A bent needle driving mechanism and a sewing machine

Abstract

The present invention provides a bent needle driving mechanism, comprising: a rotary driving member; a bent needle driving crank, which is L-shaped, a fixing hole connected to the output end of the rotary driving member is formed at the first end thereof, a connecting section is provided at the second end thereof, and a first included angle exists between the axis of the fixing hole and the axis of the connecting section; a spherical connecting rod, an installation hole rotatably connected to the connecting section is formed at the first end thereof, and a spherical surface groove is formed at the second end thereof; a spherical crank, a sphere cooperating with the spherical surface groove is provided at the first end thereof, and the sphere is spherical hinge-connected with the spherical surface groove; a bent needle sliding rod, a bent needle is provided at the end thereof, and the second end of the spherical crank is fixedly connected to the bent needle sliding rod; a second included angle exists between the extending direction of the bent needle sliding rod and the axis of the fixing hole. The present invention also provides a sewing machine, comprising the foregoing bent needle driving mechanism. Compared with the prior art, the present invention can achieve the compound movement of the bent needle through a set of transmission structures, and the structure is simpler.

Description

Technical Field

[0001] The present invention relates to the technical field of sewing machines, and particularly to a bent needle driving mechanism and a sewing machine. Background Art

[0002] As Figures 1-4 shown, in an existing overlock sewing machine, the bent needle mechanism includes a lower rear shaft 100 and a lower front shaft 600 fixedly connected to the lower rear shaft 100. Both are rotatably arranged in the machine housing. An eccentric ball 170 is arranged on the lower rear shaft 100. The upper end of a ball connecting rod 110 is hinged to the eccentric ball 170, and the lower end is hinged to the spherical part of a ball crank 120. A bent needle driving shaft 130 is rotatably installed in the machine housing. The ball crank 120 is fixedly installed on the bent needle driving shaft 130. A bent needle crank 140 is fixed on the bent needle driving shaft 130 and forms a fixed angle with the ball crank 120. As the lower rear shaft 100 rotates, the bent needle crank 140 swings around the bent needle driving shaft 130. A front slider sleeve 700 and a rear sleeve 800 are fixedly installed on the machine housing. A bent needle slider 300 is arranged through the front slider sleeve 700 and the rear sleeve 800, and can rotate and move back and forth. A front stop block 160 and a rear stop block 150 are both fixedly connected to the bent needle slider 3. The upper end of the bent needle crank 140 is installed between the front stop block 160 and the rear stop block 150 and abuts against the front stop block 160 and the rear stop block 150 respectively. The swing of the bent needle crank 140 is transmitted through the front stop block 160 and the rear stop block 150 to drive the bent needle slider 300 to move back and forth. A bent needle 500 is fixed to the end of the bent needle slider by a bent needle holder 400. The back-and-forth movement of the bent needle slider 300 can drive the back-and-forth movement of the bent needle 500.

[0003] An eccentric sleeve 200 is fixedly installed on the lower rear shaft 100. One end of a connecting rod 210 is hinged to the eccentric sleeve 200, and the other end is hinged to a driving pin 220. The driving pin 220 is fixedly connected to a slider frame 230. Both ends of the slider frame 230 are rotatably installed on the front slider sleeve 700 and the rear sleeve 800. The rotation of the lower rear shaft 100 can drive the slider frame 230 to swing around the front slider sleeve 700 and the rear sleeve 800. A small slider 240 is fixed to the front stop block 160 and can slide in the slot of the slider frame 230 at the same time. The swing of the slider frame 230 is transmitted through the small slider 240 to drive the front stop block 160 fixed to the bent needle slider 300 to swing, and further drive the bent needle slider 300 to swing, finally realizing the swing of the bent needle 500.

[0004] The back-and-forth movement and swing of the bent needle 500 are combined into a quasi-elliptical trajectory on the top view projection of the bent needle tip, as Figure 5 shown.

[0005] In practical applications, it is found that the above-mentioned bent needle mechanism has the following disadvantages:

[0006] 1. The swing and the forward and backward movement of the bent needle 500 are respectively driven by two eccentric components on the lower rear shaft, and the complex movement of the bent needle trajectory is realized by two sets of transmission structures. The transmission structure is complex, with a large number of parts and complex assembly.

[0007] 2. The eccentric ball 170 with high-precision requirements on the lower rear shaft will limit the overall machining process of the lower shaft, forcing the lower shaft to be set in a split-joint shaft form to ensure the machining accuracy of the eccentric ball 170. This results in a concentricity difference between the lower rear shaft and the lower front shaft, making it difficult to ensure the assembly torque of the whole machine. Summary of the Invention

[0008] In view of the above defects, the purpose of the present invention is to provide a bent needle driving mechanism with a simple transmission structure and easy to machine and assemble, so as to solve the problems existing in the prior art.

