Sewing machine, adjustment method, and sensor unit

Abstract

To provide: a sewing machine which can accurately adjust the positional relation between a sewing needle mounted on a needle bar and a sword point or a needle guard of a shuttle mechanism; an adjustment method for adjusting the position of the shuttle mechanism with respect to the sewing needle in the sewing machine; and a sensor unit.SOLUTION: A sewing machine includes: a needle bar; a shuttle mechanism including a sword point and a movable body which has a needle guard; a shuttle shaft for rotationally driving the movable body; a position adjustment mechanism capable of adjusting a position of the movable body in an axial direction of the shuttle shaft; a frame 7 for accommodating the shuttle mechanism, a shuttle shaft and the position adjustment mechanism; a first sensor 4A which has a contact surface 433 that comes into contact, from one side in the axial direction, with respect to a sewing needle 31A arranged at an encounter position which is a position of the sewing needle 31A at a timing when the sword point supplements a loop formed at a needle thread, and which is for detecting a displacement amount of the sewing needle 31A in the axial direction; and an arm part 4B for supporting the first sensor 4A, and fixed to the frame 7.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a sewing machine, an adjustment method, and a sensor unit. [Background technology]

[0002] In order to perform a sewing operation appropriately in a sewing machine, it is necessary to adjust the positional relationship between the sewing needle attached to the needle bar and the shuttle. Patent Document 1 discloses a shuttle position adjustment member that is attached to the needle bar instead of the sewing needle. The shuttle position adjustment member has a detection shaft. When the detection shaft is not in contact with the hook tip of the shuttle, no current flows through the shuttle position adjustment member, and when the detection shaft is in contact with the hook tip of the shuttle, a current flows through the shuttle position adjustment member. A detector connected to the shuttle position adjustment member detects whether or not a current flows through the shuttle position adjustment member. An operator aligns the shuttle by using the detector to confirm that the hook tip of the shuttle is in contact with the detection shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-25594 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above method, the adjustment is performed by attaching a shuttle position adjustment member to the needle bar instead of the sewing needle. Therefore, if the shapes of the sewing needle and the detection shaft are different, the positional relationship between the sewing needle and the shuttle cannot be adjusted with high precision. Thus, with the above method, there are cases where the positional relationship between the sewing needle attached to the needle bar and the shuttle cannot be adjusted with high precision.

[0005] An object of the present invention is to provide a sewing machine that can precisely adjust the positional relationship between a sewing needle attached to a needle bar and the point or needle guard of a shuttle mechanism, an adjustment method for adjusting the position of the shuttle mechanism relative to the sewing needle in a sewing machine, and a sensor unit. [Means for solving the problem]

[0006] The sewing machine according to a first aspect of the present invention is characterized in that it comprises a shuttle mechanism having a movable body which has a needle bar which can be moved in an up and down direction and which has a sewing needle attached to its tip, a tip which captures the upper thread passed through the sewing needle attached to the needle bar, and a needle guard which contacts and guides the sewing needle; a shuttle shaft which has an axis extending in a direction intersecting the up and down direction and which rotates and drives the movable body in a rotational direction around the axis; a position adjustment mechanism which can adjust the position of the movable body in the axial direction of the shuttle shaft; a frame which houses the shuttle mechanism, the shuttle shaft and the position adjustment mechanism; a sensor which has a contact surface which contacts from one side in the axial direction with the sewing needle which is positioned at a meeting position which is the position of the sewing needle at the time when the tip captures the loop formed in the upper thread, for detecting the amount of displacement of the sewing needle in the axial direction; and an arm which supports the sensor and is fixed to the frame.

[0007] The sewing machine is equipped with a sensor that detects the amount of displacement of the sewing needle that is displaced by contact with the tip or needle guard of the movable body. The operator of the sewing machine can check the positional relationship between the tip or needle guard of the movable body and the sewing needle based on the amount of displacement detected by the sensor. Therefore, the operator can accurately adjust the positional relationship between the tip or needle guard of the movable body and the sewing needle.

[0008] In the first aspect, a display unit may be provided that displays information based on the amount of displacement of the sewing needle detected by the sensor. An operator can visually check the display unit to confirm the positional relationship between the point or needle guard of the shuttle mechanism and the sewing needle.

