CN109652931B - Sewing machine and thread trimming mechanism thereof - Google Patents

Abstract

The invention discloses a thread trimming mechanism of a sewing machine. A left thread trimmer drive cylinder hinged with the left thread trimmer drive rod and a switch for switching the contact state between the piston rod and the cylinder barrel of the left thread trimmer drive cylinder. Adjust the switch, the piston rod and the cylinder are in a relatively fixed state, the right thread trimmer drive rod drives the left thread trimmer drive rod to act synchronously to cut the double stitches; then adjust the switch, the piston rod and the cylinder are in a relative sliding state, the right The thread trimmer drive rod drives the cylinder to slide relative to the piston rod, so that the right thread trimmer drive rod moves independently relative to the left thread trimmer drive rod to cut a single suture; when the right thread trimmer drive rod moves, the left thread trimmer drive rod It can be inactive to effectively prevent the suture from falling off, so the working reliability is improved. The invention also discloses a sewing machine including a sewing machine thread trimming mechanism.

Description

A sewing machine and its thread trimming mechanism

technical field

The invention relates to the field of clothing equipment, in particular to a thread trimming mechanism of a sewing machine. The invention also relates to a sewing machine comprising a sewing machine thread trimming mechanism.

Background technique

Existing mechatronics sewing equipment, especially automatic sewing machines, are increasingly used by garment manufacturers, which has steadily improved the overall production efficiency and product quality of garment manufacturers. Existing automatic sewing machines are usually equipped with a thread trimming mechanism to replace manual thread trimming to improve production efficiency, so it is particularly necessary to improve the thread trimming mechanism.

As shown in FIG. 1 , the existing thread trimmer mechanism includes a right thread trimmer 01, a left thread trimmer 02, and a left thread trimmer connecting rod 03 whose ends are hinged to the right thread trimmer 01 and the left thread trimmer 02, respectively. , wherein, the right thread trimming part 01 includes a right moving knife shaft that drives the right moving knife to move relative to the right fixed knife, and the left thread trimming part 02 includes a left moving knife shaft that drives the left moving knife to move relative to the left fixed knife, so that the right Both the thread trimmer 01 and the left thread trimmer 02 can be used to cut the suture, and both the right thread trimmer 01 and the left thread trimmer 02 can hold one end of the trimmed thread after cutting the suture. When the right thread trimmer 01 moves, the right thread trimmer 01 drives the left thread trimmer 02 to move synchronously through the left thread trimmer connecting rod 03, and the right moving knife shaft and the left moving knife shaft move synchronously, so that the right thread trimmer 01 and the left thread trimmer move synchronously. The left thread trimming part 02 realizes linkage, and then realizes the cutting of double sutures. However, the existing thread trimmer mechanism cannot make the right thread trimmer 01 act independently with respect to the left thread trimmer 02. When the right thread trimmer 01 acts alone, the left thread trimmer 02 is very likely to follow the right thread trimmer 01. The synchronous action causes the caught stitches to fall off, which seriously affects the next smooth sewing of the left thread trimmer 02 . Therefore, the working reliability of the existing thread trimming mechanism is relatively poor.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a thread trimming mechanism for a sewing machine, in which the right moving knife shaft can move relative to the left moving knife shaft, effectively preventing the thread from falling off, and improving the working reliability. Another object of the present invention is to provide a sewing machine including a sewing machine thread trimming mechanism, with improved work efficiency.

Its specific plan is as follows:

The present invention provides a thread trimming mechanism for a sewing machine, comprising:

The right thread trimmer drive rod used to drive the rotation of the right moving knife shaft;

Left thread trimmer drive rod for driving the rotation of the left moving knife shaft;

a left thread trimming drive cylinder hinged with the right thread trimmer drive rod and the left thread trimmer drive rod at both ends;

A switch for switching the contact state between the piston rod and the cylinder barrel of the left thread trimming driving cylinder; when the piston rod and the cylinder barrel are in a relatively fixed state, the left thread trimming driving cylinder drives the The right moving knife shaft and the left moving knife shaft rotate synchronously; when the piston rod and the cylinder are in a relative sliding state, the left thread trimming drive cylinder drives the right moving knife shaft to move relative to the left The shaft rotates.

Preferably, it also includes a left shuttle frame, a first end hinged to the left thread trimmer drive rod, and a second end detachably connected to the end of the piston rod away from the cylinder, for avoiding the left shuttle frame of the left trimmer link.

