JP2762698B2 - Eyelet overhole sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an eyelet sewing machine with an improved structure for swinging a needle bar right and left for overlock sewing.

(Prior art) Generally, a sewing machine moves up and down a needle bar provided on an arm portion based on rotation of a main shaft, and operates a looper provided on a bed portion in synchronization with needle bar movement. A stitch is formed by the needle thread and the looper thread each time the sewing needle attached to the needle bar is pierced into the cloth. For this reason,
A needle bar drive cam and a looper drive cam are provided on the sewing machine spindle, and a cam follower is moved with the rotation of each cam,
The movement of these cam followers is transmitted to a needle bar drive mechanism and a looper drive mechanism via an interlocking lever and a link mechanism. In particular, in a sewing machine that performs overlock stitching, it is necessary to swing the needle bar left and right in synchronization with the vertical movement of the needle bar so that the sewing needle alternately falls at different points. For this reason, in this type of sewing machine, a needle swing mechanism for swinging the needle bar to the left and right is provided in addition to the needle bar vertical drive mechanism and the looper drive mechanism.

Conventionally, this needle swing mechanism is configured as follows. That is, the needle bar guide member is vertically movably supported by the arm portion of the sewing machine frame, and the needle bar guide member is formed with an oblique groove extending obliquely, and the oblique groove is formed in the arm portion of the sewing machine frame. A needle swing projection slidably engaged with the groove is fixedly projected. A needle bar is inserted through the needle bar guide member so as to be vertically movable. On the other hand, a needle swing cam is provided on the sewing machine main shaft in addition to the needle bar drive cam and the looper drive cam. The movement of the cam follower, which is displaced in accordance with the rotation, is transmitted to the needle bar guide member via the drive lever and the link mechanism as the vertical movement thereof. With this configuration, the needle swing cam rotates with the rotation of the sewing machine main shaft, and the needle bar guide member reciprocates up and down via the drive lever and the link mechanism. Then, the vertical movement of the needle bar guide member is converted into a left-right swinging motion by the engagement between the oblique groove and the needle swing projection, and eventually the needle bar inserted therethrough is swung left and right. become.

(Problems to be Solved by the Invention) However, in the above configuration, the rotation of the main shaft of the sewing machine is
Since the needle swing guide, the cam follower, the drive lever, and the link mechanism are transmitted to the needle bar guide member in this order, the structure is complicated, the number of parts is increased, and there is a disadvantage that cost disadvantage is large. . Moreover, in order to be able to adjust the swing width, a swing range adjustment structure must be incorporated into the link mechanism, which further complicates the structure,
There is a problem that the adjustment is troublesome.

The present invention has been made in view of the above circumstances. Accordingly, it is an object of the present invention to provide an eyelet hole drilling machine which can simplify the structure for swinging the needle bar and can easily adjust the swing width.

[Structure of the Invention] (Means for Solving the Problems) The eyelet buttonhole sewing machine of the present invention includes a needle bar guide member provided on an arm portion so as to be vertically movable, and a needle bar guide provided at a lower end portion thereof. A needle bar inserted vertically through the member, a needle bar vertical drive mechanism for moving the needle bar up and down, an oblique groove provided on the needle bar guide member side, and the oblique groove provided on the arm portion side. A needle swing projection provided to be slidably engaged with the groove and swinging the needle bar guide member left and right based on the vertical movement of the needle bar guide member, and a work cloth provided on the upper surface of the bed portion is set. A feeder, a cutter device for forming an eyelet-shaped cut in the work cloth set on the feeder, a feeder for feeding the feeder along the cut shape of the eyelet, and an eyelet Needle bar and looper provided on the bed at the time of overlocking the round hole A rotation mechanism for rotating the base in association with the base, a needle swing driving body provided separately from a drive source of the needle bar vertical drive mechanism as a drive source for vertically moving the needle bar guide member, and a needle bar The needle bar position sensor detects the position of the needle bar in the up-down direction, and the control means controls the needle swing driving body based on the detection signal from the needle bar position sensor.

