JP2010035679A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent defective operation of a knife by removing cloth waste or the like attached to the upper surface of a knife support table. <P>SOLUTION: A sewing machine 100 includes: a sewing needle 20a; the knife 30 forming a linear slit in a cloth; a knife support table 31 supporting the knife; a knife bar 32 the lower end of which is connected with the knife support table; a knife drive mechanism 33 which arranges the knife bar at a waiting position normally but continuously and vertically moves the same when the sewing needle generates stitches; a bearing 34 supporting the knife bar in a vertically movable manner; a needle thread cutting knife 51 which cuts a needle thread, an air cylinder 53 which moves the needle thread cutting knife forward and backward; an electromagnetic valve 54 which supplies air to an air cylinder when the sewing needle finishes the generation of the stitches; and a supply tube 55 as the channel of the air supplied to the air cylinder. The sewing machine 100 is provided with an air supply tube 56 branched from the supply tube 55 and with the end facing the upper surface of the knife support table at the waiting position of the knife support table to spray air for removing dust on the upper surface of the knife support table from the end. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewing machine that forms a seam while forming a cut with a knife on a cloth to be sewn.

The sewing machine is provided with many drive mechanisms inside the sewing machine frame. There is a sewing machine provided with a dustproof device for preventing the entry of dust and dirt into the inside of the sewing machine frame because dust and dust get entangled in the drive mechanism, which adversely affects driving.
Specifically, the dustproof device rotates the fan provided on the main shaft of the sewing machine together with the main shaft, thereby causing the air inside the sewing machine frame to flow, discharging the air inside the sewing machine frame to the outside, and (See, for example, Patent Document 1).
JP 2006-326032 A

Incidentally, as shown in FIG. 8, there is a sewing machine 200 including a knife 201 that forms a cut in a cloth by vertical movement. Usually, the knife 201 is supported by a knife support table 202, and the knife support table 202 is connected to the lower end of the knife bar 203. The scalpel bar 203 is connected to a scalpel drive mechanism 205 (see FIG. 9) inside the sewing machine frame 204 so as to be movable up and down. The knife rod 203 is supported by a bearing 206 so as to be movable up and down above the knife support table 202.
Since the mechanism related to the knife 201 is configured as described above, cloth waste, dust, and the like generated by cutting the cloth due to the vertical movement of the knife 201 adhere to the upper surface 202a of the knife support base 202 and accumulate. Therefore, as shown in FIGS. 9 (a) and 9 (b), after moving the knife 201 up and down to cut the cloth, as shown in FIG. 9 (c), when raising the knife 201 to the standby position, the knife support Cloth waste, dust, and the like are compressed between the table 202 and the bearing 206. By repeating this, cloth waste, dust and the like enter from the gap between the female bar 203 and the bearing 206, and the appropriate clearance between the female bar 203 and the bearing 206 is clogged. As a result, smooth sliding between the knife rod 203 and the bearing 206 is blocked, and the knife rod 203 is locked, causing the knife 201 to malfunction.
Here, in the conventional dustproof device, the air in the sewing machine frame 204 flows out to the outside through a slight gap between the female bar 203 fixed to the sewing machine frame 204 and the bearing 206 to prevent entry of cloth waste or dust. Was impossible and could not solve the above problem. Further, in the conventional dustproof device, it is conceivable to remove cloth waste or dust on the upper surface 202a of the knife support base 202 with the wind of the fan. However, the conventional dustproof device uses the drive of the upper shaft. It is impossible to remove cloth waste, dust, and the like on the female support base that is located below and away from the upper shaft with the wind of the fan.

  Therefore, the present invention has been made to solve the above-described problem, and provides a sewing machine that can prevent the operation failure of the knife by removing cloth waste, dust, and the like that adheres to the upper surface of the knife support base. The purpose is to do.

