JP2004113430A - Sewing machine and presser foot of the sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the structure for cutting a needle thread, to prevent a bobbin thread from being cut at the same time as the needle thread is cut, and to prevent the needle thread from being cut during the sewing. <P>SOLUTION: The presser foot 46 for pressing a textured fabric comprises a needle hole 50 for a sewing needle 40 to pass during the sewing, a cutter 51 for cutting the needle thread 47 between a thread hole of the sewing needle 40 and the textured fabric, and a guide passage 52 for guiding the needle thread 47 from the needle hole 50 to the cutter 51, having an acute bending part 52a bending acutely in the direction of extension. Accordingly, it is possible to cut the needle thread 47 only with a simple structure, and it is also possible to prevent the needle thread 47 from being cut by the cutter 51 during the sewing. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine and a presser foot of the sewing machine, and more particularly to a sewing machine having a simplified structure for cutting a needle thread.
[0002]
2. Description of the Related Art Conventionally, there are various sewing machines capable of cutting an upper thread and a lower thread. For example, a fixed blade and a movable blade provided on a bed portion of a sewing machine main body and a movable blade drive for driving the movable blade are provided. There is a device that is configured to drive the movable blade to the yarn cutting side by the movable blade driving unit and to simultaneously cut the upper thread and the lower thread by cooperation of the fixed blade and the movable blade (for example, Patent Document 1). When this sewing machine is an embroidery sewing machine for applying an embroidery pattern to a work cloth, cutting of the upper thread is often performed when the upper thread is exchanged for color change. In the cutting mechanism, the lower thread that does not need to be cut when changing colors is also cut at the same time as the upper thread.
[0003]
On the other hand, it has a fixed knife and a movable knife provided on the presser foot that holds the work cloth, moves the movable knife with respect to the fixed knife, and cooperates with the fixed knife and the movable knife to remove the upper thread on the surface of the work cloth. There is also a sewing machine configured to surely cut (for example, see Patent Document 2).
[0004]
[Patent Document 1]
JP-A-9-239177 (pages 4, 5; FIG. 6)
[Patent Document 2]
Japanese Utility Model Publication No. 4-9996 (pages 3, 4; Fig. 1-5)
[0005]
In the sewing machine described in Patent Document 1, it is necessary to provide a fixed blade and a movable blade, a movable blade driving means for driving the movable blade, and the like in a bed portion of the sewing machine. This increases the complexity of the structure for cutting the upper thread, and inevitably increases the size of the bed. If the sewing machine is an embroidery sewing machine, the lower thread that does not need to be cut at the time of color change is also cut at the same time as the upper thread. There is a possibility that the lower thread does not become entangled, and every time the color is changed, the end of the lower thread is held by a fixed blade and a movable blade so that the cut lower thread does not become entangled with the surrounding members. And the structure for cutting the yarn is further complicated.
[0006]
On the other hand, also in the sewing machine described in Patent Document 2, it is necessary to provide a fixed knife and a movable knife on the presser foot, and a mechanism for moving the movable knife with respect to the fixed knife. Is also complicated.
[0007]
An object of the present invention is to simplify the configuration for cutting the upper thread, to configure so that the lower thread is not cut at the same time when the upper thread is cut, and the like.
[0008]
According to a first aspect of the present invention, there is provided a sewing machine having a presser foot for pressing a work cloth to be sewn, wherein the presser foot has a needle drop hole through which a sewing needle passes during sewing. A cutter for cutting the upper thread between the eye hole of the sewing needle and the work cloth; and a guide passage for guiding the upper thread from the needle drop hole to the cutter, wherein the extension direction is bent at an acute angle. And a guide passage having an acute bent portion.
[0009]
When cutting the upper thread for color change, etc., the upper thread from the eye of the sewing needle to the stitch formed on the work cloth is guided by the guide passage from the needle drop hole to the cutter at the presser foot. The upper thread is cut by the cutter. Here, since the presser foot located above the needle plate is provided with a cutter, only the upper thread is necessarily cut by the cutter, and the lower thread is not cut. Further, since the guide passage has an acute-angle bent portion in which the extension direction is bent at an acute angle, the acute-angle bent portion prevents the upper thread from moving along the guide passage to the cutter during sewing.
