JPH1133265A - Device for removing dust in sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and surely remove rubbish and dust stored at the lower side of a needle plate without affecting the quality of sewing products. SOLUTION: A thread cutting mechanism 35, an air nozzle 50 for blowing air and an air supply source for supplying pressurized air to the air nozzle 50 are provided between the needle plate 31 and a semi-rotary shuttle 16, pressurized air from the air supply source is strongly injected from the air nozzle 50 where a tip part is formed to be a width-widened and flattened tip enlarged state and air is injected between the needle plate 31 and the semi-rotary shuttle 16 so that rubbish and dust such as waste thread, etc., occurring at the lower side of the needle plate 31 during sewing or at the time of thread cutting is stored in areas D1 and D2 which are enclosed by an alternate long and two short dashes line. But, they are surely blown off, which are stored in the areas at the lower side of the needle plate 31 by strong and wide-range injected air from the air nozzle 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removing device for a sewing machine, and more particularly to a device for forcibly removing dust and lint accumulated on a sewing machine between a needle plate and a thread catching means. .

[0002]

2. Description of the Related Art Conventionally, a sewing machine main body of a normal sewing machine mainly includes a bed portion, a pillar portion, an arm portion and a head portion, and a main shaft driven by a sewing machine motor is provided in the arm portion. The needle bar, sewing needle and balance of the section are driven up and down by the driving force of the main shaft. In addition, a lower shaft and a thread wheel catching hook cooperating with the sewing needle are provided below the needle plate of the bed portion, and the thread catching hook is driven by the driving force from the main shaft via the lower shaft. It is designed to be driven to rotate. If a thread cutting mechanism consisting of a movable blade and a fixed blade is provided between the needle plate and the thread wheel catching hook, the upper thread and the lower thread are thread-cut at the end of the sewing operation. It is designed to be cut by a mechanism.

When sewing a work cloth with a sewing machine of this type, not only a work cloth fed on a needle plate by a feed plate while being pressed by a presser foot but also an upper thread or bobbin fed from a thread spool is used. Dust and dust are also generated from the bobbin thread unwound from the case, and the dust and dust enter the narrow space between the needle plate and the spool for catching the spool and the inside of the spool for catching the spool. Accumulates in the drive shaft or bed portion that drives the shuttle. In particular, if a thread trimming mechanism is provided between the needle plate and the yarn catching hook, a large amount of thread waste is generated at the time of thread cutting, and thread waste and dust are generated in a narrow space below the needle plate. When a large amount of is accumulated, it also affects the thread trimming operation by the thread trimming mechanism and the rotation of the thread wheel catching hook, and the sewing operation and the thread trimming operation cannot be performed normally.

[0004] Therefore, there have been proposed various removing devices for forcibly removing dust and dirt accumulated around the yarn catching hook. For example, in Japanese Patent Application Laid-Open No. 54-143368, a horizontal shuttle is entirely surrounded by a cover member, one end of a suction pipe is connected to the cover member, and the other end of the suction pipe is connected to a dust box via a dust box. By connecting the suction fan and driving the suction fan with a sewing machine motor driven for sewing operation, the suction force generated by the suction fan sucks the air in the cover member, and during sewing work A dust removal device is described which forcibly absorbs dust and dust generated from a work cloth or a thread and accumulated in a horizontal shuttle and its surroundings.

[0005]

As described above, in the dust removing device described in Japanese Patent Application Laid-Open No. 54-143368, a suction fan is driven by a rotatably driven sewing machine motor, and the horizontal shuttle and its surroundings are driven. Dust and dust generated by
The sewing machine always sucks from the start to the end of the sewing operation, so especially when the sewing speed is high, the suction force of the suction fan increases due to the high speed rotation of the sewing machine motor, and a large An air flow is generated, and the air flow causes deformation of the loop formed by being caught by the blade point of the horizontal shuttle, or the loop loop does not come off from the blade point. There is a problem that it becomes defective and the quality of sewing products deteriorates.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dust removing device for a sewing machine capable of removing dust and dirt accumulated on the lower side of a needle plate efficiently and reliably without affecting the quality of a sewn product. That is.