  The invention according to claim 1 includes a sewing needle that forms a seam in the cloth by vertical movement, a knife that forms a linear cut in the cloth by vertical movement, and a knife support that supports the proximal end side of the knife. The scalpel is arranged along the vertical movement direction of the scalpel and has a lower end connected to the scalpel support base and a scissor connected to the scalpel bar. The scalpel is always in a standby position, and the sewing needle forms a seam. A knife drive mechanism that continuously moves up and down, a bearing that supports the knife bar so as to move up and down, and an upper thread whose tip moves forward and backward near the sewing needle and cuts the upper thread A cutting knife, an air cylinder that moves the upper thread trimming knife forward and backward, an electromagnetic valve that supplies air to the air cylinder at the end of stitch formation by the sewing needle, the air cylinder and the electromagnetic valve are connected, Supply to air cylinder And a supply pipe that serves as a flow path for air to be branched from the supply pipe, the end of which is provided toward the upper surface of the female support in the standby position of the female support, and the end An air blowing tube for blowing air for removing dust on the upper surface of the knife support is provided.

According to the first aspect of the present invention, since the air blowing pipe is configured to branch from the supply pipe, when the solenoid valve is driven, the air sent out from the solenoid valve passes through the supply pipe to the air cylinder. The upper thread trimming knife is lowered from the standby position. On the other hand, the air in the supply pipe is divided into the supply pipe side and the air blowing pipe side at the branch point with the air blowing pipe, and the air flowing into the air blowing pipe side is at the standby position of the knife support from the end. It is discharged toward the upper surface of the knife support.
Thereby, when the knife support is raised to the upper standby position, the cloth waste and dust on the upper surface of the knife support are removed by the air discharged from the air blowing tube. Therefore, the cloth support and the dust can be removed before the knife support rises to the standby position and compresses the cloth and dust with the bearing. Etc. do not accumulate, and it becomes difficult for cloth waste, dust, etc. to enter from the gap between the female bar and the bearing.
Therefore, it is possible to prevent the operation failure of the knife by removing the cloth waste, dust and the like which adheres to the upper surface of the knife support base.
In addition, since the air blowing from the air blowing tube can be linked to the raising and lowering of the upper thread trimmer, the upper surface of the knife support can be cleaned each time the thread trimmer is finished after sewing is completed. Since cloth scraps and dust on the upper surface of the support base are periodically removed, there is no need to perform any work just to clean the upper surface of the female support base, and the worker always remembers to clean. There is no need.

According to the first aspect of the present invention, when the knife support is raised to the upper standby position, cloth waste and dust on the upper surface of the knife support are removed by the air discharged from the air blowing tube. Therefore, the cloth support and the dust can be removed before the knife support rises to the standby position and compresses the cloth and dust with the bearing. Etc. do not accumulate, and it becomes difficult for cloth waste, dust, etc. to enter from the gap between the female bar and the bearing.
Therefore, it is possible to prevent the operation failure of the knife by removing the cloth waste, dust and the like which adheres to the upper surface of the knife support base.
In addition, since the air blowing from the air blowing tube can be linked to the raising and lowering of the upper thread trimmer, the upper surface of the knife support can be cleaned each time the thread trimmer is finished after sewing is completed. Since cloth scraps and dust on the upper surface of the support base are periodically removed, there is no need to perform any work just to clean the upper surface of the female support base, and the worker always remembers to clean. There is no need.

Hereinafter, the best mode of a sewing machine according to the present invention will be described in detail with reference to the drawings.
<Configuration of sewing machine>
As shown in FIG. 1, the sewing machine 100 according to the present embodiment is an edge stitch sewing machine that forms a seam with two sewing needles while making a cut in a cloth. A bead-sewn sewing machine sews a cloth on a body cloth, and forms straight cuts along the feeding direction of these fabrics and substantially V-shaped cuts at both ends of the straight cuts. The sewing machine to be formed.
In this embodiment, the respective directions are determined with reference to the XYZ axes shown in the drawings, the Z-axis direction coincides with the vertical movement direction of the knife, which will be described later, and the plane on which the sewing operation is performed is Z A direction that is perpendicular to the axial direction and is parallel to the work plane and in which cloth feeding is performed is defined as an X-axis direction, and a direction that is parallel to the work plane and orthogonal to the X-axis direction is defined as a Y-axis direction.