[0010]
In the sewing machine according to the second aspect, in the invention according to the first aspect, the guide passage extends from the needle drop hole to the acute angle bent portion in a direction at a predetermined angle from a direction extending from the needle drop hole to the cutter. It has one guide portion. As described above, since the first guide portion extends in a direction making a predetermined angle with the direction extending from the needle drop hole to the cutter, the needle thread can be also sewn during sewing by the first guide portion in addition to the acute bent portion. From the needle drop hole to the cutter is prevented.
[0011]
According to a third aspect of the present invention, in the second aspect of the invention, the guide passage has a second guide portion extending from the acute bent portion in an arc shape centered on the needle drop hole. Since the second guide portion extends in an arc around the needle drop hole, the guide passage is formed compactly in the presser foot, so that the size of the presser foot is reduced.
[0012]
The sewing machine according to claim 4 is the cloth holding frame for holding the work cloth according to any one of claims 1 to 3, which is movable in a predetermined direction with respect to a sewing machine body and is movable in the predetermined direction. A cloth holding frame that is rotatably arranged about an extending rotation axis, a movement driving unit that drives the cloth holding frame in the predetermined direction, a rotation driving unit that rotates the cloth holding frame, and Control means for controlling the movement drive means and the rotation drive means, respectively, wherein the control means moves the upper thread from the needle drop hole to the cutter along the guide path, And the rotation driving means.
[0013]
In this sewing machine, with the work cloth held by the cloth holding frame, the cloth holding frame is driven to move in a predetermined direction by the moving driving means with respect to the sewing machine main body, or extends in the predetermined direction by the rotary driving means. The work cloth is sewn at a predetermined position by being driven to rotate about the rotation axis. Here, during sewing, the upper thread is prevented from moving from the needle drop hole to the cutter by the acute angle bent portion of the guide passage, but when cutting the upper thread for color change, etc., The control means controls the movement driving means and the rotation driving means, respectively, so that the upper thread moves from the needle drop hole to the cutter beyond the acute bend, so that the upper thread moves to the cutter and the upper thread is moved by the cutter. Is disconnected.
[0014]
The presser foot of the sewing machine according to claim 5, wherein the presser foot of the sewing machine presses a work cloth to be sewn, wherein a needle drop hole through which a sewing needle passes during sewing and an eye hole of the sewing needle and the work cloth. A cutter for cutting the upper thread, and a guide path for guiding the upper thread from the needle drop hole to the cutter, the guide path having an acute bent portion in which the extension direction is bent at an acute angle. It is. The operation of the presser foot at the time of cutting the upper thread is the same as that of the first aspect, and the description thereof will be omitted.
[0015]
Embodiments of the present invention will be described. In the present embodiment, the present invention is applied to a household embroidery sewing machine which can sew various embroidery patterns on a cylindrical work cloth forming a sleeve of a garment or the like. In addition, since the worker performs various operations from left to right in FIG. 1, the following description will be made assuming that the left side (foreground as viewed from the worker) in FIG.
[0016]
As shown in FIGS. 1 and 2, the embroidery sewing machine M includes a horizontal base 1, a pillar 2 erected at a rear end portion of the base 1, and a horizontal front from the pillar 2. The extended cylinder bed 3 is supported on the upper end of the pillar 2 so as to be switchable between a forwardly horizontally sewn position indicated by a solid line in FIG. 2 and a retracted position retracted upward as indicated by a chain line in FIG. An arm 4 and a head 5 provided at the front end of the arm 4 are provided.
[0017]
In this embroidery sewing machine M, before starting sewing, the operator sets the cylindrical work cloth 53 (see FIG. 5) on the cloth holding frame 67 which is fitted onto the cylinder bed 3; Since the sewing needle 40, the threading mechanism 45, and the like provided in the portion 5 may hinder the work of setting the work cloth 53, the worker can easily perform the work of setting the work cloth 53. Then, the arm 4 is switched from the sewing position to the retracted position. After the work cloth 53 is set on the cloth holding frame 67 by the operator with the arm section 4 in the retracted position, the arm section 4 is switched to the sewing position again, and in this state, the embroidery sewing work on the work cloth 53 is performed. Done.
