A sewing machine needle bar drive device

Abstract

This utility model discloses a sewing machine needle bar drive device, belonging to the field of sewing machine technology. It includes: a machine housing, a drive mechanism disposed within the housing, a needle bar module mounted on the housing, an upper shaft rotatably mounted on the needle bar module, a needle bar crank mounted on the upper shaft, one end of a connecting rod hinged to the needle bar crank, and the other end of the connecting rod hinged to the middle portion of the needle bar, which is inclined and slidably disposed within the needle bar module. This application, by setting a drive mechanism within the machine housing and utilizing the upper shaft on the needle bar module to drive the needle bar crank, and the structure connecting the crank to the middle portion of the needle bar via the connecting rod, aims to construct a drive method with a simple transmission path and better motion coordination. This solves the technical problem of the difficulty in balancing transmission efficiency and motion stability when achieving inclined sliding in traditional needle bar drive devices, thereby improving the reliability of sewing machine needle bar movement and the quality of sewing operations.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology, and in particular to a sewing machine needle bar drive device. Background Technology

[0002] Traditional sewing machine needle bar drive mechanisms suffer from insufficient coordination between the transmission structure and needle bar movement. Existing technologies often rely on complex transmission paths or rigid connections for the tilting and sliding of the needle bar, limiting its flexibility and leading to issues such as movement jamming and trajectory deviation during sewing, thus affecting sewing accuracy and equipment stability. Furthermore, the traditional structure's support and guiding design for the tilting and sliding of the needle bar is not optimized enough, making it difficult to ensure both transmission efficiency and smooth movement. Utility Model Content

[0003] Purpose of the utility model: To provide a sewing machine needle bar drive device to solve the above-mentioned problems existing in the prior art.

[0004] Technical solution: A sewing machine needle bar drive device, comprising: a machine housing, a drive mechanism disposed inside the machine housing, a needle bar module disposed on the machine housing, an upper shaft rotatably disposed on the needle bar module, a needle bar crank disposed on the upper shaft, one end of a connecting rod hinged to the needle bar crank, and the other end of the connecting rod hinged to the middle part of the needle bar that is inclined and slidably disposed inside the needle bar module.

[0005] Furthermore, the drive mechanism includes: a main shaft, which is rotatably mounted on the housing; one end of an aluminum connecting rod is movably mounted on the main shaft; and the other end of the aluminum connecting rod is hinged to a crank mounted on the upper shaft.

[0006] Furthermore, the crank is clamped onto the upper shaft and locked in place by bolts.

[0007] Furthermore, the needle bar includes: a needle bar body, a needle bar fastener provided in the middle of the needle bar body, a first hinge hole provided on the needle bar fastener, and the first hinge hole is hinged to the other end of the connecting rod through a first hinge shaft.

[0008] Furthermore, the needle bar crank includes: a middle arm, one end of which is provided with a clamping part, and the other end is provided with a second hinge hole. The clamping part is fitted onto the upper shaft and locked with bolts. A second hinge shaft is rotatably disposed in the second hinge hole, and the second hinge shaft is connected to the first hinge shaft through a connecting rod.

[0009] Furthermore, the connecting rod is an H-shaped connecting rod, and both ends of the connecting rod are respectively hinged to the first hinge axis and the second hinge axis.

[0010] Furthermore, the middle arm is provided with reinforcing ribs.

[0011] Furthermore, the needle bar module is provided with a needle bar cap, which is coaxially arranged with the needle bar.

[0012] Furthermore, the end of the needle cap is a closed end for dust prevention.

[0013] Furthermore, the needle bar module is provided with a side cover. Beneficial effects

[0014] This application aims to construct a driving method with a simple transmission path and better motion coordination by setting a driving mechanism in the machine housing, using the upper shaft on the needle bar module to drive the needle bar crank, and the structure is connected to the middle of the needle bar via a connecting rod. This solves the technical problem that traditional needle bar drive devices are difficult to balance in terms of transmission efficiency and motion stability when achieving tilting and sliding, thereby improving the reliability of sewing machine needle bar movement and sewing operation quality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the drive mechanism of this utility model;

[0017] Figure 3 This is a schematic diagram of the structure of the needle crank of this utility model;

[0018] Figure 4 This is a utility model Figure 3 A magnified view of part A in the image.

