CN107447377B

CN107447377B - Sewing machine

Info

Publication number: CN107447377B
Application number: CN201710851772.XA
Authority: CN
Inventors: 田国兵; 张建波
Original assignee: Jack Sewing Machine Co Ltd
Current assignee: Jack Technology Co Ltd
Priority date: 2017-09-19
Filing date: 2017-09-19
Publication date: 2020-07-07
Anticipated expiration: 2037-09-19
Also published as: CN107447377A

Abstract

The invention provides a sewing machine, which comprises a main shaft, an upper shaft, a needle rod crank, a needle rod binding head, a feed lifting tooth shaft, a feed feeding shaft, a feed lifting tooth eccentric wheel, a feed feeding eccentric wheel and a connecting frame, wherein the connecting frame is driven by the needle rod crank and reciprocates up and down along the extension direction of the needle rod; the feed lifting eccentric wheel or the feed conveying eccentric wheel is fixed on the main shaft, a first connecting part is arranged on the feed lifting eccentric wheel, a second connecting part is arranged on the feed conveying eccentric wheel, and the first connecting part and the second connecting part are mutually sleeved; when the cloth feeding mechanism is in a cloth feeding state, the first connecting part and the second connecting part are relatively static; when the cloth feeding eccentric angle is adjusted, the first connecting part and the second connecting part rotate relatively. This application can provide great needle bar puncture power and can adjust the eccentric time of work feed, and then promotes sewing machine's thick material adaptability.

Description

Sewing machine

Technical Field

The present invention relates to a sewing machine.

Background

At present, as shown in fig. 1 and fig. 2, when a needle bar driving mechanism in a sewing machine mainly comprises an upper shaft 100, a needle bar crank 200 fixed on the upper shaft 100, a needle bar connecting rod 300, a vertically extending needle bar 400 and a needle bar puncturing head 500 fixed on the needle bar 400, two ends of the needle bar connecting rod 300 are respectively hinged with the needle bar crank 200 and the needle bar puncturing head 500, the upper shaft 100 is driven by a motor to rotate, the upper shaft 100 drives the needle bar crank 200 to synchronously rotate, so the needle bar crank 200 makes a circular motion, the needle bar puncturing head 500 is driven by the needle bar connecting rod 300 to do a vertical reciprocating motion, the needle bar 400 and a needle 600 mounted at the lower end of the needle bar 400 are finally driven to do the vertical reciprocating motion, a downward puncturing force required when the needle bar punctures the fabric is finally transmitted to the needle bar by the needle bar crank through a plurality of row mechanisms, according to analysis, the needle bar crank starts to puncture the fabric downwards when the needle bar crank is at the position shown in fig. 2, the needle bar driving mechanism, the transmission analysis shows that the needle bar driving mechanism has a force F3, the needle bar crank provides F3, the puncturing force F3, the needle bar F-puncturing force F-F component force required by the needle bar driving mechanism, and the needle bar driving mechanism also provides a larger vertical puncturing noise component of the needle bar driving mechanism which is larger than the needle bar driving mechanism which is needed to cause the needle bar driving mechanism, and the needle bar driving mechanism which causes the needle bar driving.

Further, as shown in fig. 4, the cloth feeding mechanism in the sewing machine mainly includes a main shaft 700 driven by a motor to rotate, a feed lifting tooth shaft 800 and a cloth feeding shaft 900 parallel to the main shaft 700, an eccentric wheel fixed on the main shaft 700, a feed lifting tooth transmission unit, and a cloth feeding transmission unit; as shown in fig. 5, the eccentric wheel includes a feed lifting connection section, a main shaft connection section, and a feed delivery connection section along an axial direction thereof, the main shaft connection section is fixed to the main shaft using screws, the feed lifting connection section is eccentric to the main shaft connection section and connected to the feed lifting shaft 800 through a feed lifting transmission unit, and the feed delivery connection section is eccentric to the main shaft connection section and connected to the feed delivery shaft 900 through a feed delivery transmission unit. When the main shaft 700 rotates, the eccentric wheel is driven to synchronously rotate, the main shaft 700 drives the feed lifting shaft 800 to swing through the feed lifting connecting section and the feed lifting transmission unit, the main shaft 700 drives the feed feeding shaft 900 to swing through the feed feeding connecting section and the feed feeding transmission unit, the feed lifting shaft 800 acts on the tooth frame and drives the tooth frame to swing up and down, the feed feeding shaft 900 acts on the tooth frame and drives the tooth frame to swing back and forth, and finally the tooth frame and the feed feeding teeth arranged on the tooth frame are driven to move along a preset feed feeding track to realize feed feeding. In the cloth feeding mechanism, the eccentric wheel is an integral part and is fixed on the main shaft through a screw, so that the relative position between the cloth feeding eccentricity and the feed lifting tooth eccentricity is fixed, and the cloth feeding eccentricity time cannot be changed. However, when thick materials are sewn, the cloth feeding eccentric time needs to be adjusted by several degrees, otherwise, the cloth feeding is unsmooth; obviously, the prior art cloth feeding mechanism cannot meet the above requirements.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a sewing machine capable of providing a large needle bar piercing force and adjusting a cloth feed eccentricity time within a certain range.

