CN1321235C - Sewing machine needle oscillating apparatus - Google Patents

Abstract

A needle swinging device for a sewing machine, which has a needle bar support table 20 supporting a needle bar 14 that moves up and down, and a needle swing motor 4 that rotates intermittently in any direction forward or reverse and can control the rotation angle, and one end is fixed on On the needle bar support table, the needle swing drive shaft 24 that can be moved in a direction perpendicular to the cloth feeding direction, and the connecting member 22 connected to the other end of the needle swing motor and the needle swing drive shaft, 26, 30, and the pressurizing mechanism 42, 48, 50, 52 that applies radial pressure to the swing drive shaft of the machine needle. The device can prevent the offside operation of the needle swing device due to the stepping motor's imbalance.

Description

Needle swinging device for sewing machine

technical field

The invention relates to a sewing machine, in particular to a needle swinging device in the sewing machine which makes the machine needle reciprocate and swing in a direction perpendicular to the cloth feeding direction to perform zigzag sewing.

Background technique

Conventionally, as a needle swinging device for a sewing machine, a device described in Japanese Patent Application Publication No. 61-8843 is known. In this needle swing device, as shown in Figure 6, the needle swing table 2 supports the needle bar 14 which is linked with the main shaft 12 and can slide in the up and down direction, and at the same time it can swing in the direction perpendicular to the cloth feeding direction. The upper end is supported on a fulcrum 16 .

Its base end is fixed on the action link 6 on the output shaft 4a of the stepping motor 4, and its other end is protrudingly provided with the action pin 6a. On the rocking lever 8 rotatably supported in the frame by the support shaft 17, a long hole 8a for engaging the operating pin 6a of the operating link 6 is formed along the length direction thereof. The interlocking body 10 is rotatably connected to the middle part of the needle swing table 2 and the rocking lever 8 respectively via the support shafts 10a, 10b.

The machine needle oscillating device biases the stepper motor 4 to an arbitrary phase angle for each needle, so that the needle bar 14 supported on the machine needle oscillating table 2 is in the direction perpendicular to the cloth feeding direction through the rocking rod 8 and the interlocking body 10 . Up swing, various stitches can be sewn by the machine needle 18 fixed on the lower end of the needle bar 14 .

Usually, in an industrial sewing machine, sewing is performed at a number of thousands of stitches per minute during high-speed operation, so the stepping motor 4 is also controlled at a rotational speed of several thousand revolutions per minute. In addition to the control of such high-speed rotation, since the parts driven by the stepping motor 4 (needle swing table 2, rocking lever 8, interlocking body 10, etc.) It is very difficult to stop at the prescribed swing position of the machine needle. That is, overrunning occurs due to fluctuations in the rotational output of the stepping motor 4 and inertia of components, and the needle stops at a predetermined needle swing position. Or, due to the variation of the rocking load with the parts, it will cause overrunning and stop beyond the prescribed needle swing position.

If the machine needle 18 cannot stop at the prescribed position in this way, the pattern of the desired sewing stitch cannot be formed, and the quality of the sewn product is significantly reduced.

Contents of the invention

Therefore, the object of the present invention is to provide a needle oscillating device capable of preventing off-side operation of the needle oscillating device due to stepping motor imbalance.

According to the needle oscillating device of the sewing machine provided by the present invention, there is a needle bar supporting platform supporting the needle bar moving up and down, and a needle oscillating drive shaft fixed on the needle bar supporting platform at one end, and is connected with the needle through a connecting mechanism. The other end of the rod support table is connected to and controls the needle swing motor of the needle rod support table to move in a direction perpendicular to the cloth feeding direction. The drive shaft is associated with the device to give the needle oscillating drive shaft sliding resistance. The sliding resistance relative to the horizontal movement of the needle oscillating drive shaft is given by the pressing mechanism.

The pressurizing mechanism preferably has a cylindrical or semi-cylindrical pressurizing member that encloses the needle swing drive shaft.

Moreover, the pressurizing mechanism has two bushings fixed on the sewing machine frame, supporting the needle swing drive shaft so as to be movable in the axial direction, and a clamping member arranged between the two bushings. Pressed parts are ideal.

Furthermore, it is desirable that the pressing mechanism further has an elastic body that urges the pressing member.

Furthermore, it is desirable to have a screw that is in contact with the elastic body, and it is desirable that the force of the elastic body can be adjusted by the screw.

