JPH0426434A - Eyelet hole overlock sewing machine - Google Patents

Abstract

PURPOSE:To form an elaborate sewing pattern by turning a looper base by a minute angle each by constituting this sewing machine so that a first sector gear is made large, and also, a driving gear is made small, etc., without enlarging the diameter of a follower gear provided on the looper base. CONSTITUTION:Two first and second sector gears 70a, 70b are constituted integrally. Rotating force from a step motor 61 is transmitted to a motion shaft 63 through a driving gear 62, an idle gear 69 and a first sector gear 70a in order, and also, transmitted to the driven gear 71 of a looper base 17 from the second sector gear 70b. By setting the first sector gear 70a to a comparatively large diameter, a radius ratio (R2/R1) can be made large. Thus, even if a ratio (R4/R3) is not set large by setting the driven gear 71 provided on the base 17 to a large diameter, the rotational comparison of the whole gear train can be made small. In such a manner, even if the step motor 61 of the same resolution as conventional one is used, the looper base 17 can be turned at a minuter angle, and the overlock sewing of an elaborate sewing pattern can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Field of Application) The present invention relates to an eyelet sewing machine with an improved structure for integrally rotating a needle bar and a looper base.

(Prior Art) The basic configuration of an eyelet sewing machine is as follows. The needle bar is moved up and down by a needle bar vertical drive mechanism provided on the arm of the sewing machine frame, and in conjunction with this, a looper is operated by a looper drive mechanism provided in the bed, and a stitch is formed by the cooperation of the two. In addition, in order to swing the needle drop point from side to side for each stitch, a needle swinging mechanism is provided on the arm. It is driven to feed.

By the way, in order to overstitch a buttonhole etc. in which a round hole-shaped cut and a linear cut are made in succession, the stitching pattern of the sewing thread S should be set in the upper half of the round hole part A as shown in Fig. 12. It becomes radial in the part. Therefore, when sewing the upper half of the round hole part A, it is necessary to integrally rotate the looper base provided with the looper and the needle bar by half a rotation in conjunction with the vertical movement and needle swing movement of the needle bar.

As a configuration for this purpose, conventionally, for example,
There is one described in Japanese Patent No.-54033, which is shown in FIG. In the same figure, drive motor 1
is provided on the bed portion of the sewing machine frame, and its rotational force is transmitted to the interlocking shaft 3 via the timing belt 2. The interlocking shaft 3 is provided so as to cross between the bed part and the arm part provided with the needle bar mechanism, and the part located inside the bed part is connected to the driven gear 5 provided on the looper base 4.
A fan-shaped gear 6 is provided which meshes with the . Further, a fan-shaped gear 8 that meshes with a needle bar driven gear 7 provided in the needle bar mechanism of the arm is provided near the upper end of the interlocking shaft 3, and the interlocking shaft 3 is driven by the drive motor 1. Then, the needle bar 9 and the looper base 4 are rotated integrally via each fan-shaped gear 6.8.

(Problems to be Solved by the Invention) In this type of sewing machine, in order to form a precise sewing pattern, the looper base 4 and needle bar 9 need to be rotated by small angles. For this reason, conventional configurations have been adopted in which a step motor or the like is used as the drive motor 1 to drive one step at a time. Since the rotation ratio becomes large in , even if the drive motor 1 is slightly rotated, the rotation angle of the looper base 4 tends to become large.

To deal with this, it is conceivable to increase the diameter of the driven gear 5 of the looper base 4 and reduce the diameter of the fan-shaped gear 6 accordingly, but in reality,
Since many components of the looper drive mechanism are arranged in the space below, it is difficult to increase the diameter of the driven gear 5 due to space problems. It is also possible to increase the rotation ratio of the pulleys 2a and 2b that drive the timing belt 2, but in that case, the timing belt 2
There is also a certain limit to this, as the possibility of slippage occurring increases. For this reason, with conventional sewing machines of this type, it was not possible to sufficiently reduce the rotation angle of the looper base, and there was a limit to the ability to perform overlock stitches with precise sewing patterns.

The present invention has been made in view of the above circumstances, and its object is to provide an eyelet sewing machine in which the rotation angle of the looper base can be made sufficiently small.

