Sewing machine

Abstract

To achieve stable sewing even under a condition in which bend of a sewing needle occurs.SOLUTION: A sewing machine includes: a needle bar which holds a machine needle, and which performs the needle location on an object to be sewn by vertical movement; a needle plate for supporting the object to be sewn from below, below the needle bar; a bottom feed mechanism for feeding the object to be sewn supported by the needle plate from the lower side; and a shuttle arranged below the needle plate and for supplying a bobbin thread to the object to be sewn. The bottom feed mechanism includes: a feed dog which feeds and moves the object to be sewn; a feed dog table which holds the feed dog, and which moves according to a feed track; and a receiving member provided at the feed dog table and arranged on the lateral side with respect to a needle location path of the sewing needle. The receiving member includes a receiving surface which faces the needle position path and whose position can be adjusted in the adjustment direction to come closer to or separate from the needle location path.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a sewing machine. [Background technology]

[0002] Patent Document 1 discloses a sewing machine in which a sewing needle penetrates a sewing object (object to be sewn) while a feed dog feeds the object, and a horizontal shuttle hook is used to entangle a lower thread with an upper thread to perform sewing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4913575 Summary of the Invention [Problem to be solved by the invention]

[0004] When sewing thick sewing objects or hard sewing objects such as leather or resin, the sewing needle may bend when it penetrates the sewing object. If the sewing needle is bent, the needle tip position after penetrating the sewing object will deviate from the correct position. Therefore, a bent sewing needle can cause poor sewing such as skipped stitches (when the upper thread cannot be entangled with the lower thread and the stitch is not formed) or thread breakage. There is a need to achieve stable sewing even under conditions where the sewing needle is bent.

[0005] The technology disclosed in this specification aims to achieve stable sewing even under conditions that may cause the sewing machine needle to bend. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a sewing machine comprising: a needle bar which holds a sewing needle and moves up and down to drop the needle into an object to be sewn; a needle plate which supports the object to be sewn from below below the needle bar; a bottom feed mechanism which feeds the object to be sewn supported by the needle plate from below; and a hook which is arranged below the needle plate and supplies a bobbin thread to the object to be sewn, wherein the bottom feed mechanism includes a feed dog which feeds and moves the object to be sewn, a feed dog table which holds the feed dog and moves according to a feed orbit, and a receiving member which is provided on the feed dog table and arranged laterally with respect to the needle drop path of the sewing needle, and the receiving member has a receiving surface which faces the needle drop path and can be adjusted in an adjustment direction to approach or move away from the needle drop path. Effect of the Invention

[0007] According to the technology disclosed in this specification, stable sewing can be achieved even under conditions that would cause the sewing machine needle to bend. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a sewing machine according to an embodiment of the present invention, seen from the upper left rear. [Diagram 2] FIG. 2 is an enlarged perspective view showing the inside of the sewing machine frame according to the embodiment, taken from the upper left rear. [Diagram 3] FIG. 3 is a schematic diagram for explaining the operation of the sewing machine needle and the shuttle. [Figure 4] FIG. 4 is a schematic diagram for explaining the feed of the sewing machine. [Diagram 5] FIG. 5 is a perspective view showing the lower feed mechanism from the upper left rear. [Figure 6] FIG. 6 is a perspective view showing the lower feed mechanism from the upper right rear. [Figure 7] FIG. 7 is a plan view showing the receiving member attached to the feed dog base. [Figure 8] FIG. 8 is a side view from the right showing the bottom feed mechanism and the sewing needle. [Figure 9]FIG. 9 is a cross-sectional view showing the bottom feed mechanism, the sewing machine needle and the shuttle as seen from the rear to the front. [Figure 10] FIG. 10 is a schematic diagram showing a comparative example in which no receiving member is provided. [Figure 11] FIG. 11 is a schematic diagram showing an embodiment in which a receiving member is provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described with reference to the drawings. In the embodiment, an XYZ orthogonal coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ orthogonal coordinate system. The direction parallel to the X axis in a predetermined plane is defined as the X axis direction. The direction parallel to the Y axis in a predetermined plane perpendicular to the X axis is defined as the Y axis direction. The direction parallel to the Z axis perpendicular to the predetermined plane is defined as the Z axis direction. The direction of rotation or tilt around the X axis is defined as the θX direction. The direction of rotation or tilt around the Y axis is defined as the θY direction. The direction of rotation or tilt around the Z axis is defined as the θZ direction. The plane including the X axis and the Y axis is appropriately referred to as the XY plane. The plane including the X axis and the Z axis is appropriately referred to as the XZ plane. The plane including the Y axis and the Z axis is appropriately referred to as the YZ plane. The XY plane is parallel to the predetermined plane. The XY plane, the XZ plane, and the YZ plane are perpendicular to each other.

[0010] In the embodiment, the XY plane and the horizontal plane are parallel. The X-axis direction is the front-rear direction. The Y-axis direction is the left-right direction. The Z-axis direction is the up-down direction. The +X direction is the front direction, and the -X direction is the rear direction. The +Y direction is the left direction, and the -Y direction is the right direction. The +Z direction is the upward direction, and the -Z direction is the downward direction. The XY plane may be inclined with respect to the horizontal plane. The horizontal direction includes the front-rear direction and the left-right direction.

