reliably and reached the standard grade, and can carry out the take-up action more reliably.

In addition; Owing to before cut-out is reached the standard grade, carry out the forward motion of spudger; So compare with the existing Sewing machines of retreating rotation action with the rotation action of advancing of after the cut-out of reaching the standard grade, carrying out spudger; Under the situation of Sewing machines of the present invention, can only retreat rotation action after cutting off and accomplish just to get into and make operation next time reaching the standard grade through wait, can reduce the stand-by period and realize making continuously the rapid of operation.

The invention that technical scheme 2 is put down in writing and since the anglec of rotation of driving shaft become can make spudger through suture needle below and between the needle plate after, carry out the forward motion of spudger, can realize the spudger action reliably so can not receive the influence of suture needle.

The invention that technical scheme 3 is put down in writing; Owing to suture needle position detector and angle detector or timing unit are made up the back use as detecting unit; So can utilize simple structure correctly to carry out the control of spudger, need not to use this accurate checkout gear of absolute value type encoder.

In addition, can be easily to as benchmark, suitably change from the timing of the detected lower position signal of suture needle position detector to spudger action starting position, thereby adjust.

Description of drawings

Fig. 1 is the integrally-built oblique view of expression as the sewing machine for covering chain stitch of this embodiment.

Fig. 2 (A) is the front view from the thread take-up mechanism of this embodiment of cloth direction of feed upstream side observation, (B) is the rearview of observing from the cloth direction of feed downstream of this embodiment.

Fig. 3 is the block diagram of control system of the Sewing machines of this embodiment of expression.

Fig. 4 is the sequential chart that the tangent line of this embodiment is controlled the each several part when carrying out.

Fig. 5 is the action timing of each several part when being illustrated in tangent line control and the key diagram of the relation between the main shaft angle.

Fig. 6 is that expression begins time history plot to solenoidal drive current from energising.

The sequential chart of the each several part when Fig. 7 is the tangent line control execution in the Comparative Examples.

The specific embodiment

Below, based on Fig. 1～Fig. 6, specify embodiment of the present invention.In addition; In following explanation; With after the above-below direction that moves up and down of the suture needle 11 stated be made as Z-direction; To be made as Y direction (fore-and-aft direction) with its quadrature and along the horizontal direction of the length direction of Sewing machines arm, will be made as X-direction (left and right directions) with the horizontal direction of Y direction quadrature.

(overall structure of embodiment)

As shown in Figure 1, sewing machine for covering chain stitch is called Sewing machines 10 below 10) mainly have: sewing machine stand 2, it supports overall structure; As the suture needle reciprocating mechanism (omitting diagram) of suture needle driver element, it makes and keeps the needle bar 12 of suture needle 11 to move up and down; Anchoring (omitting diagram), it applies tension force to reaching the standard grade; Not shown tangent line unit, its cut-out is reached the standard grade; As the thread take-up mechanism 70 of take-up unit, it has the spudger that moves up and down the path 71 of suture needle of crossing 11; And as the control part 100 of control module, it carries out the action control that cloth moves unit (omitting diagram).

(sewing machine stand)

Sewing machine stand 2 has: Sewing machines arm 2a, and it forms the top of this sewing machine stand 2, extends along fore-and-aft direction; Sewing machines base portion 2b, it forms the bottom of sewing machine stand 2, extends along fore-and-aft direction; And vertical 2c of body portion, it links Sewing machines arm 2a and Sewing machines base portion 2b.

On Sewing machines, dispose not shown known driving mechanism and container mechanism.

Set inside at Sewing machines arm 2a has the main shaft as driving shaft, and it extends along Y direction.In addition, an end (rear end) of main shaft is driven by sewing machine electromotor 5 rotations.In addition, in Sewing machines base portion 2b, be provided with lower shaft, it links via synchronous band and main shaft, if main axis rotation, the transmission of power of main shaft to lower shaft side then, lower shaft rotation.

Front end at lower shaft is provided with container mechanism.If lower shaft and main shaft interlock and rotating, then still rotates, and utilizes the co-operating of suture needle 11 and still and forms stitching.