It is desirable to form a radial gap between the pressing member and the sewing machine frame.

Preferably, the pressurizing member has an oil supply hole extending from its outer diameter to its inner diameter. Moreover, a hole through which the elastic body and the screw pass is formed on the sewing machine frame, and through this hole and the oil supply hole, lubricating oil can be injected into the sliding movement between the pressing member and the needle swing drive shaft. Ideal on the surface.

Preferably, the surface of the sliding portion between the needle swing drive shaft and the pressing member is made of metal or ceramics.

Furthermore, it is desirable to form unevenness on the end surface of the pressing member.

Description of drawings

Hereinafter, a brief description will be given of the drawings and their reference numerals.

Fig. 1 is an overall view of the needle oscillating device of the present embodiment.

Fig. 2 is a cross-sectional view of the supporting structure of the needle oscillating drive shaft in this embodiment.

Fig. 3 is a sectional view of III-III in Fig. 2 .

Fig. 4 is a sectional view of a bearing and a pressurizing member of this embodiment.

Fig. 5 is a perspective view of the pressing member of the present embodiment.

Fig. 6 is a perspective view of a conventional needle swinging device.

Among the figure: 4—stepper motor, 4a—output shaft, 14—needle bar, 20—needle bar support platform, 22—needle swing connecting rod, 24—machine needle swing drive shaft, 26—machine needle swing drive rod, 28,32—pin, 30—arch seat part, 34—sewing machine frame, 40,44—shaft bushing, 42—collar (pressurized part), 48—spring (elastomer), 50,52—screw.

Detailed ways

Example

Embodiments of the needle swinging device of the sewing machine according to the present invention will be described with reference to FIGS. 1 to 5 . The machine needle swing device has a needle bar support table 20, a stepping motor 4, a machine needle swing connecting rod 22, and a machine needle swing drive shaft 24. Needle bar 14, its lower end is equipped with machine needle 18, moves up and down with upper shaft (sewing machine main shaft) 12 linkages. The needle bar supporting table 20 supports the needle bar 14 which can move up and down. The output shaft 4a of the stepping motor 4 can rotate intermittently in any direction of its positive and negative directions.

On the output shaft 4a of stepper motor 4, machine needle swing drive lever 26 is fixed, on machine needle swing drive lever 26, is connected with an end of rotatable machine needle swing link 22 by pin 28. Machine needle swing drive shaft 24 passes through abutment part 30, and one end is connected with the other end of machine needle swing connecting rod 22 by pin 32, and simultaneously, its other end is fixed on the needle bar supporting platform 20. The needle swing drive shaft 24 is slidably supported in the axial direction by first and second bearings 36, 38 installed on the lower part of the sewing machine frame 34 head. Above-mentioned machine needle swing link 22, abutment part 30, pin 28, 32 constitute connection mechanism.

When the output shaft 4a of the stepping motor 4 rotates, the needle swing drive shaft 24 reciprocates through the needle swing drive rod 26 and the needle swing link 22 . When the reciprocating motion of the needle swing drive shaft 24 makes the needle bar 14 reciprocate in the left and right direction (arrow direction in Fig. 1), zigzag stitches are sewed in cooperation with the cloth feeding motion in the vertical direction.

Among the first and second bearings 36, 38, the first bearing 36 disposed at the front is fixed to the sewing machine frame 34 with a bushing. The second bearing 38 is composed of two bushes 40 and 44 and a collar (pressurizing member) 42 provided between the two bushes. The two bushings 40, 44 have the same shape. As shown in FIG. Therefore, the bushings 40, 44 are pressed into the through holes 34a to be fixed to the sewing machine frame 34. As shown in FIG.

In addition, the outer diameter 42a of the collar 42 in the center is slightly smaller than the inner diameter of the through hole 34a. Further, a slight gap is formed in the axial direction between the collar 42 and the two bushes 40 and 44 . Therefore, the collar 42 has a gap in the radial direction with respect to the through hole 34a, and at the same time has a gap in the axial direction with respect to the bushings 40, 44 on both sides.