[Structure of the Invention] (Means for Solving the Problems) The eyelet sewing machine of the present invention includes a needle bar that is provided with a sewing needle at the lower end and is movable up and down on an arm, and a needle bar that is movable up and down. A needle bar vertical drive mechanism is used to move the needle bar, a feed table is provided on the upper surface of the bed section and the work cloth is set therein, and the feed table is moved along the cut shape of the eyelet hole formed in the work cloth. a louver provided on the bed section that cooperates with the sewing needle to form stitches on the workpiece cloth, and a drive provided on the bed section that is driven during the stitching period of the round hole section of the eyelet. morph, a gear mechanism for the looper base that transmits the rotation of the drive motor to the looper base provided with the looper and rotates the looper base during the overlocking period of the round hole portion of the eyelet, a bed portion, and an arm. an interlocking shaft that is installed in the arm section and transmits the rotational force in the gear mechanism for the looper base to the arm section; a needle bar gear mechanism that rotates in conjunction with the needle bar gear mechanism; the looper base gear mechanism is connected to a drive gear provided on the output shaft of the drive motor; fan-shaped gear and the first gear on the interlocking shaft.
The feature is that it consists of a second sector gear that is provided integrally with the sector gear and has a different diameter from the second sector gear, and a driven gear that is provided on the looper base and receives the rotational force from the second sector gear. It is something that you have.

(Operation) The rotational force from the drive motor is transmitted to the interlocking shaft via the drive gear and the first sector gear, and further transmitted from the first sector gear to the driven gear. Therefore, without increasing the diameter of the driven gear provided on the looper base, the rotation ratio can be reduced on the first sector gear and drive gear sides by, for example, making the first sector gear large and the drive gear small. This allows the looper base to be rotated by minute angles. Moreover, since the first and second fan-shaped gears are integrated, the number of parts is reduced and the structure is simplified.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 10.

(1) Overall structure First, the overall structure of this sewing machine will be briefly described based on FIG. The sewing machine frame 11 is configured by integrally having a bed part 12 having a substantially rectangular box shape and an arm part 13 extending forward from the rear upper part of the bed part 12, and a sewing machine motor 88 (shown only in FIG. 10) to be described later. The sewing machine table 14 is placed on a sewing machine table 14. A needle bar 16 to which a sewing needle 15 is attached is provided at the front end of the arm section 13 so as to be movable up and down, and the bed section 12 has two loopers (not shown) positioned directly below the needle bar 16. A looper base 17 is provided. These loopers operate in synchronization with the vertical movement of the needle bar 16 to form stitches on the work cloth in cooperation with the sewing needle 15.

Further, a cutter device 20 is provided in the bed portion 12 and is located on the back side of the looper base 17 and includes a lower knife 18 and a hammer 19 that approaches and separates from the lower knife 18 from above. It is possible to form an eyelet-like cut in which a round hole part and a straight part are connected in the processed cloth.

A feed stand 21 on which the work cloth is set is provided on the upper surface of the bed section 12, and a pair of cloth pressers (not shown) for holding the set work cloth on both sides of the notch are provided on the feed stand. 21. The feed table 21 has a thin rectangular box shape as a whole, and is driven by a feed device (not shown) equipped with two pulse motors 89 and 90 (shown only in FIG. 10) for the X direction and the Y direction.
It is moved to a required position in the X direction (left-right direction) and Y direction (front-back direction), which are orthogonal to each other. The movement pattern of the feed table 21 is set by a control device to be described later to follow the cut shape of the eyelet hole formed in the workpiece cloth, so that the workpiece presser presses the fixed workpiece cloth directly below the sewing needle 15. By moving the sewing machine to the required position, overlock stitches can be sequentially applied to the edges of the eyelet-shaped cuts formed in the work cloth.

(2) Peripheral structure of the needle bar 15 First, a large diameter through hole 13a is formed on the lower surface of the tip of the arm portion 13 to allow the needle bar 15 to pass through it vertically. It is fitted so that it can rotate. As shown in FIG. 6, this needle bar rotation bracket 23 includes a cylindrical portion 23a located within the through hole 3a, a gear portion 23b located on the lower surface of the cylindrical portion 23a,
This gear part 23b integrally has a pair of leg parts 23c protruding downward at symmetrical positions on the lower surface of the gear part 23b, and each leg part 23C
A storage hole 24 extending laterally is formed in the housing. A needle bar guide member 25 is housed in the cylindrical portion 23a of the needle bar rotation bracket 23 so as to be movable up and down.
is provided so as to be movable up and down relative to the arm portion 13.