[0019] The attached figures are labeled as follows: housing 1, drive mechanism 2, needle bar module 3, upper shaft 4, needle bar crank 5, middle arm 51, clamping part 52, second hinge hole 53, second hinge shaft 54, connecting rod 6, needle bar 7, needle bar body 71, needle bar fastener 72, first hinge hole 73, first hinge shaft 74, main shaft 21, aluminum connecting rod 22, crank 23, needle bar cap 8, side cover 9. Detailed Implementation

[0020] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0021] Combined with appendix Figures 1-4Description: A sewing machine needle bar drive device includes: a machine housing 1, a drive mechanism 2 disposed within the machine housing 1, a needle bar module 3 disposed on the machine housing 1, an upper shaft 4 rotatably disposed on the needle bar module 3, a needle bar crank 5 disposed on the upper shaft 4, one end of a connecting rod 6 hinged to the needle bar crank 5, and the other end of the connecting rod 6 hinged to the middle of a needle bar 7 obliquely slidably disposed within the needle bar module 3. The drive mechanism 2 includes: a main shaft 21, rotatably disposed on the machine housing 1, one end of an aluminum connecting rod 22 movably mounted on the main shaft 21, and the other end of the aluminum connecting rod 22 hinged to a crank 23 disposed on the upper shaft 4. The crank 23 is clamped to the upper shaft 4 and locked with bolts. The needle bar 7 includes a needle bar body 71, with a needle bar fastener 72 located in the middle of the needle bar body 71. The needle bar fastener 72 has a first hinge hole 73, which is hinged to the other end of the connecting rod 6 via a first hinge shaft 74. The needle bar crank 5 includes a middle arm 51, with a clamping part 52 at one end and a second hinge hole 53 at the other end. The clamping part 52 is fitted onto the upper shaft 4 and locked with bolts. A second hinge shaft 54 ​​is rotatably disposed within the second hinge hole 53, and the second hinge shaft 54 ​​is connected to the first hinge shaft 74 via a connecting rod 6. The connecting rod 6 is an H-shaped connecting rod, with both ends hinged to the first hinge shaft 74 and the second hinge shaft 54, respectively. The middle arm 51 has reinforcing ribs. The needle bar module 3 has a needle bar cap 8, which is coaxially arranged with the needle bar 7. The end of the needle bar cap 8 is closed for dust prevention. The needle bar module 3 is provided with a side cover 9.

[0022] The housing 1, serving as the basic support structure of the device, is cast from high-strength metal and provides a rigid mounting platform for the drive mechanism 2 and the needle bar module 3. It has an internal mounting chamber for the drive mechanism 2 and an external fixing interface for the needle bar module 3. Bolt connections ensure the stability of the overall structure, effectively suppressing component displacement caused by vibration during movement. This provides a stable support base for rotating components such as the main shaft 21, preventing deformation of the base from affecting transmission accuracy.

[0023] The drive mechanism 2 is the core of power input and conversion, comprising a main shaft 21, an aluminum connecting rod 22, and a crank 23. The main shaft 21 is rotatably mounted within the housing 1 via bearings. Its eccentric shaft design converts the motor's rotational motion into reciprocating oscillation. By adjusting the eccentricity, the travel of the needle bar 7 can be flexibly changed to adapt to the different sewing processes' requirements for needle bar travel. One end of the aluminum connecting rod 22 is movably fitted onto the eccentric shaft of the main shaft 21, forming a rotatable connection. The other end is hinged to the crank 23. This combination of a "rotating joint + hinged joint" design reduces rigid impact through flexible transmission and improves force transmission efficiency using the triangular transmission principle, making the oscillation of the upper shaft 4 more stable and uniform. The crank 23 is clamped to the upper shaft 4 and locked with bolts, achieving a detachable connection between the drive mechanism 2 and the upper shaft 4. This allows for adjustment of the crank 23's circumferential position during assembly according to sewing needs, thereby changing the initial oscillation angle of the needle bar crank 5. It also allows for quick disassembly and maintenance later.

[0024] The needle bar module 3 provides an enclosed movement space for moving components such as the needle bar 7 and needle bar crank 5. It has internally machined guide grooves that mate with the needle bar 7, and externally fitted with a side cover 9. Quick assembly and disassembly are achieved via snap-fit ​​or bolt connections, facilitating cleaning, lubrication, or replacement of internal components. The upper shaft 4, rotatably mounted on the housing, is coupled to the housing via high-precision bearings, ensuring low frictional resistance and high coaxiality during rotation, providing a stable rotational center for the oscillation of the needle bar crank 5.

