JP4450947B2 - Sewing machine needle swing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a needle swing device in a sewing machine that performs so-called zigzag sewing while alternately swinging a needle in a direction orthogonal to a cloth feeding direction.
[0002]
[Prior art]
As a sewing machine needle swinging device, the one shown in FIG. 6 is conventionally known (see Japanese Utility Model Publication No. 61-8843). This needle swing device includes a needle bar swing base 2, a stepping motor 4, an operating body 6, a swing body 8, and an interlocking body 10. The needle bar swinging table 2 supports a needle bar 14 that moves up and down in conjunction with the main shaft 12 so that the needle bar 14 can slide in the vertical direction, and the support shaft 16 can swing in a direction perpendicular to the cloth feeding direction. It is supported by.
[0003]
The needle bar 14 has a needle 18 attached to the lower end thereof. The stepping motor 4 has its output shaft 4 a directed in the cloth feeding direction of the needle bar rocking base 2. One end of the operating body 6 is fixed to the output shaft 4 a of the stepping motor 4, and the operating shaft 6 a protrudes from the other end. One end of the oscillating body 8 is rotatably supported by a support shaft 17 of the machine frame that faces in the cloth feeding direction, and the other end has a long hole 8a that can be rotated by engaging the operating shaft 6a of the operating body 6. Formed on the side. The interlocking body 10 is rotatably connected to intermediate portions of the needle bar swing base 2 and the swing body 8 by connecting pins 10a and 10b, respectively.
[0004]
This needle swinging device swings the stepping motor 4 at an arbitrary phase angle for each stitch, thereby moving the needle bar swinging table 2 in a direction orthogonal to the cloth feeding direction via the swinging member 8 and the interlocking member 10. It can be swung to form various seams.
[0005]
[Problems to be solved by the invention]
In this way, the needle swinging device swings the needle 18 in a direction perpendicular to the cloth feeding direction for each stitch. However, when operating at a high speed, sewing is performed with several thousand stitches per minute. 4 also performs rotation control several thousand times per minute. In addition to the high-speed rotation control, the weight of the members (needle bar rocking base 2, rocking body 8, interlocking body 10, etc.) moved by the stepping motor 4 is large. It may be difficult to stop at the required needle swing position. In other words, an overrun caused by fluctuations in the rotational output of the stepping motor 4 or the inertial force of the member may occur, and may stop beyond the required needle position. Alternatively, an overrun may occur due to a load variation accompanying the vibration of the member, and stop beyond a required needle position.
[0006]
Thus, if the needle | hook 18 cannot be stopped in a required position, a required seam will not be formed. If the overrun is large, a large load is applied to the needle 18 and the needle may be broken.
[0007]
Accordingly, an object of the present invention is to provide a needle swinging device that can prevent an overrun of the needle swinging device due to a stepping motor stepping out.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1
A needle bar support that supports the needle bar so as to be movable up and down;
A needle bar support base shaft having one end fixed to the needle bar support base;
Two bearing metals fixed to a sewing machine frame and supporting the needle bar support base shaft movably in the axial direction;
A needle swing motor that controls movement of the needle bar support in a direction orthogonal to the cloth feeding direction;
Pressing force applying means for applying sliding resistance to the needle support base shaft,
The pressing force applying means is
A cylindrical pressing member disposed between the two bearing metals and surrounding the needle bar support base shaft;
It is formed in a cylindrical shape surrounding the needle bar support base shaft, and its outer diameter is smaller than the through hole of the sewing machine frame to be mounted, and its axial length is between the two bearing metals. A screw hole formed in the sewing machine frame at a position corresponding to the pressing member defined to form a predetermined amount of gap in the axial direction ;
An elastic body that is inserted into the screw hole and applies an urging force radially inward to the pressing member;
A screw attached to the screw hole and having one end abutting against the elastic member;
The urging force of the elastic body is adjusted by the screw to adjust the sliding resistance between the needle bar support base shaft and the pressing member.