[0009] In a first aspect, the sensor may include a detector that is rotatable about a rotation axis that intersects with the axial direction and has the contact surface, and a detection unit that detects a rotational position of the detector that rotates about the rotation axis when the sewing needle comes into contact with the contact surface. The sensor can detect the displacement of the sewing needle with high accuracy, regardless of the size or shape of the sewing needle, compared to a case in which the sensor directly detects the displacement of the sewing needle.

[0010] In the first embodiment, a plate may be provided to cover the shuttle mechanism from above, the plate extending from one end on one side in the axial direction to the other side, and the plate may have a notch through which the detector enters from the one side in the axial direction. In this case, the detector of the sensor can be prevented from coming into contact with the plate.

[0011] In the first aspect, the point and the needle guard may be capable of contacting the sewing needle from the other side in the axial direction. When the sewing needle is bent to one side in the axial direction in response to the shuttle mechanism coming into contact with the sewing needle from the other side in the axial direction, the sensor can detect the amount of bending as a displacement amount.

[0012] An adjustment method according to a second aspect of the present invention is a method for adjusting a position of the movable body relative to the sewing needle in the sewing machine according to the first aspect, comprising a first step of locating the sewing needle at the meeting position, a second step of fixing a sensor unit having the sensor and the arm portion to the frame, a third step of moving the movable body from the other side in the axial direction toward the sewing needle after the sewing needle is located at the meeting position in the first step and the sensor unit is fixed to the frame in the second step, a fourth step of detecting an amount of displacement of the sewing needle by the sensor when the movable body moved in the third step comes into contact with the sewing needle and bends, and a fifth step of determining a reference position when adjusting the axial position of the movable body by the position adjustment mechanism based on the amount of displacement of the sewing needle detected in the fourth step. According to the second aspect, it is possible to achieve an effect similar to that of the first aspect.

[0013] A sensor unit according to a third aspect of the present invention is a sensor unit for use in a sewing machine including a shuttle mechanism having a movable body including a needle bar movable in a vertical direction and having a sewing needle attached to a tip thereof, a point for capturing an upper thread to be inserted into the sewing needle attached to the needle bar, and a needle guard for contacting and guiding the sewing needle, a shuttle shaft having an axis extending in a direction intersecting the vertical direction and for rotating the movable body in a rotational direction around the axis, a position adjustment mechanism for adjusting a position of the movable body in the axial direction of the shuttle shaft, and a frame for accommodating the shuttle mechanism, the shuttle shaft, and the position adjustment mechanism, the sensor comprising: a sensor having a contact surface that contacts the sewing needle from one side in the axial direction and capable of detecting an amount of displacement of the sewing needle in the axial direction; [Brief description of the drawings]

[0014] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view of the head 24 and the frame 7. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 2 is an exploded perspective view of the shuttle unit 8. [Figure 6] FIG. [Figure 7] 7 is a cross-sectional view taken along line AA in FIG. 6, seen from the direction of the arrow. [Figure 8] FIG. 2 is a perspective view of the sensor unit 4. [Figure 9] 2 is a perspective view of the sensor unit 4 detached from the frame 7. FIG. [Figure 10] FIG. 2 is a perspective view of a sensor unit 4 mounted on a frame 7. [Figure 11] 2 is a block diagram showing the electrical configuration of the sewing machine 1. FIG. [Figure 12] 4 is a flowchart showing a first adjustment method. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. 13 is a diagram showing a state in which the sewing needle 31A is disposed at the meeting position. [Figure 16] FIG. [Figure 17] FIG. [Figure 18] 13 is a diagram showing a state in which a detection object 84F is detected by a second sensor 6B. FIG. [Figure 19] 13 is a flowchart showing a second adjustment method. [Figure 20] 20 is a flowchart showing the second adjustment method, which is a continuation of FIG. 19. [Figure 21] 13 is a diagram showing a state in which a needle receiver 84C of a driver 84 is in contact with a sewing needle 31A. FIG. [Figure 22] 13 is a diagram showing a state in which a hook tip 83C of a hook 83 is in contact with a sewing needle 31A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A sewing machine 1 according to a first embodiment of the present invention will be described with reference to the drawings. In the following description, arrows in the drawings will be used to indicate left and right, front and rear, and up and down.

[0016] <Overview of Sewing Machine 1> The sewing machine 1 is a gate-type sewing machine capable of sewing a material to be sewn. As shown in FIG. 1, the sewing machine 1 has a bed 21, a pair of pillars 22, a beam 23, a head 24, a feed mechanism 25, and an operation unit 27.