Preferably, it also includes:

Support base;

The first end is hinged to the support seat and the second end is mounted on the main driving rod of the main driving cam, and the second end of the main driving rod is matched with the cam groove of the main driving cam to drive the main driving Drive rollers for lever action;

The first end is hinged with the second end of the main drive rod through the right drive shaft, and the second end is hinged with the end of the right wire-cutting drive rod away from the cylinder, for driving the right wire-cutting drive Right thread trimmer link for lever rotation.

Preferably, it also includes:

The first end is installed on the right drive shaft and the second end is installed on the right support column provided by the support base, a right reset elastic member for assisting the automatic reset of the main drive rod after the main drive rod moves .

Preferably, it also includes:

The first end is mounted on the left thread trimmer drive rod and the second end is mounted on the left support column provided by the left shuttle frame, for limiting the The left limit elastic piece for the rotation of the left thread trimmer drive rod.

Preferably, it also includes:

right shuttle frame;

a right stop column fixed on the right shuttle frame and used to limit the rotation of the right thread trimming drive rod;

A left stop column fixed on the left shuttle frame and used to limit the rotation of the left thread trimming drive rod.

Preferably, it also includes:

An anti-loosening fastener that is fixedly connected between the left thread trimmer connecting rod and the piston rod and is used to prevent the two from loosening.

Preferably, it further comprises a right thread trimming assembly and a left thread trimming assembly respectively connected with the right moving knife shaft and the left moving knife shaft, and the structure of the right thread trimming assembly and the left thread trimming assembly is the same, The right thread trimmer assembly includes:

right-hand knife

the right fixed knife fixed on the right shuttle frame;

a right driving guide frame fixed on the right shuttle frame and having a right driving guide groove;

It is installed in the right driving guide groove and is fixedly connected with the right moving knife, and is matched with the right driving roller provided at the end of the right moving knife shaft to drive the right driving roller when the right driving roller slides. a right movable knife driving slider that moves the right movable knife relative to the right fixed knife;

A right elastic support member fixed on the right shuttle frame and abutting against the bottom of the right movable knife for supporting the right movable knife and keeping the right movable knife in contact with the right fixed knife.

Preferably, the left thread trimming drive cylinder is specifically an air cylinder, further comprising:

a pressure detection device for detecting the pressure of the rodless cavity, which is arranged in the rodless cavity of the left thread trimmer driving cylinder;

an air pump connected to the air inlet of the rodless cavity for supplying gas to the rodless cavity through the air inlet;

A control device connected to the pressure detection device and the air pump respectively, and used for controlling the volume of the gas supplied by the air pump according to the signal sent by the pressure detection device.

The present invention also provides a sewing machine, a sewing machine body and the sewing machine thread trimming mechanism provided on the sewing machine body according to any one of claims 1 to 9.

Compared with the background art, the sewing machine of the sewing machine thread trimming mechanism provided by the present invention includes a right thread trimming drive rod for driving the rotation of the right moving knife shaft, a left thread trimming driving rod for driving the rotation of the left moving knife shaft, and two ends. The left thread trimmer drive cylinder hinged with the right thread trimmer drive rod and the left thread trimmer drive rod respectively includes a switch for switching the contact state between the piston rod and the cylinder barrel of the left thread trimmer drive cylinder switch.

Adjust the switch so that the piston rod and the cylinder are in a relatively fixed state. At this time, the left thread trimmer drive cylinder is equivalent to a connecting rod. When the right thread trimmer drive rod moves, the The right thread trimmer drive rod drives the left thread trimmer drive rod to act synchronously through the left thread trimmer drive cylinder, so that the right moving knife shaft and the left moving knife shaft rotate synchronously to cut double stitches;

Adjust the switch again so that the piston rod and the cylinder are in a relative sliding state. At this time, the left thread trimmer drive cylinder is equivalent to a telescopic rod nested in each other. When the right thread trimmer drive rod When in action, the right thread trimming drive rod drives the cylinder to slide relative to the piston rod, so that the right thread trimming drive rod can act independently relative to the left thread trimming drive rod, effectively preventing the right thread trimming The thread driving rod and the left thread trimming driving rod act synchronously, so that the right moving knife shaft can rotate independently relative to the left moving knife shaft, so as to cut a single suture. Further, when the right thread trimmer drive lever is actuated, the left thread trimmer drive lever may not act, and the left thread trimmer drive lever does not move synchronously with the right thread trimmer drive lever to keep the seam being cut. thread, effectively preventing the suture from falling off.

Therefore, the working reliability of the thread trimming mechanism of the sewing machine provided by the present invention is improved.