[0011] [Sewing machine overview] FIG. 1 is a perspective view from the upper left rear showing a sewing machine 1 according to an embodiment. FIG. 1 shows only the main structure of the sewing machine 1, and omits details. In the embodiment, the sewing machine 1 is an industrial sewing machine. The sewing machine 1 is a so-called lock stitch sewing machine that forms seams by intertwining an upper thread and a lower thread. As shown in FIG. 1, the sewing machine 1 has a sewing machine frame 3.

[0012] The sewing machine frame 3 has an arm 3A, a bed 3B, a base 3C, and a head 3D. The arm 3A is long in the left-right direction. The bed 3B is disposed below the arm 3A. The bed 3B is also long in the left-right direction. The bed 3B faces the arm 3A vertically. The base 3C connects the right end of the arm 3A and the bed 3B. The base 3C is long in the up-down direction. The head 3D is provided at the left end of the arm 3A. The head 3D protrudes downward from the left end of the arm 3A.

[0013] 1, the sewing machine 1 includes a thread take-up lever 5, a needle bar 6, a needle plate 7, a presser foot 8, a thread tensioner, a lower feed mechanism 9, a sewing machine motor 10, a pulley 11, an upper feed mechanism 12, and a shuttle 13 (see FIG. 2). The sewing machine 1 also includes a controller that controls each part of the sewing machine 1, and a pedal and an operation panel that accept operational inputs to the sewing machine 1.

[0014] Fig. 2 is an enlarged perspective view from the upper left rear showing the inside of the sewing machine frame 3 according to the embodiment. In Fig. 2, only the main structure is shown, and details are omitted.

[0015] As shown in FIG. 1 and FIG. 2, the needle bar 6 holds the sewing needle 4 (see FIG. 2). The needle bar 6 holds the sewing needle 4 so that the sewing needle 4 and the Z-axis are parallel. The needle bar 6 moves up and down. The needle bar 6 is supported by the head 3D. The needle bar 6 moves up and down to drop into the sewing object MS. The sewing needle 4 has a threading hole through which the upper thread UT (see FIG. 3) passes. The sewing needle 4 holds the upper thread UT on the inner surface of the threading hole. As the needle bar 6 moves up and down, the sewing needle 4 moves up and down while holding the upper thread UT. The needle bar 6 also moves up and down, as well as forward and backward (X-axis direction). The needle bar 6 moves in a trajectory linked to the operation of the lower feed mechanism 9 and the operation of the upper feed mechanism 12 by a combination of up and down and forward and backward movements. As the needle bar 6 moves, the sewing needle 4 moves in a predetermined needle feed trajectory in the XZ plane.

[0016] The thread take-up 5 (see FIG. 1) supplies the upper thread UT to the sewing machine needle 4. The thread take-up 5 moves up and down reciprocatingly. The thread take-up 5 is supported by the arm 3A. The thread take-up 5 moves up and down reciprocatingly while holding the upper thread UT. The thread take-up 5 has a holding hole through which the upper thread UT passes. The thread take-up 5 holds the upper thread UT on the inner surface of the holding hole. The thread take-up 5 moves up and down reciprocatingly to pay out and pull up the upper thread UT used to sew the sewing object MS. The thread tension adjuster applies tension to the upper thread UT supplied to the sewing machine needle 4 between the thread take-up 5 and the needle bar 6. The thread tension adjuster is supported by the head 3D.

[0017] The needle plate 7 is disposed below the needle bar 6. The needle plate 7 supports the sewing workpiece MS from below. The needle plate 7 supports the sewing workpiece MS below the needle bar 6. The sewing machine needle 4 held by the needle bar 6 and the needle plate 7 face each other. The needle plate 7 has an opening through which the feed dog 31 of the lower feed mechanism 9 can pass.

[0018] The presser foot 8 presses down the sewing workpiece MS supported by the needle plate 7 from above. The presser foot 8 is arranged around at least a portion of the sewing needle 4. The presser foot 8 is fixed to the lower end of a presser bar 8A (see FIG. 2). The presser bar 8A is supported by the head 3D. The presser bar 8A is movable in the vertical direction. The presser foot 8 is pressed down against the sewing workpiece MS from above by the elastic force generated by a presser spring provided in the head 3D. The presser foot 8 has a pair of pressing pieces that branch out at the tip that comes into contact with the sewing workpiece MS. One pressing piece is arranged in the +Y direction relative to the sewing needle 4, and the other pressing piece is arranged in the -Y direction relative to the sewing needle 4.

[0019] The lower feed mechanism 9 is disposed below the needle plate 7. The lower feed mechanism 9 feeds the sewing workpiece MS supported by the needle plate 7 from below. The lower feed mechanism 9 includes a feed dog 31 and a feed tooth base 32. The feed dog 31 feeds and moves the sewing workpiece MS forward. The feed dog 31 is disposed below the needle plate 7. A sawtooth is formed on the upper surface of the feed dog 31 to increase frictional resistance with the sewing workpiece MS. The feed tooth base 32 holds the feed dog 31. The feed tooth base 32 moves (swings) in conjunction with the needle bar 6. The feed dog 31 moves on a predetermined feed track in accordance with the movement of the feed tooth base 32, and appears and disappears from an opening provided in the needle plate 7. When the sewing workpiece MS is fed, at least a part of the feed dog 31 protrudes upward from the upper surface of the needle plate 7 through the opening provided in the needle plate 7.