[0007]

According to a first aspect of the present invention, there is provided a dust removing device for a sewing machine, wherein a sewing needle driven via a main shaft by a sewing machine motor, a needle plate having a sewing hole, and a needle plate are provided below the needle plate. In a sewing machine provided with a thread catching means, an air nozzle for blowing air between the needle plate and the thread catching means, an air supply means for supplying pressurized air to the air nozzle, and after completion of sewing Drive control means for driving the air supply means.

When sewing is started, the upper thread is fed from the thread spool, the lower thread is fed from the bobbin case, and the work cloth is fed on the needle plate by the feed plate while being pressed by the presser foot. Since the seam is formed by these upper and lower threads, dust and dust are generated not only from the work cloth but also from the upper thread and the lower thread, and part of the dust and dust passes through the needle holes and various gaps. The needles penetrate and accumulate between the needle plate and the yarn catching means such as the full rotary hook and the looper. On the other hand, when the sewing is completed, the air supply means is driven by the drive control means, and the pressurized air supplied from the air supply means is vigorously ejected from the air nozzle, and is interposed between the needle plate and the yarn catching means. Air is blown. As a result, dust or dust accumulated on the lower side of the needle plate during sewing is blown off by the air.

According to a second aspect of the present invention, in the dust removing device for a sewing machine according to the first aspect of the present invention, the sewing machine includes a thread cutting mechanism for cutting an upper thread and a lower thread, and a thread control mechanism for operating a thread cutting mechanism when sewing is completed. Means, wherein the drive control means drives the air supply means when the thread cutting operation by the thread cutting control means is completed. In this case, when the upper thread and the lower thread are cut by the thread cutting mechanism, thread scraps, that is, chips when cutting, are generated from the upper and lower threads, and the needle plate and the thread wheel provided with the thread cutting mechanism are formed. When the thread cutting operation is completed, the air supply means is driven, and the air blasted from the air nozzle is blown between the needle plate and the yarn wheel catching means. The yarn waste generated during the yarn cutting is reliably blown off. In addition, the same operation as the first aspect is achieved.

A dust removing device for a sewing machine according to a third aspect of the present invention is the sewing machine according to the first or second aspect, further comprising: a standby time detecting means for measuring a continuous time from the start of the standby state in which the sewing operation is not performed; A drive commanding means for receiving the standby time measured by the standby time detecting means and driving the drive control means at predetermined time intervals in the standby state. In this case, in a standby state in which the sewing operation is not performed, the drive control unit is driven at predetermined time intervals, and air is repeatedly blown between the needle plate and the thread wheel catching unit. Even when the lint generated therein cannot be sufficiently removed by air blowing after the sewing is completed, the remaining lint can be reliably removed at the time of sewing standby. In addition, the same operation as the first or second aspect is achieved.

According to a fourth aspect of the present invention, in the dust removing apparatus for a sewing machine according to any one of the first to third aspects, the tip of the air nozzle has an enlarged tip which is wider and flatter toward the tip. It is characterized by being formed as described above. In this case, by forming the tip of the air nozzle so as to have an enlarged tip that becomes wider and flatter toward the tip, the flow velocity of the jet air jetted from the air nozzle becomes faster and the jet is jetted over a wider area. Therefore, a large amount of dust and dust can be blown off over a wide range by a single air jet. In addition, the same effect as any one of claims 1 to 3 is exerted.