The sewing machine provided by the present invention including the sewing machine thread trimming mechanism improves the working reliability of the sewing machine thread trimming mechanism, reduces the failure rate of the sewing machine thread trimming mechanism, shortens the invalid working time, and thus improves the work efficiency.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

Fig. 1 is the structure diagram of existing sewing machine thread trimming mechanism;

2 is a structural diagram of a thread trimming mechanism of a sewing machine provided by an embodiment of the present invention;

Fig. 3 is the top view of Fig. 2;

Fig. 4 is the front assembly structure diagram of the components installed on the support seat;

Figure 5 is an exploded view of the structure of the parts close to one side of the left thread trimming drive cylinder of Figure 4;

Fig. 6 is the rear structure diagram of Fig. 5;

Fig. 7 is the structure diagram of the right trimmer assembly in Fig. 5;

Figure 8 is the state diagram of the hook line of the right moving knife;

Fig. 9 is the state diagram of the thread trimming of the right moving knife.

The reference numbers are as follows:

Right thread trimmer 01, left thread trimmer 02 and left thread trimmer connecting rod 03;

Right moving knife shaft 1, left moving knife shaft 2, right thread trimmer drive rod 3, left thread trimmer drive rod 4, left thread trimmer drive cylinder 5, switch 6, left shuttle frame 7, left thread trimmer link 8, support Seat 9, main driving rod 10, right thread trimming link 11, main driving cam 12, main connecting plate 13, right reset elastic member 14, left limit elastic member 15, right shuttle frame 16, right stop column 17, left stop column 18, right trimmer assembly 19 and left trimmer assembly 20;

Cylinder barrel 51, piston rod 52 and anti-loosening fastener 53;

Left needle bar separation button 61, right needle bar separation button 62 and main adjustment button 63;

The right movable knife 191 , the right fixed knife 192 , the right driving guide frame 193 , the right movable knife driving sliding block 194 and the right elastic support 195 .

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to make those skilled in the art better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Please refer to FIGS. 2 to 6. FIG. 2 is a structural diagram of a thread trimming mechanism of a sewing machine provided by an embodiment of the present invention; FIG. 3 is a top view of FIG. 2; Structural diagram; FIG. 5 is a structural exploded view of the components close to the left trimming drive cylinder side of FIG. 4 ; FIG. 6 is the rear structure diagram of FIG. 5 .

The embodiment of the present invention discloses a thread trimming mechanism of a sewing machine, which includes a right moving knife shaft 1 , a left moving knife shaft 2 , a right thread trimming drive rod 3 , a left thread trimming drive rod 4 , a left thread trimming drive cylinder 5 and a switch 6 .

The right thread trimming drive rod 3 is fixedly sleeved on the outer circumference of the right movable knife shaft 1 , so that the right thread trimming drive rod 3 drives the right movable knife shaft 1 to rotate. In this specific embodiment, the cross section of the right movable knife shaft 1 is preferably circular. The structure of the right wire-cutting drive rod 3 is V-shaped, and its transitional connection is provided with a circular arc-shaped installation sleeve with a gap, and the two ends of the gap are detachably connected together by a set screw, so that the circular arc-shaped installation sleeve is detachably connected. The installation sleeve is suitable for installing the right movable cutter shaft 1 whose outer diameter varies within a certain range, which is beneficial to improve the adaptability.

Similarly, the left thread trimming drive rod 4 is fixedly sleeved on the outer periphery of the left movable knife shaft 2 , so that the left thread trimming drive rod 4 drives the left movable knife shaft 2 to rotate. In this specific embodiment, the left thread trimming drive rod 4 is disc-shaped and has three evenly distributed connecting claws, the first connecting claw is hinged with the left thread trimming drive cylinder 5, and the second connecting claw is fixed with A circular arc-shaped mounting sleeve with a notch for installing the left movable knife shaft 2. The fixing method of the left movable knife shaft 2 is the same as that of the right movable knife shaft 1. For details, please refer to the above content.

Both ends of the left thread trimming drive cylinder 5 are hinged with the right thread trimmer drive rod 3 and the left thread trimmer drive rod 4 respectively. The left thread trimming drive cylinder 5 is specifically a single-piston cylinder, including a cylinder 51 rotatably connected to the right thread trimmer drive rod 3 through a rotating shaft and a piston rod 52 rotatably connected to the left thread trimmer drive rod 4, thereby forming a cylinder with a piston rod 52. There is a rod cavity and a rodless cavity, and the rodless cavity is provided with an air inlet. Of course, the left thread trimming drive cylinder 5 may also be a hydraulic cylinder, which is not specifically limited here.

