CN113668146A

CN113668146A - Sewing machine

Info

Publication number: CN113668146A
Application number: CN202010413591.0A
Authority: CN
Inventors: 管建平; 谭新民; 许君辉; 洪志敏
Original assignee: Jack Sewing Machine Co Ltd
Current assignee: Jack Technology Co Ltd
Priority date: 2020-05-15
Filing date: 2020-05-15
Publication date: 2021-11-19
Anticipated expiration: 2040-05-15
Also published as: WO2021227264A1; CN113668146B

Abstract

The invention provides a sewing machine, which comprises a presser foot lifting assembly, wherein the presser foot lifting assembly comprises a press rod capable of moving up and down, a presser foot arranged at the lower end of the press rod, a guide frame fixed on the press rod, a driving source, a driving crank driven to rotate by the driving source, an automatic presser foot lifting clutch assembly connected between the driving crank and the guide frame, a hand wrench positioned outside a sewing machine shell and a manual presser foot lifting clutch assembly connected between the hand wrench and the guide frame; when the automatic pressure foot lifting clutch assembly enables power transmission between the driving crank and the guide frame, the manual pressure foot lifting clutch assembly enables the hand wrench and the guide frame to have no power transmission; when the manual pressure foot lifting clutch component enables power transmission between the portable wrench and the guide frame, the automatic pressure foot lifting clutch component enables power-free transmission between the driving crank and the guide frame. The application relates to a sewing machine can lift the presser foot automatically, can manually lift the presser foot again to improve the operation convenience, promote sewing machine's performance.

Description

Sewing machine

Technical Field

The present invention relates to a sewing machine.

Background

At present, a presser foot lifting mechanism is arranged in a flat sewing machine and is used for executing the action of lifting a presser foot. The existing tooth foot lifting mechanisms are all automatic foot lifting mechanisms, and a foot lifting driving source is usually an electromagnet, for example, a foot lifting mechanism disclosed in the chinese utility model patent specification with the application number of 201821897744.8. However, when the presser foot lifting action is executed, the sewing machine must be in a power-on state, otherwise, an electric control module of the sewing machine cannot drive the electromagnet to be powered on or off. Obviously, the existing automatic presser foot lifting mechanism is limited by whether the sewing machine is powered on or not, and cannot meet all working conditions of the sewing machine, such as the presser foot lifting action cannot be executed when the sewing machine is stopped and powered off. In addition, when the electromagnet drives the presser foot lifting, the movement stroke of the iron core of the electromagnet is a fixed value, the presser foot can only be lifted to the highest point once when the electromagnet acts, and the presser foot cannot be lifted upwards to any height below the highest point, namely the height of the lifted presser foot is not adjustable; and because of the motion property of the electromagnet, a large impulse exists in the lifting process of the presser foot, and the buffer is difficult to control when the presser foot is put down, so that the impact force is large when the presser foot is lifted and put down, and further large noise vibration is generated.

Furthermore, the sewing machine is also provided with a thread clamping device which is an electronic thread clamping device and a driving source which is an electromagnet, the thread clamping device clamps thread and gives a certain thread tension to the upper thread during sewing, and the thread clamping device loosens the thread during thread cutting so as to obtain a longer thread end of the upper thread on the side of the machine needle, thereby avoiding the upper thread from being separated from the machine needle. Therefore, at least two electromagnets are arranged in the sewing machine and are respectively used for carrying out presser foot lifting, thread clamping and thread loosening, so that the cost of the sewing machine is increased, and the sewing machine is relatively large in size.

Furthermore, an adjusting knob is arranged on the thread clamping device and acts on a thread clamping spring in the thread clamping device, and a user manually rotates the adjusting knob to adjust the spring force of the thread clamping spring, so that the thread clamping force applied to the upper thread by the thread clamping device is adjusted, and the thread tension is also adjusted. Therefore, the thread clamping force of the thread clamping device in the existing sewing machine is manually adjusted, which wastes time and labor.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a sewing machine capable of lifting a presser foot both automatically and manually.

In order to achieve the purpose, the invention provides a sewing machine, which comprises a presser foot lifting assembly, a driving source, a driving crank, an automatic presser foot lifting clutch assembly, a portable wrench and a manual presser foot lifting clutch assembly, wherein the presser foot lifting assembly comprises a pressing rod capable of moving up and down, a presser foot arranged at the lower end of the pressing rod, and a guide frame fixed on the pressing rod; when the automatic presser foot lifting clutch component enables power transmission between the driving crank and the guide frame, the manual presser foot lifting clutch component enables unpowered transmission between the portable wrench and the guide frame; when the manual pressure foot lifting clutch component enables power transmission between the portable wrench and the guide frame, the automatic pressure foot lifting clutch component enables power transmission between the driving crank and the guide frame to be free.

Further, the sewing machine also comprises a thread clamping device and a thread tension adjusting clutch assembly; the wire clamping device comprises a wire clamping rod capable of moving axially, a wire clamping sheet and a wire clamping spring sleeved on the wire clamping rod, and a spring limiting piece arranged on the wire clamping rod, wherein two ends of the wire clamping spring are abutted against the wire clamping sheet and the spring limiting piece; the tension adjusting clutch assembly is connected between the driving crank and the wire clamping rod; the driving source is a driving motor, and the output corner of the driving motor has a presser foot lifting range and a wire tension adjusting range; when a motor shaft of the driving motor rotates in the range of the pressure foot lifting, the automatic pressure foot lifting clutch assembly enables power transmission between the driving crank and the guide frame, and the wire tension adjusting clutch assembly enables the driving crank and the wire clamping rod to have no power transmission; when a motor shaft of the driving motor rotates in a linear tension adjusting range, the automatic pressure lifting foot clutch assembly enables power transmission between the driving crank and the guide frame to be free, and the linear tension adjusting clutch assembly enables power transmission between the driving crank and the wire clamping rod to be available.