  As shown in FIG. 1, a sewing machine 100 includes a sewing machine table 11 serving as a sewing work table, and a needle bar mechanism (not shown) that controls the operation of a needle bar that holds a pair of balances and sewing needles (not shown). A sewing machine frame 12 disposed on the table 11, a large pressing mechanism 1 as a cloth feeding mechanism for feeding a cloth made of cloth and a drape, a binder 2 for pressing the drape from the upper side of the cloth, and a sewing machine A knife mechanism 3 (see FIG. 3) that is supported by the frame 12 and that is arranged on the downstream side in the cloth feed direction of each sewing needle to raise and lower the middle of each sewing needle to form a linear cut in each cloth. As a corner knife mechanism 4 that forms a substantially V-shaped cut at positions that become both ends of a straight cut, an upper thread trimming mechanism 5 that cuts the upper thread at the end of sewing, and a control means that controls each of the above parts Control device 6 ( 5 reference), and a.

(Sewing table and sewing frame)
As shown in FIG. 1, the sewing machine table 11 is used in a horizontal state with its upper surface parallel to the XY plane. The upper surface of the sewing machine table 11 is formed in a long rectangular shape along the cloth feeding direction F, that is, the X-axis direction. A large presser mechanism 1 and a binder 2 are disposed on the sewing table 11, and a corner knife mechanism 4 is disposed on the lower side of the sewing table 1.
The sewing machine frame 12 is provided with two sewing needles 20a and 20a that move up and down by driving the upper shaft to form seams in the fabric. A needle plate 13 is provided at a position below the two sewing needles 20 a, 20 a in the sewing machine table 11. The needle plate 13 is provided with a needle hole corresponding to each of the two sewing needles 20a, 20a, and a horizontal hook (not shown) is provided below each needle hole. That is, the sewing thread inserted through each of the sewing needles 20a and 20a is captured by the corresponding horizontal hook at the lower side of the needle plate 13, and is entangled with the lower thread fed out from the horizontal hook. It is like that.
Furthermore, a slit into which the knife 30 is inserted is formed in the middle of the two needle holes of the needle plate 13 and downstream in the cloth feeding direction F, and a fixing (not shown) that cuts the cloth in cooperation with the knife 30. A knife is placed. This fixed knife constitutes the knife mechanism 3.

  The sewing machine frame 12 extends along the Y-axis direction from the bed portion 12a disposed immediately next to the intermediate position in the longitudinal direction of the sewing machine table 11, the vertical body portion 12b erected from the bed portion 12a, and the upper end portion of the vertical body portion 12b. The arm part 12c is extended and the main structure of the female mechanism 3 is stored in the arm part 12c. Further, the two needles 20a, 20a and the knife 30 are supported in a suspended manner from the lower end on the distal end side of the arm portion 12c.

(Large holding mechanism)
As shown in FIG. 1, the large presser mechanism 1 includes large pressers 15 and 15 for pressing each of both ends in the width direction of the ball set set on the binder 2, and support for supporting these large pressers 15 and 15. A body 16, an air cylinder (not shown) that moves the large pressers 15, 15 up and down via the support body 16, and the cloth and body cloth pressed by the large pressers 15, 15 through the support body 16 in the cloth feed direction F The holding motor 18 (see FIG. 5) is provided separately from the spindle motor 17 (see FIG. 5).
Each of the large pressers 15 and 15 is a rectangular flat plate, and each of the large pressers 15 and 15 is supported by the support 16 in a state where the longitudinal direction is along the X-axis direction. The large pressers 15 and 15 are supported so that the flat plate surfaces thereof are parallel to the XY plane. Then, it can be switched to two upper and lower positions by driving the air cylinder. When the air cylinder is in the upper position, it is separated from the upper surface of the sewing machine table 11 and becomes the upper surface height of the sewing machine table 11 at the lower position. Further, the two large pressers 15 and 15 are supported in a state of being separated so that at least the standing plate portion 22 of the binder 2 can be passed therebetween.
The support 16 is supported on the sewing machine table 11 so as to be movable along the X-axis direction, and the two large pressers 15 and 15 to be supported pass through both sides of the vertical movement path of the two needles 20a and 20a. Is arranged. The support 16 is driven by a pressing motor 18 through a ball screw mechanism (not shown).