The switch has several operation buttons for switching the contact state between the piston rod 52 of the left thread trimmer driving cylinder 5 and the cylinder barrel 51 . Among them, some of the operation buttons are used to separate the left and right needle bars, specifically including the left needle bar separation button 61 and the right needle bar separation button 62. When the left needle bar separation button 61 or the right needle bar separation button 62 is pressed down, the left needle bar or The right needle bar is correspondingly separated, so it is suitable for corner sewing in the double needle bar mode, preventing the stitches from being disordered and improving the beauty and quality of the sewing material. A part of the operation buttons are the main adjustment buttons 63 for cyclically switching the contact state between the piston rod 52 and the cylinder 51 .

In this specific embodiment, the switch is adjusted to inflate the rodless chamber through the air inlet, and the piston rod 52 extends outward relative to the cylinder barrel 51. When the gas volume of the rodless chamber is greater than a certain value, the piston rod 52 is relatively The cylinder barrel 51 is fixed, and the left thread trimmer drive cylinder 5 is equivalent to a connecting rod at this time; when the right thread trimmer drive rod 3 moves, the right thread trimmer drive rod 3 drives the left thread trimmer drive rod 4 through the left thread trimmer drive cylinder 5 Synchronous action, so that the right moving knife shaft 1 and the left moving knife shaft 2 rotate synchronously to cut double stitches;

Adjust the switch again, stop filling the gas into the rodless cavity, the pressure of the rodless cavity is reduced, the sliding resistance of the piston rod 52 is reduced, the piston rod 52 can slide relative to the cylinder 51, and the left thread trimmer drives the cylinder. 5 is equivalent to a telescopic rod nested in each other; when the right thread trimmer drive rod 3 moves, the right thread trimmer drive rod 3 drives the cylinder 51 to slide relative to the piston rod 52, so that the right thread trimmer drive rod 3 is relative to the left trimmer. The thread drive lever 4 can act independently, effectively preventing the right thread trimmer drive lever 3 and the left thread trimmer drive lever 4 from acting synchronously, so that the right moving knife shaft 1 can rotate independently relative to the left moving knife shaft 2 to cut a single suture .

To sum up, under the control of the switch, the right thread trimmer drive lever 3 and the left thread trimmer drive lever 4 can act synchronously or independently, which means that when cutting the suture corresponding to the right moving knife shaft 1, it can be avoided. Due to the action of the left moving knife shaft 2, the stitched thread falls off, which effectively ensures that the next sewing action can be carried out smoothly, so the work reliability is improved.

The present invention also includes the left shuttle frame 7. In order to avoid the installed components on the left shuttle frame 7, the present invention also includes a left thread trimmer link 8, the first end of the left thread trimmer link 8 and the left thread trimmer drive rod 4 The second end is detachably connected with the end of the piston rod 52 away from the cylinder barrel 51, so as to avoid the components mounted on the left shuttle frame 7 to prevent the piston rod 52 of the left thread trimming drive cylinder 5 from colliding during the expansion and contraction process. It is beneficial to prolong the service life of the left thread trimmer driving cylinder 5 . In this specific embodiment, the left thread trimming connecting rod 8 is substantially V-shaped, and the end of the left thread trimming connecting rod 8 close to the piston rod 52 is provided with an inner bolt that matches the external thread at the end of the piston rod 52 to ensure The piston rod 52 is reliably connected with the left thread trimmer link 8 .

In this specific embodiment, the length of the threaded connection between the piston rod 52 and the left thread trimming link 8 can be appropriately increased according to requirements, which is beneficial to improve the connection reliability of the piston rod 52 and the left thread trimming link 8 on the one hand, and on the other hand On the one hand, it is beneficial to conveniently adjust the distance between the left shuttle frame 7 and the right shuttle frame 16 .

In order to further improve the reliability of the connection between the piston rod 52 and the left thread trimmer connecting rod 8, preferably, the present invention further includes an anti-loosening fastener 53 fixed between the left thread trimming connecting rod 8 and the piston rod 52 to prevent the left The thread trimming connecting rod 8 and the piston rod 52 are loosened during the thread trimming process. Specifically, the anti-loosening fastener 53 is a locking nut, but the type of the anti-loosening fastener 53 is not limited thereto.