Further, when a motor shaft of the driving motor rotates in the range of lifting the presser foot, the wire clamping device is in a wire loosening state.

Furthermore, the automatic presser foot lifting clutch assembly comprises a presser foot lifting connecting rod, a presser foot lifting rocker with a first fixed swing fulcrum and a presser foot lifting push rod fixed on the presser foot lifting connecting rod, wherein two ends of the presser foot lifting connecting rod are respectively hinged with the driving crank and the presser foot lifting rocker, and a hinged point of the presser foot lifting connecting rod and the driving crank is eccentric to a rotation center of the driving crank; when a motor shaft of the driving motor rotates in the range of lifting the presser foot, the presser foot lifting push rod is in butt fit with the guide frame; when the manual pressure foot lifting clutch component enables power transmission between the hand wrench and the guide frame or a motor shaft of the driving motor rotates in a linear tension adjusting range, the pressure foot lifting push rod is located below the guide frame, and the pressure foot lifting push rod and the guide frame are separated.

Furthermore, the wire tension adjusting clutch assembly comprises a roller wheel arranged on the driving crank, a driving lever with a second fixed swing fulcrum and a connecting joint fixed on the wire clamping rod, wherein one end of the driving lever is provided with a lever driving part, the other end of the driving lever is provided with a sliding groove extending along the length direction of the driving lever, the connecting joint is provided with a connecting shaft part, and the connecting shaft part is arranged in the sliding groove in a penetrating manner and is in sliding fit with the sliding groove; when a motor shaft of the driving motor rotates in the range of lifting the presser foot, a lever driving part of the driving lever is separated from the roller; when a motor shaft of the driving motor rotates in the linear tension adjusting range, a lever driving part of the driving lever is in butt fit with the roller.

Further, the thread clamping device further comprises a thread clamping seat fixed on the shell of the sewing machine, the thread clamping rod is movably arranged in the thread clamping seat in a penetrating mode, two thread clamping pieces are provided, a thread clamping cavity is formed between the two thread clamping pieces, one thread clamping piece is abutted to the thread clamping seat, and the other thread clamping piece is abutted to the thread clamping spring.

Furthermore, the spring limiting part is a knob, a split structure is arranged between the knob and the wire clamping rod, and the wire clamping rod is fixedly connected with the knob or in threaded connection with the knob.

Further, the spring limiting part is a hat brim part which is integrally formed on the wire clamping rod.

Further, the manual presser foot lifting clutch assembly comprises a hand crank and a hand connecting rod which are rotatably arranged in the sewing machine shell; the portable crank is fixedly connected with the portable wrench; a connecting screw is fixed on the hand crank, a connecting chute extending along the extending direction of the hand connecting rod is arranged at one end of the hand connecting rod, and the connecting screw is arranged in the connecting chute in a penetrating way and is in running fit with the connecting chute; the other end of the portable connecting rod is connected with the guide frame; when the automatic presser foot lifting clutch assembly enables power transmission between the driving crank and the guide frame, the connecting screw slides in the connecting sliding groove; when the manual pressure lifting foot clutch assembly enables power transmission between the portable wrench and the guide frame, the connecting screw is abutted to the end part of the connecting sliding groove.

Furthermore, the manual presser foot lifting clutch assembly further comprises a limiting pin fixed on the sewing machine shell, an upward lifting limiting surface and a downward pressing limiting surface are arranged on the hand crank, and the limiting pin is located between the upward lifting limiting surface and the downward pressing limiting surface; when the limit pin is abutted against the upper lifting limit surface, the presser foot is in a presser foot lifting state; when the limiting pin is abutted to the pressing limiting surface, the presser foot is in a pressing state.

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

in the application, the presser foot can be driven to move upwards by the driving source, the driving crank and the automatic presser foot lifting clutch assembly, so that the automatic presser foot lifting is realized; the presser foot can be driven to move upwards through the portable wrench and the manual presser foot lifting clutch assembly, and manual presser foot lifting is achieved. Therefore, the sewing machine that this application relates to can lift the presser foot automatically, can manually lift the presser foot again to improve the operation convenience, promote sewing machine's performance.

Drawings

Fig. 1 is a schematic view of a sewing machine according to the present application.

Fig. 2 is a schematic diagram of the connection between the presser foot lifting assembly, the driving source, the driving crank, the automatic presser foot lifting clutch assembly, the portable wrench, the manual presser foot lifting clutch assembly, the wire clamp and the wire tension adjusting clutch assembly in the application.

Fig. 3 is a schematic view of the connection between the presser foot lifting assembly, the portable wrench and the manual presser foot lifting clutch assembly in the present application.

Fig. 4 is a schematic diagram of the connection between the presser foot lifting assembly, the drive source, the drive crank and the automatic presser foot lifting clutch assembly in the present application.

Fig. 5 is a schematic view showing the connection among the driving source, the driving crank, the wire gripper, and the wire tension adjusting clutch assembly according to the present application.

Fig. 6 is a schematic view of the connections between the drive crank, the wire gripper, and the wire tension adjustment clutch assembly of the present application.

Fig. 7 to 9 are views illustrating a process of manually lifting a presser foot of the sewing machine according to the present application.