[0018]
As shown in FIG. 2, the pillar 2 has a main body frame 10. The main body frame 10 includes a sewing machine motor 11, and a sewing needle 40 provided on the head section 5. A main part of the driving force transmission mechanism 12 that transmits the force to the balance 41 is provided. The driving force transmission mechanism 12 includes a main shaft 14, transmission shafts 13 and 15, belts 16, 17 and 18, gears 19 and 20, and the rotational driving force of the sewing machine motor 11 is first transmitted via the belt 16. The power is transmitted to the shaft 13, then transmitted from the transmission shaft 13 to the main shaft 14 via the gears 19 and 20, and the rotational driving force transmitted to the main shaft 14 is transmitted to the transmission shaft 15 via the belt 17. . A driving force is transmitted from the transmission shaft 15 to the sewing needle 40 and the balance 41 via the belt 18. In addition, a hand pulley 21 for manually rotating the main shaft 14 to move the sewing needle 40 up and down is also provided. The components that constitute the driving force transmission mechanism 12 are appropriately dispersed in the axial direction of the main shaft 14 and the transmission shafts 13 and 15.
[0019]
The rear end of the arm frame 30 of the arm 4 is rotatably and slidably fitted to a pair of left and right bearings 31 that rotatably support the transmission shaft 15 with respect to the main body frame 10. 2 can be rotated between a sewing position indicated by a solid line and a retracted position indicated by a chain line in FIG. An arm cover 32 (see FIG. 1) that covers the arm portion 4 is formed with a protrusion 33 that projects substantially horizontally to the right, and a liquid crystal display 100 (see FIG. 9) is provided on the upper surface of the protrusion 33. On the upper surface of the liquid crystal display 100, a touch panel 101 (see FIG. 9) provided with various operation keys such as a pattern selection key for selecting an embroidery pattern and a thread cutting key for cutting a needle thread is provided. ) Is also provided. Here, in order to make it easier for a worker in front to operate the touch panel 101, the protruding portion 33 is slightly inclined forward and downward.
[0020]
The head unit 5 includes a sewing needle 40, a balance 41 supported swingably back and forth on the arm frame 30, a needle holder 42 for holding the sewing needle 40, a guide shaft 43 for guiding the needle holder 42 up and down, and a needle thread. A thread tension mechanism 44 for adjusting the thread tension, a threading mechanism 45 for passing the upper thread through the eye of the sewing needle 40, a presser foot 46 provided at the lower end of the guide shaft 43 and pressing the work cloth 53 from above are provided.
[0021]
A pin 48a at the upper end of a link member 48 connected to the needle holder 42 is engaged with a guide groove 41a formed in the longitudinal direction of the balance 41, and the link member 48 is rotated via the pin 48a. It is connected to a plate 49. Accordingly, when the rotation driving force of the sewing machine motor 11 is transmitted from the transmission shaft 15 of the driving force transmission mechanism 12 to the rotation plate 49 via the belt 18 and the rotation plate 49 rotates, the link member 48 moves up and down to move the needle holder 42. The sewing needle 40 also moves up and down while being guided by the guide shaft 43, and at the same time, the balance 41 swings back and forth in conjunction with the up and down movement of the link member 48.
[0022]
As shown in FIGS. 3 to 5, the presser foot 46 is a plate member made of a synthetic resin and having a substantially triangular shape in a plan view. The presser foot 46 has a needle drop hole 50 through which the sewing needle 40 passes at the time of sewing, and a sewing needle. There is provided a cutter 51 for cutting the upper thread 47 between the eye 40a of the 40 and the work cloth 53, and a guide passage 52 for guiding the upper thread 47 from the needle drop hole 50 to the cutter 51.
[0023]
The front end portion of the presser foot 46 is vertically slidably fitted to the lower end of the guide shaft 43, and the presser foot 46 is urged downward by a coil spring 54 provided on the guide shaft 43. A needle drop hole 50 is formed in the left portion of the presser foot 46, and an annular presser formed so as to surround the needle drop hole 50 and protruding downward is formed in the lower surface of the left portion of the presser foot 46. A portion 46a is formed. When the arm portion 4 is in the sewing position shown by the solid line in FIG. 2, the pressing portion 46a contacts the work cloth 53 as shown in FIG. Press the periphery of the position from above.