In order to realize the thread trimming function, the present invention further includes a support base 9 , a main driving rod 10 and a right thread trimming link 11 . Among them, the support seat 9 is used to support other components. It should be noted here that the left movable knife shaft 2 and the right movable knife shaft 1 both pass through the support seat 9, and one end is on the first side of the support seat 9 and the left trimmer The driving cylinder 5 is connected, and the other end is connected with the corresponding movable knife on the second side of the support base 9, so as to utilize the support base 9 reasonably and reduce the occupied space.

The first end of the main driving rod 10 is hinged with the support base 9 , and the second end thereof is mounted on the main driving cam 12 . Specifically, a main connecting plate 13 is detachably mounted on the support base 9 , one end of the main connecting plate 13 is fixed on the support base 9 by screws, and the other end of the main connecting plate 13 is connected to the first end of the main driving rod 10 through a rotating shaft Turn the connection. The second end of the main driving rod 10 is provided with a driving roller. Correspondingly, the present invention also includes a main driving cam 12 whose central axis intersects with the main driving rod 10 and can rotate. The main driving cam 12 is preferably a cylindrical cam. The cam grooves of the drive rollers are matched. Taking the current view of FIG. 2 as the criterion, when the main driving cam 12 rotates, the special trend of the cam groove drives the driving roller to move to the right or left accordingly.

The first end of the right thread trimming link 11 is hinged with the second end of the main drive rod 10 through the right drive shaft, and the second end of the right thread trimming link 11 is connected to the end of the right thread trimming drive rod 3 away from the cylinder 51 . Hinged, so that the right thread trimming link 11 drives the right thread trimming drive rod 3 to rotate. In this specific embodiment, the right thread trimming link 11 and the right thread trimming drive rod 3 are also rotatably connected through a rotating shaft. It should be noted here that the top ends of the rotating shafts that play the role of rotational connection in the text are all provided with stop flanges to prevent the two rotationally connected from being disconnected and ensure that the two rotationally connected are rotated reliably.

Preferably, in this specific embodiment, the right wire-cutting link 11 includes a first connecting sleeve and a second connecting sleeve that are rotatably connected with the main driving rod 10 and the right wire-cutting driving rod 3, respectively, and can be connected in a threaded manner. It is detachably connected to the middle connecting rod between the first connecting sleeve and the second connecting sleeve, so as to adjust the length of the right wire trimmer link 11 within a certain range, to compensate the assembly error or processing error between the related parts, and to facilitate the lifting adaptability. Of course, the structure of the right thread trimming link 11 is not limited to this.

The present invention also includes an electromagnetic driving member for attracting the driving roller into the cam groove and a driving motor for driving the main driving cam 12 to rotate, so as to provide power for the rotation of the right thread trimmer driving rod 3 .

The present invention also includes a right reset elastic member 14, the first end of the right reset elastic member 14 is installed on the right drive shaft, and the second end of the right reset elastic member 14 is installed on the right support column provided by the support base 9, when the main drive rod 10 After rotating to the target position under the action of the driving roller, the main driving rod 10 returns to the initial position under the action of the cam groove, and at the same time, the right reset elastic member 14 assists the main driving rod 10 to reset to prevent the main driving rod 10 from being connected to the cam groove. The friction between them is too large to be reset, which is conducive to improving reliability. Preferably, the right reset elastic member 14 is a common cylindrical elastic member with hooks at both ends, but the type is not limited thereto.

The present invention also includes a left limit elastic piece 15 , the first end of the left limit elastic piece 15 is installed on the left thread trimming drive rod 4 , and the second end of the left limit elastic piece 15 is installed on the left side of the left shuttle frame 7 . The support column is used so that when the piston rod 52 and the cylinder barrel 51 are in a relative sliding state, the left limit elastic member 15 can limit the rotation of the left thread trimmer driving rod 4 . In this specific embodiment, the left limit elastic member 15 is preferably a common cylindrical spring with hooks at both ends, but the type is not limited to this. Specifically, the first end of the left limit elastic member 15 is connected with the third connection claw of the left thread trimming driving rod 4 . It should be noted that the elastic force of the left limit elastic member 15 must be greater than the frictional resistance between the piston rod 52 and the cylinder 51 to ensure that the left limit elastic member 15 does not rotate when the piston rod 52 slides relative to the cylinder 51 .