In order to achieve the purpose, the invention provides a sewing machine, which comprises a main shaft, an upper shaft, a needle rod crank fixed on the upper shaft, a needle rod extending up and down, a needle rod binding head fixed on the needle rod, a feed lifting shaft, a feed conveying shaft, a feed lifting eccentric wheel, a feed conveying eccentric wheel, a feed lifting transmission unit connected between the feed lifting eccentric wheel and the feed lifting shaft, and a feed conveying transmission unit connected between the feed conveying eccentric wheel and the feed conveying shaft, wherein the main shaft and the upper shaft are driven by a motor to rotate; the feed lifting eccentric wheel or the feed conveying eccentric wheel is fixed on the main shaft, a first connecting part is arranged on the feed lifting eccentric wheel, a second connecting part is arranged on the feed conveying eccentric wheel, and the first connecting part and the second connecting part are mutually sleeved; when the cloth feeding mechanism is in a cloth feeding state, the first connecting part and the second connecting part are relatively static; when the cloth feeding eccentric angle is adjusted, the first connecting part and the second connecting part rotate relatively.

The needle bar binding head is connected with the guide rail part, the driving sliding block is matched with the first sliding groove and can slide in the first sliding groove along the extending direction of the first sliding groove, the guide rail part is matched with the second sliding groove and can slide in the second sliding groove along the extending direction of the second sliding groove, and the needle bar binding head is connected with the guide rail part.

The needle bar crank is provided with a protruding slide block connecting part, one end of the connecting pin is fixed in the slide block connecting part, and the driving slide block is rotatably arranged at the other end of the connecting pin.

Preferably, the connecting frame is T-shaped and comprises a horizontal part extending front and back and a vertical part extending up and down, the first sliding groove is formed in the horizontal part, and the vertical part forms the guide rail part.

Furthermore, the second connecting part is provided with a containing cavity for containing the first connecting part; the outer peripheral surface of the first connecting portion is provided with a clamping groove extending along the circumferential direction of the first connecting portion, the second connecting portion is connected with a set screw in a threaded mode, and the end portion of the set screw is located in the clamping groove and is abutted to the first connecting portion.

Preferably, the clamping groove is a V-shaped groove, and the end of the set screw has a conical part matched with the V-shaped groove.

Furthermore, the first connecting part is provided with an adjusting notch, and the first connecting part is respectively provided with a first notch end face and a second notch end face at two ends of the adjusting notch; the second connecting portion is provided with an adjusting connecting portion protruding towards the adjusting notch, an adjusting screw is connected in the adjusting connecting portion in a threaded mode, and the end portion of the adjusting screw is abutted to the end face of the first notch.

Preferably, the first connecting portion is provided with an accommodating hole at the end face of the second notch, a spring is installed in the accommodating hole, one end of the spring is fixed to the first connecting portion, and the other end of the spring abuts against the adjusting connecting portion.

Preferably, the end of the adjustment screw has a hemispherical surface abutting the first cut end surface.

Preferably, the second connecting portion is provided with an operation notch at the adjusting connecting portion, and the adjusting screw is exposed from the operation notch.

As described above, the sewing machine according to the present invention has the following advantageous effects:

firstly, after the acting force F1 provided by the needle bar crank is decomposed, the acting force in the vertical direction is directly transmitted to the needle bar binding head and the needle bar through the connecting frame, thereby providing larger needle bar puncturing force; secondly, when the sewing machine stops, the included angle between the eccentricity of the cloth feeding and the eccentricity of the feed lifting teeth is adjusted within a certain range through the relative rotation of the first connecting part and the second connecting part, so that the eccentric time of the cloth feeding is changed, and in the operation process of the sewing machine, the feed lifting teeth shaft and the swing of the cloth feeding shaft are driven respectively through the relative stillness of the first connecting part and the second connecting part, so that the requirement of adjusting the eccentric time of the cloth feeding after the thick material sewing can be met by the sewing machine, and the thick material adaptability of the sewing machine is finally improved.

Drawings

Fig. 1 is a schematic view showing a structure of a sewing machine in the prior art.

Fig. 2 is a schematic structural view of the needle bar driving mechanism in fig. 1.

Fig. 3 is a force transfer analysis diagram of the needle bar drive mechanism of fig. 2.

Fig. 4 is a schematic structural diagram of a cloth feeding mechanism in the prior art.

Fig. 5 is a schematic structural view of the cloth feeding eccentric wheel in fig. 4.