[0017] Bed 21 has base 21A and frame 21B. Base 21A is substantially rectangular. The upper surface of base 21A forms flat holding surface 21U extending horizontally. Holding plate 21P extending forward along holding surface 21U is provided at the front end of base 21A. Opening 210L is formed near the left end of holding surface 21U, and bellows 21L extending in the front-rear direction covers opening 210L. Opening 210R is formed near the right end of holding surface 21U, and bellows 21R extending in the front-rear direction covers opening 210R. Bellows 21L and 21R each extend linearly between the front end and rear end of holding surface 21U. Bellows 21L and 21R expand and contract in response to reciprocating movement of feed mechanism 25 (described later) in the front-rear direction. Frame 21B is a lattice-shaped structure and supports base 21A from below.

[0018] The feed mechanism 25 has connecting parts 25L and 25R. The connecting part 25L is connected to a rail arranged in the opening 210L of the bed part 21. The connecting part 25R is connected to a rail arranged in the opening 210R of the bed part 21. The connecting parts 25L and 25R are connected to the holding mechanism 26. The holding mechanism 26 holds the sewing workpiece. The holding mechanism 26 has an upper frame, a lower frame 261, and air cylinders 262L and 262R (not shown). The upper frame and the lower frame 261 are rectangular frames in a plan view, and hold the sewing workpiece therebetween. The upper frame is moved up and down by the air cylinders 262L and 262R. In FIG. 1, the upper frame is detached from the air cylinders 262L and 262R. The feed mechanism 25 moves the holding mechanism 26 holding the sewing workpiece in the front-rear direction.

[0019] The pair of pillars 22 have pillars 22L and 22R. Each of pillars 22L and 22R is substantially rectangular prism-shaped. Pillar 22L extends upward from the left end of base 21A of bed 21 and a position forward of the center in the front-rear direction. Pillar 22L is located to the left of bellows 21L in the left-right direction. Pillar 22R extends upward from the right end of base 21A of bed 21 and a position forward of the center in the front-rear direction. Pillar 22R is located to the right of bellows 21R in the left-right direction. Pillar 22L and 22R are spaced apart in the left-right direction.

[0020] The beam 23 is installed between the pillars 22L and 22R. The beam 23 extends in the left-right direction between the pair of pillars 22. The beam 23 has a housing 23U. The housing 23U extends between the upper end and the rear end of each of the pillars 22L and 22R. A rail (not shown) is provided in the space surrounded by the pillars 22L and 22R and the housing 23U. The rail has a rod shape and is installed between the pillars 22L and 22R. The rail supports the head 24 described later so that it can move in the left-right direction. The bellows 23F is provided between the front ends of the pillars 22L and 22R and the housing 23U, and both left and right ends of the head 24 described later. The bellows 23F covers the rail supporting the head 24 from the front. Bellows 23F expands and contracts in response to head 24 reciprocating in the left-right direction along the rail.

[0021] The operation unit 27 is fixed to the front surface of the left end portion of the beam portion 23. The operation unit 27 includes a switch group 27A and a display unit 27B. Various instructions are input to the switch group 27A in response to operations by an operator. The display unit 27B is a liquid crystal display and can display various images.

[0022] The head 24 is provided in front of the beam 23. The head 24 includes a needle bar 31, a presser foot 32, a thread take-up lever 33, a thread tension device 34, a sub-thread tension device 35, thread guides 36, 37, etc. The needle bar 31 extends vertically, and a sewing needle 31A (see FIG. 2) can be attached to the lower end. A drive unit 5 (see FIG. 3, described later) that drives the needle bar 31 is provided inside the head 24. The presser foot 32 has a through hole through which the sewing needle 31A passes in response to the movement of the needle bar 31, and presses the sewing object from above. The thread take-up lever 33 operates in response to the vertical movement of the needle bar 31 to pull up the upper thread. The thread tension device 34 adjusts the tension of the upper thread. The sub-thread tension device 35 winds around the upper thread extending from a thread spool (not shown) and guides the upper thread toward the thread tension device 34 below. The thread guides 36 and 37 each come into contact with the upper thread extending from the thread tension device 34 and guide the upper thread toward the thread take-up lever 33.

[0023] The rails within the beam portion 23 support the head portion 24 so that the head portion 24 can move in the left-right direction. Therefore, the head portion 24 can move in the left-right direction along the front end portion of the beam portion 23.