[0009] The present invention provides a bent needle driving mechanism, including:

[0010] A rotary driving member;

[0011] A bent needle driving crank, in an L shape, with a fixing hole opened at its first end for connecting to the output end of the rotary driving member, and a connecting section provided at its second end. There is a first included angle between the axis of the fixing hole and the axis of the connecting section.

[0012] A spherical link, with a mounting hole opened at its first end for rotatably connecting to the connecting section, and a spherical surface groove opened at its second end.

[0013] A spherical crank, with a sphere provided at its first end for mating with the spherical surface groove, and the sphere is ball-jointed with the spherical surface groove.

[0014] A bent needle slide rod, with a bent needle provided at its end. The second end of the spherical crank is fixedly connected to the bent needle slide rod; the extending direction of the bent needle slide rod has a second included angle with the axis of the fixing hole.

[0015] Preferably, the first included angle is an acute angle.

[0016] Preferably, the second included angle is 90°.

[0017] Preferably, it further includes a slide rod sleeve fixed in the machine shell of the sewing machine, and the bent needle slide rod is movably inserted into the slide rod sleeve.

[0018] Preferably, the bent needle is fixed to the end of the bent needle slide rod through a bent needle holder.

[0019] Preferably, the rotary driving member is connected to a control system.

[0020] The present invention also provides a sewing machine, including the aforementioned bent needle driving mechanism.

[0021] The bent needle driving mechanism provided by the present invention is a spatial four-bar mechanism. Driven by a rotary driving member, the forward and backward movement and left and right swing of the bent needle are realized. Compared with the prior art, the present invention can achieve the composite movement of the bent needle through a set of transmission structures, and the structure is simpler. At the same time, when using the bent needle driving mechanism of the present invention, there is no need to set an eccentric ball and an eccentric sleeve on the lower shaft. The lower shaft is simplified from a split structure to an integral structure, making the processing and assembly of the lower shaft simpler and the accuracy control more accurate. In addition, the rotary driving member can independently drive the composite movement of the bent needle, which helps to digitally control the relevant parameters of the bent needle driving mechanism (such as the timing of cooperation with the main shaft and the lower shaft), and is more adaptable to the digital development trend. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the existing bent needle mechanism;

[0023] Figure 2 is a schematic connection structure diagram of the bent needle slide bar and the eccentric ball;

[0024] Figure 3 is a schematic connection structure diagram of the lower rear shaft and the lower front shaft;

[0025] Figure 4 is a schematic connection structure diagram of the bent needle slide bar and the eccentric sleeve;

[0026] Figure 5 is a schematic diagram of the movement track of the bent needle;

[0027] Figure 6 is a schematic diagram of the bent needle driving mechanism of the present invention in the machine housing;

[0028] Figure 7 is a schematic structural diagram of the bent needle driving mechanism of the invention;

[0029] Figure 8 is a schematic structural diagram of the bent needle driving crank;

[0030] Figure 9 is a schematic structural diagram of the ball connecting rod;

[0031] Figure 10 is a schematic structural diagram of the ball crank.

[0032] Description of Component Labels:

[0033] 1 Rotary driving member

[0034] 2 Bent needle driving crank

[0035] 21 Fixed hole

[0036] 211 Axis of the fixed hole

[0037] 22 Connecting section

[0038] Axis of the 221 connecting section

[0039] 3 Ball connecting rod

[0040] 31 Mounting hole

[0041] 32 Spherical surface groove

[0042] 4 Ball crank

[0043] 41 Sphere

[0044] 42 Mounting part

[0045] 5 Bent needle slide bar

[0046] 6 Bent needle holder

[0047] 7 Bent needle

[0048] 8 Slide bar sleeve [[ID=३३]]

[0049] 9 Housing

[0050] 100 Lower rear axle

[0051] 110 Ball connecting rod

[0052] 120 Ball crank

[0053] 130 Bent needle drive shaft

[0054] 140 Bent needle crank

[0055] 150 Rear stop

[0056] 160 Front stop

[0057] 200 Eccentric sleeve

[0058] 210 Connecting rod

[0059] 220 Drive pin

[0060] 230 Slide bar holder

[0061] 240 Small slider

[0062] 300 Bent needle slide bar

[0063] 400 Bent needle holder

[0064] 500 Bent needle

[0065] 600 Lower front axle

[0066] 700 Slide bar front sleeve

[0067] 800 Rear sleeve Specific implementation mode

[0068] The following further describes in detail the specific embodiments of the present invention with reference to the accompanying drawings. These embodiments are only used to illustrate the present invention and are not intended to limit the present invention.