Description of the element reference numerals

10 casing

20 lift presser foot subassembly

21 pressure lever

22 presser foot

23 guide frame

231 connecting projection

24 liner

30 thread clamping device

31 wire clamping rod

32 wire clamping sheet

33 wire clamping spring

34 spring stop

35 wire clamping seat

40 driving motor

50 driving crank

60 automatic presser foot lifting clutch assembly

61 lifting presser foot connecting rod

62 lifting pressure foot rocker

63 lifting presser foot push rod

64 first supporting pin

70 line tension adjustment clutch assembly

71 roller

72 drive lever

721 Lever Driving part

722 chute

73 connecting joint

731 contact body portion

732 connecting shaft part

74 second support pin

75 circlip

80 hand wrench

81 rotation operation part

90 manual presser foot lifting clutch assembly

91 hand crank

911 uplift limit surface

912 pressing limit surface

92 hand-held connecting rod

921 connecting sliding groove

922 mounting hole

93 limit pin

94 connecting shaft

95 connecting screw

110 motor base

120 shaft sleeve

130 presser foot spring

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.

The application provides a sewing machine. For convenience of description, in the following examples, the directions are defined as follows: defining the axial direction of a main shaft in the sewing machine as a left-right direction, wherein the direction of the main shaft towards the head (namely the needle side) of the sewing machine is a left direction, and the direction of the main shaft towards the tail of the sewing machine is a right direction; defining the moving direction of the sewing material when the sewing machine is used for sewing as a front direction; a direction orthogonal to both the left-right direction and the front-rear direction is defined as an up-down direction.

As shown in fig. 1 and 2, the sewing machine according to the present invention includes a housing 10, a presser foot lifting assembly 20, a driving source, a driving crank 50, an automatic presser foot lifting clutch assembly 60, a hand wrench 80, and a manual presser foot lifting clutch assembly 90. The presser foot lifting assembly 20 includes a pressing rod 21 extending up and down, a presser foot 22 mounted at the lower end of the pressing rod 21, and a guide 23 fixed at the upper end of the pressing rod 21, wherein the pressing rod 21 is mounted in the sewing machine housing 10 in a manner of moving up and down. The driving source is installed on the sewing machine shell 10, and the output end of the driving source is connected with the driving crank 50 to drive the driving crank 50 to rotate. An automatic presser foot lifting clutch assembly 60 is connected between the drive crank 50 and the guide frame 23. The portable wrench 80 is disposed outside the sewing machine housing 10 at the front side of the sewing machine housing 10, and the manual presser foot lifting clutch assembly 90 is connected between the portable wrench 80 and the guide frame 23.

When the sewing machine needs to lift the presser foot, two modes of automatically lifting the presser foot and manually lifting the presser foot can be provided. When the presser foot needs to be automatically lifted, the sewing machine is in a power-on state when being started, and the driving source is correspondingly in a power-on state; the driving source acts, but the hand wrench 80 does not act, the driving source drives the driving crank 50 to rotate, the driving crank 50 drives the guide frame 23 to move upwards through the automatic presser foot lifting clutch assembly 60, the guide frame 23 drives the pressing rod 21 and the presser foot 22 to move upwards together, and automatic presser foot lifting is realized; in addition, in the automatic presser foot lifting process, the manual presser foot lifting clutch assembly 90 enables no power transmission between the portable wrench 80 and the guide frame 23, so that the upward movement of the guide frame 23 does not act on the portable wrench 80 through the manual presser foot lifting clutch assembly 90, and the portable wrench 80 is maintained at the current position. When the presser foot is required to be manually lifted, the portable wrench 80 is rotated, but the driving source does not act, the portable wrench 80 drives the guide frame 23 to move upwards through the manual presser foot lifting clutch assembly 90, the guide frame 23 drives the pressing rod 21 and the presser foot 22 to move upwards together, and the manual presser foot lifting is realized; in addition, in the manual pressure raising process, the automatic pressure raising clutch assembly 60 causes no power transmission between the driving crank 50 and the guide frame 23, so that the guide frame 23 does not move upward through the automatic pressure raising clutch assembly 60 and acts on the driving crank 50 and the driving source, and the driving crank 50 and the driving source are maintained at the current positions. Therefore, the sewing machine related to the application can not only automatically lift the presser foot, but also manually lift the presser foot, and the operation of manually lifting the presser foot is not restricted by whether the sewing machine is powered on or not, and the action of manually lifting the presser foot can be executed when the sewing machine is powered on and powered off when the sewing machine is stopped, so that the operation convenience is improved, and the use performance of the sewing machine is improved.

Further, as shown in fig. 1 and 2, the sewing machine further includes a thread gripper 30 and a thread tension adjusting clutch assembly 70. The thread clamping device 30 comprises a thread clamping rod 31 extending forwards and backwards, a thread clamping piece 32 and a thread clamping spring 33 which are sleeved on the thread clamping rod 31, and a spring limiting piece 34 arranged at the rear end of the thread clamping rod 31, wherein the thread clamping rod 31 is installed in the sewing machine shell 10 in a back-and-forth moving mode, the thread clamping spring 33 extends forwards and backwards, the front end and the rear end of the thread clamping spring 33 are respectively abutted to the thread clamping piece 32 and the spring limiting piece 34, and namely the thread clamping piece 32, the thread clamping spring 33 and the spring limiting piece 34 are sequentially distributed from front to back. The tension adjusting clutch assembly is connected between the drive crank 50 and the clamping lever 31. The driving source is a driving motor 40, and a motor shaft of the driving motor 40 is connected to the driving crank 50 to drive the driving crank 50 to rotate. In particular, the output angle of the drive motor 40 has a foot lifting range and a line tension adjustment range, the line tension adjustment range including an angle value corresponding to a line tension of zero.