[0024] As shown in FIG. 3, the drive unit 5 includes a main shaft 50, a rotary knob 51, a pulley 52, a counterweight 53, a crank 54, rods 56 and 57, and a needle bar receiver 58.

[0025] The main shaft 50 has a cylindrical shape and extends in the left-right direction. The rotating knob 51 is fixed to the right end of the main shaft 50. The rotating knob 51 is manually rotated when an operator moves the needle bar 31 in the up-down direction or rotates a movable body 80 (see FIG. 4) described later. The pulley 52 is fixed to the left of the rotating knob 51 on the main shaft 50. A gear 52A is formed on the side of the pulley 52. ​​A belt (not shown) is stretched between the rotating shaft of the main motor 131 (see FIG. 11) and the pulley 52. ​​The pulley 52 receives a rotational driving force from the belt, which rotates in response to the drive of the main motor 131, and rotates the main shaft 50.

[0026] The counterweight 53 is fixed to the main shaft 50 to the left of the pulley 52. ​​The counterweight 53 suppresses vibrations that occur when the main shaft 50 rotates. The crank 54 is fixed to the main shaft 50 to the left of the counterweight 53. A first support shaft (not shown) extending leftward is fixed to the crank 54 at a position spaced apart from the main shaft 50 in a radial direction based on the center of rotation of the main shaft 50. The lower end of the rod 56 is rotatably supported by the first support shaft. The rod 56 extends upward from the portion supported by the first support shaft. The balance 33 is fixed to the upper end of the rod 56. The balance 33 extends diagonally upward and forward from the upper end of the rod 56.

[0027] A balance receiver 55 is provided behind the balance 33. The balance receiver 55 has a rotation shaft 55A extending in the left-right direction, and a crank 55B extending forward from the rotation shaft 55A. The front end of the crank 55B is connected to the upper end of the rod 56. The crank 55B is rotatable relative to the rod 56. The balance receiver 55 controls the speed at which the balance 33 moves up and down.

[0028] When the main shaft 50 rotates in response to the drive of the main motor 131, the upper end of the rod 56 moves vertically. Therefore, the balance 33 fixed to the upper end of the rod 56 also moves vertically in response to the rotation of the main shaft 50.

[0029] A connecting plate 56A is fixed to the left surface of the lower end of the rod 56, extending in a radial direction centered on the first support shaft and away from the first support shaft. A second support shaft 57A extending to the left is fixed to the end of the connecting plate 56A opposite the first support shaft. One end of the rod 57 is rotatably supported by the second support shaft 57A. The other end of the rod 57 rotatably supports a needle bar holder 58. The needle bar holder 58 is fixed to the needle bar 31. The needle bar holder 58 has a third support shaft (not shown) extending to the right. The third support shaft is rotatably supported by the other end of the rod 57.

[0030] When the main shaft 50 rotates in response to the drive of the main motor 131, the other end of the rod 57 moves up and down. At this time, the needle bar holder 58 rotatably supported on the other end of the rod 57 also moves up and down. Therefore, the needle bar 31 to which the needle bar holder 58 is fixed also moves up and down in response to the rotation of the main shaft 50.

[0031] Sewing needle 31A is attached to the lower end of needle bar 31. A notch 30 is cut out to the left on the right side near the tip of sewing needle 31A.

[0032] <Frame 7> 2, a frame 7 is provided below the head 24 and inside the base 21A (see FIG. 1). The frame 7 has a housing 70A and a pair of legs 70B.

[0033] Housing 70A accommodates shuttle unit 8 (see FIG. 5, etc.), which will be described later. Housing 70A has a main portion 701 and a protruding portion 702. Main portion 701 is box-shaped. Protruding portion 702 is provided on the left surface of main portion 701 near the front end portion and protrudes to the left. Needle plate 74 is detachably fixed to the upper side of protruding portion 702. Needle plate 74 has a needle hole 74A through which sewing needle 31A (see FIG. 3) can be inserted. Needle hole 74A is located below needle bar 31. FIG. 4 shows the state in which needle plate 74 is detached.

[0034] As shown in Fig. 4, a pair of legs 70B are provided at both the front and rear ends of the main part 701. The pair of legs 70B are supported by rails (not shown) extending in the left-right direction. The shuttle unit 8 (see Fig. 5) in the housing 70A can move in the left-right direction in synchronization with the head 24 as the pair of legs 70B move along the rails. A transport mechanism (not shown) moves the head 24 and the frame 7 in the left-right direction.