[0024]
Here, during sewing, the work cloth 53 moves integrally with the cloth holding frame 67 in a state where the press part 46a is in contact with the work cloth 53, as described later. In order to minimize the sliding resistance with the work cloth 53, the presser portion 46a is formed such that the area of the portion that comes into contact with the work cloth 53 is considerably smaller than the area of the presser foot 46.
[0025]
The cutter 51 is detachably mounted on a cutter mounting portion 55 formed at a rear end side portion of the presser foot 46, and a lid member 56 for preventing the cutter 51 mounted on the cutter mounting portion 55 from coming off is also provided on the presser foot 46. Have been.
[0026]
As shown in FIGS. 3 to 5, the guide passage 52 includes an acute bent portion 52 a whose extension direction is bent at an acute angle, and the needle drop hole 50 in a direction forming a predetermined angle with the direction extending from the needle drop hole 50 to the cutter 51. And a second guide portion 52c extending from the acute angle bent portion 52a to an arc centered on the needle drop hole 50. During sewing, the needle thread 47 between the eye hole 40a and the work cloth 53 is prevented from moving to the cutter 51 by the acute angle bent portion 52a. The direction in which the first guide portion 52b extends from the needle drop hole 50 (the direction of the straight line AB in FIG. 3) is a predetermined angle with respect to the direction in which the first guide portion 52b extends from the needle drop hole 50 to the cutter 51 (the direction of the straight line AC in FIG. 3). (For example, about 50 degrees), and the width of the starting end of the first guide portion 52b is formed to be considerably smaller than the diameter of the needle drop hole 50, so that the first guide portion 52b extends from the needle drop hole 50 to the first guide portion 52b. The upper thread 47 is difficult to move, and the first guide portion 52b also prevents the upper thread 47 from moving from the needle drop hole 50 to the cutter 51 during sewing.
[0027]
The second guide portion 52c extends in an arc from the point B around the point A in FIG. 3, and the blade portion 51a of the cutter 51 is located above the rear end of the second guide portion 52c. . As described above, since the second guide portion 52c is formed to extend in an arc shape centering on the needle drop hole 50, the guide passage 52 is formed in the presser foot 46 in a compact manner, and the size of the presser foot 46 is reduced. Can be reduced as much as possible.
[0028]
When cutting the upper thread 47, as described later, the cloth holding frame 67 holding the work cloth 53 is driven backward by the front-rear movement drive motor 69, and is rotated by a predetermined angle by the rotation drive motor 79. Then, with the movement of the cloth holding frame 67 (work cloth 53), the upper thread 47 between the eye hole 40a and the work cloth 53 passes from the first guide portion 52b, passes through the acute angle bent portion 52a, and moves to the second position. Since the upper thread 47 moves to the cutter 51 through the two guides 52 c, only the upper thread 47 is cut by the cutter 51 above the work cloth 53.
[0029]
By the way, the head section 5 is provided with a cassette mounting section 58 on which a thread cassette 57 containing a thread spool as a thread supply source is mounted. When the thread cassette 57 is mounted on the cassette mounting section 58, In conjunction with the mounting operation, the upper thread is passed through the eye of the sewing needle 40 by the threading mechanism 45, and the upper thread is hung on the balance 41 and the thread tension mechanism 44.
[0030]
Next, the cylinder bed 3 will be described. As shown in FIGS. 1, 2, 6, and 7, the cylinder bed 3 is formed of a cylindrical synthetic resin cover member 60 extending in the front-rear direction, and is provided at the upper end of the front end portion of the cover member 60. Is formed with a cutout hole 60a for mounting the needle plate 59. Inside the cylinder bed 3, a vertical shuttle 61 and a shuttle shaft 62 for rotating and driving an outer shuttle 61a of the vertical shuttle 61 are accommodated. A needle plate 59 is provided on the upper side of the vertical shuttle 61, and a needle hole through which the sewing needle 40 passes is formed in the needle plate 59. When the sewing needle 40 descends through the needle hole of the needle plate 59, the needle plate 59 On the lower side, the upper thread 47 is hooked by the blade point of the outer hook 61a, the upper thread 47 and the lower thread are entangled, and a seam is formed on the work cloth 53 on the upper side of the needle plate 59.