As shown in FIG. 6, the needle bar guide member 25 integrally includes a vertically elongated cylindrical portion 25a and a rectangular parallelepiped-shaped slide block portion 25b integrally provided at the lower end of the cylindrical portion 25a. It consists of In its assembly, the cylindrical part 25a passes through the cylindrical part 23a of the needle bar rotation bracket 23, and the slide block part 25b is sandwiched between the pair of legs 23c of the needle bar rotation bracket 23. It's located like that. Two oblique grooves 26 extending diagonally in the same direction are formed on two surfaces of the slide block portion 25b that contact the leg portions 23C, and on the other hand, the storage holes 26 of the leg portions 23C A guide bin 27 is housed movably in the axial direction, and a needle oscillating projection 28 that engages with the diagonal groove 26 is integrally provided at the tip of the guide bin 27. Each guide bin 27 has a compression spring 30 provided between it and the presser plate 29.
As a result, the needle oscillating protrusion 28 is constantly urged toward the slide block portion 25b, so that the oscillating protrusion 28 is slidably engaged with the oblique groove 26. Therefore, when the needle bar guide member 25 moves up and down, the slide block portion 2 having the diagonal groove 26
Since the needle bar guide member 5b also moves up and down integrally, the needle bar guide member 25 swings from side to side while being guided by the needle swing protrusion 28 of the guide bin 27 which is fixedly provided on the arm portion 13 side. become. 20. A connecting collar 33 is rotatably fitted to the upper end of the cylindrical portion 25a of the needle bar guide member 25, and is sandwiched between a washer 31 and a fixed collar 32. protrudes from left to right.

The driving source for the needle bar guide member 25 described above is a needle swing motor 34 provided separately from the sewing machine motor 78. This needle swing pulse motor 34 is fixed to the left side surface of the tip of the arm portion 13, and a drive shaft 35 is attached to its output shaft. The drive shaft 35 is rotatably provided through the left and right side walls of the arm portion 13, and a pair of connecting arms 36 that are slightly slidable in the front and rear directions are provided at a portion located inside the arm portion 13. is mounted facing forward. The distal end of the connecting arm 36 is connected to the connecting collar 3 fitted to the needle bar guide member 25.
The needle bar guide member 25 is rotatably fitted into the connecting pin 33a of No. 3, so that the needle bar guide member 25 can be driven up and down in accordance with the rotation of the drive shaft 35. In order to detect the origin position of the drive shaft 35, a slit 37a is provided at the tip of the drive shaft 35 that protrudes from the right side of the arm portion 13.
A rotating disk 37 having a rotational speed is fixed to the arm 13, and a magnetic detection type needle swing sensor 3 facing the rotating disk 37 is fixed to the arm portion 13.
8 is fixed.

The needle bar 16 is inserted into the needle bar guide member 25 such that it can move up and down and is prevented from rotating. That is, the slide block portion 2 of the needle bar guide member 25 of the needle bar 16
Above and below the portion penetrating through 5b, flat surface portions 16a are formed at symmetrical positions on the circumferential surface, and the slide block portions 25b
A presser member 40 is housed in a pair of holes 39 formed in each of the holes 39, and is fixed with a screw 41 to prevent removal (see FIG. 8). Due to the relationship between the flat surface portion 16a and the presser member 40, the needle bar 16 is prevented from rotating.