In addition to the invention described in claim 1, the invention described in claim 2
The pressing member includes an oil supply hole leading from the outer diameter to the inner diameter portion, and constitutes the grease can be injected into the sliding surface between the pressing member and the needle bar support platform shaft through the oil supply hole and the threaded hole did.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a needle swinging device for a sewing machine according to the present invention will be described with reference to FIGS. This needle swing device includes a needle bar support base 20, a stepping motor 4, a needle swing link 22, and a needle bar support base shaft 24. The needle bar 14 has a needle 18 attached to the lower end thereof and moves up and down in conjunction with the upper shaft (sewing machine main shaft) 12. The needle bar support 20 supports the needle bar 14 so that it can move up and down. The stepping motor 4 can rotate its output shaft 4a intermittently in either forward or reverse direction.
[0014]
A needle swing drive arm 26 (connecting member) is fixed to the output shaft 4 a of the stepping motor 4, and one end of the needle swing link 22 (connecting member) is rotated to the needle swing drive arm 26 via a needle swing link pin 28. Connected as possible. One end of the needle bar support base shaft 24 is connected to the other end of the needle swing link 22 by a needle swing link pin 32 via a needle bar support base shaft holder 30, and the other end is fixed to the needle bar support base 20. ing. The needle bar support base shaft 24 is supported by first and second needle bar support base bearings 36 and 38 attached to the lower part of the arm portion of the sewing machine frame 34 so as to be slidable in the axial direction. Yes.
[0015]
When the output shaft 4 a of the stepping motor 4 rotates, the needle bar support base shaft 24 reciprocates via the needle swing driving arm 26 and the needle swing link 22. Zigzag sewing is performed by a combination of the reciprocating motion of the needle bar 14 in the left-right direction (in the direction of the arrow in FIG. 1) due to the reciprocating motion of the needle bar support base shaft 24 and the cloth feed orthogonal thereto.
[0016]
Of the first and second needle bar support base bearings 36 and 38, the first needle bar support base bearing 36 disposed forward is a bearing metal and is fixed to the sewing machine frame 34. The second needle bar support base bearing 38 is composed of two bearing metals 40 and 44 and one collar (pressing member) 42 disposed between the two bearing metals. The two bearing metals 40 and 44 have the same shape, and the outer diameter 44a is slightly larger than the inner diameter of the through hole 34a formed in the sewing machine frame 34, as shown in FIG. Accordingly, the bearing metals 40 and 44 are press-fitted into the through holes 34 a and fixed to the sewing machine frame 34.
[0017]
On the other hand, the outer diameter 42a of the central pressing member 42 is slightly smaller than the inner diameter of the through hole 34a. Further, the pressing member 42 and the two bearing metals 40 and 44 are arranged so that a slight gap is formed in the axial direction. Accordingly, the pressing member 42 is given play in the radial direction with respect to the through hole 34a, and is also given play in the axial direction with respect to the bearing metals 40 and 44 on both sides.
[0018]
As shown in FIG. 3, screw holes 46 are formed in the sewing machine frame 34 at positions corresponding to the pressing members 42. A spring 48 is inserted into the screw hole 46 to apply a biasing force inward in the radial direction to the pressing member 42. Due to this urging force, the pressing member 42 is pressed against the needle bar support base shaft 24, so that a sliding resistance is generated between the needle bar support base shaft 24 and the pressing member 42. Since the spring 48 is used, the above-mentioned sliding resistance maintains a substantially constant value over a long period of time. The magnitude of this sliding resistance can be adjusted by screws 50 and 52. The two screws 50 and 52 are used to prevent loosening, but only one screw may be used.