[0020] The upper feed 12 is disposed above the needle plate 7. The upper feed 12 feeds the sewing workpiece MS supported by the needle plate 7 from above. The upper feed 12 is disposed at least partially around the sewing machine needle 4. The upper feed 12 is located between a pair of pressing pieces provided at the tip of the presser foot 8. The upper feed 12 is fixed to the lower end of the upper feed bar 12A. The upper feed bar 12A is supported by the head 3D. The upper feed bar 12A moves (swings) in conjunction with the needle bar 6. The upper feed 12 moves on a predetermined upper feed orbit in conjunction with the movement of the upper feed bar 12A. The lower surface of the upper feed 12 has sawtooth teeth formed thereon to increase frictional resistance with the sewing workpiece MS.

[0021] The shuttle 13 supplies the lower thread to the sewing workpiece MS. The shuttle 13 is disposed below the feed dog 31. In this embodiment, the shuttle 13 is a so-called horizontal shuttle whose rotation axis faces the Z-axis direction. In other words, the shuttle 13 is rotatable in the θZ direction. The shuttle 13 has an inner shuttle that stores a bobbin that holds the lower thread, and an outer shuttle that rotates in the θZ direction. The shuttle 13 is supported by a shuttle holder 14.

[0022] Sewing machine motor 10 (see FIG. 1) generates power to operate each of needle bar 6, feed dog 31, upper feed 12, and shuttle 13. Sewing machine motor 10 generates power to move needle bar 6 on a needle feed track. Sewing machine motor 10 generates power to rotate shuttle 13 in the θZ direction. Sewing machine motor 10 generates power to move feed dog 31 on the feed track. Sewing machine motor 10 generates power to move upper feed 12 on the upper feed track. Sewing machine motor 10 includes a pulse motor. Sewing machine motor 10 is supported on the right part of arm 3A.

[0023] The sewing machine motor 10 is connected to the needle bar 6, the feed dog 31, the upper feed 12, and the shuttle 13 via a sewing machine power transmission mechanism. The sewing machine power transmission mechanism operates each of the needle bar 6, the feed dog 31, the upper feed 12, and the shuttle 13 based on the power generated by the sewing machine motor 10. The sewing machine power transmission mechanism transmits the power generated by the sewing machine motor 10 to each of the needle bar 6, the feed dog 31, the upper feed 12, and the shuttle 13.

[0024] Specifically, an upper shaft extending in the Y-axis direction is disposed inside the arm 3A. The sewing machine motor 10 is connected to the +Y end of the upper shaft. The -Y end of the upper shaft is connected to the needle bar 6 via a swing link mechanism disposed inside the head 3D. The upper shaft rotates due to operation of the sewing machine motor 10. Power generated by the sewing machine motor 10 is transmitted to the needle bar 6 via the upper shaft and the swing link mechanism. The needle bar 6 and the sewing machine needle 4 held by the needle bar 6 reciprocate (swing) in the up-down and back-and-forth directions on the needle feed track based on the power generated by the sewing machine motor 10.

[0025] The upper shaft is connected to the upper feed bar 12A via a swing link mechanism disposed inside the head 3D. Power generated by the sewing machine motor 10 is transmitted to the upper feed bar 12A via the upper shaft and the swing link mechanism. The upper feed bar 12A and the upper feed 12 held by the upper feed bar 12A reciprocate (swing) in the up-down and back-and-forth directions on the upper feed track based on the power generated by the sewing machine motor 10.

[0026] A timing belt extending in the Z-axis direction is disposed inside the base 3C. A bed shaft 20 (see FIG. 2) extending in the Y-axis direction is disposed inside the bed 3B. A pulley is disposed on each of the upper shaft and the bed shaft 20. A timing belt is wound around each of the pulleys disposed on the upper shaft and the bed shaft 20. The upper shaft and the bed shaft 20 are connected via the timing belt.

[0027] As shown in Fig. 2, the bed shaft 20 is connected to a shuttle shaft extending in the Z-axis direction provided on the shuttle holder 14 via a bevel gear so that power can be transmitted. The upper shaft and the bed shaft 20 each rotate when the sewing machine motor 10 is operated. Power generated by the sewing machine motor 10 is transmitted to the shuttle 13 via the upper shaft, a timing belt, the bed shaft 20, and the shuttle shaft. As a result, the shuttle 13 rotates in the θZ direction in synchronization with the movement of the needle bar 6 so that the lower thread is supplied to the sewing workpiece MS.