When the motor shaft of the driving motor 40 rotates in the range of lifting the presser foot, the clutch component 60 for automatically lifting the presser foot enables power transmission between the driving crank 50 and the guide frame 23, and the clutch component 70 for adjusting the line tension enables no power transmission between the driving crank 50 and the line clamping rod 31; at this time, when the driving motor 40 drives the driving crank 50 to rotate, the automatic presser foot lifting clutch assembly 60 drives the pressure lever 21 to move upwards, the pressure lever 21 drives the presser foot 22 to move upwards together to perform the automatic presser foot lifting action, and the wire clamp 30 does not act and maintains the current state; in addition, the output rotation angle of the driving motor 40 is controllable, so that the upward movement stroke of the pressure lever 21 is also controllable, the lifting height of the presser foot 22 is also controllable when the presser foot is automatically lifted, and the presser foot 22 can be lifted upwards to any height below the highest point. When the motor shaft of the driving motor 40 rotates in the linear tension adjusting range, the automatic pressure foot lifting clutch assembly 60 enables no power transmission between the driving crank 50 and the guide frame 23, and the linear tension adjusting clutch assembly 70 enables power transmission between the driving crank 50 and the thread clamping rod 31; at this time, when the driving motor 40 drives the driving crank 50 to rotate, the wire clamping rod 31 is driven to move forward or backward by the wire tension adjusting clutch assembly 70; when the thread clamping rod 31 drives the spring limiting piece 34 to move forward, the length of the thread clamping spring 33 is reduced, and the pressure of the thread clamping spring 33 acting on the thread clamping sheet 32 is increased, so that the thread clamping device 30 can perform thread clamping action, or the thread clamping force applied to the upper thread by the thread clamping device 30 is increased, namely the thread tension of the upper thread is increased; when the thread clamping rod 31 drives the spring limiting piece 34 to move backwards, the length of the thread clamping spring 33 is increased, and the pressure of the thread clamping spring 33 acting on the thread clamping sheet 32 is reduced, so that the thread clamping device 30 can perform a thread releasing action, or the thread clamping force applied to the upper thread by the thread clamping device 30 is reduced, namely the thread tension of the upper thread is reduced; when the thread tension spring 33 is completely restored to the original length, the thread tension force applied to the upper thread by the thread tension sheet 32 is zero; while the presser foot lifting assembly 20 is not actuated and the presser foot 22 remains in the current state.

Therefore, the sewing machine according to the present application can realize automatic presser foot lifting and manual presser foot lifting, and also realize automatic presser foot lifting and automatic thread tension adjustment by using the same driving motor 40, and includes the thread clamping action and the thread loosening action of the thread clamping device 30 when the thread tension is automatically adjusted, and can lift the presser foot 22 up to any height below the highest point when the presser foot is automatically lifted, and the driving motor 40 does not generate impact force in the operation process. Therefore, the cost of the sewing machine can be reduced, the structure of the sewing machine is optimized, and the noise generated when the presser foot 22 is lifted and put down, the thread tension is adjusted, the thread is clamped by the thread clamp 30, the thread of the thread clamp 30 is loosened, and the lifting height of the presser foot 22 is controllable.

Preferably, as shown in fig. 2, the pressing rod 21 is vertically movably inserted into a bushing 24, the bushing 24 is fixed in the housing 10, and a needle plate of the sewing machine is located below the presser foot 22. The drive motor 40 is a stepping motor, and the control accuracy can be improved. The driving motor 40 is fixedly installed on a motor base 110, and the motor base 110 is fixedly installed on the casing 10 through screws, so as to install the driving motor 40 on the casing 10. A shaft sleeve 120 is further fixed on the left side surface of the motor base 110, the motor shaft of the driving motor 40 extends left and right and is rotatably supported in the shaft sleeve 120, the driving crank 50 is fixed at the left end of the motor shaft of the driving motor 40, and the driving motor 40 directly drives the driving crank 50 to rotate. As shown in fig. 4, a presser foot 22 spring is sleeved on the upper end of the pressing rod 21, and the presser foot 22 spring presses the pressing rod 21 downwards, so that the presser foot 22 has a downward acting force, and the presser foot 22 has a pressure for pressing the cloth downwards on the needle plate.

Further, when the motor shaft of the driving motor 40 rotates within the range of lifting the presser foot, the thread tension device 30 is in the thread releasing state, and at this time, the thread tension spring 33 in the thread tension device 30 is completely restored to the original length, and the thread tension of the upper thread is zero.