Fig. 6 is a schematic view of the structure of the sewing machine of the present application.

Fig. 7 is a schematic structural view of fig. 6 with upper and lower casings omitted.

Fig. 8 is a schematic view of the structure of the needle bar drive mechanism in the present application.

Fig. 9 is a schematic view of the connection of the needle bar crank and the drive slider in the present application.

Fig. 10 is a schematic structural view of the connection frame in the present application.

Fig. 11 is a schematic structural view of the needle bar tying head in the present application.

Fig. 12 is a force transmission analysis diagram of the needle bar drive mechanism in the present application.

Fig. 13 is a schematic structural view of the cloth feeding mechanism in the present application.

Fig. 14 is a schematic view of the connection of the spindle, the feed lifting eccentric and the feed conveying eccentric in the present application.

Fig. 15 is a schematic view of the connection between the feed lifting eccentric and the feed delivery eccentric according to the present application, which is an exploded view.

Fig. 16 is a schematic structural diagram of the tooth lifting eccentric wheel in the application.

Fig. 17 is a schematic structural diagram of the cloth feeding eccentric wheel in the application.

Fig. 18 is a schematic structural view of the feed-forward gear unit of the present application.

Fig. 19 and 20 are schematic structural views of the cloth feeding transmission unit in the present application.

Fig. 21 is a schematic diagram of adjustment of cloth feed eccentricity time in the present application.

Description of the element reference numerals

1 upper shaft 16 cloth feeding eccentric wheel

2 second connecting part of needle bar crank 161

21 slide block connecting part 162 accommodating cavity

3 needle bar 163 adjustment connection

4 needle bar tieing head 164 operating incision

41 mounting hole 165 work feed connecting part

42 connecting shaft part 17 set screw

5 conical portion of connecting bracket 171

51 first runner 18 adjusting screw

52 hemispherical surface of guide rail part 181

53 horizontal part 19 spring

54 vertical part 20 dental articulator

55 through hole 201 first drive chute

551 first through hole 202 second driving sliding groove

552 second through hole 221 teething link

56 connecting hole 222 lifting tooth driving crank

6 drive slide 223 first slide

7 second slide block of guide seat 224

71 second chute 231 first cloth feeding connecting rod

8 connecting pin 232 second feed link

81 flange 233 cloth feeding driving crank

9-position-limiting pressing plate 234 cloth feeding crank

10 copper sleeve 235 third cloth feeding connecting rod

11 upper casing 241 regulating support shaft

12 main shaft 242 adjusting crank

121 first shaft segment 243 needle pitch adjusting connecting rod

122 second shaft section 244 adjusting copper sleeve

13 lifting tooth shaft 245 adjusting screw

14 cloth feeding shaft 246 limiting block

15 eccentric wheel 25 lower shell of lifting tooth

151 first connection 26 feed dog

152 card slot

153 regulating incision

154 first cut end face

155 second notch end face

156 receiving hole

157 lifting tooth connecting part

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, proportions, and dimensions shown in the drawings and described herein are for illustrative purposes only and are not intended to limit the scope of the present invention, which is defined by the claims, but rather by the claims. In addition, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description only and are not intended to limit the scope of the present invention, and changes or modifications of the relative relationship thereof may be made without substantial technical changes and modifications.

In the following examples, the directions are defined as follows: defining the axial direction of the main shaft 12 as a left-right direction, defining one end of the main shaft 12 facing to the head of the sewing machine as a left direction, and defining one end of the main shaft 12 facing to the tail of the sewing machine as a right direction; therefore, as shown in fig. 6, the left side of the paper surface is the left direction, the right side of the paper surface is the right direction, the upper side of the paper surface is the upper direction, the lower side of the paper surface is the lower direction, the front side of the paper surface is the rear direction, and the back side of the paper surface is the front direction.

As shown in fig. 6 and 7, the present application provides a needle bar driving mechanism and a cloth feeding mechanism in a sewing machine, in particular, a sewing machine, which can provide a large needle bar piercing force without changing the torque of the original motor by improving the needle bar driving mechanism, and can adjust the cloth feeding eccentric time within a certain range by improving the cloth feeding mechanism, and the structures of the needle bar driving mechanism and the cloth feeding mechanism are described below.