[0028] A pair of lower shafts 21A and 21B extending in the Y-axis direction are arranged inside the bed 3B. The lower shaft 21A and the lower shaft 21B are each connected to the upper shaft via a cam mechanism passing through the base 3C. The lower shaft 21A is arranged on the front side (+X direction) inside the bed 3B. The lower shaft 21A is connected to the front end of the feed tooth table 32 via an arm portion 22A extending in the radial direction. The lower shaft 21B is arranged on the rear side (-X direction) inside the bed 3B. The lower shaft 21B is connected to the rear end of the feed tooth table 32 via an arm portion 22B extending in the radial direction. When the sewing machine motor 10 is operated, the upper shaft rotates, and the lower shaft 21A and the lower shaft 21B each perform periodic motion via the cam mechanism. The power generated by the sewing machine motor 10 is transmitted to the feed tooth table 32 via the upper shaft, the cam mechanism, the lower shaft 21A, and the lower shaft 21B. As a result, feed dog table 32 swings in synchronization with the movement of needle bar 6. As feed dog table 32 swings, feed dog 31 reciprocates (swings) up and down and back and forth on the feed track.

[0029] With this configuration, the sewing machine 1 sews the sewing object MS through cooperation between the sewing needle 4 held by the needle bar 6 and the shuttle 13. The sewing machine 1 feeds the sewing object MS forward (in the +X direction) through cooperation between the upper feed 12, the feed dog 31 and the sewing needle 4.

[0030] FIG. 3 is a schematic diagram for explaining the operation of the sewing needle 4 and the shuttle 13. During sewing, the sewing needle 4 holding the upper thread UT descends in the -Z direction and penetrates the sewing object MS (see FIG. 1) from above. The sewing needle 4 descends to the bottom dead center position in the Z axis direction and then ascends. When the sewing needle 4 starts to ascend, the upper thread UT loosens between the threading hole of the sewing needle 4 and the sewing object MS, forming a loop of the upper thread UT. The shuttle 13 rotates in the Zθ direction in conjunction with the movement of the sewing needle 4, and the blade tip 13A of the outer shuttle enters the loop of the upper thread UT and captures the loop. The shuttle 13 continues to rotate while capturing the loop of the upper thread UT, and passes the inner shuttle through the loop. As a result, the shuttle 13 inserts the lower thread (not shown) pulled out from the inner shuttle into the loop of the upper thread UT and entangles it, forming a stitch.

[0031] FIG. 4 is a schematic diagram for explaining the feed of the sewing machine 1. During sewing, the feed dog 31 swings on the feed orbit, the upper feed 12 swings on the upper feed orbit, and the needle bar 6 (sewing needle 4) swings on the needle feed orbit in the XZ plane. These feed orbit, upper feed orbit, and needle feed orbit are circular orbits along the feed direction (X-axis direction), and are, for example, elliptical orbits. The upper feed 12 and the feed dog 31 sandwich the sewing object MS from above and below, and move the sewing object MS in the feed direction (+X direction). At this time, the needle bar 6 (sewing needle 4) moves in the feed direction (+X direction) in conjunction with the upper feed 12 and the feed dog 31 while the sewing needle 4 penetrates the sewing object MS. In this way, the sewing machine 1 is an integrated feed sewing machine in which the feed dog 31 of the lower feed mechanism 9, the upper feed 12, and the needle bar 6 are operated on feed orbits that are mutually linked. The integrated feed is a feed method that can increase the feed force of the sewing workpiece MS, and is suitable for sewing a sewing workpiece MS having a large thickness.

[0032] The controller controls the sewing machine motor 10. The controller has a processor such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an input / output interface including an input / output circuit capable of inputting and outputting signals and data.

[0033] The pedal is operated by an operator of the sewing machine 1. The operator operates the pedal with his foot. An operation signal generated by operating the pedal is sent to the controller. The sewing machine motor is driven or stopped based on the operation state of the pedal. The operation panel includes a flat panel display and a touch panel. The operation panel is operated by an operator of the sewing machine 1. The operation panel is provided on at least a part of the sewing machine frame 3. The operator operates the operation panel with his fingers. The operator operates the operation panel to make settings related to the operation of the sewing machine 1.

[0034] [Downfeed mechanism] Next, a detailed description will be given of the structure of the lower feed mechanism 9. Fig. 5 is a perspective view showing the lower feed mechanism 9 from the upper left rear. Fig. 6 is a perspective view showing the lower feed mechanism 9 from the upper right rear.

[0035] As shown in FIG. 5 and FIG. 6, the feed dog 31 is fixed to the upper end of the feed dog base 32 at the center in the X-axis direction. The feed dog 31 has a fixed portion 31A attached to the feed dog base 32, a wall portion 31B rising upward from the fixed portion 31A, and an upper surface portion 31C provided at the upper end of the wall portion 31B and contacting the sewing object MS. The wall portion 31B is disposed at the right end of the fixed portion 31A. The wall portion 31B has an upright plate shape along the XZ plane. The upper surface portion 31C protrudes to the right (-Y direction) from the upper end of the wall portion 31B. The upper surface portion 31C is provided with saw-tooth teeth 31D and a pinhole 31E. The pinhole 31E penetrates the upper surface portion 31C vertically at a position shifted to the right (-Y direction) from the wall portion 31B. When the sewing needle 4 descends, the sewing needle 4 penetrates the sewing workpiece MS and passes through the needle hole 31E.