According to a fifth aspect of the present invention, there is provided a dust removing device for a sewing machine, wherein a sewing needle driven via a main shaft by a sewing machine motor, a needle plate having a sewing hole, and a thread catching means provided below the needle plate. A suction nozzle for sucking dust between the needle plate and the yarn catching means together with air, a suction means connected to the suction nozzle, and a drive control means for driving the suction means after sewing is completed. It is characterized by having. When sewing is started, as described in claim 1, dust and dirt are generated not only from the work cloth but also from the upper thread and the lower thread and enter between the needle plate and the thread catching means. Will accumulate. On the other hand, when sewing is completed, the suction means is driven by the drive control means, and the suction nozzle connected to the suction means sucks dust and dirt between the needle plate and the yarn catching means together with air.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 conceptually illustrates a two-needle sewing machine according to the present embodiment. The two-needle sewing machine 1 is a sewing machine for simultaneously performing bar-tacking sewing on both ends of a belt loop piece of pants. . As shown in FIG.
The sewing machine main body has a bed 2, a pillar 3 rising from a base end on the rear end side, an arm 4 and a head 5 extending horizontally forward from an upper end of the pillar 3.

The main shaft 6 in the arm portion 4 is driven by a sewing machine motor 7 composed of an AC servomotor, and the needle bar 8 is driven up and down via a needle bar crank mechanism 9 to move the needle bar 8 to a needle support 10 at the lower end of the needle bar 8. Has a pair of sewing needles 11a and 11b attached thereto,
The sewing needle 11b is mounted so that the mounting position can be adjusted in the front-rear direction. The bed section 2 includes a bed section main body section 12,
At the front end side, there is a shuttle module 13 arranged at a predetermined interval, and at the front end of the bed body 12, a half-rotary shuttle 15 for catching the yarn loop is provided. A half-turn shuttle 16 (corresponding to a thread catching means) for catching a thread wheel is provided at the end, and a lower thread bobbin is mounted in each of the half-rotation hooks 15 and 16.

A lower shaft 17 is disposed inside the bed main body 12 to drive the half-rotary shuttle 15 with the driving force of the main shaft 6. The lower shaft 17 is connected to a crank rod 18 connected to the crank 6 a of the main shaft 6. The gear 20 at the right end of the lower shaft 17 is driven to reciprocate via the sector gear 19, and the half rotary hook 15 is driven in synchronization with the vertical movement of the sewing needle 11a, as in a normal sewing machine.

The shuttle module 13 is basically a unit of a half-turn shuttle 16 and a shuttle drive motor 21 for driving the half-turn shuttle 16 independently of the main shaft 6. Is driven via a shuttle drive shaft by a shuttle drive motor 21 that is synchronously controlled with the main shaft 6, and performs bar-tacking on the sewing object in cooperation with the vertical movement of the sewing needle 11b. Here, the needle bar 8, sewing needles 11a and 11b provided on the two-needle sewing machine 1, the drive mechanism thereof, the balance mechanism, and the cloth feed mechanism for feeding and moving the work cloth independently in the front-rear direction and the left-right direction are described below. Since the configuration is the same as that of the existing two-needle sewing machine, a detailed description thereof will be omitted.

FIG. 2 shows a two-needle sewing machine 1 and a work table 22.
FIG. 3 is a right side view thereof, and as shown in FIG. 2 and FIG.
A control box 23 and a manual operation unit 24 are provided below the work table 22, and an operation having a liquid crystal display 26 and an operation unit 27 is provided at the right end of the work table 22. A panel 25 is provided upright. The description of the belt loop supply device 28 that is provided on the work table 22 and supplies the belt loop continuous body of the belt loop will be omitted.

Next, the internal mechanism of the shuttle module 13 will be briefly described. As shown in FIGS. 4 and 5, the shuttle module 13 includes a housing 30, a needle plate 31 attached to an upper end surface of the housing 30 with a screw, a half-turn shuttle 16,
A hook driving motor 21 for driving the half-turn hook 16 via a driving force transmission system, and a thread cutting mechanism 3 for cutting an upper thread and a lower thread.
5 and so on. At the rear end near the upper end of the shuttle module 13, a half-turn shuttle 16 is provided. The half-turn shuttle 16 has a shuttle shaft 32 oriented in the front-rear direction, a driver (not shown), and a tip at a tip end. It is composed of an inner hook driven back and forth by a driver, a bobbin case provided inside the inner hook, a cauldron body and the like.