Further, a needle bar holder 43 having a connecting pin 42 protruding from the upper end of the needle bar 16 is rotatably fitted onto the needle bar 16 with its axial movement being prevented by a pair of upper and lower collars 44. ing. On the other hand, a sewing machine main shaft 45 that is rotationally driven by a sewing machine motor 78 is provided inside the arm portion 13, and a circular cam body 46 having two types of cam grooves formed on both end faces is attached thereto. A needle bar drive lever 47 extending in the front-rear direction is pivotally supported by a shaft 47a within the arm portion 13, and a cam follower 48 is provided at the rear end thereof to engage with a cam groove for driving the needle bar of the cam body 46. It is being Further, a connecting arm 49 that can be slid forward and backward is fitted to the front end of the needle bar drive lever 47, and the tip of the connecting arm 49 connects to the connecting pin 4 of the needle bar holder 43.
is engaged in. As a result, when the main shaft 45 of the sewing machine rotates, the cam body 46 also rotates, and the needle bar drive lever 47 swings in the direction of arrow A in FIG. will be driven up and down. Therefore, these structures correspond to the needle bar vertical drive mechanism 50 for driving the needle bar 16 up and down.

(3) Interlocking mechanism between the needle bar 16 and the looper base 17 Now, when sewing the round hole part of the eyelet, not only does the feed base 21 move, but the needle bar 16 and the looper base 17 are moved together little by little. As it rotates, the sewing thread draws a radial pattern. Next, this interlocking mechanism will be explained with reference also to FIGS. 1 and 2.

The drive source of this mechanism is a pulse motor 61, which corresponds to a drive motor provided inside the bed section 12.

This pulse motor 61 is fixed to the sewing machine frame 11 with the output shaft facing downward, and a drive gear 62 is fixed to the output shaft.

On the other hand, an interlocking shaft 63 is attached to the sewing machine frame 11 at the bed portion 1.
2 and the arm part 13, and is rotatably supported by bearings 64 and 65, and a needle bar gear mechanism 66 for rotating the needle bar 16 is configured on the upper part thereof, A looper base gear mechanism 67 for rotating the looper base 17 is provided at the lower part. Of these, the needle bar gear mechanism 66 is composed of the gear portion 23b of the needle bar rotation bracket 23 and the needle bar sector gear 68 that is attached to the interlocking shaft 63 and meshes with the gear portion 23b. Rotation of the shaft 63 is transmitted to the needle bar 16 via the needle bar rotation bracket 23. The looper base gear mechanism 67 also includes a drive gear 62 attached to the pulse motor 61 and an idle gear 69 meshing with the drive gear 62.
, a fan-shaped gear 70 attached to the interlocking shaft 63, and a driven gear 71 provided on the looper base 17. The sector gear 70 has first and second gears having different radial dimensions.
The first sector gear 70a located on the pulse motor 61 side is connected to the pulse motor 6 via the idle gear 69.
It meshes with the drive gear 62 of No. 1. Further, the second fan-shaped gear 70b located on the side of the looper base 17 is connected to the looper base 17.
It meshes directly with the driven gear 71 provided in the. Furthermore, on the back side of the bed section 12, as shown in FIG.
Two stoppers 72 and 73 are attached to the sides of the rotor to restrict its two-way rotation limit position.

(4) Structure for controlling each mechanism In order to control each of the mechanisms described above, a control device having a structure centered on a CPU 81 is provided under the sewing machine table 14, as shown in FIG.

The CPU 81 is connected to the ROM 82 and the RAM B 5 via a bus, and also includes a start/stop switch 84, a spindle rotation speed sensor 85, a needle bar position sensor 86, and a needle vibration resensor 38.
In response to a signal from a stitch width setting switch 87 provided on an operation panel (not shown), a sewing machine motor 88 and two pulse motors 89.9 for the X direction and Y direction of the feed device are activated.
0, the aforementioned pulse motor 61, hammer drive mechanism 91
In addition, the needle swing pulse motor 34 is controlled via a driver circuit (not shown).