In addition, at the upper surface of Sewing machines base portion 2b, relatively dispose needle plate 13 with the position that moves up and down of suture needle 11.On this needle plate 13, form the pin hole that suture needle 11 is inserted, below needle plate 13, dispose said still.

(suture needle reciprocating mechanism)

Sewing machines arm 2a is built-in with known suture needle driving mechanism.That is, dispose, be fixed with suture needle 11 in the lower end of needle bar 12 via the needle bar 12 with the front end binding of main shaft such as not shown eccentric cam or toggle-action lever.And the rotation of main shaft is transformed to via eccentric cam or toggle-action lever etc. and moves up and down, thereby needle bar 12 moves up and down, and makes suture needle 11 run through the cloth on the needle plate 13, forms stitching with the still co-operating.

In addition, on Sewing machines arm 2a, be adjacent to be provided with cloth moving up and down by pressure bar 14A, be supported with cloth pressing 14 by the lower end of pressure bar 14A at cloth with needle bar 12.Cloth pressing rod 14A disposes not shown elastomer, and it applies the elastic force towards the below to cloth pressing 14 usually, so that cloth pressing 14 is pressed the cloth on the eedle presser 13 from the top.And the solenoid of stating after the utilization 15 that raises is resisted elastomeric elastic forces and is applied vertical motion.

(tangent line unit)

In addition, Sewing machines 10 has the tangent line unit of the structure same general configuration of the thread cutting device of being put down in writing with said patent documentation 1.

That is, the tangent line unit is not shown, and it is arranged on the downside of needle plate 13, constitutes by rotary movable cutting knife, fixed cutting tool with to the Poewr transmission mechanism that movable cutting knife applies rotation action.Poewr transmission mechanism has: grooved cam, and it is rotated through lower shaft; Cam roller (follower), its can switch with grooved cam on formed cam path engage and the state that do not engage; Cam arm, it keeps cam roller, moves along cam path through cam roller and carries out rotation action; Drive disk assembly, its from cam arm to the reciprocal rotation action of movable cutting knife transmission; And tangent line solenoid 16, its with cam roller to the guiding of the inlet of grooved cam and cam roller is engaged with cam path.

Above-mentioned grooved cam can insert cam roller in the phase place of main shaft and lower shaft during for prescribed limit, and tangent line solenoid 16 is controlled to be by control part 100, drives in the timing of above-mentioned phase place, and cam roller is engaged with grooved cam.

Movable cutting knife moves back and forth to carry out front and back along the needle plate horizontal direction through the mode under the pin hole, when advancing, only to selecting to distinguish as the suture that cuts off object, when retreating, engages and co-operating with fixed cutting tool, carries out suture and cuts off.

(thread take-up mechanism)

In Fig. 2, thread take-up mechanism 70 has: spudger 71, and it crosses the moving up and down the path of suture needle 11 and back and forth rotates below suture needle 11; Bend 76, it is arranged on the spudger front end; Rotate wrist 72, it keeps spudger 71; Take-up solenoid 73, it becomes the drive source of spudger 71; Bell crank 74, it rotates through take-up solenoid 73; And connecting rod body 75, it links bell crank 74 and rotates wrist 72.

The plunger of take-up solenoid 73 is remained by contained spring and keeps the state of retreating to inside usually, if flow through drive current, then the plunger antagonistic spring and downwards the protrusion.The knee-action of said plunger is transformed to rotation action by bell crank 74, connecting rod body 75 and rotation wrist 72, is passed to spudger 71.

When the non-energising of take-up solenoid 73 (OFF), plunger is retreated, and therefore, the bend 76 of spudger 71 is positioned at the initial position (double dot dash line with Fig. 2 is represented) away from suture needle.The plunger protrusion if utilize exerting pressure (ON) of take-up solenoid 73; It is mobile that spudger 71 is advanced; Then bend 76 advances towards the path that moves up and down of suture needle 11, between the lower end of suture needle 11 and needle plate 13, pass through, in the specified action position (solid line with Fig. 2 is represented) locate to stop.