In order to further improve reliability, the present invention further includes a right shuttle frame 16 , a right stop column 17 and a left stop column 18 , and the right shuttle frame 16 is disposed opposite to the left shuttle frame 7 . The right stop column 17 is fixed on the right shuttle frame 16 . When the right thread trimming drive lever 3 rotates to a certain angle, the right thread trimming drive lever 3 collides with the right stop column 17, preventing the right thread trimming drive lever 3 from continuing to rotate due to factors such as inertial force, and ensuring that the right thread trimming drive lever 3 and The rotation angle between the left thread trimmer drive rods 4 enables the left thread trimmer drive cylinder 5 to reliably drive the left thread trimmer drive rod 4 to rotate. The left stopper post 18 is fixed on the left shuttle frame 7 so that the left stopper post 18 restricts the transitional rotation of the left thread trimmer driving rod 4 . The right stopper post 17 and the left stopper post 18 are preferably connected with bolts, but not limited thereto.

Please refer to FIG. 7 . FIG. 7 is a structural diagram of the right wire trimmer assembly in FIG. 5 .

The present invention also includes a right thread trimming assembly 19 and a left thread trimming assembly 20 respectively connected with the right moving knife shaft 1 and the left moving knife shaft 2, wherein the right thread trimming assembly 19 includes a right moving knife 191, a right fixed knife 192, The right drive guide frame 193 and the right movable knife drive slider 194 are provided.

The right fixed knife 192 is detachably fixed on the right shuttle frame 16 by a set screw. The right drive guide frame 193 is fixed on the right shuttle frame 16 and has a right drive guide groove for accommodating the right movable knife drive slider 194 . One end of the right moving knife shaft 1 passes through the right shuttle frame 16, and one end of the right moving knife shaft 1 close to the right shuttle frame 16 is provided with a right driving roller for driving the right moving knife driving slider 194 to move. The knife drive slide 194 is provided with a right drive mounting slot for receiving the right drive roller. When the right moving knife shaft 1 rotates under the driving of the right thread trimming drive rod 3, the right driving roller pushes the right moving knife driving slider 194 to move along the right driving guide groove, and the right moving knife driving slider 194 drives the right moving knife 191 Move relative to the right stationary knife 192 . The right elastic support 195 is fixed on the right shuttle frame 16 , and the right elastic support 195 abuts against the bottom of the right movable knife 191 , so that the right movable knife 191 can always keep in contact with the right fixed knife 192 . In this specific embodiment, the right elastic support member 195 is preferably two elastic metal sheets with one end fixed on the right shuttle frame 16, but the structure of the right elastic support member 195 is not limited thereto.

In order to improve the versatility, the structure of the right thread trimming assembly 19 is the same as that of the left thread trimming assembly 20, and details are not described herein again.

The present invention also includes a pressure detection device, an air pump and a control device. The pressure detection device is arranged in the rodless cavity of the left thread trimming drive cylinder 5, and is used to detect the pressure of the rodless cavity. The pressure detection device is preferably a pressure sensor, but its type is not limited thereto. The air pump is connected to the air inlet of the rodless cavity, so that the air pump supplies gas to the rodless cavity through the air inlet. The control device is respectively connected with the pressure detection device and the air pump, so that the control device controls the volume of the gas supplied by the air pump according to the signal sent by the pressure detection device. When the pressure in the rodless cavity is less than the preset pressure, the pressure detection device sends a signal to the control device, and the control device controls the operation of the air pump to inflate the rodless cavity and increase the rodless cavity pressure until the rodless cavity pressure reaches the preset pressure. Set the value; the pressure detection device sends a signal to the control device again, and the control device controls the air pump to stop inflating, so as to automatically adjust the pressure of the rodless cavity by automatically inflating and deflating the rodless cavity, so that the pressure of the rodless cavity is constant, thereby ensuring the left The thread trimming drive rod 4 works stably, which is conducive to further improving the work reliability.

Please refer to Fig. 8 and Fig. 9, Fig. 8 is a state diagram of the hook thread of the right movable knife; Fig. 9 is a state diagram of the thread trimming state of the right movable knife.