Next, as shown in FIGS. 4 and 5, the thread cutting mechanism 35 is connected to a rear end of a movable blade drive lever 39 which is disposed in the vicinity of the lower side of the needle plate 31 in the front-rear direction. A movable blade 36 rotatably supported by the housing 30, and a fixed blade 3 fixed to the housing 30 below the movable blade 36.
7 and the lower thread guide plate 38 cooperate to form a needle hole 31a of the needle plate 31 and a guide hole 38a of the thread guide plate 38 from the work cloth.
To cut both upper and lower yarns extending downwardly.
The front end of the movable blade drive lever 39 is connected to the left end of the link plate 40 oriented in the left-right direction, and the right end of the link plate 40 is rotatably supported by the housing 30 via the vertical interlocking rod 43. I have.

Then, the link plate 40 swings from the release position indicated by the solid line in FIG. 5 to the operating position indicated by the dashed line, and the movable blade 36 rotates to the rotation position indicated by the dashed line. When returning to the release position, the movable blade 36
The upper and lower yarns are cut at the same time by the cooperation of the blade and the fixed blade 37.
The link plate 40 is urged toward its operating position by a tension coil spring 41 at the left end thereof, and is always driven by the extension driving of the thread cutting air cylinder 42 (see FIG. 7). At a predetermined thread trimming timing when the thread trimming air cylinder 42 is retracted and driven, the link shaft 40 is connected to the shuttle drive motor 21 by the drive shaft ( (Not shown) so as to reciprocate.

As shown in FIGS. 4 and 5, an air blow-out pipe 51 having a horizontal air nozzle 50 at its distal end facing between the needle plate 31 and the half-turn kettle 16 is attached to the upper end of the housing 30. Have been. This air nozzle 5
Numeral 0 is oriented so as to be directed to the swing range of the movable blade 36 of the thread cutting mechanism 35, and as shown in FIG. . The air nozzle 50 is, as shown in FIG. 4, composed of an electromagnetic switching valve via an air supply pipe 52 connected to an air blowing pipe 51 and a flexible air supply pipe 53 such as a vinyl tube. The air supply valve 54 is connected to an air supply source 55.

The air supply source 55 can supply pressurized air of about 5 kg / cm ² which is sufficient to blow off dust and dirt by the air nozzle 50 as described later. Here, the air supply source 55 and the air supply valve 5
4. The air supply means is constituted by the air blowing pipe 51, the air supply pipe 52, the air supply pipe 53, and the like.

Next, the control box 23 of the two-needle sewing machine 1
The outline of the control system of the control unit 60 provided in the first embodiment will be described with reference to the block diagram of FIG. Here, the belt loop supply device 28 is connected to the control unit 60. The control unit 60 includes a CPU 62 and a ROM 63
Microcomputer 61 including a RAM 64, an input / output interface (not shown), a drive circuit 65 for driving the sewing machine motor 7, a drive circuit 66 for driving the shuttle drive motor 21, an R-axis drive motor 67, and a θ-axis drive Driving circuits 69 and 70 for driving the motor 68 and a driving circuit 71 for driving the air cylinder 42 for thread trimming are provided.

The microcomputer 61 includes an operation panel 25, a start switch 72, a manual operation unit 24, a spindle origin sensor 73, and a shuttle shaft origin sensor 76.
And a first rotary encoder 7 provided on the sewing machine motor 7.
4, a second rotary encoder 75 provided on the shuttle drive motor 21, a thread cutting detection switch 77 for detecting that the movable blade 36 has returned to the original position and the thread cutting has been completed, and a control from the air supply source 55. Air nozzle 50 by switching pressure air
Air supply valve 54 comprising an electromagnetic switching valve for supplying air
And are connected respectively. Note that the R-axis drive motor 67 and θ
The shaft drive motor 68 is a motor that independently feeds the work cloth to be sewn in the R direction and the θ direction in the R-θ coordinate system.