The bend 76 of the front end of spudger 71 forms the hook-shaped of U word roughly, at the inboard suture seizure 76a of portion that forms of bend, forms suture in the bend outside and slips over the 76b of portion.

When spudger 71 advanced, the bend of the spudger front end outside was that suture slips over the 76b of portion side and advances mobile towards the path that moves up and down of suture needle 11.Thus, through suture needle 11 move up and down the path time, the bend of the spudger 71 front ends outside is that suture slips over the 76b of portion and contacts with the T that reaches the standard grade, the T that reaches the standard grade is not bent portion's 76 seizure to the outside slip mistake of spudger radius of gyration direction.

When spudger 71 was retreated, it is mobile that the bend inboard of spudger front end is that the suture seizure 76a of portion side is retreated towards suture needle 11 above-below directions, and therefore, this suture seizure 76a of portion catches the T that reaches the standard grade, and will cut off to hold and pull out from cloth W.

(the control system of Sewing machines)

In Fig. 3, the control part 100 of Sewing machines 10 has: CPU 101, and its each several part to Sewing machines is carried out control; And memory 102, setting data and performing a programme that its storage is relevant with various controls.

In addition, control part 100 via not shown drive circuit respectively with sewing machine electromotor 5, tangent line solenoid 16, take-up solenoid 73, raise solenoid 15 and be connected.

In addition, control part 100 is connected with via not shown interface: suture needle position detector 21, and when it was positioned at the angular range of regulation at main shaft, lower position signal and the top position signal of ON and OFF switched in output; Angular transducer 22, its anglec of rotation to the output shaft of sewing machine electromotor 5 detects; As the tangent line switch 23 of operating unit, it is imported the indication of carrying out tangent line by the operator; Pedal 24, its input are made beginning or are stopped and the Sewing machines rotating speed; And guidance panel 25, the various settings during its input is made.

Suture needle position detector 21 is made up of photosensitive sensor, and its utilization is fixedly installed on the shadow shield on the said main shaft, is positioned at main shaft under the situation of scope of predetermined angular, and sensitization is covered.

Said suture needle position detector 21 has two groups of shadow shields and photosensitive sensor; Thus; When main shaft rotated in comprising the regulation rotation angle range that moves up and down bottom dead centre of suture needle 11, the lower position signal was ON, in addition; When main shaft rotated in comprising the regulation rotation angle range that moves up and down top dead-centre of suture needle 11, the top position signal was ON.

The suture needle phase place that angular transducer 22 sense cycle change or the anglec of rotation of main shaft.That is, this angular transducer 22 is an encoder, with the variable quantity of the anglec of rotation of the output shaft of sewing machine electromotor 5 output pulse signal correspondingly.Control part 100 has the counter 103 that said pulse signal is counted.And the count value that control part 100 produces according to this counter 103 and the output shaft of sewing machine electromotor 5 calculate the anglec of rotation of main shaft with respect to the speed reducing ratio of the main shaft of Sewing machines.In addition, if counter 103 has carried out the number of times of the machine spindle amount of rotating a circle, then its count value is reset.

In addition, said angular transducer 22 works as " detecting unit " with 21 co-operatings of suture needle position detector.

In addition, speed detection unit 104 detect sewing machine electromotors 5 rotary speed, be the rotary speed of machine spindle, and feed back to control part 100.

Pedal 24 as the operation input block has known configurations; This structure does; Can step on operation and step on back operations by operator's tiptoe, will import to control part 100 with the rotational speed signal of the corresponding Sewing machines of depression amount of stepping on the operation generation by heel.With said rotational speed signal correspondingly, in control part 100, carry out the speed controlling of sewing machine electromotor 5.In addition, as the operation input block, also can replace pedal 24 and the press button of push type is set on Sewing machines arm 2a or guidance panel 25 etc.

In addition, tangent line switch 23 produces the tangent line signal owing to the back operations of stepping on of said pedal 24 becomes ON.The tangent line signal inputs to control part 100, the tangent line control of stating after control part 100 beginnings.