As shown in FIG. 3 , in the sewing machine frame 34 , a screw hole 46 is formed at a position facing the side surface of the collar (pressurizing member) 42 . The spring 48 inserted into the screw hole 46 is compressed by the screws 50 and 52 to apply a radially inward force to the collar 42 . Due to this force, the collar 42 presses the needle swing drive shaft 24 , so that sliding resistance occurs between the needle swing drive shaft 24 and the collar 42 . Due to the use of the spring 48, the above-mentioned sliding resistance can be kept substantially constant for a long time. The magnitude of this sliding resistance can be adjusted by the screws 50 , 52 . Also, to prevent loosening, it is better to use 2 screws than only 1.

Grooves 40b, 42b, and 44b are formed in inner diameter portions of the collar 42 and the two bushes 40, 44, respectively. Furthermore, a small hole 42c communicating with the groove 42b from the outer diameter is formed in the collar 42 . As shown in Figure 4, in the space formed between the bushings 40, 44, the collar 42 and the sewing machine frame 34, lubricating oil such as grease is injected from the screw hole 46 of the sewing machine frame 34, and the lubricating oil can be injected through the small hole 42c. The sliding surfaces between the collar 42 and the needle oscillating drive shaft 24 and the sliding surfaces between the bushings 40 , 44 and the needle oscillating drive shaft 24 are supplied. In the second bearing 38, in addition to sliding as a normal bearing, the collar 42 is biased by the coil spring 48, and thus constitutes an ideal structure capable of supplying oil.

In this embodiment, the outer diameter 42a of the above-mentioned collar (pressurizing member) 42 is made small so as to form a radial gap with the inner diameter of the through hole 34a of the sewing machine frame 34. Axial gaps are formed with the collar 42, so lubricating oil can be held in these gaps. Moreover, as shown in FIG. 5, the end surface 42d of the collar 42 is formed in a concave-convex shape. Lubricating oil can be held more easily by this concave and convex shape. In this embodiment, the lubricating oil provided in the second bearing 38 has a large holding force. Therefore, it is possible to prevent scorching and wear which are caused by applying a sliding force to the needle swing drive shaft 24 by the collar 42, and also to reduce the number of times of oil supply.

The collar 42 and the pivoting drive shaft 24 of the needle are made of metal, ceramics or a material whose sliding surface has been coated with a ceramic film. For example, the collar 42 is made of a metal material, and the needle swing drive shaft 24 is made of a metal material and only its sliding surface is coated with a ceramic thin film.

The gap along the axial direction of the central collar 42, that is, the gap between the bushings 40 and 44 on both sides is set at 0.01 to 0.5mm, which can effectively prevent the stepping motor 4 from being out of adjustment. offside. Furthermore, it is possible to prevent the rattling sound between the collar 42 and the bushings 40, 44.

Although the embodiment of the present invention has been described with reference to the drawings, it is not limited to this embodiment, and various modifications are possible. For example, as the structure of the pressurizing member, an example of a cylindrical collar enclosing the needle swing drive shaft 24 was shown, but a semi-cylindrical collar that cuts the cylindrical member in half in the axial direction may also be used. . In addition to such a cylindrical shape or a semi-cylindrical shape, various structures can be adopted as a pressurizing mechanism for applying radial pressure to the needle swing drive shaft 24 . But, when using cylindrical or semi-cylindrical collar 42 to wrap machine needle swing drive shaft 24, if push down with spring 48, just can obtain the ideal surface contact that contacts with machine needle swing drive shaft 24. In this way, the contact area is enlarged, and the gap amount generated by partial wear can be eliminated while preventing partial wear.

Moreover, since the material of the pressurizing member of the present invention has a bearing function, although enamel bronze is used, if the material of the pressurizing member is changed to a spring material, the spring 48 of this embodiment can be easily considered to be omitted. Furthermore, it can be easily considered that the use of the seal ring for the pressurizing member can give sliding friction to the needle swing drive shaft.

In addition, although the example in which the bearing 38 on the rear side of the sewing machine has the collar 42 among the first and second bearings 36 and 38 is shown, the collar 42 may be provided on the first bearing 36 on the front side. , the second bearing 38 is only used as a bushing.

In addition, although an example of the coil spring 48 used as an elastic body biasing the collar 42 inward in the axial direction was shown, a leaf spring may also be used. Although an example in which force is applied to the collar 42 in the horizontal direction from the front is shown, force may be applied in the horizontal direction from the top to the bottom, from the bottom to the top, or from the back side.