[0035] Support shafts 751 and 752 are provided at the front end of the upper surface of protruding portion 702. Support shafts 751 and 752 each have a cylindrical shape, and protrude upward from the upper surface of protruding portion 702.

[0036] <Kettle Unit 8> 5 to 7, the shuttle unit 8 will be described. The shuttle unit 8 has a shuttle mechanism 8A, a shuttle shaft 8B, and position adjustment mechanisms 8C and 8D. The shuttle unit 8 is housed in a housing 70A of the frame 7.

[0037] As shown in FIG. 5, the shuttle shaft 8B has a shaft body 85, a shuttle shaft gear 86, and an end assembly 87.

[0038] The shaft body 85 has a cylindrical shape and extends in the left-right direction. The shaft body 85 is rotatably supported within the housing 70A of the frame 7. The axis extending in the left-right direction through the center of the shaft body 85 is called "axis C". A terminal assembly 87 is provided at the right end of the shaft body 85. The terminal assembly 87 has a cylindrical shape with a larger radius than the shaft body 85. The terminal assembly 87 is supported by the housing 70A of the frame 7. The terminal assembly 87 does not rotate even when the shaft body 85 rotates. On the other hand, the terminal assembly 87 can move in the left-right direction relative to the frame 7. In response to the terminal assembly 87 moving in the left-right direction relative to the frame 7, the shaft body 85 also moves in the left-right direction relative to the frame 7. A groove 87A extending in the up-down direction is provided on the front side surface of the terminal assembly 87. A bottom 870 of the groove 87A is perpendicular to the front-rear direction.

[0039] The shuttle shaft gear 86 is provided on the shaft body 85 to the left of the end assembly 87. A belt (not shown) is stretched between the rotating shaft of the main motor 131 and the shuttle shaft gear 86. The shuttle shaft gear 86 receives a rotational driving force from the belt, which rotates in response to the driving of the main motor 131, and rotates the shaft body 85. Note that the main shaft 50 (see FIG. 3) of the drive unit 5 also rotates in response to the driving of the main motor 131. Therefore, the main shaft 50 and the shaft body 85 rotate in conjunction with each other in response to the driving of the main motor 131.

[0040] The shuttle mechanism 8A is a vertical shuttle in which a bobbin is set vertically. The shuttle mechanism 8A has a large shuttle body 81, a large shuttle 82 (see FIGS. 6 and 7), and a movable body 80.

[0041] The kettle body 81 has a first storage section 81A and a second storage section 81B. The first storage section 81A has a cylindrical shape and extends in the left-right direction. A groove 817 extending in the up-down direction is provided on the front side surface of the first storage section 81A. A bottom 817A of the groove 817 is perpendicular to the front-rear direction. The second storage section 81B is provided at the left end of the first storage section 81A. The second storage section 81B has a cylindrical shape and extends in the left-right direction. The second storage section 81B has a first section 811 and a second section 812 with different diameters. The second section 812 is disposed to the left of the first section 811. The outer diameter of the second section 812 is larger than the outer diameter of the first section 811. The outer diameters of the first section 811 and the second section 812 are larger than the outer diameter of the first storage section 81A.

[0042] A through hole extending in the left-right direction is formed in the center of the first housing portion 81A. The left end of the shaft body 85 of the shuttle shaft 8B is inserted from the right into the through hole of the first housing portion 81A. A space 810 is formed in the second housing portion 81B. The movable body 80 described later is housed in the space 810. A circular opening 813 is formed in the left end of the second part 812 of the second housing portion 81B. The left end of the space 810 is opened by the opening 813. A hole 814 communicating with the space 810 is formed in the upper end of the second housing portion 81B. The upper end of the opening 813 and the left end of the hole 814 are connected. A hole 815 communicating with the space 810 is formed in the rear end of the first part 811 of the second housing portion 81B. The hole 815 is an elongated hole that is long in the vertical direction, and a female screw is formed on the inside of the upper end of the hole 815, and another female screw is also formed on the inside of the lower end of the hole 815. A hole 816 communicating with the space 810 is formed in the front end portion of the first portion 811 of the second housing portion 81B. The hole 816 is a hole having a circular cross-sectional shape.