(binder)
As shown in FIGS. 1 and 2, the binder 2 includes a bottom plate portion 21 that is an elongated flat plate, a standing plate portion 22 that is erected vertically on the top surface along the longitudinal direction of the bottom plate portion 21, and a vertical plate. The guide member 23 that guides the ball cloth B while avoiding the knife 30 and the both end portions in the width direction of the ball cloth are fed along both surfaces of the standing plate portion 22 to the downstream end portion of the plate portion 22 in the cloth feeding direction. And a vertical guide portion 24 for guiding as described above.
The binder 2 is supported by a support mechanism (not shown) including an air cylinder, and is retracted away from the position below the two sewing needles 20a and 20a when not in use, as shown in FIG. And in use, it is set to the needle plate position by driving the air cylinder.

The bottom plate portion 21 is formed in a rectangular shape and is supported so that, when in use, the longitudinal direction thereof is parallel to the X-axis direction and the bottom surface thereof is placed facing the upper surface of the sewing machine table 11. ing. Further, substantially U-shaped cutouts 21a and 21a are formed at the front end portion of the bottom plate portion 21 in the cloth feeding direction as grooves for allowing the two sewing needles 20a and 20a to drop needles, respectively.
The standing plate portion 22 is a flat plate having a rectangular shape as a whole except for a portion in the vicinity of the guide member 23, and on the upper surface of the bottom plate portion 21, at an intermediate position in the width direction (Y axis direction) of the bottom plate portion 21. It is erected vertically with the bottom plate portion 21 aligned with the longitudinal direction. That is, the binder 2 is integrally formed so that the bottom plate portion 21 and the upright plate portion 22 have an inverted T-shape when viewed from the longitudinal direction.

  Then, when the bedcloth is set on the needle plate 13 so as to overlap the upper side of the cloth, the binder 2 is placed from above, and both end portions in the width direction of the ball cloth are folded back and both ends in the width direction of the bottom plate portion 21. It is raised upward from the upper portion, and is further held by the large pressers 15 and 15 so that both ends in the width direction of the ball are along the side surfaces on both sides of the upright plate portion 22 respectively. In other words, the ball cloth is in a state of being lined from one side surface of the standing plate portion 22 to the other side surface 22 through the bottom plate portion 21. In this way, in a state where the ball 2 is set to be wound around the binder 2, sewing is performed with the two sewing needles 20 a and 20 a on both sides of the standing plate portion 22 while feeding the ball and the cloth, and the knife 30 A straight cut is formed by vertical movement.

  As described above, two flat plates are provided at both ends in the width direction of the ball cloth so as to be close to and opposite to both side surfaces of the upright plate portion 22 so as to maintain a state along both side surfaces of the upright plate portion 22. Shaped vertical guide portions 24, 24 are provided. Each of the vertical guide portions 24 is bent so that a gap with the upright plate portion 22 is enlarged at the upstream end portion in the cloth feeding direction, and a constant gap is maintained on the downstream side. That is, the width direction one end part of the ball cloth is invited into the gap between each vertical guide part 24 and the upright plate part 22, and the one end part is guided so as to maintain a state along one side surface of the upright plate part 22. It is supposed to be.