The preferred structure of the automatic presser foot lifting clutch assembly 60 is as follows: as shown in fig. 4, the automatic presser foot lifting clutch assembly 60 includes a presser foot lifting connecting rod 61, a presser foot lifting rocker 62 having a first fixed swing fulcrum, and a presser foot lifting push rod 63 fixed to the presser foot lifting connecting rod 61; the upper end of the pressure foot lifting connecting rod 61 is hinged on the left end surface of the driving crank 50 through a shaft position screw extending left and right, the hinged point of the pressure foot lifting connecting rod 61 and the driving crank 50 is eccentric to the rotation center of the driving crank 50, and the rotation center of the driving crank 50 is the rotation center of the motor shaft of the driving motor 40; the lower end of the pressure foot lifting connecting rod 61 is hinged with the front end of the pressure foot lifting rocker 62 through a shaft position screw extending left and right; the rear end of the pressure lifting and pressing foot rocker 62 is rotatably sleeved on a first supporting pin 64 extending left and right, the first supporting pin 64 is fixed on the shell 10 of the sewing machine, and the first supporting pin 64 forms a first fixed swinging fulcrum of the pressure lifting and pressing foot rocker 62; the presser foot lifting push rod 63 extends left and right, a fixing point of the presser foot lifting push rod 63 and the presser foot lifting connecting rod 61 is positioned at the middle lower section of the presser foot lifting connecting rod 61, and the part of the presser foot lifting push rod 63 extending leftwards out of the presser foot lifting connecting rod 61 is positioned at the lower side of the guide frame 23 and can be abutted against the guide frame 23. Specifically, when the motor shaft of the driving motor 40 rotates within the range of the presser foot lifting, the presser foot lifting push rod 63 is in abutting fit with the guide frame 23, at this time, when the driving motor 40 drives the driving crank 50 to rotate, the driving crank 50 drives the presser foot lifting push rod 63 to move upwards through the presser foot lifting connecting rod 61, the presser foot lifting push rod 63 pushes the guide frame 23 to move upwards together, and further the pressing rod 21 and the presser foot 22 are driven to move upwards, so that the presser foot lifting action is executed. When the motor shaft of the driving motor 40 rotates within the linear tension adjusting range, or when the manual pressure foot lifting clutch assembly 90 enables power transmission between the portable wrench 80 and the guide frame 23 (i.e. during manual pressure foot lifting), the pressure foot lifting push rod 63 is always positioned below the guide frame 23 and separated from the guide frame 23, at this time, when the driving motor 40 drives the driving crank 50 to rotate, although the pressure foot lifting push rod 63 moves, the pressure foot lifting push rod 63 is always not in contact with the guide frame 23, so the guide frame 23 maintains the current state, and the pressure foot lifting assembly 20 is enabled to maintain the current state as a whole.

The preferred construction of the wire tension adjustment clutch assembly 70 is: as shown in fig. 5 and 6, the wire tension adjusting clutch assembly 70 includes a roller 71 mounted on the right end surface of the driving crank 50, a driving lever 72 having a second fixed swing fulcrum, and a connecting joint 73 fixed to the wire clamping bar 31; the roller 71 is eccentric to the rotation center of the drive crank 50; the upper end of the driving lever 72 is provided with a lever driving part 721, and the lower end is provided with a sliding chute 722 extending along the length direction of the driving lever 72; the connecting joint 73 includes a joint body portion 731, and a connecting shaft portion 732 extending rightward from a right end of the joint body portion 731, a front end of the wire clamping rod 31 is fixed to the joint body portion 731, and the connecting shaft portion 732 is inserted into the sliding groove 722 at the lower end of the driving lever 72 and is slidably engaged with the sliding groove. When the motor shaft of the driving motor 40 rotates within the range of lifting the presser foot, the lever driving part 721 of the driving lever 72 is separated from the roller 71, and at this time, when the driving motor 40 drives the driving crank 50 to rotate, the driving lever 72 does not act, so that the wire clamping rod 31 does not move and maintains the current state, and the whole wire clamp 30 maintains the current state. When the motor shaft of the driving motor 40 rotates within the wire tension adjusting range, the lever driving portion 721 of the driving lever 72 is in abutting fit with the roller 71, and at this time, when the driving motor 40 drives the driving crank 50 to rotate, the driving crank 50 rotates the driving lever 72 around the second fixed swing fulcrum thereof through the roller 71, and further drives the wire clamping rod 31 to move forward or to move right through the connecting joint 73, thereby adjusting the wire tension, or enabling the wire clamping device 30 to perform a wire clamping action, or enabling the wire clamping device 30 to perform a wire releasing action.

Preferably, as shown in fig. 5 and 6, a second support pin 74 extending left and right is fixed to a left end surface of the bearing, the drive lever 72 is rotatably fitted over the second support pin 74, and the second support pin 74 constitutes a second fixed swing fulcrum of the drive lever 72. The second support pin 74 is further provided with a snap spring 75, and the snap spring 75 cooperates with the bearing to limit the driving lever 72 in the left-right direction. The thread tension 30 further comprises a thread tension seat 35 fixed to the sewing machine housing 10, thereby integrally mounting the thread tension 30 to the sewing machine housing 10; the wire clamping rod 31 is arranged in the wire clamping seat 35 in a penetrating mode in a back-and-forth moving mode, the two wire clamping pieces 32 are arranged oppositely in a front-and-back mode, a wire clamping cavity is formed between the two wire clamping pieces 32, the wire clamping piece 32 located on the front side is abutted to the front end face of the wire clamping seat 35, and the wire clamping piece 32 located on the rear side is abutted to the rear end of the wire clamping spring 33.

Further, the spring retainer 34 has the following two embodiments. In the first embodiment of the spring limiting part 34, the spring limiting part 34 is a knob, the knob and the wire clamping rod 31 are of a split structure, and the two connection modes are that the knob and the wire clamping rod 31 are fixedly connected, the knob is directly fixed at the rear end of the wire clamping rod 31, and at this time, the wire tension can be automatically adjusted only by the driving motor 40; in the second mode, the two are in threaded connection, and the knob is in threaded connection with the spring limiting part 34, so that the wire tension can be adjusted manually by manually rotating the knob besides automatically adjusting the wire tension by the driving motor 40. In the second embodiment of the spring limiting member 34, the spring limiting member 34 is a brim integrally formed at the rear end of the wire clamping rod 31, that is, the spring limiting member 34 and the wire clamping rod 31 are of an integral structure, and at this time, the wire tension can be automatically adjusted only by the driving motor 40.