[0043] As shown in Figs. 6 and 7, the kettle 82 is provided at the left end of the kettle body 81. As shown in Fig. 6, the kettle 82 has a circular plate shape. The outer diameter of the kettle 82 is approximately the same as the outer diameter of the second part 812 of the second accommodation part 81B of the kettle body 81. A circular hole 821 is formed in the center of the kettle 82, penetrating in the left-right direction. The diameter of the hole 821 is smaller than the diameter of the opening 813 (see Fig. 5) of the kettle body 81. The kettle 82 covers a part of the opening 813 of the kettle body 81 from the left side.

[0044] As shown in FIG. 4, the second housing portion 81B of the large shuttle body 81 protrudes leftward from the left surface of the protruding portion 702 of the housing 70A of the frame 7. A shuttle thread guide 90 is fixed to the upper side of the second housing portion 81B. The shuttle thread guide 90 is a plate and is perpendicular to the up-down direction. The shuttle thread guide 90 covers the hole 814 of the second housing portion 81B from above. The shuttle thread guide 90 is located below the needle plate 74 (see FIG. 2). The shuttle thread guide 90 has a notch 90A. The notch 90A extends rightward from the left end of the shuttle thread guide 90.

[0045] 5, the movable body 80 has an inner shuttle 83 and a driver 84. The inner shuttle 83 and the driver 84 are disposed in a space 810 of the main shuttle body 81.

[0046] The inner hook 83 is made of metal and has a base 83A, a peripheral portion 83B, a point 83C, and a stud 830.

[0047] The base 83A has a fan-shaped plate shape and is perpendicular to the left-right direction. The axis C passes through the center of the fan shape of the base 83A. The peripheral portion 83B is provided on the arc portion of the base 83A. The end of the peripheral portion 83B on one side in the circumferential direction centered on the axis C is called the "intermediate hook end 831." The end of the peripheral portion 83B on the other side in the circumferential direction centered on the axis C is called the "intermediate hook end 832." The intermediate hook end 831 corresponds to the end of the peripheral portion 83B on the counterclockwise side when viewed from the left. The intermediate hook end 832 corresponds to the end of the peripheral portion 83B on the clockwise side when viewed from the left.

[0048] The tip 83C extends to the other side in the circumferential direction centered on the axis C. The tip 83C has a sharp tip. The tip 83C captures the upper thread inserted into the sewing needle 31A during the sewing process by the sewing machine 1. The stud 830 extends leftward from the base 83A along the axis C. A bobbin case (not shown) containing a bobbin around which a lower thread is wound is rotatably supported by the stud 830.

[0049] The inner hook 83 is disposed within the space 810 of the hook body 81. The inner hook 83 is rotatably supported by the hook body 81 and the hook 82 in a state in which the hook 82 is fixed to the hook body 81.

[0050] The driver 84 is made of metal and has a fixed portion 84A, a base portion 84B, a needle receiver 84C, an engaged body 84E, and a detected body 84F.

[0051] The fixing portion 84A has a cylindrical shape and extends in the left-right direction. A through hole 840 of the fixing portion 84A extends in the left-right direction. An axis C passes through the center of the through hole 840. The fixing portion 84A is provided with a protrusion 841 extending in a radial direction centered on the axis C. Hereinafter, the radial direction centered on the axis C will be referred to as the "axial radial direction". Slits are formed in the fixing portion 84A and the protrusion 841. A fixing screw 842 is screwed into the protrusion 841. The distance between the slits of the fixing portion 84A and the protrusion 841 can be adjusted by the fixing screw 842.

[0052] When the fixing screw 842 is tightened with the shaft body 85 of the shuttle shaft 8B inserted into the through hole 840, the fixed part 84A is connected to the shaft body 85 and is in a state in which the rotational force of the shaft body 85 can be transmitted. On the other hand, when the fixing screw 842 is loosened, the fixed part 84A is detached from the shaft body 85 and the transmission of the rotational force of the shaft body 85 is cut off.

[0053] The base portion 84B extends radially outward from a side surface of the fixing portion 84A. The tip of the base portion 84B is bent to the left.

[0054] The needle guard 84C is provided at the tip of the base 84B. The needle guard 84C extends in the circumferential direction centered on the axis C. The needle guard 84C comes into contact with the sewing needle 31A during sewing by the sewing machine 1, and guides the sewing needle 31A so as not to bend. The end of the needle guard 84C on one side in the circumferential direction centered on the axis C is referred to as the "needle guard end 843." The end of the peripheral portion 83B on the other side in the circumferential direction centered on the axis C is referred to as the "needle guard end 844." The needle guard end 843 corresponds to the end of the needle guard 84C on the counterclockwise side when viewed from the left. The needle guard end 844 corresponds to the end of the needle guard 84C on the clockwise side when viewed from the left.