The working principle of the sewing machine thread trimming mechanism provided by the present invention is as follows:

Adjust the switch 6, select the double needle rod working mode, the left thread trimmer drive cylinder 5 is inflated, and the piston rod 52 is fixed relative to the cylinder 51;

The electromagnetic driving element is electrically absorbed, and the driving roller of the adsorption main driving rod 10 falls into the cam groove of the main driving cam 12; when the main driving cam 12 rotates forwardly, the cam groove drives the main driving rod 10 to move to the right; the main driving rod 10 Push the right thread trimming link 11 to move to the right, the right thread trimming link 11 drives the right thread trimming drive rod 3 to rotate counterclockwise, the right moving knife shaft 1 rotates counterclockwise, and the right driving roller drives the right moving knife driving slider 194 along the The right driving guide groove of the right driving guide frame 193 moves forward, the right moving knife driving slider 194 drives the right moving knife 191 to move forward relative to the right stationary knife 192, the right moving knife 191 moves toward the direction close to the right hook, and the right moving knife 191 goes out. At the same time, the right thread trimmer drive rod 3 drives the left thread trimmer drive rod 4 to rotate through the left thread trimmer drive cylinder 5, the left movable knife shaft 2 rotates counterclockwise, and the left movable knife shaft 2 drives the left movable knife to rotate relative to the The left fixed knife advances synchronously, and the left moving knife draws the hook line;

When the main driving cam 12 continues to rotate in the forward direction, the cam groove drives the main driving rod 10 to move to the left, the right reset elastic member 14 assists the main driving rod 10 to reset, the main driving rod 10 pulls the right thread trimming link 11 to move left, and the right thread trims The connecting rod 11 drives the right thread trimming drive rod 3 to rotate clockwise, the right thread trimming drive rod 3 drives the right moving knife shaft 1 to rotate clockwise, and the right driving roller drives the right moving knife driving slider 194 along the right side of the right drive guide frame 193 . The guide groove is driven to retreat, and the right movable knife driving slider 194 drives the right movable knife 191 to retreat relative to the right fixed knife 192. The right movable knife 191 moves in the direction away from the right rotary hook. The knives 192 are engaged with each other, thereby cutting the suture hooked by the right moving knife 191; at the same time, the right thread trimmer drive rod 3 drives the left thread trimmer drive cylinder 5 to act, and the left thread trimmer drive cylinder 5 drives the left thread trimmer drive rod 4 to rotate clockwise. The thread trimming drive rod 4 drives the left moving knife shaft 2 to rotate clockwise, the left moving knife shaft 2 drives the left moving knife to retreat relative to the left fixed knife, and the left moving knife meshes with the left fixed knife during the retreat process, thereby cutting the left moving knife The suture is cut by the knife; thus, the double suture is cut.

Adjust the switch 6 again, select the single needle rod working mode, the left thread trimmer drive cylinder 5 is deflated, and the piston rod 52 can slide relative to the cylinder barrel 51;

The electromagnetic drive part is electrically absorbed, the main drive cam 12 drives the main drive rod 10 to move to the right, the right thread trimmer link 11 drives the right thread trimmer drive rod 3 to drive the right movable knife shaft 1 to rotate counterclockwise, and the right movable knife shaft 1 passes through the right The movable knife driving slider 194 drives the right movable knife 191 to move forward relative to the right fixed knife 192, and the right movable knife 191 generates the knife hook line; The thread trimmer drive rod 4 does not move;

When the main driving cam 12 continues to rotate in the forward direction, the cam groove drives the main driving rod 10 to move to the left, the right reset elastic member 14 assists the main driving rod 10 to reset, the main driving rod 10 pulls the right thread trimming link 11 to move left, and the right thread trims The drive rod 3 drives the right movable knife shaft 1 to rotate clockwise, and the right movable knife shaft 1 drives the right movable knife 191 to retreat relative to the right fixed knife 192 through the right movable knife drive slider 194 . The fixed knife 192 is engaged with each other, thereby cutting the suture line drawn by the right movable knife 191, thereby realizing the cutting of a single suture line.

The present invention also provides a sewing machine, including a sewing machine body and the above-mentioned sewing machine thread trimming mechanism. Due to the improvement of the working reliability of the sewing machine thread trimming mechanism, the failure rate of the sewing machine thread trimming mechanism is reduced, which is beneficial to shorten the invalid working time, so the work efficiency is high. raised.

The sewing machine and its thread trimming mechanism provided by the present invention have been introduced in detail above. The principles and implementations of the present invention are described with specific examples in this paper. Its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. limit.

Claims (10)

1. A thread trimming mechanism of a sewing machine, comprising:

a right trimming drive rod (3) for driving the right moving blade shaft (1) to rotate;

a left trimming drive rod (4) for driving the left moving blade shaft (2) to rotate;

a left trimming driving cylinder (5) with two ends respectively hinged with the right trimming driving rod (3) and the left trimming driving rod (4);

a switch (6) for switching the contact state between the piston rod (52) and the cylinder (51) of the left trimming drive cylinder (5); when the piston rod (52) and the cylinder barrel (51) are in a relatively fixed state, the left trimming driving cylinder (5) drives the right moving blade shaft (1) and the left moving blade shaft (2) to synchronously rotate; when the piston rod (52) and the cylinder barrel (51) are in a relative sliding state, the left trimming driving cylinder (5) drives the right moving knife shaft (1) to rotate relative to the left moving knife shaft (2).