In addition, guidance panel 25 carries out various setting inputs to control part 100, and control part 100 is stored each setting data in memory 102.

(tangent line control)

Above-mentioned CPU 101 controls thereby carry out with the sequential chart corresponding action of Fig. 4 through the control program in the execute store 102.

At first, if at the tangent line signal (T1) that produces tangent line switch 23 of stepping in the operation of pedal 24, then begin the deceleration control of sewing machine electromotor 5.And; Detect by speed detection unit 104 sewing machine electromotor 5 be decelerated to can the speed of tangent line after, at lower position detection signal (T2) when OFF switches to ON, drive tangent line solenoid 16; Thus, the cam roller of the Poewr transmission mechanism of tangent line unit engages with grooved cam.Thus, cam roller is accompanied by the rotation of main shaft and in the groove of grooved cam, moves, and accompanies with it, and movable cutting knife begins reciprocating action.

T4 is based on grooved cam and the suture set cuts off regularly, roughly is set in from 0 ° of main shaft angle between the target stop position.

This Sewing machines 10 has following characteristics, that is, take-up solenoid 73 is begun to drive so that spudger 71 carries out the timing T3 of forward motion, is set in suture and cuts off regularly before the T4.

In addition, when spudger 71 rotates, must make suture needle 11 be positioned at the top of needle plate 13, and be positioned at the top that can make the height that spudger 71 passes through.

Thus; As shown in Figure 5; As long as in when suture needle is risen, becoming the main shaft angle that can make the suture needle height lower limit height that spudger 71 passes through, the scope of main shaft angular range Hs till carry out main shaft angle that suture cuts off, spudger 71 rotation of advancing gets final product.

Here, the setting range of the timing T3 that take-up solenoid 73 is begun to drive remarks additionally.

Solenoid is as shown in Figure 6 usually; If flow through drive current; Then electric current rises to the time that needs N1 till the value that obtains carrying out the required output of shift action, and during N1 to N2, plunger carries out shift action; During N2 to N3, keeping operating position, returning initial position for the OFF plunger at the N3 place.

Thus, even in take-up solenoid 73, flow through drive current, the delay that also can produce N1 till between spudger 71 is through suture needle 11 and needle plate 13.Strict must saying also produces the delay of the value between N1 and the N2, but that this error is compared with N1 is very little, describes so be regarded as N1.

In addition, in solenoid, exist this delay N1 to receive the character of influence of the variation of solenoidal variations in temperature and service voltage.That is, have property: if solenoidal temperature uprises, then postponing N1 increases, and in addition, if service voltage reduces, then time delay, N1 also increased.

Thus; Voltage drop-out value (the decline of voltage that consideration might produce based on the environment for use temperature of Sewing machines and when using; In environment for use, exist under the situation of equipment of a lot of consumes power; The inferior meeting generation of situation more than the number of devices quantitative change of moving) N1 time delay sets the timing T3 that take-up solenoid 73 begins to drive.If changing, main shaft angle that will be suitable with N1 time delay that obtains is made as θ n1; Then as long as in the scope of the main shaft angular range Has that the main shaft angular range Hs integral body that will be used to make said spudger 71 to begin to advance to rotate obtains behind main axis rotation direction upstream side skew θ n1, make the drive current of take-up solenoid 73 begin energising and get final product.

In addition, owing to be used to make the spudger 71 main shaft angular range Hs that rotates that begins to advance to confirm according to the specification of Sewing machines, so login in advance in memory 102.

In addition, the value that changes timing (main shaft angle) T3 that the drive current of θ n1 and take-up solenoid 73 begins to switch on the suitable main shaft angle of N1 time delay can be set through guidance panel 25, if set, then is stored in the memory 102.

In addition; For control part 100; Also can constitute and have following function, that is, and when the timing T3 that begins to switch at the drive current to take-up solenoid 73 sets input; Calculating proper range according to the setting value of Hs and θ n1 in advance is main shaft angular range Has, and the scope that whether value from the T3 of guidance panel 25 inputs is positioned at main shaft angular range Has is judged.