[0069] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0070] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] Figure 6 is a schematic diagram of the bent needle driving mechanism of the present invention in the casing. In the following description, the accompanying drawings in Figure 6 are used as the reference basis for directions. In Figure 6 , the length direction of the casing 9 is the front-rear direction, and the width direction of the casing 9 is the left-right direction.

[0072] As shown in Figure 6 and Figure 7 , a bent needle driving mechanism provided by the present invention includes a rotation driving member 1, a bent needle driving crank 2, a ball link 3, a ball crank 4, and a bent needle slide rod 5 that are connected in sequence.

[0073] As shown in Figure 7 and Figure 8 , the bent needle driving crank 2 is L-shaped. A fixing hole 21 connected to the output end of the rotation driving member 1 is opened at its first end, and a connecting section 22 in the shape of a cylinder is provided at its second end. There is a first included angle between the fixing hole axis 211 of the fixing hole 21 and the connecting section axis 221 of the connecting section 22, and the first included angle is preferably an acute angle.

[0074] As shown in Figures 7-10As shown in the figure, the first end of the spherical link 3 is provided with a mounting hole 31 for rotatably connecting with the connecting section 22, and the second end thereof is provided with a spherical surface groove 32. The first end of the spherical crank 4 is provided with a sphere 41 that cooperates with the spherical surface groove 32. The sphere 41 is embedded in the spherical surface groove 32 and is spherically hinged with the spherical surface groove 32.

[0075] As Figures 6-10 shown in the figure, a slide rod sleeve 8 is also fixedly connected in the sewing machine housing 9. The curved needle slide rod 5 is movably inserted through the slide rod sleeve 8 and can move in the front-back direction or swing left and right in the slide rod sleeve 8. The end of the curved needle slide rod 5 is fixedly connected to the curved needle 7 through the curved needle holder 6. The second end of the spherical crank 4 is provided with a mounting portion 42, and the mounting portion 42 is fixedly connected to the curved needle slide rod 5. There is a second included angle between the extending direction of the curved needle slide rod 5 and the axis of the fixing hole 211. Preferably, the second included angle is 90°.

[0076] Combined with Figure 6 and Figure 7 it can be seen that the rotary drive member 1 is fixed in the sewing machine housing 9. When the rotary drive member 1 operates, its output end drives the curved needle drive crank 2 to rotate. The curved needle drive crank 2 drives the spherical crank 4 fixed on the curved needle slide rod 5 through the spherical link 3, so that the curved needle slide rod 5 makes a combined movement including left-right swing and front-back movement, realizing the elliptical-like trajectory movement of the curved needle 7 in the top view projection direction. Those skilled in the art can select appropriate values of the first included angle and the second included angle according to needs to ensure that the movement trajectory of the curved needle 7 meets the sewing requirements. The rotary drive member 1 can be a motor, a cylinder or a hydraulic cylinder, preferably a stepping motor. By connecting the stepping motor to the control system, the digital control of the curved needle drive mechanism is realized, thus laying a foundation for realizing the flexible adjustment of the curved needle thread hooking timing.

[0077] The present invention also provides a sewing machine, including the aforementioned curved needle drive mechanism.

[0078] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and replacements can be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A bent needle driving mechanism, characterized in that, Comprising: A rotary drive member; A bent needle drive crank, in an L shape, having a fixing hole at its first end connected to the output end of the rotary drive member, and a connecting section at its second end, with a first included angle between the axis of the fixing hole and the axis of the connecting section; A ball link, having a mounting hole at its first end rotatably connected to the connecting section and a spherical surface groove at its second end; A ball crank, having a sphere at its first end that mates with the spherical surface groove, and the sphere is ball-jointed with the spherical surface groove; A bent needle slide rod, having a bent needle at its end, and the second end of the ball crank is fixedly connected to the bent needle slide rod; there is a second included angle between the extending direction of the bent needle slide rod and the axis of the fixing hole.

2. The bent needle driving mechanism according to claim 1, wherein The first included angle is an acute angle.

3. The bent needle driving mechanism according to claim 1, wherein The second included angle is 90°.

4. The curved needle driving mechanism according to claim 1, wherein It further includes a slide rod sleeve fixed in the housing of the sewing machine, and the bent needle slide rod is movably inserted into the slide rod sleeve.

5. The bent needle driving mechanism according to claim 1, wherein The bent needle is fixed to the end of the bent needle slide rod through a bent needle holder.

6. The bent needle driving mechanism according to claim 1, characterized in that The rotary drive member is connected to a control system.

7. A sewing machine, characterized in that, Comprising a bent needle drive mechanism according to any one of claims 1-6.

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