[0031]
On the left side of the hook shaft 62 extending forward and backward, a vertical plate-shaped hook shaft support frame 63 extending forward from the main frame 10 in parallel with the hook shaft 62 is provided. 63 and a pair of front and rear bearings 64 provided on the main body frame 10 are rotatably supported. The rotary drive force of the sewing machine motor 11 is transmitted to the shuttle shaft 62 from the main shaft 14 via gears 65 and 66, and the rotary drive force drives the outer shuttle 61a to rotate.
[0032]
As shown in FIGS. 1 and 2, a cloth holding frame 67 for holding the work cloth 53 is slidably fitted to the front half of the cylinder bed 3. A pair of cloth holding portions 67a and 67b are formed at both ends. The work cloth 53 is pressed against the cloth holding frame 67 from above by a cloth holder (not shown) in the pair of cloth holding portions 67a and 67b, and is held by the cloth holding frame 67.
[0033]
A movable body 68 that supports the cloth holding frame 67 is provided in the rear half of the cylinder bed 3 so as to be movable in the front-rear direction with respect to the cylinder bed 3. As shown in FIGS. 6 to 8, a pair of guided portions 68 a and 68 b in which the shuttle shaft 62 is inserted are provided at both front and rear end portions of the movable body 68, respectively. In the portions 68a and 68b, the movable body 68 is guided by the shuttle shaft 62 so as to be movable in the front-rear direction. A front-rear movement drive motor 69 (movement drive means) for driving the movable body 68 in the front-rear direction is a pulse motor. The front-rear movement drive motor 69 is provided above the sewing machine motor 11 in the main body frame 10.
[0034]
The driving force of the forward / backward drive motor 69 is transmitted via two gears 70 and 71 to a belt 72 laid over the main body frame 10 from a middle part in the longitudinal direction of the shuttle shaft support frame 63. Since the belt 72 is connected to the movable body 68 by a belt connecting member 73 screwed to the movable body 68, a driving force is transmitted from the belt 72 to the movable body 68, and the movable body 68 is driven in the front-rear direction. You.
[0035]
By the way, the movable body 68 is integrally formed with a protrusion 74 extending downward through the cylinder bed 3. As shown in FIG. Is engaged with the rail-shaped rotation restricting member 75 made of synthetic resin extending in the front-rear direction so as to be slidable in the front-rear direction and immovable in the left-right direction. Regulated.
[0036]
As shown in FIG. 2, an annular driving ring 77 is provided around a rotation axis 80 (see FIG. 5) extending in the front-rear direction on a mounting plate 76 provided integrally with the front end of the movable body 68. 68 so as to be rotatable. A cloth holding frame 67 is attached to the front end of the drive ring 77 integrally with the drive ring 77. An annular groove 77 a that engages with a plurality (for example, three) of rollers 78 fixedly provided on the mounting plate portion 76 of the movable body 68 is formed on the outer peripheral portion of the drive ring 77. Is rotatable relative to the movable body 68 while being guided by the plurality of rollers 78. The rotation drive motor 79 (rotation drive means) for rotating the drive ring 77 is a pulse motor. The rotation drive motor 79 is mounted on the rear surface of the mounting plate 76. The rotation drive force of the rotation drive motor 79 is: The power is transmitted to the drive ring 77 via a gear (not shown) provided inside the drive ring 77 and a gear (not shown) formed on the inner peripheral portion of the drive ring 77.
[0037]
The amount of movement of the movable body 68 in the front-rear direction by the front-rear movement drive motor 69 and the amount of rotation of the drive ring 77 by the rotation drive motor 79 are stored in the embroidery data storage area 93a of the RAM 93 from the flexible disk 98 before sewing as described later. Each is determined based on the embroidery data read in advance. When the movable body 68 is driven in the front-rear direction by the forward / backward movement drive motor 69 by the predetermined moving amount determined in this way, the cloth holding frame 67 supported by the movable body 68 via the drive ring 77 also moves to the main body frame 10. (The sewing machine main body) is moved in the front-rear direction by the predetermined movement amount. Similarly, when the drive ring 77 is driven by the rotation drive motor 79 by the predetermined rotation amount determined as described above, the cloth holding frame 67 attached to the drive ring 77 also moves the body frame 10 by the predetermined rotation amount. With respect to the rotation axis 80.