Here, when the desired stitch width is set with the stitch width setting switch 87 and the start/stop switch 84 is turned on, the sewing machine motor 88 is started based on a signal from the CPU 81, and the sewing machine main shaft 45 is rotated. . As a result, the cam body 46 provided on the main shaft 45 of the sewing machine rotates, and as described above, the movement is transmitted and the needle bar 16 is driven up and down, and the looper is synchronized with the up and down movement of the needle bar 16. It works. Further, as the sewing machine main shaft 45 rotates, a detection signal is provided from the needle bar position sensor 86 to the CPU 81 when the needle bar 16 reaches a specific phase, such as the top dead center position. Then, when a predetermined period of time has elapsed since the needle bar 16 reached the top dead center position, the CPU 81 updates the RAM.
A numerical value corresponding to the set width of needle swing stored in 83 is read out, and a number of pulses corresponding to the read value are outputted to the needle swing pulse motor 34 to rotate it, for example, in the forward direction. As a result, the needle bar guide member 25 moves upward, for example, as described above, so that the needle bar guide member 25 and eventually the needle bar 16 move to the fifth position.
It swings to the left in the figure, and the sewing needle 15 falls to the left of the center. Next, when the needle bar 16 rises again after passing through the bottom dead center and reaches the top dead center position, the needle bar position sensor 86 again indicates
A detection signal is given to PU81. Then, this time, C
After a predetermined period of time has elapsed since the needle bar 16 reached the top dead center position, the PU 81 reads the numerical value stored in the RAM 33 and outputs a number of pulses corresponding to the numerical value to the needle swing pulse motor 34. Now reverse this. As a result, the needle bar guide member 25 moves downward, so the needle bar guide member 25 and, in turn, the needle bar 16 swing to the right in FIG. 5, and the sewing needle 15 falls to the right from the center. . Hereinafter, in the same manner as described above, after a predetermined period of time has elapsed since the needle bar 16 reached the top dead center position, the pulse motor 34 for swinging the needle is alternately rotated in the normal direction.
By repeating the reverse rotation, the needle bar guide member 25
is reciprocated up and down, swings left and right, and eventually the sewing needle 15 falls alternately on a stitch-by-stitch basis at two points separated left and right by the needle swing width set by the swing width setting switch 87.

Furthermore, while this overlocking operation is being performed, the feeder 21 is fed by the feeder in accordance with the shape of the cut in the eyelet hole, and as a result, the needle drop point of the sewing needle 15 is relatively aligned with the eyelet hole. It moves from the straight line part Bl (see FIG. 12) on the outbound side, passes through the round hole part A, and traces the straight line part B2 on the return side. In this case, when sewing the upper half of the round hole portion A shown in the figure, the CPU 81 drives the step motor 61 step by step to sew a total of 180 degrees at minute angles.
The rotation of the step motor 61 rotates the interlocking shaft 63 via the idle gear 69 and the second sector gear 70b, so the needle bar rotation bracket 23 rotates via the needle bar gear mechanism 66. As a result, the needle bar guide member 35 and the needle bar 16 gradually rotate.Furthermore, based on the rotation of the interlocking shaft 63, the rotational force is applied to the second fan-shaped gear 70b and the driven gear 7.
1 to the looper base 17, which gradually rotates in synchronization with the needle bar 16. As a result, the stitching pattern of the sewing thread becomes radial in the upper half of the round hole portion of the eyelet as shown in FIG. When the entire eyelet has been sewn in this way, the thread trimming operation is performed, and then the feed bar 2
At the same time, the needle bar 16 and the looper base 17 are reversed by 1000 degrees and returned to their original states.

According to the above embodiment, the following effects are achieved.

The rotational force from the step motor 61 is transmitted to the interlocking shaft 63 via the drive gear 62, the idle gear 69, and the first sector gear 70a in order, and then from the second sector gear 70b to the driven gear 71 of the looper base 17. communicated. In this configuration, the drive gear 62 and the driven gear 7 of the looper base 17
The element that determines the rotation ratio with respect to 1 is the first sector gear 70a.
The ratio of the radius R2 of the drive gear 62 to the radius R1 of the drive gear 62 (R2/R
1) and the radius R4 of the driven gear 71 and the second sector gear 7
0b to the radius R3 (R4/R3), and the larger these values, the smaller the rotation angle of the looper base 17 for each step of the step motor 61 (for example, approximately 1.8' rotation). Thus, a precise sewing pattern can be formed in the round hole portion A. In this regard, in the above embodiment, the drive gear 6
2 and the first sector-shaped gear 70a are located at a distance from the looper base 17, and by making use of the fact that there is ample space, the first sector-shaped gear 70a is set to have a relatively large diameter. The radius ratio (R2/R1) can be increased. As a result, the rotation ratio of the entire gear train from the drive gear 62 to the driven gear 71 can be reduced without increasing the diameter of the driven gear 71 provided on the looper base 17 and setting the ratio (R4/R3) large. can. This means that even if the step motor 6 with the same resolution as the conventional one is used, the looper base 17 can be rotated at a smaller angle, making it possible to overlock and mend with a precise sewing pattern. do. Furthermore, since the first and second sector gears 70a and 70b are integrally formed, the eleventh
Compared to the conventional structure shown in the figure, the number of parts can be reduced and manufacturing costs can be reduced. However, in particular, according to this embodiment in which the stoppers 72 and 73 are provided on the sides of the fan-shaped gear 70, it is possible to easily match the rotational phases of the needle bar 16 and the looper upper stand 17. It becomes like this.