In addition, also can constitute and have following function, that is, drop on this situation of report under the situation outside the scope in result of determination, perhaps refusal drops on the setting input outside the main shaft angular range Has.

In the tangent line control of Fig. 4; If drive tangent line solenoid 16; Then CPU 101 bases are calculated current main shaft angle based on the value of the resulting counter of detection of angular transducer 22, keep watch on the driving that whether arrives the take-up solenoid of confirming as stated 73 and begin regularly T3.

And, if the main shaft angle arrives T3, then supply with drive current to take-up solenoid 73, spudger 71 advances.At this regularly; Because movable cutting knife does not cut off as yet and reaches the standard grade; If so since before the spudger 71 so suture slip over the 76b of portion and will reach the standard grade to horizontal promotion, then reaching the standard grade to utilize and to roll off the production line twines or the tension force that resistance produced of cloth W, and is reset to the position that moves up and down of suture needle 11.

Then, take-up solenoid 73 keeps spudger 71 at operating position, reaches the standard grade through utilizing movable cutting knife to cut off behind the main shaft angle T4.

In addition, switch to ON (T5) from OFF, then begin the judgement that stops of sewing machine electromotor 5 if signal is surveyed in the top position.Said stop to judge according to the count value of being undertaken by counter 103 angle sensors 22 increase halted state and detected.

In addition, according to the output of angular transducer 22, accomplish angle (T6) if arrive tangent line, then the drive current with tangent line solenoid 16 and take-up solenoid 73 stops.

At this regularly, because the cam roller of tangent line unit moves to the outlet of the groove of grooved cam, so, return initial position owing to tangent line solenoid 16 stops to leave grooved cam.

In addition, spudger 71 is because take-up solenoid 73 is retreated rotation from operating position towards initial position for OFF.At this regularly, owing to, be cut off, reach the standard grade and caught and chosen, reach the standard grade thereby extract from cloth by the suture seizure 76a of portion of spudger 71 so reach the standard grade through as cutting off main shaft angle T4 regularly.

In addition; Main shaft angle T6 for the drive current that makes take-up solenoid 73 stops can make spudger 71 through in the main shaft angular range between suture needle 11 and the needle plate 13 as long as drop on through cutting off the main shaft angle T4 that reaches the standard grade and making suture needle highly become.In addition; Under the situation of this main shaft angle T6; Because as long as to make solenoid is OFF, so need not shown in the situation of said main shaft angle T3, consideration is flow through solenoid from drive current and is begun to rise to the required time till the required output current of shift action of carrying out to electric current.

Then,, and passed through the predetermined regulation stand-by period, then raised solenoid 15, cloth is discharged from hold mode, thereby tangent line control has been accomplished for ON (in making, being OFF) if through stopping to judge that detect sewing machine electromotor 5 stops.

(the effect explanation of embodiment)

Here, on one side will Comparative Examples shown in Figure 7 tangent line control related tangent line control compares with this embodiment, technique effect of the present invention is explained on one side.

The Comparative Examples of Fig. 7 is roughly the control of existing tangent line, and it is the use angle sensor not, according to the detection of the upper-lower position signal being carried out by the suture needle position detector and the elapsed time after detecting, carries out the control of each several part.

That is, in Comparative Examples, until the tangent line signal (T01) that receives tangent line switch 23, utilize lower position detection signal ON and till making tangent line solenoid 16 become ON (T02); Identical with above-mentioned Sewing machines 10; Then, at main shaft angle T03 place, carry out suture and cut off based on the grooved cam defined.

And, be ON (T04) if detect the top position detection signal, then, make tangent line solenoid 16 become OFF waiting for through after the predefined stipulated time, make take-up solenoid 73 become ON (T05) simultaneously.Thus, spudger 71 advances.

In addition, take-up solenoid 73 become ON begin to wait for passed through the predefined stipulated time after, make take-up solenoid 73 become OFF (T06).Thus, spudger 71 is retreated, and carries out the take-up of reaching the standard grade.

And, become from take-up solenoid 73 OFF begin to wait for passed through the predefined stipulated time after, make to raise solenoid 15 and become ON (T07), discharge cloth, tangent line control finishes.