(Operation) When the drive source of the needle bar up / down drive mechanism is activated, the needle bar up / down drive mechanism drives the needle bar up / down. Further, when the needle swing driving body provided separately from the drive source of the needle bar vertical drive mechanism is activated, the needle bar guide member is driven up and down. An inclined groove is provided on the needle bar guide member side,
Since a needle swinging protrusion engaging with the oblique groove is provided on the arm portion side, a left and right swinging motion is added to the vertical movement of the needle bar guide member. As a result, the needle bar inserted through the needle bar guide member swings right and left, and the sewing needles alternately fall to different points. Further, since the feed table on which the work cloth is set is fed to the work cloth along the eyelet-shaped cut shape formed by the cutter device, overcasting is performed along the opening edge of the cut. Furthermore, at the time of the overlocking of the round hole of the eyelet, the needle bar and the looper base provided on the bed are rotated in conjunction with each other by the rotating mechanism. Start to draw a radial pattern.

With the above configuration, the needle swing driving body is provided as a drive source separate from the drive source of the needle bar vertical drive mechanism, and the needle bar guide member is driven by this. Therefore, a cam mechanism and a link mechanism are unnecessary. And the structure becomes simple. Further, in the present invention, the needle bar position sensor for detecting the position of the needle bar in the vertical direction is provided, and the control means for controlling the needle swing driving body based on the detection signal from the needle bar position sensor is provided. The vertical movement of the needle bar and the swinging movement of the needle bar can be easily synchronized to enable appropriate needle movement, and the needle swing drive unit is driven separately from the drive source of the needle bar vertical drive mechanism. Since it is a source, it is easy to change the amount of needle movement.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

(1) Overall Structure First, the overall structure of the sewing machine will be briefly described with reference to FIG. The sewing machine frame 11 is constituted by integrally forming a bed part 12 having a substantially rectangular box shape with an arm part 13 extending forward from an upper part in the back, and a sewing machine motor 78 (to be described later only in FIG. 9). Is mounted on the sewing machine table 14 on which the is mounted. A needle bar 16 on which a sewing needle 15 is attached is provided at the forward end of the arm portion 13 so as to be movable up and down. The bed portion 12 has two loopers (not shown) located immediately below the needle bar 16. A provided looper base 17 is provided. These loopers operate in synchronization with the vertical movement of the needle bar 16 to form a seam in the work cloth in cooperation with the sewing needle 15. Further, the bed unit 12 is provided with a cutter device 20 including a lower knife 18 located on the back side of the looper base 17 and a hammer 19 which comes into contact with and separates the lower knife 18 from above. An eyelet-shaped notch in which a round hole and a straight line are continuous can be formed in the work cloth.

A feed base 21 on which a work cloth is set is provided on the upper surface of the bed portion 12, and a pair of cloth holders (not shown) for holding the set work cloth on both sides of the cuts are provided on the feed base. 21 is provided. Slide 21
Has a thin rectangular box shape as a whole, for X direction and Y
Movement to a required position in the X direction (left and right direction) and the Y direction (front and back direction) orthogonal to each other by a feeder (not shown) provided with two pulse motors 78 and 79 (shown only in FIG. 9) for directions. Is done. The movement pattern of this feed bar 21 is
It is set so as to follow the cut shape of the eyelet formed in the work cloth by the control device described later, thereby moving the work cloth pressed and fixed by the cloth presser 22 to a required position immediately below the sewing needle 15, 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 for vertically penetrating the needle bar 15 is formed in the lower surface of the distal end of the arm portion 13, and the needle bar rotation bracket 23 is held in this state in a state where it cannot be removed. It is rotatably fitted. As shown in FIG. 4, the needle bar rotating bracket 23 includes a cylindrical portion 23a located in the through hole 13a and a cylindrical portion 23a.
A gear portion 23b located on the lower surface of a, and a pair of leg portions 23c projecting downward at symmetrical positions on the lower surface of the gear portion 23b are integrally formed, and each leg portion 23c extends in the lateral direction. Storage hole 24
Are formed. Cylindrical part of this needle bar rotation bracket 23
The needle bar guide member 25 is housed in the needle bar 23a so as to be vertically movable, and the needle bar guide member 25 is provided so as to be vertically movable with respect to the arm unit 13.