[0019]
Both the pressing member 42 and the two bearing metals 40 and 44 are formed with grooves 40b, 42b and 44b in the inner diameter portion. The pressing member 42 has a small hole 42c communicating with the groove 42b from the outer diameter portion. By injecting lubricating oil such as grease from the screw hole 46 of the sewing machine frame 34, the sliding surface of the pressing member 42 and the needle bar support base shaft 24 and the bearing metals 40 and 44 and the needle bar support base shaft through the small hole 42c. Oil can be supplied to the sliding surface with 24. In the second needle bar support base bearing 38, a biasing force is applied to the pressing member 42 by the coil spring 48 in addition to sliding as a normal bearing.
[0020]
In the present embodiment, as described above, the outer diameter 42 a of the pressing member 42 is reduced to form a gap in the radial direction between the inner diameter of the through hole 34 a of the sewing machine frame 34 and the two bearing metals 40. , 44 and the pressing member 42 are formed with a gap in the axial direction, so that the lubricating oil can be held in these gaps. Further, the end surface 42d of the pressing member 42 is formed with irregularities as shown in FIG. This unevenness makes it easier to hold the lubricating oil. Thus, in the present embodiment, the holding force of the lubricating oil in the second needle bar support base bearing 38 is increased. Therefore, seizure and wear associated with applying a sliding force to the needle bar support base shaft 24 using the pressing member 42 can be prevented and the number of times of oil supply can be reduced.
[0021]
The pressing member 42 and the needle bar support base shaft 24 are made of a metal, a ceramic material, or a material whose sliding surface is coated with a ceramic thin film. For example, the pressing member 42 is made of a metal material, and the needle bar support base shaft 24 is made of a metal material, but only the sliding surface thereof is coated with a ceramic thin film.
[0022]
If the play in the axial direction of the central pressing member 42, that is, the gap between the bearing metals 40 and 44 on both sides is set to 0.01 to 0.5 mm in particular, the overrun due to the stepping motor 4 stepping out can be effectively performed. Can be prevented. Further, it is possible to prevent a collision sound between the pressing member 42 and the bearing metals 40 and 44.
[0023]
Although the present invention has been described based on the embodiment shown in the drawings, the present invention is not limited to this embodiment and can be variously modified. For example, an example of a cylindrical collar surrounding the needle bar support base shaft 24 has been shown as the structure of the pressing member 42, but a pressing member that is cut in half in the axial direction to form a semi-cylindrical member is used. be able to. In addition to the cylindrical or semi-cylindrical shape as described above, various structures can be employed as the pressing force applying means for applying the pressing force in the radial direction to the needle bar support base shaft 24. However, when the needle bar support base shaft 24 is surrounded by the cylindrical or semi-cylindrical pressing member 42, the contact with the needle bar support base shaft 24 is an ideal surface contact when pressed by the spring 48. Get closer. By widening the contact area in this way, it is preferable because uneven wear can be prevented and play associated with uneven wear can be eliminated.
Further, in the present invention, since the material of the pressing member has a bearing function, linseed copper is used. However, if the material of the pressing member is a spring material instead of this, the spring 48 of the present embodiment may be omitted. Easy to think. It is also conceivable to apply sliding friction to the needle bar support base shaft by using an oil seal as the pressing member.
[0024]
Moreover, although the 2nd needle bar support stand bearing 38 of the back side of a sewing machine showed the example provided with the press member 42 among 1st and 2nd needle bar support stand bearings 38, 38, the 1st of the front side was shown. The needle bar support pedestal bearing 36 may include a pressing member 42, and the second needle bar support pedestal bearing 38 may be a single bearing metal bearing.
[0025]
Furthermore, although the example using the coil spring 48 as an elastic body that urges the pressing member 42 radially inward has been shown, a plate spring or the like can also be used. Although an example in which the pressing member 42 is urged in the horizontal direction from the front side has been shown, it can be urged in the horizontal direction from the back side from the upper side to the lower side or from the lower side to the upper side.
[0026]
【The invention's effect】
According to the present invention, since the pressing force applying means for applying a pressing force in the radial direction to the needle bar support base shaft is provided, it becomes a sliding resistance against the horizontal movement of the needle bar support base shaft, and at the required needle swing position. It becomes easy to stop. Therefore, the overrun of the needle swinging device due to the stepping motor stepping out can be prevented.