In the above embodiment, the needle swing pulse motor 34 is provided as a drive source separate from the sewing machine motor 88 for the needle swing mechanism that swings the needle bar 16 from side to side.
The present invention is not limited to this, and as in the past, the sewing machine main shaft 45
The rotational force is transferred to the needle bar guide member 2 using a cam and a link mechanism.
It is also possible to convert the movement into the vertical movement of 5 and transmit it. Also,
Idle gear 69 provided in gear mechanism 67 for looper base
may be omitted; conversely, the second sector gear 7 may be omitted if necessary.
An idle gear may be provided between 0b and the driven gear 71. In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications within the scope of the invention.

[Effects of the Invention] As described above, the present invention makes it possible to sufficiently reduce the rotation angle of the looper base, making precise overlocking possible, and furthermore, reducing the number of parts and reducing manufacturing costs. It has excellent effects.

[Brief explanation of the drawing]

1 to 10 show an embodiment of the present invention, and a first embodiment of the present invention is shown in FIG.
The figure is a bottom view of the bed section showing the main parts, FIG. 2 is a side view of the bed section schematically showing the sewing machine frame and showing its internal structure, FIG. 3 is a left side view of the arm section, and FIG. 4 is a side view of the bed section showing the internal structure of the sewing machine frame. 5 is a front view of the same, FIG. 6 is an exploded perspective view showing the needle bar support structure, and FIG. 7 is a plan view of the arm section schematically showing the sewing machine frame and showing the internal structure. Figure 8 is a sectional view taken along the line ■-■ in Figure 4, Figure 9 is a side view of the whole, and
FIG. 0 is a block diagram of the control device. This is number 11. In the drawing, 11 is a sewing machine frame, 12 is a bed section, and 13 is a sewing machine frame.
15 is a sewing needle, 16 is a needle bar, 17 is a looper base, 21 is a feed base, 50 is a needle bar vertical movement mechanism, 61 is a drive motor, 63 is an interlocking shaft, 66 is a gear mechanism for the needle bar, 67
is a gear mechanism for the looper base, 70a is a first fan-shaped gear,
70b is a second fan-shaped gear, and 1 is a driven gear.

Claims (1)

[Scope of Claims] 1. A needle bar provided with a sewing needle at the lower end and movable up and down on an arm; a needle bar vertical drive mechanism for moving the needle bar up and down; and an upper surface of the bed. a feed table provided on the bed portion and onto which the work cloth is set; a feed device configured to feed the feed table along the cut shape of an eyelet formed in the work cloth; and a feed device provided on the bed portion and configured to feed the sewing needle. a looper for forming a seam on the work cloth in cooperation with the work cloth; a drive motor provided in the bed portion and driven during the overlocking period of the round hole portion of the eyelet; and a drive motor that controls the rotation of the drive motor. a gear mechanism for the looper base for transmitting information to the looper base provided with the looper and rotating the looper base during oversewing of the round hole portion of the eyelet; and a gear mechanism for the looper base extending between the bed portion and the arm portion. an interlocking shaft that is provided in the arm section and transmits rotational force in the gear mechanism for the looper base to the arm section; and a needle bar gear mechanism that rotates in conjunction with the needle bar gear mechanism, and the looper base gear mechanism includes a drive gear provided on the output shaft of the drive motor and a rotational force from the drive gear provided on the interlocking shaft. a first sector gear that receives the first sector gear; a second sector gear that is provided on the interlocking shaft integrally with the first sector gear and has a different diameter; and a second sector gear that is provided on the looper base and is provided with the second sector gear. An eyelet sewing machine characterized by comprising a driven gear that receives rotational force from a fan-shaped gear.