[0036] The feed dog table 32 is a plate-like member extending along the front-rear direction. A connection part 32A with the lower shaft 21A (arm part 22A) is provided at the front end part of the feed dog table 32. A connection part 32B with the lower shaft 21B (arm part 22B) is provided at the rear end part of the feed dog table 32. A holding part 32C that holds the feed dog 31 is provided between the connection parts 32A and 32B in the front-rear direction. A fixing part 31A of the feed dog 31 is attached to the upper surface of the holding part 32C.

[0037] Here, in this embodiment, the lower feed mechanism 9 includes a receiving member 33 arranged laterally with respect to the needle drop path NP (see FIG. 6) of the sewing needle 4. The receiving member 33 is provided on the feed dog table 32. The receiving member 33 is provided on the side of the holding portion 32C of the feed dog table 32. The receiving member 33 is arranged in a position directly below the feed dog 31. As shown in FIG. 6, the needle drop path NP is a relative movement path (trajectory) of the sewing needle 4 with respect to the lower feed mechanism 9. The needle drop path NP is a path along the Z-axis direction that passes through the needle hole 31E. The receiving member 33 has a receiving surface 34 facing the needle drop path NP. The receiving surface 34 is a side surface of the receiving member 33 in the right direction (-Y). The receiving surface 34 can be adjusted in a position in an adjustment direction to approach or move away from the needle drop path NP. In this embodiment, the adjustment direction is the Y-axis direction.

[0038] FIG. 7 is a plan view showing the receiving member 33 attached to the feed dog table 32. FIG. 7 shows a state in which the feed dog 31 has been removed from the feed dog table 32. The receiving member 33 has a first portion 33A, a second portion 33B, and a third portion 33C. The receiving member 33 has a roughly inverted U-shape with the first portion 33A, the second portion 33B, and the third portion 33C. The receiving member 33 is a single article in which the first portion 33A, the second portion 33B, and the third portion 33C are integrally formed. The receiving member 33 is made of metal, for example, spring steel.

[0039] The first portion 33A constitutes the left side (+Y side) of the receiving member 33 and extends linearly in the front-rear direction. The first portion 33A is a portion fixed to the feed dog base 32. The first portion 33A is formed with two through holes (non-threaded holes) for inserting the mounting screws 35. The mounting screws 35 inserted into each through hole are attached to threaded holes provided in the side of the holding portion 32C of the feed dog base 32. The receiving member 33 is fastened to the side of the holding portion 32C in the first portion 33A by the two mounting screws 35. In addition, the first portion 33A is formed with an insertion hole 33D between the two through holes for inserting an adjustment member 36 (see FIG. 5) described later. The first portion 33A is connected to the third portion 33C at the front end.

[0040] The second portion 33B forms the right side (-Y side, needle drop path NP side) of the receiving member 33 and extends linearly in the front-rear direction. The second portion 33B has a receiving surface 34. That is, the outer surface of the right side (-Y side) of the second portion 33B is the receiving surface 34. The second portion 33B extends backward (-X direction) from the third portion 33C. The second portion 33B extends at least to a position that is rearward (-X direction) of the needle drop path NP. That is, the receiving surface 34 is formed in a range from a position on the +X side of the needle drop path NP to a position on the -X side of the needle drop path NP. In the example of FIG. 7, the X-direction length of the second portion 33B is smaller than the X-direction length of the first portion 33A.

[0041] The third portion 33C constitutes a side surface on the front side (+X side) of the receiving member 33 and extends linearly in the left-right direction. The third portion 33C connects the first portion 33A and the second portion 33B. A left end portion of the third portion 33C is connected to the first portion 33A, and a right end portion of the third portion 33C is connected to the second portion 33B.

[0042] FIG. 8 is a side view from the right showing the lower feed mechanism 9 and the sewing needle 4. The receiving surface 34 faces the side of the sewing needle 4 passing through the needle drop path NP in the Y-axis direction. The receiving member 33 moves in the vertical and front-rear directions on the feed track together with the feed dog 31 and the feed dog base 32. The receiving member 33 maintains a state of facing the side of the sewing needle 4 in the Y-axis direction near the bottom dead center of the sewing needle 4. As shown in FIG. 7, the receiving surface 34 is disposed at a position away from the needle drop path NP in the +Y direction. When the sewing needle 4 moves normally along the needle drop path NP, the receiving surface 34 is not in contact with the sewing needle 4. When the sewing needle 4 bends toward the feed dog 31 (i.e., in the +Y direction) during sewing, the receiving surface 34 comes into contact with the bent sewing needle 4. As a result, the receiving surface 34 has a function of restricting the sewing needle 4 from bending more than the allowable amount. The "bending" of the sewing needle 4 referred to here means a very small deformation that allows the sewing needle 4 to be inserted into and removed from the needle hole 31E and is within a range that allows sewing to continue.