  Further, a knife 30 is disposed on an extension line of the upright plate portion 22 immediately downstream of the binder 2 in the cloth feeding direction F. Since both end portions in the width direction of the ball cloth move to the downstream side in the cloth feeding direction F along the upright plate portions 22, guide members 23 are provided so as not to be cut by the knife 30. The guide member 23 is integrally formed from the downstream end portion of the upright plate portion 22 in the cloth feeding direction F, and is bifurcated in the cloth feeding direction F so that the shape in plan view is substantially V-shaped. It forms so that it may become a shape. And the guide member 23 is arrange | positioned so that it may approach as close as possible with respect to the knife 30, and may cover the said knife 30 from both sides, in order to guard a drape from the knife 30 more effectively. With this shape, both ends in the width direction of the bead fabric are guided in a direction away from the standing plate portion 22 through the gap between the vertical guide portion 24 and the guide member 23 when feeding the cloth, and the knife 30 is moved. Guided in a direction to avoid.

(Female mechanism)
As shown in FIG. 3, the knife mechanism 3 is always in the upper standby position when no seam is formed, and when the sewing needles 20a, 20a form a seam, a linear cut is formed in the fabric by continuous vertical movement. A knife 30, a fixed knife (not shown) that is fixed under the needle plate 13 and slidably contacts the knife 30 to promote cutting of the fabric, a knife support base 31 that supports the proximal end side of the knife 30, and the longitudinal direction is the knife 30 is arranged along the up-and-down movement direction of 30, is provided with a female support base 31 at the lower end portion and is supported to be slidable along the Z-axis direction in the arm portion 12c, and is connected to the female rod 32, A scalpel drive mechanism 33 that moves the scalpel bar 32 up and down, and a scalpel bar metal 34 as a bearing that is provided on the arm 12c and supports the scalpel bar 32 so as to be movable up and down above the scalpel support base 31 are provided. .
The knife drive mechanism 33 is provided with a knife motor 331 that is a stepping motor serving as a driving source for the standby position of the knife 30 and a continuous vertical movement, and an eccentric cam 332 that is eccentrically attached to the output shaft 331a of the knife motor 331. A plurality of link bodies 333 that transmit the vertical movement driving force to the knife rod 32, and an air cylinder as an actuator that serves as a drive source for switching operation between the knife 30 in a cutable state (lower position) and a cutting restricted state (upper position). 334, and a stopper 335 for stopping the plunger when the air cylinder 334 protrudes at a predetermined position.

When the air cylinder 334 is in the retracted position (the state shown in FIG. 3), the knife mechanism 3 is in a severable state in which the rotational driving force of the knife motor 331 is converted into a vertical reciprocating motion to the knife 30 and transmitted. Can be switched to a cutting restriction state in which the rotational driving force of the knife motor 331 is not transmitted to the knife 30 when the position is the forward position (not shown).
When the knife motor 331 is driven to rotate with the air cylinder 334 retracted, the knife rod 32 and the knife 30 are moved via the plurality of link bodies 333 by the eccentric cam 332 mounted on the output shaft 331a directed in the Y-axis direction. The cutting operation is performed by moving up and down.
On the other hand, when the air cylinder 334 is in the advanced state, the plurality of link bodies 333 are arranged so that the power of the female motor 331 is not transmitted to the female bar 32 and the female 30 is retracted above the needle plate 13. Is maintained.
Therefore, the air cylinder 334 is driven so that the knife 30 can be switched between the cuttable state and the cutting restricted state.

(Corner knife mechanism)
As shown in FIG. 1, the corner knife mechanism 4 is arranged below the sewing machine table 11 and in the passage of the large pressers 15 and 15 by the large presser mechanism 1, and the balls conveyed by the large presser mechanism 1. By cutting the corner knife 41 through the edge cloth and the body cloth from below, a substantially V-shaped cut is formed at the positions corresponding to both ends of the straight cut.
In other words, the corner knife mechanism 4 includes two corner knives 41 and 41 arranged at intervals along the cloth feeding direction F, and a vertical movement motor (not shown) that moves the corner knives 41 and 41 up and down, respectively. ing.