[0038]
Next, a control system of the embroidery sewing machine M will be described. As shown in FIG. 9, a control device 90 (control means) for controlling the entire embroidery sewing machine M includes a microcomputer including a CPU 91, a ROM 92 and a RAM 93, and an input / output interface 94. The CPU 91, the ROM 92, and the RAM 93 are each connected to an input / output interface 94 via a bus 95. The bus 95 is also connected to a flexible disk controller 96 (FDC) that drives a flexible disk drive 97 (FDD).
[0039]
A flexible disk 98 (FD) storing embroidery data is inserted into the FDD 97, and the embroidery data is read from the FD 98 to the RAM 93 by the FDD 97. A start / stop key 99, a touch panel 101, and the like are connected to the input / output interface 94. Further, the sewing machine motor 11, the forward / backward movement drive motor 69, the rotation drive motor 79, the liquid crystal display 100, and the like are also connected to the input / output interface 94 via a drive circuit (not shown).
[0040]
The ROM 92 stores various programs related to embroidery sewing, such as a main routine of a sewing control program for controlling the embroidery sewing work of the embroidery sewing machine M and a thread cutting processing program for controlling a thread cutting process of the upper thread 47 described later. I have. The embroidery data storage area 93a of the RAM 93 stores the embroidery data read from the FD 98. The embroidery data includes various types of stitch data indicating the relative movement amount of the cloth holding frame 67 from the current needle drop position to the next needle drop position, and color change data for replacing the upper thread 47 at the time of color change. Consists of data.
[0041]
Based on the embroidery data, the control device 90 controls the front-rear movement drive motor 69 and the rotation drive motor 79 during sewing to move the movable body 68 back and forth by a predetermined amount, and moves the drive ring 77 to the rotation axis 80. , The work cloth 53 is moved to a predetermined position. Further, as described below, even when the upper thread 47 is cut, the control device 90 controls the front-rear movement drive motor 69 and the rotation drive motor 79 so that the upper thread between the eye hole 40a and the work cloth 53 is controlled. 47 is moved from the needle drop hole 50 to the cutter 51 along the guide passage 52.
[0042]
Next, a thread cutting process for cutting the upper thread 47 by the cutter 51 of the presser foot 46 will be described with reference to the flowcharts of FIGS. 3, 5, and 10. In the following description, Si (i = 10, 11, 12,...) Indicates each step.
[0043]
This thread cutting process is executed each time a series of embroidery data is sequentially read from the embroidery data storage area 93a of the RAM 93. First, if the read embroidery data is the color change data (S10: Yes), it is necessary to cut the upper thread in order to replace the upper thread 47, so that the process proceeds to S14. Even if the embroidery data is not the color change data (S10: No), if the operator has turned on the thread cut key of the touch panel 101 (S11: Yes), if the sewing is stopped (S12: Yes), Similarly, the flow shifts to S14. If the thread trimming key is turned ON during the sewing operation (S12: No), a warning indicating that the sewing operation is being performed is displayed on the display 100 (S13), and the thread trimming of the upper thread 47 is performed. Return. If the embroidery data is not the color change data and the thread trimming key is not operated (S11: No), the process returns without executing the thread trimming process of the upper thread 47.
[0044]
In S14, as shown in FIG. ₁ Only in the + Y direction (rearward), and as shown in FIG. ₁ Only by rotating in the -θ direction (counterclockwise direction in FIG. 5) to move the work cloth 53 held by the cloth holding frame 67, the upper thread 47 is moved from the point A in the needle drop hole 50. It is moved along the first guide portion 52b to the point B of the acute angle bent portion 52a. Further, in S15, the movable body 68 is ₂ Only in the + Y direction, and the drive ring 77 is ₂ Only by rotating in the + θ direction (clockwise direction in FIG. 5) to move the work cloth 53, the upper thread 47 is moved from the point B of the acute angle bent portion 52a along the arc-shaped second guide portion 52c. The cutter 51 is moved to a point C where the tip of the blade portion 51 a is located, and the cutter 51 cuts only the upper thread 47 above the work cloth 53.