[0043] As shown in FIG. 7, in this embodiment, the distance CL between the receiving surface 34 and the needle drop path NP (i.e., the sewing machine needle 4) in the adjustment direction (Y-axis direction) is adjustable according to the position of the receiving surface 34. The receiving member 33 is formed from spring steel or the like as described above, and has a spring property that allows the second portion 33B to be displaced in the adjustment direction (Y-axis direction) by elastic deformation. The lower feed mechanism 9 includes an adjustment member 36 that displaces the second portion 33B in the adjustment direction (Y-axis direction). The receiving member 33 is capable of adjusting the position of the receiving surface 34 by displacing the second portion 33B in the adjustment direction (Y-axis direction) with the adjustment member 36.

[0044] The adjustment member 36 is attached to the feed tooth base 32 so as to abut against the second portion 33B, and is a feed screw provided so as to be movable forward and backward in the adjustment direction (Y-axis direction). As shown in FIG. 5, the adjustment member 36 is inserted into a screw hole formed in the holding portion 32C of the feed tooth base 32 through the insertion hole 33D of the first portion 33A. The screw hole formed in the holding portion 32C penetrates the holding portion 32C in the Y-axis direction. As shown in FIG. 7, the adjustment member 36 penetrates the holding portion 32C in the -Y direction and abuts against the side surface on the +Y side of the second portion 33B. The adjustment member 36 presses the second portion 33B in the -Y direction.

[0045] FIG. 7 shows the adjustment member 36 in the standard position. In a natural state where the adjustment member 36 is not pressed, the second portion 33B is formed in a state where it is bent toward the +Y side from the standard position in FIG. 7. The second portion 33B is disposed in the position shown in FIG. 7 by being pushed in the -Y direction by the adjustment member 36 to the standard position. By rotating the adjustment member 36 in the screw hole of the holding part 32C and feeding the adjustment member 36 in the -Y direction, the second portion 33B is deformed in the -Y direction from the standard position, and the receiving surface 34 can be displaced in the -Y direction. As a result, the distance CL between the receiving surface 34 and the needle drop path NP becomes smaller. On the other hand, when the adjustment member 36 is fed in the +Y direction from the standard position, the second portion 33B is restored in the +Y direction by the spring property, and the receiving surface 34 can be displaced in the +Y direction. As a result, the distance CL between the receiving surface 34 and the needle drop path NP becomes larger.

[0046] 9 is a cross-sectional view of the lower feed mechanism 9, the sewing needle 4, and the shuttle 13, seen from the rear toward the front. The position of the receiving surface 34 can be adjusted between a position closer to the needle path NP than the side surface 31F of the wall portion 31B on the needle path NP side, and a position farther from the needle path NP than the side surface 31F of the feed dog 31. In other words, the receiving surface 34 can be displaced to a position in the -Y direction from the side surface 31F. The receiving surface 34 can be displaced to a position in the +Y direction from the side surface 31F.

[0047] Incidentally, the sewing needle 4 may bend in the -Y direction during sewing. For this reason, as shown in FIG. 3, the shuttle 13 has a needle receiver 13B that contacts the bent sewing needle 4 when the sewing needle 4 is bent in the -Y direction and regulates the sewing needle 4 not to bend beyond the allowable amount. The needle receiver 13B is provided on the outer shuttle of the shuttle 13 and rotates together with the blade point 13A. The receiving surface 34 of the receiving member 33 faces the needle receiver 13B of the shuttle 13 in the adjustment direction (Y-axis direction). The receiving surface 34 is disposed on the +Y side of the needle drop path NP, and the needle receiver 13B is disposed on the -Y side of the needle drop path NP. For this reason, in the sewing machine 1, even if the sewing needle 4 is bent in the +Y direction or the -Y direction, the bending is limited to within the allowable range.

[0048] [Effect] Next, the operation of the sewing machine 1 according to this embodiment will be described. FIG. 10 is a schematic diagram showing a comparative example in which the receiving member 33 is not provided. FIG. 11 is a schematic diagram showing an embodiment in which the receiving member 33 is provided. The bending of the sewing needle 4 typically occurs when the sewing object MS is thick or contains a hard material (such as leather or resin material) due to an external force applied to the sewing needle 4 during sewing. It is assumed that the sewing needle 4 is bent in the +Y direction in which the lower feed mechanism 9 is disposed. When the receiving member 33 is not provided as in the comparative example of FIG. 10, the deformation of the sewing needle 4 is not prevented, so the distance D between the sewing needle 4 and the point 13A becomes large. In this case, depending on the shape of the loop of the upper thread UT, the point 13A may not be able to capture the loop, and the upper thread UT may fail to be entangled with the lower thread. If the point 13A cannot capture the loop, a skipped stitch (no stitch is formed) may occur at that needle drop position, or the upper thread UT may break.

[0049] In the comparative example, in order to prevent skipped stitches and thread breakage, for example, an adjustment method such as shifting the positions of the shuttle 13 and the shuttle holder 14 can be considered. That is, taking into consideration the bending deformation of the sewing machine needle 4, the position of the needle point 13A is adjusted so that the distance D becomes appropriate. However, adjusting the positions of the shuttle 13 and the shuttle holder 14 requires partial disassembly of the connection points with the sewing machine power transmission mechanism, including the bed shaft 20 and the shuttle shaft, which is cumbersome and requires a large workload.