2. The thread trimming mechanism of a sewing machine according to claim 1, further comprising a left shuttle frame (7) and a left thread trimming connecting rod (8) having a first end hinged to the left thread trimming driving rod (4) and a second end detachably connected to an end of the piston rod (52) away from the cylinder (51) for avoiding the left shuttle frame (7).

3. The thread trimming mechanism of a sewing machine of claim 2, further comprising:

a support base (9);

a main driving rod (10) with a first end hinged to the supporting seat (9) and a second end mounted on a main driving cam (12), wherein the second end of the main driving rod (10) is provided with a driving roller which is matched with a cam groove of the main driving cam (12) to drive the main driving rod (10) to act;

the first end is hinged with the second end of the main driving rod (10) through a right driving rotating shaft, the second end is hinged with one end, far away from the cylinder barrel (51), of the right trimming driving rod (3), and the right trimming connecting rod (11) is used for driving the right trimming driving rod (3) to rotate.

4. The thread trimming mechanism of a sewing machine of claim 3, further comprising:

the first end of the right driving rotating shaft is arranged on a right supporting column arranged on the supporting seat (9), and the second end of the right driving rotating shaft is arranged on a right reset elastic piece (14) used for assisting the main driving rod (10) to automatically reset after the main driving rod (10) acts.

5. The thread trimming mechanism of a sewing machine of claim 2, further comprising:

the first end of the left trimming driving rod (4) is mounted on the left support column arranged on the left shuttle frame (7), and the second end of the left trimming driving rod is mounted on the left support column, and the left limiting elastic piece (15) is used for limiting the rotation of the left trimming driving rod (4) when the piston rod (52) and the cylinder barrel (51) are in a relative sliding state.

6. The thread trimming mechanism of a sewing machine of claim 2, further comprising:

a right shuttle frame (16);

a right stop column (17) fixedly arranged on the right shuttle frame (16) and used for limiting the rotation of the right trimming drive rod (3);

and the left stop column (18) is fixedly arranged on the left shuttle frame (7) and is used for limiting the rotation of the left trimming drive rod (4).

7. The thread trimming mechanism of a sewing machine of claim 2, further comprising:

and the anti-loosening fastener (53) is fixedly connected between the left trimming connecting rod (8) and the piston rod (52) and is used for preventing the left trimming connecting rod and the piston rod from loosening.

8. The thread trimming mechanism of a sewing machine according to claim 6, further comprising a right thread trimming assembly (19) and a left thread trimming assembly (20) correspondingly connected with the right movable knife shaft (1) and the left movable knife shaft (2), respectively, wherein the right thread trimming assembly (19) and the left thread trimming assembly (20) have the same structure, and the right thread trimming assembly (19) comprises:

a right moving blade (191);

a right stationary knife (192) fixed to the right shuttle frame (16);

a right driving guide frame (193) fixedly arranged on the right shuttle frame (16) and provided with a right driving guide groove;

the right moving blade driving sliding block (194) is installed in the right driving guide groove, is fixedly connected with the right moving blade (191), and is matched with a right driving roller arranged at the end part of the right moving blade shaft (1) so as to drive the right moving blade (191) to move relative to the right fixed blade (192) when the right driving roller slides;

and the right elastic supporting piece (195) is fixedly arranged on the right shuttle frame (16), abuts against the bottom of the right moving blade (191), and is used for supporting the right moving blade (191) to ensure that the right moving blade (191) keeps contact with the right fixed blade (192).

9. The thread trimming mechanism of a sewing machine according to any one of claims 1 to 8, wherein the left thread trimming actuating cylinder (5) is embodied as an air cylinder, further comprising:

the pressure detection device is arranged in a rodless cavity of the left trimming driving cylinder (5) and is used for detecting the pressure of the rodless cavity;

the air pump is connected with the air inlet of the rodless cavity and used for providing air for the rodless cavity through the air inlet;

and the control device is respectively connected with the pressure detection device and the air pump and is used for controlling the volume of the air supplied by the air pump according to the signal sent by the pressure detection device.

10. A sewing machine characterized by a sewing machine body and a sewing machine thread trimming mechanism according to any one of claims 1 to 9 provided to the sewing machine body.

Images