[0045]
According to the embroidery sewing machine M described above, the following effects can be obtained.
[0046]
1) The embroidery sewing machine M is configured to cut the upper thread 47 by the cutter 51 of the presser foot 46 that holds the work cloth 53. Therefore, the configuration for cutting the upper thread 47 can be simplified, and the upper thread 47 can be simplified. Since the lower thread is not cut when cutting the upper thread 47, only the upper thread 47 is cut at the time of color change in which the upper thread 47 is frequently cut in the embroidery sewing machine M. When sewing is started again from above, the upper thread 47 and the lower thread can be reliably entangled.
[0047]
2) Since the guide passage 52 that guides the upper thread 47 from the needle drop hole 50 to the cutter 51 has an acute bent portion 52a that is bent at an acute angle, the upper thread 47 is moved from the needle drop hole 50 to the cutter 51 by the acute bent portion 52a. Since the movement is prevented, the upper thread 47 can be prevented from being cut by the cutter 51 during sewing. The first guide portion 52b of the guide passage 52 extends in a direction that forms a predetermined angle with the direction extending from the needle drop hole 50 to the cutter 51, and the width of the start end of the first guide portion 52b is Since it is formed to be considerably smaller than the diameter, the first guide portion 52b in addition to the acute angle bent portion 52a prevents the upper thread 47 from moving to the cutter 51 during sewing, and is cut by the cutter 51. Can be prevented more reliably.
[0048]
3) Since the second guide portion 52c of the guide passage 52 extends in an arc shape from the acute angle bent portion 52a around the needle drop hole 50, the guide passage 52 can be formed compactly in the presser foot 46, so that the size of the presser foot 46 is reduced. Can be reduced as much as possible.
[0049]
4) The control device 90 controls the forward and backward movement drive motor 69 and the rotation drive motor 79 so as to move the upper thread 47 from the needle drop hole 50 to the cutter 51 along the guide passage 52. At the time of cutting, the upper thread 47 in the guide passage 52 can move to the cutter 51 beyond the acute angle bent portion 52a.
[0050]
Next, modified embodiments in which various modifications are made to the above-described embodiment will be described.
[0051]
1] The embroidery sewing machine M according to the embodiment is configured such that an embroidery pattern can be sewn on a cylindrical work cloth 53, but embroidery can sew an embroidery pattern on a work cloth held in a plane by a cloth holding frame. The present invention can also be applied to a sewing machine. In this case, the cloth holding frame for holding the work cloth is disposed so as to be movable in the X-axis direction (left-right direction) and the Y-axis direction (front-back direction), respectively, and the cloth holding frame is driven by a motor or the like. The upper thread 47 between the eye hole 40a and the work cloth is moved along the guide passage 52 of the presser foot 46 by driving the upper thread 47 between the eye 40a and the work cloth by driving the upper thread 47 by a predetermined amount in the X-axis direction and the Y-axis direction. Cut with a cutter 51.
[0052]
2] On the lower side of the needle plate 59, inside the cylinder bed 3, a fixed blade fixed to the cylinder bed 3 and a movable blade for cutting the lower thread in cooperation with the fixed blade. The lower thread may be cut by the fixed blade and the movable blade at the end of sewing.
[0053]
3] In the above embodiment, the embroidery data for embroidery sewing is read from the FD 98. However, the embroidery data may be read from another known storage medium such as a memory card.
[0054]
According to the first aspect of the present invention, since the presser foot for holding the work cloth is provided with the cutter for cutting the upper thread, the structure for cutting the upper thread can be simplified. Since the lower thread is not cut at the same time when the thread is cut, only the upper thread is cut during color change when the upper thread is frequently cut in an embroidery sewing machine. When sewing is started, the upper thread and the lower thread can be reliably entangled, and the structure for holding the end of the lower thread in order to prevent the cut lower thread from tangling with the surrounding members is provided. It becomes unnecessary.
[0055]
Furthermore, since the guide passage that guides the upper thread from the needle drop hole to the cutter has an acute bent portion where the extension direction is bent at an acute angle, the upper thread moves from the needle drop hole to the cutter during sewing due to the acute bent portion. Therefore, it is possible to prevent the upper thread from being cut by the cutter during sewing.