[0055] The engaged body 84E is provided on a side surface of the fixed portion 84A. The engaged body 84E has an engaging extension portion 845 and an engaged portion 846. The engaging extension portion 845 extends outward from the side surface of the fixed portion 84A along the axial radial direction. The engaging extension portion 845 is shaped like a rectangular prism. The engaged portion 846 is a recess formed in the tip portion of the engaging extension portion 845. The engaged portion 846 extends from the plane of the tip portion of the engaging extension portion 845 toward the axis C.

[0056] The detectable body 84F is provided on the side surface of the fixed portion 84A. The detectable body 84F has a detectable extension 847 and a detectable surface 848. The detectable extension 847 extends outward from the side surface of the fixed portion 84A along the axial direction. The extending direction of the detectable extension 847 is different from the extending direction of the engagement extension 845 of the engaged body 84E. The angle between the engagement extension 845 and the detectable extension 847 is about 120 degrees when viewed from the left (see FIG. 13). The detectable extension 847 is disposed on the clockwise side of the engagement extension 845 when viewed from the left. The shape of the detectable extension 847 is a rectangular prism. The detectable surface 848 is provided at the tip of the detectable extension 847. The detectable surface 848 has a plane perpendicular to the axial direction.

[0057] The axial length of detection extension 847 of detection object 84F is longer than the axial length of engagement extension 845 of engagement object 84E. Detection surface 848 of detection object 84F is located outwardly of engagement portion 846 of engagement object 84E of driver 84 in the axial direction.

[0058] The driver 84 is disposed within the space 810 of the large shuttle body 81 and to the right of the inner shuttle 83. A needle receiver end 843 of a needle receiver 84C of the driver 84 contacts an inner shuttle end 832 of the inner shuttle 83. A needle receiver end 844 of the needle receiver 84C of the driver 84 contacts an inner shuttle end 831 of the inner shuttle 83. However, when one of the needle receiver ends 843, 844 is in contact with the inner shuttle 83, the other is spaced apart from the inner shuttle 83.

[0059] The driver 84, which is connected to the shaft body 85 of the shuttle shaft 8B by tightening the fixing screw 842, rotates about the axis C in response to the rotation of the shaft body 85. At this time, a rotational driving force is transmitted from the driver 84 to the shuttle 83, whose inner shuttle ends 831, 832 are in contact with the needle receiver ends 843, 844 of the needle receiver 84C of the driver 84. As a result, the inner shuttle 83 rotates about the axis C in response to the rotation of the driver 84. In other words, by connecting the driver 84 to the shaft body 85, the movable body 80 including the inner shuttle 83 and the driver 84 is connected to the shaft body 85, and the movable body 80 rotates in response to the rotation of the shaft body 85. Hereinafter, the state in which the movable body 80 is connected to the shaft body 85 will be referred to as the "connected state."

[0060] On the other hand, the driver 84, which has been detached from the shaft body 85 of the shuttle shaft 8B by loosening the fixing screw 842, does not rotate even when the shaft body 85 rotates. Moreover, the inner shuttle 83 does not rotate, either, since no rotational driving force is transmitted from the driver 84. In other words, the state in which the movable body 80 including the inner shuttle 83 and the driver 84 is connected to the shaft body 85 is released by the driver 84 being detached from the shaft body 85. Hereinafter, the state in which the connection of the movable body 80 to the shaft body 85 is released will be referred to as the "released state."

[0061] The position adjustment mechanisms 8C and 8D are each fixed to the housing 70A of the frame 7. The position adjustment mechanisms 8C and 8D have the same shape.

[0062] The position adjustment mechanism 8C has a body 88A and a head 88B. The body 88A has a cylindrical shape and extends in the front-rear direction. The body 88A is an eccentric shaft. The radius of the body 88A is not uniform in the circumferential direction, and the radius of one part in the circumferential direction is larger than the radius of the other part. The rear end of the body 88A fits into a groove 87A provided in an end assembly 87 of the shuttle shaft 8B. A groove extending in the circumferential direction is formed in the front end of the body 88A. An O-ring (not shown) is fitted into this groove. The head 88B is provided on the front side surface of the body 88A. A linearly extending groove (slot) is formed in the head 88B.