Each corner knife 41 is composed of a pair of triangular knives arranged so that the shape seen from the distal end side is V-shaped, and is supported with the distal end portion facing upward. And by moving up and down from the upper surface of the sewing machine table 11 by the vertical movement motor, it is possible to form a V-shaped cut in the fabric. Each corner knife 41 can adjust the angle between a pair of triangular knifes, and can correspond to the interval between two stitches by the two sewing needles 20a, 20a.
The two corner knives 41 are supported so that the openings of the V-shaped cuts formed by the two corner knives 41 are opposite to each other. Further, the interval between the two corner knives 41 can be adjusted.

  The corner knife mechanism 4 has two corner knife 41, when the fabric formed with two stitches and a linear cut is conveyed by the large pressing mechanism 1 to a position directly above the corner knife mechanism 4. By moving 41 up and down at each end position of the cut, two V-shaped cuts are formed in the fabric. That is, by the corner knife mechanism 4, one end cut from one end of the straight cut to the nearest end of each of the two seams, and the other of the straight cut Another cut is formed from the end to the closest end of each of the two seams.

(Upper thread trimming mechanism)
As shown in FIGS. 3 and 4, the upper thread trimming mechanism 5 functions as an upper thread trimming knife that advances and retreats in the vicinity of the sewing needles 20a and 20a and cuts the upper thread passed through the sewing needles 20a and 20a. A moving knife 51, a moving knife 51 provided adjacent to the moving knife 51, and a moving knife 51 moving in a state where the upper thread is locked to clamp and cut the upper thread, and advancing and retracting the upper thread trimming knife 51 An air cylinder 53 to be supplied, an electromagnetic valve 54 for supplying air to the air cylinder 53, a supply pipe 55 for connecting the air cylinder 53 and the electromagnetic valve 54 and serving as a flow path for air supplied to the air cylinder 53, An air blowing pipe 56 branched from the pipe 55.

  The moving knife 51 and the fixed knife 52 are attached to the sewing machine frame 12, and both the knife 51, 52 are disposed so as to overlap each other. The moving knife 51 is configured to slide along the surface of the fixed knife 52 so that the tip thereof advances and retreats with respect to the vicinity of the sewing needles 20a and 20a. A hook-like locking hook 51 a that locks the upper thread is formed at the tip of the moving knife 51.

The air cylinder 53 moves the moving knife 51 forward and backward with respect to the sewing needles 20 a and 20 a and is provided on the sewing machine frame 12. The piston of the air cylinder 53 is connected to the moving knife 51, and the moving knife 51 is moved by the movement of the piston of the air cylinder 53. An electromagnetic valve 54 for supplying air into the cylinder is connected to the air cylinder 53 by a supply pipe 55. The supply pipe 55 has one end connected to the air cylinder 53 and the other end connected to the electromagnetic valve 54. That is, the supply pipe 55 serves as a flow path for air supplied from the electromagnetic valve 54.
Further, two supply pipes 55 a and 55 b are connected to the electromagnetic valve 54, the supply pipe 55 a is connected to one end of the air cylinder 53, and the supply pipe 55 b is connected to the other end of the air cylinder 53. . That is, by providing a difference in the amount of air supplied from the supply pipes 55a and 55b to the air cylinder 53, the piston of the air cylinder 53 can be moved within the cylinder, and the moving knife 51 can be moved forward and backward. Further, by adopting such a structure, the piston can be kept stopped at one place in the air cylinder 53. This is necessary when the moving knife 51 is made to wait at the standby position.