As shown in FIG. 4, the needle bar guide member 25 integrally has a vertically long tubular portion 25a and a rectangular parallelepiped slide block portion 25b integrally provided at the lower end of the tubular portion 25a. Consisting of In the assembled state, the cylindrical portion 25a penetrates through the cylindrical portion 23a of the needle bar rotating bracket 23, and the slide block portion 2
5b is positioned so as to be sandwiched between a pair of legs 23c of the needle bar rotation bracket 23. And slide block part 25
Two oblique grooves 26 extending obliquely in the same direction are respectively formed on two surfaces of each of the legs 23c that are in contact with the respective leg portions 23c. On the other hand, guide pins 27 are formed in the storage holes 24 of the respective leg portions 23c. Are accommodated so as to be movable in the axial direction, and a needle swing projection 28 that engages with the oblique groove 26 is integrally provided at the tip of the guide pin 27. Each guide pin 27 is a compression spring provided between the
30 is constantly urged toward the slide block portion 25b side, whereby the needle swing projection 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 25b having the oblique groove 26 also moves up and down integrally, so that the guide pins 27 which are fixedly provided on the arm portion 13 side are provided. The needle bar guide member 25 swings right and left. At the upper end of the cylindrical portion 25a of the needle bar guide member 25, a connecting collar 33 is fixed between the washer 31 and the fixed collar 32, and the connecting pin 33a projects from the connecting collar 33 in the left-right direction. I have.

The drive source of the needle bar guide member 25 is a needle swing pulse motor 34 corresponding to a needle swing driver provided separately from the sewing machine motor 78. The needle swing pulse motor 34 is fixed to the left side of the distal end of the arm 13, and a drive shaft 35 is attached to the output shaft 34a. The drive shaft 35 is rotatably provided through the left and right side wall portions of the arm portion 13, and a pair of connecting arms 36 slidable in the front-rear direction is provided at a portion located inside the arm portion 13. Is mounted facing forward. The distal end of the connection arm 36 is rotatably fitted to the connection pin 33a of the connection collar 33 fixed to the needle bar guide member 25, and the needle bar guide member 25 is moved in accordance with the rotation of the drive shaft 35. It can be driven up and down.

The needle bar 16 is inserted into the needle bar guide member 25 such that the needle bar 16 can move up and down and is prevented from rotating. That is, the needle bar
Above and below the portion of the needle bar guide member 25 that passes through the slide block portion 25b, the flat surface portion 16a
A pressing member 38 is housed in each of a pair of holes 37 formed in the slide block portion 25b and is fixed by screws 39 (see FIG. 6). Due to such a relationship between the flat surface portion 16a and the pressing member 38, the needle bar 16 is in a detent state.

Further, a needle bar holder 41 having a connecting pin 40 protruding from the upper end portion of the needle bar 16 is fixed to the needle bar 16 by a pair of upper and lower collars 42. On the other hand, a sewing machine main shaft 43 rotatably driven by a sewing machine motor 78 is provided inside the arm portion 13, and a circular cam body 44 having two types of cam grooves formed on both end surfaces is attached thereto. A needle bar drive lever 47 extending in the front-rear direction is axially supported by a shaft 47a in the arm portion 13, and a cam follower 48 is provided at the rear end thereof for engaging with a cam groove for driving the needle bar of the cam body 44. Have been. A connecting arm 49 that can slide slightly forward and backward is fitted to the front end of the needle bar driving lever 47.
Is engaged with the connecting pin 40 of the needle bar holder 43. Thereby, when the main shaft 43 of the sewing machine rotates, the cam body 44 rotates,
The needle bar drive lever 47 swings in the direction of arrow A in FIG.
16 will be driven up and down. Therefore, these arrangements are used to drive the needle bar 16 up and down.
Is equivalent to