As noted above; In Comparative Examples, owing to make take-up solenoid 73 become ON in the timing of cutting off end fully of reaching the standard grade, so if when spudger advances rotation; The suture of spudger 71 slips over the 76b of portion and contacts with cut reaching the standard grade; Then owing to reach the standard grade and roll off the production line and do not twine, so do not produce tension force, the moving up and down the path position skew and keeping crooked from suture needle 11 easily of reaching the standard grade; Retreating when rotating, the suture seizure 76a of portion that is easy to generate spudger 71 can't catch and reach the standard grade and can't successfully carry out the state of take-up.Especially, when making than grenadine or the cloth that slides easily, because the frictional resistance of reaching the standard grade when running through cloth is lower, so cut reaching the standard grade is drawn out from cloth easily, it is more remarkable that suture slips over the bending of reaching the standard grade that contact caused of the 76b of portion.

On the other hand; Under the situation that the tangent line of Sewing machines 10 is controlled; Because when spudger 71 advanced rotation, reaching the standard grade was not cut off as yet, keep tension force so be in the state of the winding of reaching the standard grade and roll off the production line; Even slip over, also can return original suture needle 11 at once and move up and down the path position place from spudger 71.Thus, can be when spudger 71 be retreated rotation, making reaches the standard grade is caught by the suture seizure 76a of portion of spudger 71, carries out take-up more reliably.

In addition; If the required time to tangent line control compares; Then under the situation of Comparative Examples because from cut-outs (T03) of reaching the standard grade, detect top position signal ON (T04) beginning, start the rotation and stop to retreat rotation of advancing of carrying out spudger through take-up solenoid 73 through take-up solenoid 73; So after waiting for that above-mentioned two actions are accomplished, accomplish tangent line control through raising.

On the other hand, under the situation of the tangent line of Sewing machines 10 control, the cut-out of reaching the standard grade (T4>before timing; Take-up solenoid 73 has become ON; Reaching the standard grade cut-out (T4) afterwards, only after becoming OFF through take-up solenoid 73 and retreating rotation, accomplishing tangent line control through raising.

Therefore, because take-up shortening actuation time after the cut-out of reaching the standard grade is made so can get started next time, can realize the raising of operating efficiency.

(other)

In addition; In the above-described embodiment illustration sewing machine for covering chain stitch; But the kind of Sewing machines is not limited thereto, so long as below suture needle, utilize the reciprocating action of spudger to carry out the Sewing machines of take-up, just can in the Sewing machines of other kind, also use characteristic of the present invention.

In addition; Sewing machines 10 has suture needle position detector 21 and angular transducer 22; But as long as suture needle position detector 21 detected main shaft angles are stored in the memory; Just can utilize angular transducer 22 to detect fully, in the case, also can constitute and only carry angular transducer 22.In the case, only angular transducer 22 works as " detecting unit of main shaft angle ".

In addition, angular transducer 22 also can constitute, and is arranged on main shaft or the lower shaft and directly detects their angle.

In addition; In above-mentioned Sewing machines 10; Utilization can detect the angular transducer 22 of all 360 ° of angles of main shaft, detects the ON and the timing of OFF of take-up solenoid 73, but under the situation of correct ON of known solenoid in advance 73 and OFF timing; Also can use the detecting unit that as suture needle position detector 21, only can detect the main shaft angle of regulation, detect the ON of take-up solenoid 73 and the timing of OFF.In the case, only suture needle position detector 21 works as " detecting unit of main shaft angle ".

(other example of tangent line control)

In the example of tangent line control shown in Figure 4; Behind the tangent line signal that detects 23 generations of tangent line switch (T1); Sewing machine electromotor 5 is decelerated to fixing speed, and the lower position detection signal switches to (T2) behind the ON, drives tangent line solenoid 16; Make the cam action of tangent line unit, thereby make movable cutting knife begin reciprocal rotation action.And movable cutting knife cuts off the timing of reaching the standard grade is becoming the timing T4 of certain main shaft angle for the groove shape according to cam.Thus, carry out following control, that is, detect the timing T3 that is in T4 regulation main shaft angle before, the driving of beginning take-up solenoid 73 by angular transducer 22.