The preferred structure of the manual presser foot lifting clutch assembly 90 is: as shown in fig. 3, the manual presser foot lifting clutch assembly 90 includes a carrying crank 91 rotatably mounted in the sewing machine housing 10, and a carrying link 92. The hand crank 91 is fixedly connected to the hand wrench 80. A connecting screw 95 extending back and forth is fixed on the rear end face of the hand crank 91, a connecting chute 921 extending along the extending direction of the hand connecting rod 92 is arranged at the upper end of the hand connecting rod 92, the connecting screw 95 is arranged in the connecting chute 921 in a penetrating way, and the two are in running fit; when the presser foot 22 is in a lowered or pressed state, the connecting screw 95 abuts against the upper end of the connecting slide slot 921 or is slightly lower than the upper end of the connecting slide slot 921. The lower end of the carrying link 92 is provided with a mounting hole 922, the front side of the guide frame 23 is provided with a connecting protrusion 231 protruding forward, and the connecting protrusion 231 is inserted into the mounting hole 922 and is rotatably engaged with the mounting hole 922. When the presser foot is automatically lifted, the clutch assembly 60 for automatically lifting the presser foot enables power transmission between the driving crank 50 and the guide frame 23, the guide frame 23 drives the pressing rod 21 and the presser foot 22 to move upwards, meanwhile, the guide frame 23 can drive the portable connecting rod 92 to move upwards, the connecting chute 921 of the portable connecting rod 92 moves upwards relative to the connecting screw 95, or the connecting screw 95 slides relatively in the connecting chute 921, so that the connecting chute 921 provides a section of idle stroke when the presser foot is automatically lifted, and unpowered transmission is enabled between the portable connecting rod 92 and the portable crank 91, and also unpowered transmission is enabled between the portable wrench 80 and the guide frame 23. When the presser foot is manually lifted, the portable wrench 80 is rotated, the portable crank 91 rotates along with the portable wrench 80, the connecting screw 95 on the portable crank 91 moves upwards, the connecting screw 95 abuts against the upper end of the connecting chute 921 to drive the guide frame 23 to move upwards, and the guide frame 23 drives the pressing rod 21 and the presser foot 22 to move upwards; however, in the above process, the push rod of presser foot 22 is always located below guide 23, so no power transmission is provided between guide 23 and the push rod of presser foot 22, that is, between guide 23 and drive crank 50.

Preferably, as shown in fig. 3, the carrying crank 91 is connected to the carrying wrench 80 by a connecting shaft 94 extending forward and backward, the connecting shaft 94 is rotatably installed in the sewing machine housing 10, the carrying crank 91 is fixed to a rear end of the connecting shaft 94, and the carrying wrench 80 is fixed to a front end of the connecting shaft 94. As shown in fig. 7, a rotation operation part 81 protruding forward in a direction away from the sewing machine case 10 is provided on a front side of the carrier 80 facing away from the sewing machine case 10, and the carrier 80 can be rotated by a user through the rotation operation part 81. The connecting sliding slot 921 is a kidney-shaped slot, and the upper and lower ends of the kidney-shaped slot are arc sections.

Further, as shown in fig. 3, the manual presser foot lifting clutch assembly 90 further includes a limit pin 93 fixed to the sewing machine housing 10, the limit pin 93 extends forward and backward, the lifting crank 91 is provided with an upward lifting limit surface 911 and a downward pressing limit surface 912, and the limit pin 93 is located between the upward lifting limit surface 911 and the downward pressing limit surface 912, or the limit pin 93 is located in a region formed in the lifting crank 91 between the upward lifting limit surface 911 and the downward pressing limit surface 912. Particularly, when the limit pin 93 is abutted with the uplift limit surface 911, the presser foot 22 is in the presser foot uplifting state, that is, the rotation of the hand crank 91 is limited when the presser foot is uplifted through the abutting cooperation of the limit pin 93 and the uplift limit surface 911, so that the rotation of the hand wrench 80 is limited; when the limit pin 93 abuts against the downward pressing limit surface 912, the presser foot 22 is in a downward pressing state, that is, the rotation of the lifting crank 91 is limited when the presser foot 22 is put down through the abutting cooperation of the limit pin 93 and the downward pressing limit surface 912, so that the rotation of the portable wrench 80 is limited.

In summary, the sewing machine with the above structure works according to the following principle:

after the sewing machine is started and powered on, an electric control module of the sewing machine controls the driving motor 40 to be powered on; when the sewing machine starts to sew, the electric control module of the sewing machine controls the output rotation angle of the driving motor 40 to be a rotation angle value within the thread tension adjusting range, the thread clamping spring 33 is in a compressed state, and the thread clamping spring 33 applies pressure to the thread clamping sheet 32 at the rear side, so that the upper thread has thread tension. When the thread tension of the upper thread needs to be increased, the motor shaft of the driving motor 40 rotates counterclockwise to drive the driving crank 50 to rotate counterclockwise together, so that the roller 71 moves backward, and further the lever driving part 721 at the upper end of the driving lever 72 is pushed backward, the driving lever 72 swings clockwise around the second supporting pin 74, the connecting joint 73 drives the thread clamping rod 31 to move forward, the thread clamping rod 31 drives the spring limiting part 34 at the rear end thereof to move forward together, the thread clamping spring 33 is further compressed, and the pressure applied by the thread clamping spring 33 to the thread clamping piece 32 at the rear side is increased, thereby increasing the thread tension of the upper thread. When the thread tension of the upper thread and the thread loosening are required to be reduced, the motor shaft of the driving motor 40 rotates clockwise to drive the driving crank 50 to rotate clockwise together, so that the roller 71 moves forwards, the driving lever 72 swings anticlockwise around the second supporting pin 74, the thread clamping rod 31 is driven to move backwards through the connecting joint 73, the thread clamping rod 31 drives the spring limiting piece 34 at the rear end of the thread clamping rod to move backwards together, the thread clamping spring 33 extends, and the pressure applied by the thread clamping spring 33 to the rear thread clamping piece 32 is reduced, so that the thread tension of the upper thread is reduced. With the further backward movement of the thread clamping rod 31, the thread clamping spring 33 is fully restored to the original length, and the thread clamping force applied to the upper thread by the thread clamping piece 32 is zero, that is, the thread releasing action is performed for the thread clamping device 30. Thereafter, the motor shaft of the driving motor 40 continues to rotate clockwise, the roller 71 is disengaged from the lever driving portion 721 at the upper end of the driving lever 72, and then the presser foot lifting can be started.