(3) Interlocking mechanism between needle bar 16 and looper base 17 The needle bar 16 and the looper base 17 are integrally rotated by a rotation mechanism 61 when sewing the round hole portion of the eyelet hole. In addition, the needle bar 16 and the looper base 17 as well as the feed base 21 are slightly and integrally rotated so that the sewing thread draws a radial pattern. This rotation mechanism
61 will now be described with reference to FIGS. 7 and 8. The driving source of the rotation mechanism 61 is a rotation mechanism pulse motor 62 provided in the bed 12. The rotation mechanism pulse motor 62 is fixed to the sewing machine frame 11 with the output shaft facing downward, and the drive gear 63 is fixed to the output shaft. On the other hand, an interlocking shaft 64 is supported on the sewing machine frame 11 so as to extend in the vertical direction so as to extend between the bed portion 12 and the arm portion 13, and has a needle bar that meshes with a gear portion 23 b of the needle bar rotation bracket 23 at an upper end portion. A fan-shaped gear 65 for the looper base 17 is mounted on a lower end portion of the fan-shaped gear 65 for the looper base 17 (see FIG. 7). The fan gear 66 for the looper base 17 has a configuration in which first and second two sector gears 66a and 66b having different radial dimensions are integrated in opposite directions, and a first sector gear located on the pulse motor 62 side. 66a
Is a pulse motor for the rotation mechanism via an idle gear 67.
It meshes with the drive gear 63 of 62. Further, the second sector gear 66b located on the looper base 17 side directly meshes with the driven gear 68 provided on the looper base 17. As a result, when the rotation mechanism pulse motor 62 rotates stepwise, the interlocking shaft 64 rotates via the idle gear 67 and the second sector gear 66b, so that the needle bar rotation via the needle bar sector gear 65 is performed. Dynamic bracket
As a result, the needle bar guide member 35 and the needle bar 16 rotate. Also, based on the rotation of the interlocking shaft 64, the second sector gear 66
The looper base 17 rotates together with the needle bar 16 via b and the driven gear 68.

(4) Configuration for Control of Each Mechanism In order to control each mechanism described above, a control device having a configuration centered on the CPU 71 is provided below the sewing machine table 14 as shown in FIG.

The CPU 71 is connected to the ROM 72 and the RAM 73 by a bus, receives signals from a start / stop switch 74, a spindle rotation speed sensor 75, a needle bar position sensor 76, a needle swing sensor 77, and a swing width setting switch 90, and receives a signal from the sewing machine. Motor 78, feeder X
The two pulse motors 79 and 80 for the direction and the Y direction, the above-described pulse motor 62 for the rotation mechanism, the hammer drive mechanism 81, and the pulse motor 34 for the needle swing are respectively controlled through driver circuits (not shown).

Among them, a main shaft rotation speed sensor 75 for detecting the rotation speed of the sewing machine main shaft 43 and a needle bar position sensor 76 for detecting the position of the needle bar 16 in the vertical direction are provided as shown in FIG. That is, the sewing machine main shaft 43 is provided so that its end protrudes from the side wall of the sewing machine frame 11, and a pulley 82 is attached thereto, and reflection rings 83, 84 are integrated with the pulley 82 on the back surface of the pulley 82. Fixed to rotate. Notch portions of a predetermined pattern (not shown) are formed in the reflection rings 83 and 84, while, for example, an optical main shaft rotation speed sensor 75 and a needle bar facing the reflection rings 83 and 84 are provided on the sewing machine frame 11 side. The position sensor 76 is fixedly arranged. When the main shaft 43 of the sewing machine rotates, a speed detection pulse having a frequency corresponding to the rotation speed is given to the CPU 71 from the main shaft rotation speed sensor 75, and the needle bar 16 is moved to a specific position in the vertical direction (for example, the upper dead center position and the lower position). A needle bar position detection pulse (detection signal) that changes at the time of reaching the dead center position is supplied to the CPU 71.