Needle bar driving mechanism in sewing machine

As shown in fig. 6, the needle bar drive mechanism is mounted in an upper housing 11 of the sewing machine. As shown in fig. 7 and 8, the needle bar driving mechanism includes an upper shaft 1 driven by a motor to rotate, a needle bar crank 2 fixed to the upper shaft 1, a needle bar 3 extending vertically, a needle bar binding head 4 fixed to the needle bar 3, and a connecting frame 5, wherein the connecting frame 5 is driven by the needle bar crank 2 to reciprocate vertically along the extending direction of the needle bar 3, and the needle bar binding head 4 is connected with the connecting frame 5 and is stationary relative to the connecting frame 5. The needle rod crank 2 is sleeved at the left end of the upper shaft 1 and is fixed on the upper shaft 1 through a screw extending along the radial direction of the upper shaft 1. Preferably, the preferable structure of the needle bar crank 2 driving the connecting frame 5 to reciprocate up and down is as follows: as shown in fig. 8 to 10, the needle bar driving mechanism further includes a driving slider 6 hinged to the left end face of the needle bar crank 2, and a guide seat 7 fixed in position and located on the right side of the needle bar 3, wherein the guide seat 7 is fixed to the upper housing 11 by a plurality of screws; a first sliding groove 51 which extends forwards and backwards along the direction vertical to the upper shaft 1 is formed in the right end face of the upper end of the connecting frame 5, and a guide rail part 52 which extends upwards and downwards is arranged at the lower end of the connecting frame 5; a second sliding groove 71 extending up and down is formed in the left end face, facing the connecting frame 5, of the guide seat 7; the driving slider 6 is matched with the first sliding chute 51 and can slide in the first sliding chute 51 along the extending direction of the first sliding chute 51; the guide rail part 52 is matched with the second sliding groove 71 and can slide in the second sliding groove 71 along the extending direction of the second sliding groove 71; the guide rail portion 52 is connected to the needle bar binding head 4 and is stationary relative thereto.

When the needle bar driving mechanism operates, the motor drives the upper shaft 1 to rotate, the upper shaft 1 drives the needle bar crank 2 to synchronously make circular motion, the needle bar crank 2 drives the needle bar binding head 4, the needle bar 3 and a machine needle mounted at the lower end of the needle bar 3 to synchronously reciprocate up and down through the mutual matching of the driving slide block 6 and the first sliding groove 51 and the mutual matching of the guide rail part 52 and the second sliding groove 71 to drive the connecting frame 5, and the connecting frame 5 directly drives the needle bar binding head 4, the needle bar 3 and the machine needle mounted at the lower end of the needle bar 3 to synchronously reciprocate up and down.

In the needle bar driving mechanism, the mutual matching of the driving slide block 6 and the first sliding chute 51 enables the connecting frame 5 to reciprocate in the vertical direction when the needle bar crank 2 rotates; the cooperation of the guide rail portion 52 and the second slide groove 71 serves as a limit function so that the link frame 5 can reciprocate only in the up-down direction. In order to further improve the stability of the up-and-down reciprocating motion of the needle bar 3, as shown in fig. 8, a copper sleeve 10 is sleeved on the needle bar 3, and the copper sleeve 10 is tightly fitted in the upper housing 11 to play a guiding role.

The hinge structure of the driving slide block 6 and the needle bar crank 2 is as follows: as shown in fig. 9, the needle bar drive mechanism further includes a connecting pin 8 extending left and right, a protruding slider connecting portion 21 is provided on the needle bar crank 2, the right end of the connecting pin 8 is fixed in the slider connecting portion 21, and the drive slider 6 is rotatably mounted on the left end of the connecting pin 8. In this embodiment, the driving slider 6 has a square structure and is in surface contact with the groove wall of the first sliding groove 51; the connecting pin 8 has a ring of flanges 81, which flanges 81 are located between the needle bar crank 2 and the drive slider 6.

The needle bar binding head 4 and the connecting frame 5 have a connecting structure that: as shown in fig. 10 and 11, the needle bar binding head 4 is provided with a connecting shaft portion 42 extending in the right axial direction facing the right end of the connecting frame 5, a connecting hole 56 penetrating through the left and right is opened in the guide rail portion 52 of the connecting frame 5, and the connecting shaft portion 42 is inserted into the connecting hole 56 and is in clearance fit with the connecting hole 56; therefore, when the connecting frame 5 reciprocates up and down, the connecting frame 5 directly brings the needle bar binding head 4 and the needle bar 3 to reciprocate up and down in synchronization.

The needle bar binding head 4 and the needle bar 3 are connected in a structure that: as shown in fig. 8 and 11, the needle bar binding head 4 has a vertically penetrating mounting hole 41 formed therein, the needle bar 3 is inserted into the mounting hole 41, and the needle bar binding head 4 is locked to the needle bar 3 by a screw.