[0025] The needle bar crank 5 is mounted on the upper shaft 4, and its clamping part 52 is fixed by bolts. The installation angle of the needle bar crank 5 relative to the upper shaft 4 can be adjusted according to the sewing process requirements, thereby changing the transmission trajectory of the connecting rod 6. A second hinge shaft 54 ​​is installed in the second hinge hole 53 at the other end of the needle bar crank 5, and is hinged to one end of the connecting rod 6, converting the rotational motion of the upper shaft 4 into the reciprocating oscillation of the connecting rod 6. The arm length design of the needle bar crank 5 has been mechanically optimized to amplify the swing angle amplitude of the upper shaft 4, allowing the needle bar 7 to obtain a larger tilting sliding stroke. At the same time, the reasonable center of gravity distribution reduces the inertial force during oscillation, improving the stability of the movement.

[0026] Connecting rod 6 serves as the transmission medium between needle bar crank 5 and needle bar 7. Its two ends are hinged to needle bar crank 5 and needle bar 7 via a second hinge shaft 54 ​​and a first hinge shaft 74, respectively. It employs an H-shaped cross-section structure, reducing weight while ensuring sufficient strength and minimizing inertial impact during high-speed movement. Simultaneously, the symmetry of the H-shape ensures uniform stress distribution on connecting rod 6 under tensile and compressive loads, reducing the risk of fatigue fracture. The length of connecting rod 6 and the position of the hinge point are kinematically calculated to ensure that the inclined sliding trajectory of needle bar 7 conforms to sewing process requirements, avoiding motion lag or advance caused by an unreasonable transmission ratio.

[0027] The needle bar 7 is tilted and slidably disposed within the needle bar module 3. Its central portion is hinged to the connecting rod 6 via the first hinge hole 73 on the needle bar fastener 72. This "central hinge" design places the hinge point in the middle of the needle bar 7, balancing the forces acting on the needle bar 7 during its vertical movement through leverage, thus reducing the vibration amplitude of the sewing needle at the top of the needle bar 7. The needle bar 7 cooperates with the guide groove of the needle bar module 3, achieving precise tilting and sliding under the drive of the connecting rod 6. Compared to the traditional vertical drive structure, this design can directly complete oblique sewing or special stitch processes, avoiding the need for an additional tilting mechanism and simplifying the overall machine structure.

[0028] In this sewing machine needle bar drive device, the needle bar module 3 is equipped with an extended guide tube 8 coaxial with the needle bar 7. This design provides precise guidance for the tilted and sliding needle bar 7. Through the precise fit between the inner wall and the outer wall of the needle bar, it restricts the radial swing of the needle bar, ensuring the straightness of its movement trajectory, improving the stability of the needle bar movement during sewing, and reducing problems such as needle breakage and skewing caused by shaking. At the same time, the end of the extended guide tube 8 is a closed end, which can effectively prevent dust, fibers, and other debris from entering the needle bar module, reducing wear on the needle bar and hinge components, and extending the service life of the equipment. In addition, the coaxial structure simplifies the assembly process of the guide assembly. The needle bar installation accuracy is directly ensured through the inner wall of the guide tube, eliminating the need for complex adjustments and improving the overall assembly efficiency and transmission reliability.

[0029] The components form a closed-loop transmission chain through the above design: the rotation of the main shaft 21 of the drive mechanism 2 drives the aluminum connecting rod 22 to swing, which in turn drives the upper shaft 4 and the needle bar crank 5 to swing synchronously via the crank 23. The needle bar crank 5 pulls the needle bar 7 to tilt and slide within the needle bar module 3 via the connecting rod 6. During this process, the housing 1 provides rigid support, the needle bar module 3 and the upper shaft 4 ensure the direction of movement, the needle bar crank 5 and the connecting rod 6 realize power transmission and motion form conversion, and the needle bar 7 completes the tilting motion required for sewing. The coordinated action of the components improves the transmission efficiency and motion accuracy of the drive device, meeting the requirements of high-speed and high-precision sewing.

[0030] Work process:

[0031] 1. Power input and primary transmission

[0032] The motor outputs power to drive the main shaft 21 in the drive mechanism 2 to rotate around the housing 1. The eccentric structure of the main shaft 21 converts the rotational motion into the reciprocating oscillation of the aluminum connecting rod 22. One end of the aluminum connecting rod 22 is movably mounted on the eccentric shaft of the main shaft 21, and the oscillation amplitude can be adjusted according to the change of the eccentricity of the main shaft; the other end is connected to the crank 23 through a hinge, transmitting the oscillation power to the upper shaft 4.