When the presser foot is automatically lifted, the motor shaft of the driving motor 40 rotates clockwise to a rotation angle value within the range of the presser foot lifting, in the process, the driving crank 50 drives the presser foot lifting push rod 63 to move upwards through the presser foot lifting connecting rod 61, the presser foot lifting push rod 63 abuts against the guide frame 23, the guide frame 23 and the press rod 21 are pushed to move upwards, and the presser foot 22 is lifted; the connecting slide slot 921 at the upper end of the carry link 92 slides upward relative to the connecting screw 95, and the connecting screw 95 does not operate. As the motor shaft of the drive motor 40 is at different angles within the presser foot lifting range, the presser foot 22 is lifted up at different heights, thereby having multiple presser foot lifting heights.

In the view shown in fig. 7, the presser foot 22 is in a pressed state, and at this time, the presser foot 22 is pressed against the needle plate of the sewing machine, the stopper pin 93 abuts against the pressing stopper surface 912, and the connecting screw 95 abuts against the upper end of the connecting chute 921 or is slightly lower than the upper end of the connecting chute 921. When the presser foot is manually lifted, the portable wrench 80 in the view of fig. 7 is rotated clockwise, as shown in fig. 8, the portable wrench 80 drives the portable crank 91 to rotate together, and the connecting screw 95 fixed on the portable crank 91 moves upwards in the connecting chute 921; after the connecting screw 95 abuts against the upper end of the connecting chute 921, the connecting screw 95 is driven by the hand crank 91 to move upwards continuously, the connecting screw 95 drives the guide frame 23 to move upwards through the hand connecting rod 92, and the guide frame 23 drives the pressing rod 21 and the presser foot 22 to move upwards together; in the process, the downward pressing limiting surface 912 is separated from the limiting pin 93, and the upward lifting limiting surface 911 is close to the limiting pin 93; finally, the upward lifting limit surface 911 is abutted with the limit pin 93, so that the hand crank 91 is stopped, the hand wrench 80 is stopped to rotate, and the manual pressure foot lifting operation is completed; while the presser foot 22 pusher is always under the guide 23. When the presser foot 22 is manually put down, the portable wrench 80 shown in the drawing of fig. 8 is rotated downward counterclockwise, as shown in fig. 9, the portable wrench 80 drives the portable crank 91 to rotate together, and the connecting screw 95 fixed on the portable crank 91 moves downward in the connecting chute 921; because the spring of the presser foot 22 always presses the pressing rod 21 down, the upper end of the connecting chute 921 is always abutted with the connecting screw 95, when the connecting screw 95 moves downwards, the guide frame 23 is driven to move downwards by the portable connecting rod 92, and the guide frame 23 drives the pressing rod 21 and the presser foot 22 to move downwards together; in the above process, the upward-lifting limiting surface 911 is separated from the limiting pin 93, and the downward-pressing limiting surface 912 is close to the limiting pin 93; finally, when the press-down limit surface 912 abuts against the limit pin 93, the hand crank 91 is stopped, and the hand wrench 80 is stopped to rotate, thereby completing the operation of manually lowering the presser foot 22.

Therefore, the thread clamping action, the thread loosening action and the thread tension adjustment of the thread clamping device 30 can be carried out through the control of the electric control module of the sewing machine on the driving motor 40, meanwhile, the automatic pressure foot lifting, the controllable height of the pressure foot lifting during the automatic pressure foot lifting and the manual pressure foot lifting can be realized, the pressure foot 22 cannot generate impact when being lifted and laid down, and the noise of the sewing machine during the operation period is reduced.

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, lifts presser foot subassembly (20), lift presser foot subassembly (20) including depression bar (21) that can reciprocate, install presser foot (22) at depression bar (21) lower extreme and fix guide frame (23) on depression bar (21), its characterized in that: the sewing machine further comprises a driving source, a driving crank (50) driven by the driving source to rotate, an automatic presser foot lifting clutch assembly (60) connected between the driving crank (50) and the guide frame (23), a portable wrench (80) positioned outside the sewing machine shell (10), and a manual presser foot lifting clutch assembly (90) connected between the portable wrench (80) and the guide frame (23);

when the automatic presser foot lifting clutch assembly (60) enables power transmission between the driving crank (50) and the guide frame (23), the manual presser foot lifting clutch assembly (90) enables no power transmission between the hand wrench (80) and the guide frame (23);

when the manual pressure foot lifting clutch assembly (90) enables power transmission between the hand wrench (80) and the guide frame (23), the automatic pressure foot lifting clutch assembly (60) enables power-free transmission between the driving crank (50) and the guide frame (23).