[0050] Furthermore, in the sewing machine 1, the sewing needle 4 is replaced with one having a different thickness (diameter) depending on the sewing object MS. The amount of bending deformation of the sewing needle 4 also changes depending on the thickness of the sewing needle 4 and the sewing object MS. In other words, when the thickness of the sewing needle 4 changes, the distance D between the sewing needle 4 and the point 13A changes. Therefore, it may become necessary to adjust the positions of the shuttle 13 and the shuttle holder 14 every time the thickness of the sewing needle 4 is changed.

[0051] 11, in this embodiment, when the sewing needle 4 bends in the +Y direction, the receiving surface 34 of the receiving member 33 comes into contact with the bent sewing needle 4. The sewing needle 4 is prevented from being further bent by contact with the receiving surface 34. Since the distance D between the sewing needle 4 and the point 13A is prevented from becoming larger than the allowable range, the possibility that the point 13A will fail to capture the loop of the upper thread UT is reduced.

[0052] Furthermore, even when the sewing needle 4 is replaced with one of a different thickness (diameter), the distance CL between the receiving surface 34 and the needle drop path NP (sewing needle 4) can be easily adjusted simply by adjusting the amount of feed of the adjustment member 36. In other words, instead of adjusting the passing position of the point 13A in accordance with the bending deformation of the sewing needle 4, the allowable range of the bending deformation of the sewing needle 4 can be adjusted in accordance with the passing position of the point 13A. As a result, it is possible to prevent skipped stitches and thread breakage by simply adjusting the position of the receiving surface 34, without adjusting the positions of the shuttle 13 and the shuttle holder 14.

[0053] [effect] As described above, the sewing machine 1 of the embodiment comprises a needle bar 6 which holds the sewing needle 4 and moves up and down to drop the needle into the sewing workpiece MS, a needle plate 7 which supports the sewing workpiece MS from below below the needle bar 6, a bottom feed mechanism 9 which feeds the sewing workpiece MS supported by the needle plate 7 from below, and a shuttle 13 which is arranged below the needle plate 7 and supplies a lower thread to the sewing workpiece MS. The bottom feed mechanism 9 comprises a feed dog 31 which feeds and moves the sewing workpiece MS, a feed tooth table 32 which holds the feed dog 31 and moves according to the feed orbit, and a receiving member 33 which is provided on the feed tooth table 32 and arranged laterally with respect to the needle drop path NP of the sewing needle 4. The receiving member 33 has a receiving surface 34 which faces the needle drop path NP and can be adjusted in an adjustment direction (Y-axis direction) to approach or move away from the needle drop path NP.

[0054] According to the embodiment, even if the sewing needle 4 is bent, the amount of bending deformation of the sewing needle 4 can be limited by bringing the receiving surface 34 into contact with the bent sewing needle 4. Then, by adjusting the position of the receiving surface 34 relative to the needle drop path NP, the allowable range of the bending deformation of the sewing needle 4 can be adjusted to a range that can suppress the occurrence of skipped stitches and thread breakage. As a result, stable sewing can be achieved even under conditions where the sewing needle 4 is bent.

[0055] In this embodiment, the receiving member 33 has a first portion 33A fixed to the feed dog table 32, a second portion 33B on which the receiving surface 34 is formed, and a third portion 33C connecting the first portion 33A and the second portion 33B, and has a spring property that allows the second portion 33B to be displaced in the adjustment direction (Y-axis direction) by elastic deformation. The lower feed mechanism 9 includes an adjustment member 36 that displaces the second portion 33B in the adjustment direction (Y-axis direction). This allows the position of the receiving surface 34 to be adjusted with a simple structure by utilizing the elastic deformation of the second portion 33B of the receiving member 33. Also, even when the receiving surface 34 is displaced in the +Y direction away from the needle drop path NP, the elasticity (restoring force) of the second portion 33B can be used to suppress the positional deviation of the receiving surface 34.

[0056] In this embodiment, the adjustment member 36 is a feed screw that is attached to the feed tooth base 32 so as to abut against the second portion 33B and is provided so as to be movable forward and backward in the adjustment direction (Y-axis direction). This allows the position of the receiving surface 34 to be adjusted by the extremely simple task of simply adjusting the feed amount of the feed screw. Therefore, even if the position of the receiving surface 34 is adjusted every time the thickness of the sewing needle 4 is changed, the load and complexity of the adjustment task can be reduced.

[0057] In this embodiment, the position of the receiving surface 34 can be adjusted between a position closer to the needle path NP than the side surface 31F on the needle path NP side of the wall portion 31B and a position farther from the needle path NP than the side surface 31F. This allows the position adjustment range of the receiving surface 34 to be sufficiently large.

[0058] In this embodiment, the receiving surface 34 of the receiving member 33 faces the needle receiving portion 13B of the shuttle 13 in the adjustment direction (Y-axis direction). This makes it possible to limit the amount of bending deformation of the sewing needle 4 within the allowable range in both cases where the sewing needle 4 bends toward the feed dog 31 side (+Y direction) and where the sewing needle 4 bends toward the shuttle 13 side (-Y direction).