[0056]
According to the second aspect of the present invention, in the guide passage, the first guide portion extends from the needle drop hole to the acute bent portion in a direction at a predetermined angle to the direction extending from the needle drop hole to the cutter. In addition, the first guide portion also prevents the upper thread from moving from the needle drop hole to the cutter during sewing, so that it is possible to more reliably prevent the upper thread from being cut by the cutter during sewing.
[0057]
According to the third aspect of the invention, since the second guide portion extends in an arc shape from the acute angle bent portion centering on the needle drop hole, the guide passage can be formed in the presser foot in a compact manner, so that the size of the presser foot is reduced. can do.
[0058]
According to the invention of claim 4, since the control means controls the movement driving means and the rotation driving means so as to move the upper thread from the needle drop hole to the cutter along the guide path, the upper thread is cut. In this case, the upper thread can move to the cutter beyond the acute angle bent portion in the guide passage, and the upper thread can be reliably cut by the cutter.
[0059]
According to the invention of claim 5, the presser foot of the sewing machine includes a cutter for cutting the upper thread, and a guide path for guiding the upper thread from the needle drop hole to the cutter, and the guide path is sharply bent at an acute angle. Because of the presence of the portion, substantially the same effect as in claim 1 can be obtained.
[Brief description of the drawings]
FIG. 1 is a side view of an embroidery sewing machine according to an embodiment of the present invention.
FIG. 2 is a side view of an internal mechanism of the embroidery sewing machine.
FIG. 3 is a plan view of a presser foot.
FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;
FIG. 5 is a front view of a presser foot.
FIG. 6 is a side view of an internal mechanism of the cylinder bed.
FIG. 7 is a plan view of FIG. 6;
FIG. 8 is a sectional view taken along line VV of FIG. 6;
FIG. 9 is a block diagram showing a control system of the embroidery sewing machine.
FIG. 10 is a flowchart of a thread cutting process.
[Explanation of symbols]
M embroidery sewing machine
40 sewing needle
40a Eye hole
46 Presser foot
47 Upper thread
50 Needle entry hole
51 cutter
52 Guideway
52a sharp bend
52b 1st guide part
52c 2nd guide
53 Work cloth
67 Cloth holding frame
69 Back and forth drive motor
79 Rotary drive motor
80 Rotation axis
90 Control device

Claims (5)

In a sewing machine with a presser foot that presses a work cloth to be sewn,
The presser foot is
Needle drop holes through which sewing needles pass during sewing,
A cutter for cutting the upper thread between the eye of the sewing needle and the work cloth,
A guide passage that guides the upper thread from the needle drop hole to the cutter, the guide passage having an acute angle bent portion in which an extension direction is bent at an acute angle;
A sewing machine comprising: 2. The guide passage according to claim 1, wherein the guide passage has a first guide portion extending from the needle drop hole to the acute angle bent portion in a direction at a predetermined angle with a direction extending from the needle drop hole to the cutter. 3. sewing machine. The sewing machine according to claim 2, wherein the guide passage has a second guide portion extending from the acute bent portion in an arc shape centered on the needle drop hole. A cloth holding frame for holding the work cloth, the cloth holding frame being movable in a predetermined direction with respect to the sewing machine main body and rotatably disposed around a rotation axis extending in the predetermined direction; A movement driving unit that moves and drives the cloth holding frame in the predetermined direction, a rotation driving unit that rotates and drives the cloth holding frame, and a control unit that controls the movement driving unit and the rotation driving unit, respectively.
The said control means controls the said movement drive means and the said rotation drive means so that the said upper thread may be moved along the said guide path from the said needle drop hole to the said cutter. The sewing machine according to any one of the above. On the presser foot of the sewing machine that holds the work cloth to be sewn,
Needle drop holes through which sewing needles pass during sewing,
A cutter for cutting the upper thread between the eye of the sewing needle and the work cloth,
A guide passage that guides the upper thread from the needle drop hole to the cutter, the guide passage having an acute angle bent portion in which an extension direction is bent at an acute angle;
A presser foot of a sewing machine, comprising:

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