2. The sewing machine of claim 1, wherein: the wire clamping device also comprises a wire clamping device (30) and a wire tension adjusting clutch component (70); the wire clamping device (30) comprises a wire clamping rod (31) capable of moving axially, a wire clamping sheet (32) and a wire clamping spring (33) sleeved on the wire clamping rod (31), and a spring limiting piece (34) arranged on the wire clamping rod (31), wherein two ends of the wire clamping spring (33) are abutted to the wire clamping sheet (32) and the spring limiting piece (34); the tension adjusting clutch assembly is connected between the driving crank (50) and the wire clamping rod (31); the driving source is a driving motor (40), and the output corner of the driving motor (40) has a presser foot lifting range and a wire tension adjusting range;

when a motor shaft of the driving motor (40) rotates in a presser foot lifting range, the automatic presser foot lifting clutch assembly (60) enables power transmission between the driving crank (50) and the guide frame (23), and the wire tension adjusting clutch assembly (70) enables no power transmission between the driving crank (50) and the wire clamping rod (31);

when a motor shaft of the driving motor (40) rotates in a linear tension adjusting range, the automatic pressure lifting and pressing foot clutch assembly (60) enables no power transmission between the driving crank (50) and the guide frame (23), and the linear tension adjusting clutch assembly (70) enables power transmission between the driving crank (50) and the wire clamping rod (31).

3. The sewing machine of claim 2, wherein: when a motor shaft of the driving motor (40) rotates in a range of lifting the presser foot, the thread clamping device (30) is in a thread loosening state.

4. The sewing machine of claim 2, wherein: the automatic presser foot lifting and disengaging assembly (60) comprises a presser foot lifting and connecting rod (61), a presser foot lifting and rocking rod (62) with a first fixed swinging fulcrum and a presser foot lifting and pushing rod (63) fixed on the presser foot lifting and connecting rod (61), wherein two ends of the presser foot lifting and connecting rod (61) are respectively hinged with the driving crank (50) and the presser foot lifting and rocking rod (62), and a hinged point of the presser foot lifting and connecting rod (61) and the driving crank (50) is eccentric to the rotating center of the driving crank (50); when a motor shaft of the driving motor (40) rotates in the range of lifting the presser foot, the presser foot lifting push rod (63) is in butt fit with the guide frame (23); when the manual pressure foot lifting clutch assembly (90) enables power transmission between the hand wrench (80) and the guide frame (23) or a motor shaft of the driving motor (40) rotates in a linear tension adjusting range, the pressure foot lifting push rod (63) is located below the guide frame (23) and separated from the guide frame (23).

5. The sewing machine of claim 2, wherein: the wire tension adjusting clutch assembly (70) comprises a roller (71) arranged on a driving crank (50), a driving lever (72) with a second fixed swing fulcrum and a connecting joint (73) fixed on a wire clamping rod (31), one end of the driving lever (72) is provided with a lever driving part (721), the other end of the driving lever is provided with a sliding groove (722) extending along the length direction of the driving lever (72), the connecting joint (73) is provided with a connecting shaft part (732), and the connecting shaft part (732) is arranged in the sliding groove (722) in a penetrating way and is in sliding fit with the connecting shaft part; when a motor shaft of the driving motor (40) rotates in a range of lifting the presser foot, a lever driving part (721) of the driving lever (72) is separated from the roller (71); when the motor shaft of the driving motor (40) rotates in the linear tension adjusting range, the lever driving part (721) of the driving lever (72) is in butt fit with the roller (71).

6. The sewing machine of claim 2, wherein: the thread clamping device (30) further comprises a thread clamping seat (35) fixed on the sewing machine shell (10), the thread clamping rod (31) is movably arranged in the thread clamping seat (35) in a penetrating mode, two thread clamping pieces (32) are provided, a thread clamping cavity is formed between the two thread clamping pieces (32), one thread clamping piece (32) is abutted to the thread clamping seat (35), and the other thread clamping piece (32) is abutted to the thread clamping spring (33).

7. The sewing machine of claim 2, wherein: the spring limiting part (34) is a knob, a split structure is arranged between the knob and the wire clamping rod (31), and the wire clamping rod (31) is fixedly connected with the knob or in threaded connection with the knob.

8. The sewing machine of claim 2, wherein: the spring limiting piece (34) is a hat brim portion which is integrally formed on the wire clamping rod (31).

9. The sewing machine of claim 1, wherein: the manual presser foot lifting clutch assembly (90) comprises a hand crank (91) and a hand connecting rod (92), wherein the hand crank (91) is rotatably arranged in a sewing machine shell (10); the hand crank (91) is fixedly connected with the hand wrench (80); a connecting screw (95) is fixed on the hand crank (91), one end of the hand connecting rod (92) is provided with a connecting chute (921) extending along the extending direction of the hand connecting rod (92), the connecting screw (95) is arranged in the connecting chute (921) in a penetrating way, and the connecting screw and the connecting chute are in running fit; the other end of the portable connecting rod (92) is connected with the guide frame (23);

when the automatic presser foot lifting clutch assembly (60) enables power transmission between the driving crank (50) and the guide frame (23), the connecting screw (95) slides in the connecting chute (921);

when the manual pressure lifting and foot clutch assembly (90) enables power transmission between the hand wrench (80) and the guide frame (23), the connecting screw (95) is abutted to the end part of the connecting chute (921).

10. The sewing machine of claim 9, wherein: the manual presser foot lifting clutch assembly (90) further comprises a limiting pin (93) fixed on the sewing machine shell (10), an upward lifting limiting surface (911) and a downward pressing limiting surface (912) are arranged on the hand crank (91), and the limiting pin (93) is located between the upward lifting limiting surface (911) and the downward pressing limiting surface (912); when the limit pin (93) is abutted to the upper lifting limit surface (911), the presser foot (22) is in a presser foot lifting state; when the limiting pin (93) is abutted to the pressing limiting surface (912), the presser foot (22) is in a pressing state.