[0059] In this embodiment, the sewing machine 1 is an integrated feed sewing machine in which the feed dog 31 of the lower feed mechanism 9, the upper feed mechanism 12, and the needle bar 6 are operated on a feed trajectory that is linked to one another. This improves the feed force and enables sewing of a thick sewing object MS. Bending of the sewing needle 4 is particularly likely to occur when sewing a thick sewing object MS. Therefore, the integrated feed sewing machine can achieve stable sewing even when sewing thick materials for which bending of the sewing needle 4 is likely to occur.

[0060] [Other embodiments] In the above embodiment, an example has been shown in which the sewing machine 1 is an integrated feed sewing machine, but the feeding method of the sewing machine is not particularly limited. The feeding method of the sewing machine may be bottom feed only, feed and needle feed, up-down feed (up-down feed and bottom feed), etc. Therefore, the sewing machine 1 does not need to be provided with top feed 12, and the needle bar 6 does not need to move along a needle feed trajectory. The movement of the needle bar 6 may be only up-down movement.

[0061] In the above embodiment, an example has been shown in which the kettle 13 is a horizontal kettle, but the kettle may be a vertical kettle whose central axis of rotation is oriented horizontally.

[0062] In the above embodiment, an example in which the position of the receiving surface 34 is adjusted by elastically deforming the receiving member 33 has been shown, but the structure for adjusting the position of the receiving surface 34 is not particularly limited. For example, a receiving member having a receiving surface may be attached to the tip of the feed screw, and the receiving member may be moved horizontally in the adjustment direction according to the amount of operation of the feed screw. The adjustment member is not limited to the feed screw, and may be, for example, an eccentric cam that adjusts the position of the receiving member. A plurality of insertion holes may be provided in the receiving member along the adjustment direction, and positioning pins that are inserted into the insertion holes may be provided as the adjustment member. A long hole may be provided in the receiving member along the adjustment direction, and a screw that is inserted into the long hole and fastens the receiving member so that the position can be adjusted within the range of the long hole may be provided as the adjustment member. [Explanation of symbols]

[0063] 1... sewing machine, 3... sewing machine frame, 3A... arm, 3D... head, 3C... base, 3B... bed, 4... sewing machine needle, 5... take-up lever, 6... needle bar, 7... needle plate, 8... presser foot, 8A... presser foot bar, 9... bottom feed mechanism, 10... sewing machine motor, 11... pulley, 12... upper feed, 12A... upper feed bar, 13... shuttle, 13A... tip, 13B... needle receiver, 14... shuttle holder, 20... bed shaft, 21A... lower shaft, 21B... lower shaft, 22A... arm portion, 22B...arm portion, 31...feed dog, 31A...fixed portion, 31B...wall portion, 31C...upper surface portion, 31D...teeth, 31E...needle hole, 31F...side surface, 32...feed dog base, 32A...connection portion, 32B...connection portion, 32C...holding portion, 33D...insertion hole, 33...receiving member, 33A...first portion, 33B...second portion, 33C...third portion, 34...receiving surface, 35...mounting screw, 36...adjusting member, MS...sewing object, NP...needle drop path, UT...upper thread.

Claims

1. A needle bar that holds a sewing needle and moves up and down to drop the needle into the sewing object; a needle plate that supports the sewing object from below below the needle bar; a bottom feed mechanism that feeds the sewing object supported by the needle plate from below; a hook disposed below the needle plate and adapted to supply a bobbin thread to the sewing object; The lower feed mechanism includes: A feed dog for feeding and moving the sewing object; a feed dog table that holds the feed dog and moves along a feed track; a receiving member provided on the feed dog table and disposed laterally with respect to a needle drop path of the sewing machine needle, The receiving member has a receiving surface that faces the needle path and is positionably adjustable in an adjustment direction to approach or move away from the needle path. sewing machine.

2. the receiving member has a first portion fixed to the feed dog base, a second portion in which the receiving surface is formed, and a third portion connecting the first portion and the second portion, and has a spring property that allows the second portion to be displaced in the adjustment direction by elastic deformation, the lowering mechanism includes an adjustment member that displaces the second portion in the adjustment direction; 2. The sewing machine according to claim 1.

3. The adjustment member is a feed screw that is attached to the feed tooth base so as to abut against the second portion and is provided so as to be capable of moving forward and backward in the adjustment direction.

3. The sewing machine according to claim 2.

4. the feed dog has a fixed portion fixed to the feed dog base, a wall portion extending upward from the fixed portion, and a top surface portion provided at an upper end of the wall portion and coming into contact with the sewing object, the receiving surface is adjustable between a position closer to the needle path than a side surface of the wall portion on the needle path side and a position farther from the needle path than the side surface. A sewing machine according to any one of claims 1 to 3.

5. The shuttle has a needle receiving portion, The receiving surface of the receiving member faces the needle receiving portion of the shuttle in the adjustment direction. A sewing machine according to any one of claims 1 to 3.

6. an upper feed that feeds the sewing object supported by the needle plate from above, The feed dog of the lower feed mechanism, the upper feed mechanism, and the needle bar are operated on a feed trajectory that is linked to each other in an integrated feed sewing machine. A sewing machine according to any one of claims 1 to 3.

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