But; Switching to the elapsed time that ON begins till the timing T3 of the main shaft angle that arrives regulation from the lower position detection signal is almost fixed basically; Therefore; For the detection of timing T3, also can replace angular transducer 22 and utilize and for example to be used for the timer of instrumentation time and to detect.

That is, in control part 100, timer being set, is ON if detect the lower position detection signal; Then timer picks up counting; If timing was passed through from T2 to the stipulated time that arrives T3, then CPU 101 makes the drive current of take-up solenoid 73 become ON, makes spudger 71 carry out the rotation of advancing.

Thus, can movable cutting knife cut off reach the standard grade before, make spudger 71 from the operating position rotation of advancing.

In addition; In the example of tangent line control as shown in Figure 4; If detect the top position detection signal is ON (T5), and then CPU 101 makes the drive current of take-up solenoid 73 become OFF after utilizing angular transducer 22 to detect arrival tangent line angle at the end (T6); But also can replace angular transducer 22, carry out waiting for through stopping the control of the drive current of take-up solenoid 73 after the stipulated time.

Promptly; Since to detect the top position detection signal be ON to the elapsed time that arrives the tangent line angle at the end also be almost fixed; If so CPU 101 detects the top position detection signal is ON, then utilize timer to pick up counting, if timing the said elapsed time; Then CPU 101 stops the drive current of take-up solenoid 73, spudger 71 is carried out retreated rotation.

As stated, through based on the timing that the time timing is produced the ON and the OFF of take-up solenoid 73,, realize the action control identical with the situation of using this angular transducer 22 so can not need angular transducer 22.

In addition; Need in memory 102, to store in advance and make take-up solenoid 73 become the time of the timing timing T3 of ON; For this regularly, preferably be set to following timing, promptly; Make that spudger 71 can be through between suture needle 11 and the needle plate 13, and consider that variations in temperature and service voltage reduce the solenoidal action that is caused and postpone.

Claims

1. Sewing machines, it has: the tangent line unit, it moves in prescribed period of time according to the generation of tangent line signal, utilizes the co-operating of movable cutting knife and fixed cutting tool to cut off and reaches the standard grade;

Operating unit, it produces said tangent line signal to said tangent line unit;

Thread take-up mechanism; It has spudger and driver element; This spudger carries out from the reciprocating action of initial position to operating position, and this driver element makes said spudger carry out reciprocating action, and this thread take-up mechanism is at said spudger during from said operating position to the homing action of said initial position; Choose from the reaching the standard grade of suture needle to sewn object, extract said cut-out end of reaching the standard grade from said sewn object;

Control module, it controls the said driver element of said thread take-up mechanism; And

Detecting unit, it detects the regulation anglec of rotation that moves up and down the driving shaft that synchronously is rotated with said suture needle,

This Sewing machines is characterised in that,

Said control module is controlled said driver element; After producing at said tangent line signal; Based on the detection of said detecting unit, before cutting off said reaching the standard grade, make said spudger carry out forward motion to said operating position from said initial position by said tangent line unit.

2. Sewing machines according to claim 1 is characterized in that,

Said control module is controlled said driver element, with become said spudger can be through the regulation anglec of rotation between said suture needle and the needle plate after, make said spudger carry out forward motion to said operating position from said initial position.

3. Sewing machines according to claim 1 and 2 is characterized in that,

Said detecting unit has:

The suture needle position detector, it is at the anglec of rotation place of the Sewing machines driving shaft suitable with the lower position of said suture needle, and the lower position signal that begins moves in the said tangent line of output regulation unit; And

Angle to said driving shaft changes angle detector that detects or the timing unit that the time is carried out timing,

If begin from the said lower position signal that detects said suture needle position detector; The angle that said angle detector detects regulation changes, or said timing unit timing the elapsed time of regulation; Then said control module is controlled, so that said spudger carries out forward motion.