The ROM 63 stores a plurality of types of pattern data for bar-tacking in association with the pattern numbers.
Control program (corresponding to a thread cutting control means) for executing a thread cutting operation by driving a two-needle sewing machine 1
A control program for various controls relating to the sewing control by the CPU, a control program for standby time detection control and air supply valve drive control, which will be described later, and which are unique to the present application, are stored. Further, the RAM 64 is provided with various work memories, buffers, counters, and the like. Next, a routine of the standby time detection control executed by the control unit 60 of the two-needle sewing machine 1 will be described with reference to the flowchart of FIG. However, the reference symbol Si (i = 11, 12, 1
3) are each step.

When the power is turned on to the two-needle sewing machine 1, this control is started. First, when the start switch 72 is operated to execute the bar-tacking sewing according to the sewing control program, and when the machine is not in the standby state, S11 is executed. Is repeated, while the bar-tacking finishes and the apparatus enters the standby state (S11: Yes), the duration from the start of the standby state, that is, the standby time timer for measuring the standby time is reset (S12). ), The timer of the standby time timer is executed (S13). When the predetermined time (for example, about 1 minute) has not elapsed (S14: No) based on the timer value of the standby time timer (S14: No), and when the sewing operation has not been started (S15: No), S14 to S15 Is repeated.
Here, S11 to S13 correspond to the standby time detecting means.

Then, by cumulatively adding the predetermined time, when the predetermined time has elapsed from the previous output of the drive signal (S14: Yes), a drive command for switching and driving the air supply valve 54 is output (S17). , S13 and the subsequent steps are repeatedly executed. On the other hand, when the sewing operation is started during the repeated execution of S13 to S15 (S15: Yes), the operation of the standby time timer is stopped (S16), and S11 and the subsequent steps are executed. Here, S14 and S17 correspond to the drive command means. Next, an air supply valve drive control routine will be described with reference to the flowchart of FIG. Here, drive control means is constituted by the air supply valve drive control, the microcomputer 61 and the like.

When the power is turned on to the two-needle sewing machine 1, this control is started. First, a thread trimming completion signal from the thread trimming detection switch 77 and a drive command signal from the standby time detection control are used to control the thread. When the cutting completion signal is input and the upper thread and the lower thread are cut with the end of sewing (S20: Yes)
), The air supply valve 54 is kept for a predetermined time (for example, about 0.1
(S22), and the dust removal operation is performed (S22). Thereby, pressurized air from the air supply source 55 is gushes out of the air nozzle 50 via the air supply valve 54, the air supply pipe 52 and the air blow-out pipe 51, and the gap between the needle plate 31 and the half-rotary shuttle 16 is released. Air is blown on

As a result, dust and dirt such as thread waste generated under the needle plate 31 during sewing and thread cutting are swung by the movable blade 36 for thread cutting, as shown by a two-dot chain line in FIG. Surrounding area D1,
Dust and the like are particularly collected in D2 and the like, but dust and dirt such as lint accumulated in these areas below the needle plate 31 are reliably blown off by the powerful and wide-spray air from the air nozzle 50. On the other hand, when the drive command signal is input (S21: Yes), the dust removing operation of S22 is similarly performed. This makes it possible to use a cotton thread as the upper thread or lower thread, or to sew a fluffy work cloth that tends to emit dust. Even when the air cannot be sufficiently removed by air blowing, the remaining thread waste can be reliably removed by periodically and repeatedly air-injecting the air in the sewing standby state.

Next, the operation and effect of the air supply valve drive control will be described. An air nozzle 50 that blows air between the needle plate 31 and the half-turn kettle 16 and an air supply source 55 that supplies pressurized air to the air nozzle 50 are provided. The sewing is completed and the thread trimming operation is completed. At this time, pressurized air from the air supply source 55 is spouted vigorously from the air nozzle 50, and air is blown between the needle plate 31 and the half-turn kettle 16. In FIG. 5, dust and dirt such as lint generated on the lower side of FIG.
Dust and dust accumulated in the areas D1 and D2 and the like surrounded by the dashed-dotted line are particularly accumulated in the areas D1 and D2 below the needle plate 31 by the powerful and widespray air from the air nozzle 50. The half-turn shuttle 16 is reliably blown to the outside from the open end behind.