Further, as shown in fig. 10, the connecting frame 5 is T-shaped, and includes a horizontal portion 53 extending in the front-rear direction and a vertical portion 54 extending in the up-down direction, the first slide groove 51 is opened in the horizontal portion 53 and penetrates the horizontal portion 53 in the front-rear direction, and the vertical portion 54 constitutes the guide rail portion 52. In addition, the connecting frame 5 is provided with a plurality of through holes 55 which are communicated with each other, of the plurality of through holes 55, a part of the through holes 55 are communicated with the first sliding groove 51 and are defined as first through holes 551, the other part of the through holes 55 are communicated with the second sliding groove 71 and are defined as second through holes 552, the first through holes 551 extend up and down, the second through holes 552 extend back and forth, and the first through holes 551 and the second through holes 552 intersect to further enable the first through holes 551 and the second through holes 552 to be communicated; the first through hole 551 and the second through hole 552 are filled with lubricant oil or lubricant grease, so that the lubricant oil or lubricant grease delivered by the lubricant oil line flows into the first sliding groove 51 and the second sliding groove 71, so as to greatly reduce the friction force between the driving slider 6 and the groove wall of the first sliding groove 51 and between the guide rail portion 52 and the groove wall of the second sliding groove 71, so that the needle bar driving mechanism is durable and generates little noise. Of course, the groove walls of first runner 51 and second runner 71 may be polished and surface-hardened to further reduce friction and increase the surface hardness of the groove walls of first runner 51 and second runner 71. Preferably, the driving slide block 6 is made of copper, so that the driving slide block is more wear-resistant; the connecting frame 5 is made of aluminum and has a light weight effect.

Preferably, as shown in fig. 8, two limit pressing plates 9 arranged in a front-back direction are fixedly arranged on the left end surface of the second sliding groove 71 facing the needle bar binding head 4 through a plurality of screws, the distance between the two limit pressing plates 9 is smaller than the width of the second sliding groove 71 in the front-back direction, and the left end surface of the guide rail portion 52 abuts against the right end surface of the limit pressing plate 9, so that the guide rail portion 52 is always kept in the second sliding groove 71.

Cloth feeding mechanism in sewing machine

As shown in fig. 6, the cloth feeding mechanism is installed in the lower housing 25 of the sewing machine. As shown in fig. 13 to 17, the cloth feeding mechanism comprises a main shaft 12, a feed lifting shaft 13, a cloth feeding shaft 14, a feed lifting eccentric 15, a cloth feeding eccentric 16, a feed lifting transmission unit connected between the feed lifting eccentric 15 and the feed lifting shaft 13, and a cloth feeding transmission unit connected between the feed feeding eccentric 16 and the cloth feeding shaft 14, wherein the main shaft 12, the feed lifting shaft 13 and the cloth feeding shaft 14 are parallel and axially extend along the left-right direction, the feed lifting eccentric 15 and the cloth feeding eccentric 16 are two independent parts, and the feed lifting eccentric 15 or the feed feeding eccentric 16 is fixed on the main shaft 12; in particular, the left end of the feed lifting eccentric 15 is provided with a first connecting part 151, the right end of the feed conveying eccentric 16 is provided with a second connecting part 161, and the first connecting part 151 and the second connecting part 161 are sleeved with each other; when the cloth feeding mechanism is in a cloth feeding state, the first connecting part 151 and the second connecting part 161 are relatively static, so that the feed lifting eccentric 15 and the cloth feeding eccentric 16 rotate synchronously with the main shaft 12. The first connecting portion 151, the second connecting portion 161 and the main shaft 12 are coaxially disposed, and the feed cam 15 has a feed connecting portion 157 eccentric to the first connecting portion 151 at a right end thereof for connection to a feed transmission unit, and a feed cam 16 has a feed connecting portion 165 eccentric to the second connecting portion 161 at a left end thereof for connection to a feed transmission unit. In addition, the main shaft 12 is directly driven by a motor to rotate, and the main shaft 12 and the upper shaft 1 can be connected through a synchronous belt transmission mechanism, so that the motor synchronously drives the upper shaft 1 to rotate.