According to the needle oscillating device of the sewing machine of the present invention, since a pressurizing mechanism for radially applying pressure to the needle oscillating drive shaft is provided, a sliding resistance relative to the horizontal movement of the needle oscillating drive shaft is caused, making the needle It is easy to stop at the specified needle swing position. Therefore, it is possible to prevent overrunning of the needle oscillating device due to an out-of-adjustment of the stepping motor.

When the pressing mechanism has a cylindrical or semi-cylindrical pressing member enclosing the needle swing drive shaft, the contact area with the needle swing drive shaft is increased, so wear and clearance are less likely to occur.

If the pressing mechanism has an elastic body for biasing the pressing member in the radial direction, it is possible to maintain a substantially constant pressure for a long period of time.

If it has a screw that abuts against the elastic body, and the pressure can be adjusted by the screw, the pressure can be easily adjusted according to the sewing result.

If the pressing mechanism has a structure that is fixed on the sewing machine frame and supports two bushings that can move along the axial direction of the swinging drive shaft of the machine needle, and a pressing member arranged between the two bushings, when pressing When a radial gap is formed between the pressing part and the sewing machine frame, the pressing part is movable to pressurize the swinging drive shaft of the machine needle, and at the same time, lubricating oil can be kept in the gap.

When a gap is formed between the two bushes of the pressurizing part, the bushes move independently to pressurize the needle swing drive shaft. And lubricating oil can be held in this gap.

When the pressurizing member has a structure with an oil supply hole leading from the outer diameter to the inner diameter, since oil can be supplied from the outer diameter side to the inner diameter side (sliding part with the needle swing drive shaft), seizing and wear can be prevented point of view is valid.

In addition, the threading hole for the elastic body and the screw is formed on the sewing machine frame, and the lubricating oil can be injected into the sliding surface of the pressing member and the needle swing drive shaft through the hole and the oil supply hole, so that simple oil supply can be carried out. And it is effective from the viewpoint of preventing seizing and wear.

Since the surface of the sliding part of the needle swing drive shaft and the pressing member is formed of metal or ceramics, abrasion can be reduced.

When the concave-convex shape is formed on the end surface of the pressurizing member, since the surface area of the end surface is increased, the holding force of the lubricating oil is further improved.

Claims (11)

1. A machine needle swinging device for a sewing machine, which has a needle bar supporting platform that supports the needle bar that moves up and down, and a machine needle swing drive shaft that is fixed at one end on the needle bar supporting platform, and is supported by a connecting mechanism with the needle bar The other end of the table is connected to and controls the needle bar support table to move along the direction perpendicular to the cloth feeding direction. Associated settings are used to provide sliding resistance to the oscillating drive shaft of the machine needle. 2. The needle oscillating device for a sewing machine according to claim 1, wherein said pressurizing mechanism has a cylindrical or semi-cylindrical pressing member enclosing the needle oscillating drive shaft. 3. The needle oscillating device of a sewing machine according to claim 2, wherein said pressurizing mechanism has two bushings which are fixed on the sewing machine frame and support said machine needle oscillating drive shaft to move in the axial direction , and a pressurized part arranged between the two bushings. 4. The needle swinging device of a sewing machine according to claim 3, wherein said pressing mechanism has an elastic body that biases said pressing member. 5. The sewing machine needle oscillating device according to claim 4, characterized in that it has a screw abutted with the elastic body, and the pressure of the elastic body can be adjusted by the screw. 6. The needle swinging device of a sewing machine according to claim 3, wherein a radial gap is formed between said pressing member and said sewing machine frame. 7. The needle oscillating device of a sewing machine according to claim 3, wherein an axial gap is formed between the pressing member and the two bushes. 8. The needle oscillating device of a sewing machine according to claim 3, wherein said pressurizing member has an oil supply hole extending from an outer diameter thereof to an inner diameter thereof. 9. The sewing machine needle swinging device according to claim 8, characterized in that, a hole penetrating the elastic body and the screw is formed on the sewing machine frame, through which the hole and the oil supply hole can be supplied to Lubricating oil is injected into the sliding surface of the pressing member and the needle swing drive shaft. 10. The needle oscillating device for a sewing machine according to claim 3, wherein the surface of the sliding portion between the needle oscillating drive shaft and the pressing member is made of metal or ceramics. 11. The needle oscillating device of a sewing machine according to claim 3, wherein a concavo-convex shape is formed on an end surface of said pressing member.

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