Further, since the dust removing operation is not performed during the sewing operation, the quality of the sewn product can be maintained without affecting the stitch formation. Further, when the bar-tacking sewing is completed and the apparatus enters a standby state, the dust removing operation is repeatedly performed every time a predetermined time elapses, so that dust or dust generated during sewing or thread cutting is removed after thread cutting. Even when the air cannot be sufficiently removed by air blowing, the remaining thread waste can be reliably removed by periodically and repeatedly air-injecting the air in the sewing standby state. Further, since the tip of the air nozzle 50 is formed so as to have an enlarged tip which becomes wider and flatter toward the tip, the jet air jetted from the air nozzle 50 can be powerful and jetted at a wide angle. A large amount of dust and dust can be blown off over a wide area by one air jet.

A modification of the above embodiment will be described. 1) As shown in FIG. 10, the movable blade 36 and the link plate 40
A closed suction chamber is formed inside a movable blade drive lever 39A that connects the suction nozzle and a suction nozzle 39a formed of a plurality of minute suction holes on its lower surface wall. The air suction valve 81 and the air suction mechanism 82 are connected via the air suction pipe 80, and when the thread trimming operation is completed, and further in the standby state, the air suction valve driving control is executed to execute the air suction valve 8
By driving 1, dust is periodically sucked from the suction nozzle 39 a, and dust and dust between the needle plate 31 and the half-turn pot 16 can be sucked together with air. Here, a suction unit is configured by the air suction pipe 80, the air suction valve 81, the air suction mechanism 82, and the like.

2) The dust removing operation may be performed when a predetermined time has elapsed from the start of the thread trimming and the thread trimming operation is completed. It may be performed at the time when the grabbing is executed. Further, the dust removing operation may be performed every time the sewing operation is completed two or three times. 3) Furthermore, at times other than sewing, dust removal may be performed by any trigger signal, such as when replacing a bobbin. That is, since the specific configuration of the present embodiment is the same as that described in Japanese Patent Application No. 7-328094 filed by the present applicant, the description of the specific configuration will be omitted. Various trigger signals can be considered, such as when the value becomes "0", the sewing machine stops, when the bobbin exchange switch is operated, when the shuttle module is switched to the retracted position, or when the shuttle module is switched from the retracted position to the use position.

4) The air blowing pipe 51 may be provided with a plurality of air nozzles 50. 5) A nozzle for blowing air and a nozzle for sucking air may be provided at the same time. 6) Various modifications may be made to the above-described embodiment based on existing technology or technology obvious to those skilled in the art.
Further, the present invention is applied to dust removers of various sewing machines such as a lockstitch sewing machine having a half-rotation hook or a full-rotation hook, and the rotary hook is driven by a sewing machine motor, and a lock sewing machine having a looper instead of the shuttle. Of course you can.

[0035]

According to the first aspect of the present invention, a sewing needle driven via a main shaft by a sewing machine motor, a needle plate having a sewing hole, and a thread wheel catching means provided below the needle plate are provided. An air nozzle that blows air in a sewing machine with
Since the air supply means for supplying pressurized air to the air nozzle and the drive control means for driving the air supply means after the sewing operation is completed, the dust removing operation is not performed during the sewing operation. While maintaining the quality of the sewn product without affecting the eye formation, the pressurized air blown out from the air nozzle after the sewing is completed. Can be blown off.

According to the second aspect of the invention, the same effect as in the first aspect is obtained, but the sewing machine operates the thread cutting mechanism for cutting the upper thread and the lower thread and the thread cutting mechanism at the end of sewing. Cutting control means, wherein the drive control means drives the air supply means when the thread cutting operation by the thread cutting control means is completed, so that the yarn cutting mechanism cuts the upper thread and the lower thread. The lint generated at the time can be reliably blown off. According to the third aspect of the present invention, the same effects as those of the first or second aspect are obtained, but the standby time detecting means and the drive commanding means are provided, so that thread waste generated during sewing can be terminated. Even if the air cannot be sufficiently removed by air spraying later, the remaining thread waste can be reliably removed at the time of sewing standby.