On the other hand, the needle swing sensor 77 is provided on the arm 13 of the sewing machine frame 11 as shown in FIGS.
That is, the distal end of the drive shaft 35 attached to the output shaft 34a of the pulse motor 34 for needle swing protrudes to the side of the arm 13,
Here, an iron rotating disk 85 having a slit 85a is fixed. Further, the magnetic swing sensor 77 is attached to the sewing machine frame 11 via an attachment plate 86, and a detection unit thereof faces the outer peripheral portion of the rotating disk 85. Therefore, from the needle swing sensor 77, for example, the needle bar guide member 25 reaches a predetermined position, and the slit 85a of the rotating disk 85 is moved to the needle swing sensor 7.
A needle swing reference position pulse that rises or falls when facing 7 is supplied to the CPU 71.

The swing width setting switch 90 is set to the sewing machine table 14.
Is provided on an operation panel unit (not shown) provided on the front surface of the sewing machine, from which a sewing manufacturer can input a numerical value corresponding to a desired swing width. The numerical value corresponding to the input swing width is stored in the RAM 73 via the CPU 71.

The CPU 71 functions as control means for controlling the needle swing pulse motor 34 based on a detection signal (needle bar position detection pulse) from the needle bar position sensor 76.
The functional configuration will be apparent from the following operation description.

(5) Function When a desired needle swing width is set by the swing width setting switch 90 and the start / stop switch 74 is turned on, the CPU 71
The sewing machine motor 78 is started based on the signal from the sewing machine, and the sewing machine main shaft 43 rotates. Then, the cam body 44 provided on the sewing machine main shaft 43 rotates with this, so that the movement is transmitted and the needle bar 16 is driven up and down as described above, and the looper is synchronized with the vertical movement of the needle bar 16. Works. Also, the sewing machine spindle
When the pulley 82 rotates together with 43 and the needle bar 16 reaches a specific phase at the top dead center position from the needle bar position sensor 76,
A detection signal is given to U71. Then, when a predetermined time has elapsed from when the needle bar 16 reached the top dead center position, for example, the CPU 71 reads out a numerical value corresponding to the set width of the needle swing stored in the RAM 73, and reads out a number corresponding to the numerical value. The pulse is output to the pulse motor 34 for swinging, and the pulse is rotated forward, for example. As a result, as described above, the needle bar guide member 25 moves upward, for example, so that the needle bar guide member 25 and thus the needle bar 16
Swings to the left in FIG. 3, and the sewing needle 15 falls leftward from the center. Next, when the needle bar 16 rises again through the bottom dead center and reaches the top dead center position, the needle bar position sensor 76 returns the CP from the needle bar position sensor 76 again.
A detection signal is given to U71. Then, this time, the CPU 71 again reads out the numerical value stored in the RAM 73 when a predetermined time has elapsed since the needle bar 16 reached the top dead center position, and the number of pulses corresponding to the numerical value is used for needle swing. This is output to the pulse motor 34 and this is reversed this time. This allows
Since the needle bar guide member 25 moves downward, the needle bar guide member 25 and, consequently, the needle bar 16 will swing rightward in FIG. 3 and the sewing needle 15 will fall rightward from the center. Hereinafter, in the same manner as described above, when a predetermined time has elapsed from when the needle bar 16 reached the top dead center position, the needle swing pulse motor 34 is alternately rotated forward and backward alternately to repeat the needle movement. The bar guide member 25 is reciprocally driven up and down, and swings left and right. Eventually, the sewing needle 15 alternately drops every two needles at two points left and right separated by the needle swing width set by the swing width setting switch 90. Will be.