In the sewing machine equipped with the cloth feeding mechanism, the first connecting part 151 and the second connecting part 161 are relatively static during operation, so that the feed lifting eccentric 15 and the cloth feeding eccentric 16 are also relatively static. Therefore, the motor drives the main shaft 12 to rotate, the main shaft 12 drives the tooth lifting eccentric wheel 15 and the cloth feeding eccentric wheel 16 to synchronously rotate, the tooth lifting eccentric wheel 15 drives the tooth lifting shaft 13 to swing through the tooth lifting transmission unit, and the tooth lifting shaft 13 acts on the tooth rack 20 to drive the tooth rack 20 to swing up and down; meanwhile, the cloth feeding eccentric wheel 16 drives the cloth feeding shaft 14 to swing through the cloth feeding transmission unit, and the cloth feeding shaft 14 acts on the tooth rack 20 to drive the tooth rack 20 to swing back and forth; thereby, the feed dog 26 fixed on the upper end of the tooth holder 20 and the tooth holder 20 are moved for feeding cloth, and the moving track of the tooth holder 20 and the feed dog 26 is the combination of up-down movement and front-back movement, and is an elliptical moving track, as shown in fig. 21. Under normal conditions, the relative position between the feed lifting tooth connecting part 157 on the feed lifting tooth eccentric wheel 15 and the feed connecting part 165 on the feed feeding eccentric wheel 16 is fixed, so that the feed feeding eccentric angle is fixed, the position of the elliptic motion trail relative to the needle plate is also fixed, and the feed feeding eccentric time is also fixed; when the thickness of the sewing material changes, for example, when the sewing material is thick, in order to make the cloth feeding more smooth, the cloth feeding eccentric time needs to be adjusted later, at this time, the sewing machine stops rotating, and the first connecting part 151 and the second connecting part 161 rotate relatively, so that the relative position between the tooth lifting connecting part 157 on the tooth lifting eccentric wheel 15 and the cloth feeding connecting part 165 on the cloth feeding eccentric wheel 16 changes, that is, the included angle between the cloth feeding eccentric and the tooth lifting eccentric is adjusted within a certain range, so that the cloth feeding eccentric angle changes, the interval between the cloth feeding time and the tooth lifting time also changes, or the time difference between the tooth lifting motion and the start of the cloth feeding motion changes, therefore, the motion track of the cloth feeding tooth 26 in fig. 21 changes from the elliptical motion track 1 to the elliptical motion track, and then the cloth feeding eccentric time is adjusted later, and finally the sewing machine can meet the requirement of adjusting the cloth feeding eccentric time later when the sewing material is thick, the thick material adaptability of the sewing machine is improved. When the first connection portion 151 and the second connection portion 161 are relatively rotated, the feed pitch is not changed because the feed eccentricity between the feed connection portion 165 and the spindle 12 and the feed eccentricity between the feed connection portion 157 and the spindle 12 are not changed; or, the application realizes the stepless adjustment of the cloth feeding eccentric time in a certain range on the premise of not changing the size of the needle pitch.

The following description will be given of a preferred embodiment of the connection structure between the feed cam 16 and the feed cam 15, taking the example in which the feed cam 15 is fixed to the main shaft 12.

As shown in fig. 15 to 17, a receiving hole 156 is formed in the second connecting portion 161 for receiving the first connecting portion 151; a circle of clamping grooves 152 extending along the circumferential direction of the first connecting portion 151 are formed in the outer circumferential surface of the first connecting portion 151, a set screw 17 is connected to the second connecting portion 161 in a threaded manner, and the end portion of the set screw 17 is located in the clamping grooves 152 and is abutted against the first connecting portion 151. The first connecting portion 151 is provided with an adjusting notch 153, the adjusting notch 153 penetrates through the first connecting portion 151 along the radial direction of the first connecting portion 151, and the first connecting portion 151 is provided with a first notch end face 154 and a second notch end face 155 at two ends of the adjusting notch 153; the second connecting portion 161 is provided with an adjusting connecting portion 163 protruding toward the adjusting notch 153, an adjusting screw 18 is screwed into the adjusting connecting portion 163, and an end of the adjusting screw 18 abuts against the first notch end face 154. In the operation of the sewing machine, the set screw 17 abuts against the slot 152 to lock the first connecting portion 151 and the second connecting portion 161 so that they are relatively stationary. When the cloth feeding eccentric angle needs to be adjusted, the adjusting screw 18 is rotated, and the adjusting screw 18 feeds along the axial direction of the adjusting screw; because the feed lifting eccentric wheel 15 is fixed on the main shaft 12, the adjusting screw 18 rotates an angle relative to the feed lifting eccentric wheel 15 through acting force and reacting force while feeding axially, and the set screw 17 is screwed and locked after the feed lifting eccentric wheel 16 is adjusted to a proper position. The specific position of the adjusting notch 153 on the first connecting portion 151 is set according to actual requirements, and the adjusting range of the cloth feeding eccentric angle can be limited by changing the position of the adjusting notch 153.

Preferably, as shown in fig. 15 to 17, the locking groove 152 is a V-shaped groove, or a triangular groove, and the end of the set screw 17 has a conical portion 171 matching with the V-shaped groove, and the two cooperate to limit the axial displacement between the feed lifting eccentric 15 and the feed conveying eccentric 16 during the adjustment of the feed conveying eccentric angle. The first connecting portion 151 is provided with a receiving hole 156 at the second notch end face 155, a spring 19 is installed in the receiving hole 156, one end of the spring 19 is fixed to the first connecting portion 151, and the other end of the spring 19 abuts against the adjusting connecting portion 163, so that in the process of adjusting the cloth feeding eccentric angle, the phenomenon of random oscillation of the position of the cloth feeding eccentric wheel 16 can be avoided, and the cloth feeding mechanism can still normally and stably operate after adjustment. The end of the adjusting screw 18 is a semi-spherical surface 181, so that the adjusting screw 18 and the first cut end surface 154 are always in a contact state. The second connecting portion 161 is opened with an operation notch 164 at the adjusting connecting portion 163, and the adjusting screw 18 is exposed from the operation notch 164 to facilitate the rotation of the adjusting screw 18.