According to the fourth aspect of the present invention, the same effect as any one of the first to third aspects is obtained, but the front end portion of the air nozzle is widened and flattened toward the front end. Therefore, it is possible to intensify the jet air jetted from the air nozzle and to jet it at a wide angle, and to blow a large amount of dust or dust over a wide area by one air jet.

According to the fifth aspect of the present invention, a sewing needle driven via a main shaft by a sewing machine motor, a needle plate having a sewing hole,
In a sewing machine provided with a yarn catching means provided below the needle plate, a suction nozzle for sucking dust between the needle plate and the yarn catching means together with air, and a suction nozzle connected to the suction nozzle Means and a drive control means for driving the suction means after the sewing is completed, so that the dust removing operation is not performed during the sewing work, so that the stitch formation is not affected and the quality of the sewn product is reduced. While it can be held, after the sewing is completed, dust and dirt between the needle plate and the thread wheel catching means can be sucked together with air by the suction nozzle connected to the suction means.

[Brief description of the drawings]

FIG. 1 is a perspective view conceptually showing a two-needle sewing machine according to an embodiment of the present invention.

FIG. 2 is a front view of a sewing device including a two-needle sewing machine.

FIG. 3 is a right side view of the sewing apparatus of FIG. 2;

FIG. 4 is a vertical sectional right side view of a main part of the shuttle module.

FIG. 5 is a cutaway plan view of a main part of the shuttle module.

FIG. 6 is an enlarged perspective view of an air nozzle.

FIG. 7 is a schematic block diagram of a control system of the two-needle sewing machine.

FIG. 8 is a schematic flowchart of a standby time detection control routine.

FIG. 9 is a schematic flowchart of an air supply valve drive control routine.

FIG. 10 is a diagram corresponding to FIG. 5 according to a modified embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 2-needle sewing machine 6 Main shaft 7 Sewing machine motor 16 Half rotary hook 31 Needle plate 31a Needle hole 35 Thread cutting mechanism 36 Movable blade 37 Fixed blade 55 Air supply source 50 Air nozzle 60 Control unit 62 CPU 63 ROM 64 RAM 39a Suction nozzle 77 Thread trimming detection switch

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Akira Nishio, Inventor, Brother Industries, Ltd., 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi (72) Inventor Koichi Akabane 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi, Brother Industries, Ltd. (72) The inventor Takashi Kondo 15-1 Naeshiro-cho, Mizuho-ku, Nagoya Brother Industries, Ltd.

Claims (5)

[Claims] 1. A sewing machine comprising: a sewing needle driven by a sewing machine motor via a main shaft; a needle plate having a sewing hole; and a thread catching means provided below the needle plate. An air nozzle for blowing air between the air nozzle and the yarn catching means, an air supply means for supplying pressurized air to the air nozzle, and a drive control means for driving the air supply means after sewing is completed. A dust removing device for a sewing machine. 2. The sewing machine according to claim 1, further comprising: a thread cutting mechanism for cutting the upper thread and the lower thread; and cutting control means for activating the thread cutting mechanism at the end of sewing. The dust removing device for a sewing machine according to claim 1, wherein the air supply means is driven when the cutting operation is completed. 3. A standby time detecting means for measuring a continuous time from the start of a standby state in which the sewing operation is not executed, and a standby time measured by the standby time detecting means.
2. A drive commanding means for driving the drive control means at predetermined time intervals in a standby state.
Or the dust removing device for a sewing machine according to 2. 4. The sewing machine according to claim 1, wherein a tip portion of the air nozzle is formed so as to have an enlarged tip portion that becomes wider and flatter toward the tip. Dust removal device. 5. A sewing machine comprising: a sewing needle driven via a main shaft by a sewing machine motor; a needle plate having a sewing hole; and a thread catching means provided below the needle plate. A suction nozzle for sucking dust between the thread catching means and the air together with air, a suction means connected to the suction nozzle, and a drive control means for driving the suction means after sewing is completed. Machine that removes dust.