[0027]
When the pressing force applying means is configured to include a cylindrical or semi-cylindrical pressing member that surrounds the needle bar support base shaft, the contact area with the needle bar support base shaft is widened. It becomes difficult to occur.
[0028]
If the pressing force applying means includes an elastic body that urges the pressing member in the radial direction, the pressing force applying means can hold a substantially constant pressing force over a long period of time.
[0029]
If the screw that contacts the elastic body is provided and the pressing force can be adjusted by the screw, the pressing force can be easily adjusted according to the sewing result.
[0030]
The pressing force applying means is configured to include two bearing metals fixed to the sewing machine frame and supporting the needle bar support base shaft so as to be movable in the axial direction, and a pressing member disposed between the two bearing metals. When a gap is formed in the radial direction between the pressing member and the sewing machine frame, the pressing member can move, the needle bar support base shaft can be pressed, and lubricating oil can be held in the gap. Become.
[0031]
When a gap is formed between the two bearing metals, the pressing member can move independently of the bearing metal and can press the needle bar support base shaft. Further, the lubricating oil can be held in this gap.
[0032]
When the pressing member is configured to have an oil supply hole that leads from the outer diameter portion to the inner diameter portion, it is possible to supply oil from the outer diameter portion side to the inner diameter portion side (sliding portion with the needle bar support base shaft). It is effective from the viewpoint of image sticking and wear prevention.
[0033]
Then, a hole through which the elastic body and screw are inserted is formed in the sewing machine frame, and the lubricating oil can be injected into the sliding surface between the pressing member and the needle bar support base shaft through this hole and the oil supply hole, thereby simplifying the operation. This is effective from the viewpoint of preventing seizure and wear.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an entire needle swing device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a support structure of a needle bar support base shaft according to the present embodiment.
3 is a cross-sectional view taken along the line III-III in FIG.
FIG. 4 is a cross-sectional view of a needle bar support base bearing and a pressing member according to the present embodiment.
FIG. 5 is a perspective view showing a pressing member of the present embodiment.
FIG. 6 is a perspective view of a conventional needle swing device.
[Explanation of symbols]
4 ... Stepping motor 14 ... Needle bar 20 ... Needle bar support base 24 ... Needle bar support base shaft 34 ... Machine frame 40, 44 ... Bearing metal 42 ... Colour (press) Element)
48 springs ... (elastic body) 50, 52 ... screws

Claims (2)

A needle bar support that supports the needle bar so as to be movable up and down;
A needle bar support base shaft having one end fixed to the needle bar support base;
Two bearing metals fixed to a sewing machine frame and supporting the needle bar support base shaft movably in the axial direction;
A needle swing motor that controls movement of the needle bar support in a direction orthogonal to the cloth feeding direction;
Pressing force applying means for applying sliding resistance to the needle support base shaft,
The pressing force applying means is
It is formed in a cylindrical shape surrounding the needle bar support base shaft, and its outer diameter is smaller than the through hole of the sewing machine frame to be mounted, and its axial length is between the two bearing metals. A pressing member defined so as to form a predetermined amount of gap in the axial direction ;
A screw hole formed in the sewing machine frame at a position corresponding to the pressing member;
An elastic body that is inserted into the screw hole and applies an urging force radially inward to the pressing member;
A screw attached to the screw hole and having one end abutting against the elastic member;
A needle swinging device for a sewing machine, wherein a sliding resistance between the needle bar support base shaft and the pressing member is adjusted by adjusting an urging force of the elastic body with the screw.   The pressing member has an oil supply hole that communicates from an outer diameter portion to an inner diameter portion, and grease can be injected into the sliding surface between the pressing member and the needle bar support base shaft through the screw hole and the oil supply hole. The sewing machine needle swinging apparatus according to claim 1, wherein

Images