According to the above-described embodiment, in order to swing the needle bar 16 right and left, the needle swing pulse motor 34 is provided separately from the sewing machine motor 78, thereby directly moving the needle bar guide member 25 up and down. Thus, the structure is extremely simple compared to the conventional configuration in which the rotation of the main shaft of the sewing machine is transmitted to the needle bar guide member via a needle swing cam, a cam follower, a drive lever, a link mechanism, and the like. Therefore, it can be manufactured at low cost. Moreover, in this embodiment, in particular, the swing width setting switch 90 is provided, and the pulse motor 34 for swinging the needle is rotated by an angle corresponding to the value input here, so that special tools such as adjustment tools are used. Without using the sewing machine, the sewing manufacturer can set the desired needle swing width very easily.

Note that the present invention is not limited to the above embodiment, and the sewing machine does not necessarily need to be provided with the swing width setting switch 90 so that the sewing manufacturer can set a desired needle swing width. One type of data corresponding to the required swing width may be written in the RAM 73. Even in this case, it is only necessary to change the write data in order to make the swing width different, so that the adjustment operation is much easier than in the past. Others
The present invention is not limited to the embodiments described above and shown in the drawings. For example, the gist of the present invention is not limited to using a pulse motor as a needle swing driving body, but using an electromagnetic solenoid or an air motor or an air cylinder. Various changes can be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, the present invention has a configuration in which a dedicated drive source for swinging the needle bar is provided, so that the structure can be simplified as compared with the configuration in which power is taken from the main shaft of the sewing machine, and It has an excellent effect that the adjustment of the swing width can be easily performed.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a left side view of an arm portion schematically showing a sewing machine frame and showing an internal structure, FIG. 2 is a right side view thereof, and FIG. 3 is a front view thereof. FIG. 4 is an exploded perspective view showing a needle bar support structure, FIG. 5 is a plan view of an arm portion also showing a sewing machine frame schematically and showing an internal structure, and FIG. 6 is a line VI-VI in FIG. 7 is a bottom view of the bed portion, FIG. 8 is a side view of the whole, FIG. 9 is a block diagram of the control device, and FIG. 10 is a cross-sectional view of a pulley portion. In the drawing, 11 is a sewing machine frame, 12 is a bed portion, 13 is an arm portion, 15 is a sewing needle, 16 is a needle bar, 17 is a looper base, 20 is a cutter device, 21 is a feed bar, 25 is a needle bar guide member, 26 Is a slanting groove, 28 is a needle swing projection, 34 is a pulse motor for needle swing (needle swing driving body), 43 is the main shaft of the sewing machine, 50 is a needle bar vertical drive mechanism, 61 is a rotating mechanism, 71 is a CPU ( Control means), 76 is a needle bar position sensor, 77 is a needle swing sensor, and 90 is a swing width setting switch.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuaki Koie 9-35, Horitadori, Mizuho-ku, Nagoya-shi, Aichi, Japan Brother Industries, Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) D05B 1/00-83/00

Claims (1)

(57) [Claims] 1. A needle bar guide member provided on an arm portion so as to be vertically movable, a needle bar provided with a sewing needle at a lower end portion and vertically inserted through the needle bar guide member, A needle bar vertical drive mechanism for moving, a slant groove provided on the needle bar guide member side, and the needle bar guide provided on the arm portion side so as to slidably engage with the slant groove. A needle swinging projection for swinging the member left and right based on the vertical movement of the member, a feed stand provided on the upper surface of the bed and on which the work cloth is set, and an eyelet hole on the work cloth set on the feed base A cutter device for forming a cut in a shape of a circle, a feed device for causing the feed base to perform a feed operation along the cut shape of the eyelet hole, and the needle bar and the needle bar at the time of overlocking the round hole portion of the eyelet hole. A rotation that rotates in conjunction with the looper base provided in the bed A mechanism, a needle swing driver provided separately from a drive source of the needle bar vertical drive mechanism as a drive source for vertically moving the needle bar guide member, and detecting a position of the needle bar in a vertical direction. An eyelet drilling machine, comprising: a needle bar position sensor; and control means for controlling the needle swing driving body based on a detection signal from the needle bar position sensor.