In the middle of the supply pipe 55a, a branch valve 57 for branching the pipe is provided. The branch valve 57 divides the air supplied from the electromagnetic valve 54 into two hands. One of the discharge ports is connected to the supply pipe 55 a and the other of the discharge ports is connected to the air blowing pipe 56.
One end of the air blowing tube 56 is connected to the branch valve 57, and the other end is provided toward the upper surface of the knife support base 31 at the standby position of the knife support base 31. That is, air for removing dust on the upper surface of the knife support 31 that has moved from the other end of the air blowing tube 56 to the standby position can be blown.

(Control device)
As shown in FIG. 5, in the control device 6, a spindle motor 17, a pressing motor 18, and a female motor 331 to be controlled are connected via drivers 17a, 18a, and 331a, respectively. In addition, an air cylinder for moving the binder 2 up and down, an air cylinder for moving the large pressers 15 and 15 up and down, and motors for vertical movement (not shown) for moving up and down the corner knives 91 and 91 are connected to the control device 6 via a driver. It is connected. Further, an electromagnetic valve 340 of an air cylinder 334 that switches between an operating state and a non-operating state of the knife 30 is connected via a driver 340a. Further, a needle swing motor 19 for swinging the sewing needles 20a, 20a is connected to the control device 6 via a driver 19a. Further, an electromagnetic valve 53 of an air cylinder 52 that switches between an operating state and a non-operating state of the upper thread trimming knife 51 is connected via a driver 53a.
The control device 6 includes a CPU 61 that controls driving of each unit and a memory 62 that stores a sewing program and sewing data related to sewing. The CPU 61 is based on the sewing program and sewing data related to sewing stored in the memory 62. Then, by controlling the driving timing, driving time, and driving speed of each part, the knife 30 is driven to form a linear cut in the fabric, and the two sewing needles 20a and 20a are driven to perform the edge stitching. Can be applied.

<Operation of the sewing machine>
Next, an operation of removing cloth waste and dust on the upper surface of the knife support base 31 using the air blowing pipe 56 will be described together with the operation of the sewing machine.
As shown in FIG. 6, when the start switch for starting sewing is turned on by the operator (step S1: YES), the CPU 61 of the control device 6 detects the ball based on the sewing program and sewing data stored in the memory 62. Edge sewing is started (step S2). Further, in step S2, the knife 30 is moved up and down in conjunction with the ball stitching to form a linear cut between the two stitches.
When the set sewing and cut formation are completed (step S3: YES), the CPU 61 ends the sewing by stopping the spindle motor 17 and raises the knife 30 to the standby position (step S4).
Next, the CPU 61 drives the electromagnetic valve 54 to supply air to the air cylinder 53 (step S5). The air supplied from the electromagnetic valve 54 passes through the supply pipe 55a and eventually reaches the branch valve 57, where it is divided. The air that has flowed toward the supply pipe 55a flows into the cylinder of the air cylinder 53, and drives the piston with the air pressure in the cylinder. As a result, the moving knife 51 connected to the piston descends toward the vicinity of the sewing needles 20a, 20a (step S6). Moreover, the air which flowed to the air blowing pipe 56 side is discharged | emitted from the edge part of the air blowing pipe 56 outside a pipe | tube (step S6). At this time, as shown in FIG. 7, the end portion of the air blowing tube 56 blows the upper surface 31a of the knife support base 31, so that cloth waste, dust, etc. accumulated on the upper surface of the knife support base 31 due to cutting of the cloth or the like The air blown from the air blowing pipe 56 is blown away.
When the moving knife 51 descends and the upper thread is locked, the CPU 61 drives the electromagnetic valve 54 again, and raises the moving knife 51 by the balance of the amount of air supplied from the supply pipes 55a and 55b (step S7). . As the moving knife 51 rises, the upper thread is cut by sandwiching the upper thread between the moving knife 51 and the fixed knife 52 (step S8). This completes the sewing work.