[0033] 2. Needle bar crank linkage and motion mode conversion

[0034] Crank 23 is fixed to the upper shaft 4 by bolts, and swings the upper shaft 4 on the needle bar module 3 as the aluminum connecting rod 22 swings. The needle bar crank 5 is fitted onto the upper shaft 4 and locked by the clamping part 52, and swings synchronously with the upper shaft 4. The second hinge shaft 54 ​​in the second hinge hole 53 at the other end of the needle bar crank 5 drives the connecting rod 6 to move. The H-shaped connecting rod 6 is connected to the needle bar crank 5 and the needle bar 7 respectively through the hinge shafts at both ends, converting the rotational motion of the upper shaft 4 into the reciprocating tilting sliding motion of the needle bar 7.

[0035] 3. Needle bar tilting and precise guidance

[0036] The needle bar 7 is hinged to the connecting rod 6 at its middle through the first hinge hole 73 of the needle bar fastener 72. Under the pushing and pulling action of the connecting rod 6, it makes an inclined reciprocating motion along the inside of the needle bar module 3. At this time, the extended guide tube 8, which is coaxially arranged with the needle bar 7 on the needle bar module 3, provides a full-stroke linear guide for the needle bar 7 through a precise fit with the inner wall, limiting its radial swing and ensuring the accuracy of the inclined sliding trajectory. The closed end of the guide tube also prevents dust, fibers and other debris from entering, protecting the internal moving parts.

[0037] 4. Movement cycle and sewing execution

[0038] As the main shaft 21 continues to rotate, the above transmission process forms a periodic cycle: the upper shaft 4 and the needle bar crank 5 oscillate back and forth → the connecting rod 6 pushes and pulls the needle bar 7 to tilt up and down → the sewing needle at the top of the needle bar completes the actions of piercing the fabric and threading. By adjusting the eccentricity of the main shaft 21 or the installation angle of the needle bar crank 5, the stroke and tilt of the needle bar 7 can be changed to adapt to different sewing processes such as flat stitch, slant stitch, and zigzag stitch requirements.

[0039] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A sewing machine needle bar drive device, characterized in that, include: A housing (1) is provided with a drive mechanism (2) inside the housing (1). A needle bar module (3) is provided on the housing (1). An upper shaft (4) is rotatably provided on the needle bar module (3). A needle bar crank (5) is provided on the upper shaft (4). One end of a connecting rod (6) is hinged to the needle bar crank (5). The other end of the connecting rod (6) is hinged to the middle of a needle bar (7) that is inclined and slidably provided in the needle bar module (3).

2. The sewing machine needle bar drive device according to claim 1, characterized in that, The drive mechanism (2) includes: a main shaft (21), which is rotatably mounted on the housing (1), one end of an aluminum connecting rod (22) is movably mounted on the main shaft (21), and the other end of the aluminum connecting rod (22) is hinged to a crank (23) mounted on the upper shaft (4).

3. The sewing machine needle bar drive device according to claim 2, characterized in that, The crank (23) is clamped on the upper shaft (4) and locked with bolts.

4. The sewing machine needle bar drive device according to claim 1, characterized in that, The needle bar (7) includes: a needle bar body (71), a needle bar fastener (72) is provided in the middle of the needle bar body (71), a first hinge hole (73) is provided on the needle bar fastener (72), and the first hinge hole (73) is hinged to the other end of the connecting rod (6) through a first hinge shaft (74).

5. The sewing machine needle bar drive device according to claim 4, characterized in that, The needle bar crank (5) includes: a middle arm (51), one end of which is provided with a clamping part (52) and the other end is provided with a second hinge hole (53). The clamping part (52) is fitted on the upper shaft (4) and locked with bolts. A second hinge shaft (54) is rotatably provided in the second hinge hole (53). The second hinge shaft (54) is connected to the first hinge shaft (74) through a connecting rod (6).

6. The sewing machine needle bar drive device according to claim 5, characterized in that, The connecting rod (6) is an H-shaped connecting rod, and the two ends of the connecting rod (6) are respectively hinged to the first hinge shaft (74) and the second hinge shaft (54).

7. The sewing machine needle bar drive device according to claim 6, characterized in that, The middle arm (51) is provided with reinforcing ribs.

8. The sewing machine needle bar drive device according to claim 1, characterized in that, The needle bar module (3) is provided with a needle bar cap (8), which is coaxially arranged with the needle bar (7).

9. The sewing machine needle bar drive device according to claim 8, characterized in that, The end of the needle cap (8) is a closed end for dust prevention.

10. The sewing machine needle bar drive device according to claim 6, characterized in that, The needle bar module (3) is provided with a side cover (9).

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