As shown in fig. 18, the feed dog transmission unit includes a feed dog connecting rod 221 and a feed dog driving crank 222 fixed on the feed dog shaft 13, the front end of the feed dog connecting rod 221 is rotatably mounted on the periphery of a feed dog connecting part 157 on the feed dog eccentric 15 through a bearing, and the rear end of the feed dog connecting rod 221 is hinged with the feed dog driving crank 222; the main shaft 12 drives the cam 15 to rotate, and drives the cam shaft 13 to swing through the cam connecting rod 221 and the cam driving crank 222. In addition, the structure that the feed lifting shaft 13 drives the tooth rack 20 to swing up and down is as follows: the rear end of the dental articulator 20 is provided with a first driving sliding groove 201, the left end of the feed lifting shaft 13 is hinged with a first sliding block 223, and the first sliding block 223 is matched with the first driving sliding groove 201 and can slide in the first driving sliding groove 201 along the extending direction of the first driving sliding groove 201. Specifically, as shown in fig. 14 and 18, the right end of the main shaft 12 has a first shaft section 121 matched with the tooth lifting eccentric wheel 15 and the cloth feeding eccentric wheel 16, the left end of the main shaft has a second shaft section 122 matched with the tooth holder 20, the second shaft section 122 is eccentric to the first shaft section 121, the second shaft section 122 is hinged to a second slider 224, the front end of the tooth holder 20 has a second driving chute 202, the second slider 224 is matched with the second driving chute 202 and can slide in the second driving chute 202 along the extending direction of the second driving chute 202, so that the main shaft 12 drives the tooth holder 20 to swing up and down through the second slider 224 while rotating, and the front end and the rear end of the tooth holder 20 can swing up and down with the same amplitude under the action of the main shaft 12 and the tooth lifting shaft 13.

As shown in fig. 19 and 20, the cloth feeding transmission unit includes a first cloth feeding link 231, a second cloth feeding link 232, and a cloth feeding driving crank 233 fixed to the cloth feeding shaft 14, wherein an upper end of the first cloth feeding link 231 is rotatably mounted to an outer circumference of the cloth feeding connecting portion 165 of the cloth feeding eccentric 16 through a bearing, a lower end of the first cloth feeding link 231 is hinged to a front end of the second cloth feeding link 232, and a rear end of the second cloth feeding link 232 is hinged to the cloth feeding driving crank 233. In addition, the structure that the feed shaft 14 drives the tooth rack 20 to swing back and forth is as follows: a cloth feeding crank 234 is fixed to the left end of the cloth feeding shaft 14, the cloth feeding crank 234 is hinged to the rear end of a third cloth feeding link 235, and the front end of the third cloth feeding link 235 is connected to the tooth holder 20 through a screw.

Further, the cloth feeding mechanism further comprises a needle pitch adjusting unit, as shown in fig. 6, 19 and 20, the needle pitch adjusting unit comprises an adjusting support shaft 241 parallel to the feed lifting rod 13, an adjusting crank 242 fixed on the adjusting support shaft 241, a needle pitch adjusting link 243, an adjusting copper sleeve 244 fixed in the lower housing 25, an adjusting screw 245 in threaded fit with the adjusting copper sleeve 244, and a limit block 246 fixed at the front end of the adjusting screw 245; the adjusting support shaft 241 is rotatably installed in the lower housing 25, and the rear end of the adjusting screw 245 is located outside the lower housing 25; a long groove is formed in the adjusting crank 242, and the adjusting screw 245 penetrates through the long groove; the front end of the pitch adjusting link 243 is coaxially hinged to the lower end of the first cloth feeding link 231 and the front end of the second cloth feeding link 232, and the rear end of the pitch adjusting link 243 is hinged to the adjusting crank 242. Therefore, when the needle pitch is adjusted, the adjusting screw 245 is rotated, the adjusting screw 245 is fed along the axial direction thereof, the adjusting crank 242 and the adjusting support shaft 241 are driven to rotate around the central axis of the adjusting support shaft 241 through an angle, the position of the hinge point of the first cloth feeding connecting rod 231 and the second cloth feeding connecting rod 232 is changed through the needle pitch adjusting connecting rod 243, the swing amplitude of the main shaft 12 driving the cloth feeding shaft 14 to swing is changed, and finally the swing amplitude of the cloth feeding shaft 14 driving the tooth frame 20 to swing back and forth is changed, so that the adjustment of the needle pitch is realized.

In the above embodiment, the upper shaft 1, the main shaft 12, the feed lifting shaft 13, the cloth feeding shaft 14 and the adjusting support shaft 241 are rotatably supported in the copper bush 10, and the copper bush 10 is fixedly installed in the upper casing 11 or the lower casing 25 in an interference fit manner.

In conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. The utility model provides a sewing machine, includes main shaft (12), upper shaft (1), be fixed in needle bar crank (2) of upper shaft (1), needle bar (3) that extend from top to bottom, needle bar tieing head (4) that are fixed in needle bar (3), feed lifting teeth axle (13), work feed axle (14), lift teeth eccentric wheel (15), work feed eccentric wheel (16), connect the lift teeth transmission unit between lift teeth eccentric wheel (15) and lift teeth axle (13), and connect the work feed transmission unit between work feed eccentric wheel (16) and work feed axle (14), main shaft (12) and upper shaft (1) are rotated by motor drive, its characterized in that: the needle bar binding head is characterized by further comprising a connecting frame (5), wherein the connecting frame (5) is driven by the needle bar crank (2) and can only reciprocate up and down along the extension direction of the needle bar (3), and the needle bar binding head (4) is connected with the connecting frame (5) and is relatively static; the feed lifting eccentric wheel (15) or the feed conveying eccentric wheel (16) is fixed on the main shaft (12), a first connecting part (151) is arranged on the feed lifting eccentric wheel (15), a second connecting part (161) is arranged on the feed conveying eccentric wheel (16), the first connecting part (151) and the second connecting part (161) are mutually sleeved, an adjusting notch (153) is formed in the first connecting part (151), and a first notch end face (154) and a second notch end face (155) are respectively arranged at two ends of the adjusting notch (153) of the first connecting part (151); an adjusting connecting part (163) protruding towards the adjusting notch (153) is arranged on the second connecting part (161), an adjusting screw (18) is connected in the adjusting connecting part (163) in a threaded manner, and the end part of the adjusting screw (18) is abutted to the end surface (154) of the first notch; when the cloth feeding mechanism is in a cloth feeding state, the first connecting part (151) and the second connecting part (161) are relatively static; when adjusting the feed eccentric angle, the adjusting screw (18) is rotated to rotate the feed eccentric (16) through an angle relative to the feed lifting eccentric (15) to rotate the first connecting part (151) and the second connecting part (161) relative to each other.

2. The sewing machine of claim 1, wherein: the needle bar connecting device is characterized by further comprising a driving sliding block (6) hinged to the needle bar crank (2) and a guide seat (7) fixed in position, a first sliding groove (51) extending forwards and backwards in the direction perpendicular to the upper shaft (1) and a guide rail part (52) extending up and down are arranged in the connecting frame (5), a second sliding groove (71) extending up and down is arranged in the guide seat (7), the driving sliding block (6) is matched with the first sliding groove (51) and can slide in the first sliding groove (51) along the extending direction of the first sliding groove (51), the guide rail part (52) is matched with the second sliding groove (71) and can slide in the second sliding groove (71) along the extending direction of the second sliding groove (71), and the needle bar binding head (4) is connected to the guide rail part (52).

3. The sewing machine of claim 2, wherein: the needle bar crank (2) is provided with a protruding sliding block connecting part (21), one end of the connecting pin (8) is fixed in the sliding block connecting part (21), and the driving sliding block (6) is rotatably arranged at the other end of the connecting pin (8).

4. The sewing machine of claim 2, wherein: the connecting frame (5) is T-shaped and comprises a horizontal part (53) extending front and back and a vertical part (54) extending up and down, the first sliding groove (51) is formed in the horizontal part (53), and the vertical part (54) forms the guide rail part (52).

5. The sewing machine of claim 1, wherein: an accommodating cavity (162) for accommodating the first connecting part (151) is formed in the second connecting part (161); the outer peripheral surface of the first connecting portion (151) is provided with a clamping groove (152) extending along the circumferential direction of the first connecting portion (151), the second connecting portion (161) is connected with a set screw (17) in a threaded mode, and the end portion of the set screw (17) is located in the clamping groove (152) and is abutted to the first connecting portion (151).

6. The sewing machine of claim 5, wherein: the clamping groove (152) is a V-shaped groove, and the end part of the set screw (17) is provided with a conical part (171) matched with the V-shaped groove.

7. The sewing machine of claim 1, wherein: an accommodating hole (156) is formed in the second cut end face (155) of the first connecting portion (151), a spring (19) is installed in the accommodating hole (156), one end of the spring (19) is fixed to the first connecting portion (151), and the other end of the spring (19) is abutted to the adjusting connecting portion (163).

8. The sewing machine of claim 1, wherein: the end of the adjusting screw (18) is provided with a semi-spherical surface (181) which is abutted with the first notch end surface (154).

9. The sewing machine of claim 1, wherein: the second connecting part (161) is provided with an operation notch (164) at the adjusting connecting part (163), and the adjusting screw (18) is exposed from the operation notch (164).