<Action and effect>
As described above, since the air blowing pipe 56 is configured to branch from the supply pipe 55a, when the electromagnetic valve 54 is driven, the air sent from the electromagnetic valve 54 passes through the supply pipe 55a and the air cylinder 53. The moving knife 51 is lowered from the standby position. On the other hand, the air in the supply pipe 55a is divided into the supply pipe 55a side and the air blowing pipe 56 side by the branch valve 57 at the branch point with the air blowing pipe 56, and the air flowing into the air blowing pipe 56 side is It discharges toward the upper surface of the said knife support stand 31 in the stand-by position of the knife support stand 31 from an edge part.
As a result, when the knife support 31 is raised to the upper standby position, cloth waste and dust on the upper surface of the knife support 31 are removed by the air discharged from the air blowing pipe 56. Therefore, before the knife support 31 is raised to the standby position and the cloth rod metal 34 compresses the cloth waste, dust, etc., the cloth waste, dust, etc. can be removed, and the upper surface of the knife support base 31 can be removed for a long time. Cloth waste, dust, etc. do not accumulate over the entire length, and cloth waste, dust, etc. are less likely to enter through the gap between the knife bar 32 and the knife bar metal 34.
Therefore, it is possible to prevent malfunction of the knife 30 by removing cloth waste, dust and the like that adheres to the upper surface of the knife support 31 and accumulates.

  Further, since the blowing of air from the air blowing pipe 56 can be interlocked with the raising and lowering of the moving knife 51, the upper surface of the knife support can be cleaned every time the thread trimming is finished and the thread trimming is performed. Since cloth scraps and dust on the upper surface of the support base are periodically removed, there is no need to perform any work just to clean the upper surface of the female support base, and the worker always remembers to clean. There is no need.

<Others>
The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the air blowing tube is formed of an annular member having a circular shape in cross section. However, the opening surface of the end of the air blowing tube may be enlarged so as to blow the air over the entire female bar 32. Further, the place where cloth waste and dust are removed may be not only the upper surface of the knife support base 31, but also a knife bar and other surrounding members.

The figure which shows schematic structure of a sewing machine. The perspective view of a binder. The side view of the mechanism regarding the knife and moving knife in the sewing machine. The perspective view which shows the structure around a knife. The block diagram which shows the structure controlled by a control apparatus. The flowchart which shows the flow from the start of sewing until the upper thread is cut and the sewing is finished. The figure which shows the positional relationship of the knife support stand and the edge part of an air blowing pipe | tube at the time of an upper thread cutting | disconnection. The figure which shows the structure around the knife in a prior art. The figure which showed the movement of the knife in a prior art.

Explanation of symbols

20a sewing needle 30 knife 31 knife support base 32 knife rod 33 knife drive mechanism 34 knife rod metal (bearing)
51 Moving knife (upper thread trimming knife)
53 Air cylinder 54 Solenoid valve 55 Supply pipe 55a Supply pipe 55b Supply pipe 56 Air blowing pipe 100 Sewing machine

Claims (1)

Sewing needles that form seams in the fabric by vertical movement;
A knife that forms a linear cut in the fabric by vertical movement;
A knife support for supporting the proximal side of the knife;
A female rod disposed along the vertical movement direction of the female knife, the lower end of which is connected to the female support base;
A female drive mechanism coupled to the female bar, wherein the female bar is normally in a standby position, and continuously moves up and down when the sewing needle forms a stitch;
A bearing that supports the knife bar so as to be movable up and down above the knife support;
An upper thread trimming knife whose tip advances and retracts in the vicinity of the sewing needle and cuts the upper thread;
An air cylinder for moving the upper thread trimming knife forward and backward,
A solenoid valve for supplying air to the air cylinder at the end of stitch formation by the sewing needle;
A supply pipe that connects the air cylinder and the solenoid valve, and serves as a flow path of air supplied to the air cylinder;
In a sewing machine comprising:
Branching from the supply pipe, the end thereof is provided toward the upper surface of the female support base at the standby position of the female support base, and air for removing dust on the upper surface of the female support base from the end portion. A sewing machine provided with an air blowing tube for spraying.

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