[0063] By rotation of the position adjustment mechanism 8C, the shuttle shaft 8B moves in the left-right direction relative to the frame 7. The position adjustment mechanism 8C is capable of adjusting the left-right position of a driver 84 connected to a shaft body 85 of the shuttle shaft 8B.

[0064] The position adjustment mechanism 8D has a body 89A and a head 89B. The body 89A and the head 89B correspond to the body 88A and the head 88B of the position adjustment mechanism 8C. The rear end of the body 89A fits into a groove 817 provided in the first housing portion 81A of the hook body 81.

[0065] By rotation of the position adjustment mechanism 8D, the large shuttle body 81 moves in the left-right direction relative to the frame 7. Therefore, the position adjustment mechanism 8D can adjust the left-right position of the inner shuttle 83 rotatably supported by the large shuttle body 81.

[0066] Therefore, the position adjustment mechanisms 8C and 8D can independently adjust the left-right positions of the inner shuttle 83 and the driver 84 of the movable body 80 relative to the frame 7.

[0067] <Engagement body 6A> The engagement body 6A is provided in the second accommodation portion 81B of the large shuttle body 81 of the shuttle unit 8. The engagement body 6A has a base portion 61, a movable portion 62, an operating portion 63, and a fixed portion 64.

[0068] The base 61 has a cylindrical shape and extends rearward along the axial direction. The fixing part 64 is provided integrally with the base 61, on the inside of the base 61 in the axial direction. A screw groove for fixing is formed on the side surface of the fixing part 64. The base 61 is inserted into the upper end of a hole 815 formed in the second housing part 81B of the hook body 81, and the screw groove of the fixing part 64 is screwed into the female thread of the hole 815, thereby fixing the base 61 to the second housing part 81B. The base 61 and the fixing part 64 have a through hole extending along the axial direction.

[0069] The movable part 62 has a cylindrical shape and is inserted into the through holes of the base part 61 and the fixed part 64. The movable part 62 is movable in the axial radial direction relative to the base part 61 and the fixed part 64. An inner end part of the movable part 62 in the axial radial direction is referred to as an "engagement part 62A." When the movable part 62 moves inward in the axial radial direction, the engagement part 62A protrudes inward in the axial radial direction relative to the fixed part 64. When the movable part 62 moves outward in the axial radial direction, the engagement part 62A is disposed inside the fixed part 64 and does not protrude inward in the axial radial direction relative to the fixed part 64.

[0070] The operation unit 63 is provided on the outer side in the axial radial direction of the movable unit 62. The operation unit 63 is disposed on the outer side in the axial radial direction with respect to the base unit 61. The operation unit 63 is gripped when an operator moves the movable unit 62 along the axial radial direction.

[0071] In a state where the movable part 62 has moved outward in the axial direction, the engaging part 62A is disposed outward in the axial direction from the inner surface of the hook body 81 that forms the space 810. At this time, the engaging part 62A is disposed outward in the axial direction from the region through which the engaged body 84E and the detected body 84F pass in response to the rotation of the driver 84. Hereinafter, this state will be referred to as the "detached state."

[0072] On the other hand, in a state where the movable part 62 has moved inward in the axial direction, the engaging part 62A protrudes inward from the inner surface that forms the space 810 of the hook body 81. At this time, the engaging part 62A is disposed inward in the axial direction from the region through which the engaged body 84E and the detected body 84F pass in response to the rotation of the driver 84. Hereinafter, this state will be referred to as the "engaged state."

[0073] <Second sensor 6B> The second sensor 6B is a proximity sensor. The second sensor 6B is fixed to a lower end of a hole 815 formed in the second housing portion 81B of the kettle body 81. The second sensor 6B has a base portion 67, a holder portion 65, and a sensor head 66.

[0074] The base 67 has a cylindrical shape and extends obliquely downward toward the rear along the axial direction. A screw groove for fixing is formed on the side surface of the base 67. This screw groove is screwed into the female thread of the hole 815. The holding part 65 is provided at the outer end of the base 67 in the axial direction. The holding part 65 has a hexagonal shape. A wrench or the like is applied to the holding part 65 when the second sensor 6B is fixed to the kettle body 81 by the screw groove of the base 67. The sensor head 66 is provided at the inner end of the base 61 in the axial direction. The sensor head 66 generates a high-frequency magnetic field to detect the approach of the detection object 84F of the driver 84. The sensor head 66 is disposed outside the area through which the engagement object 84E and the detection object 84F pass as the driver 84 rotates.

[0075] The detection surface 848 of the detection object 84F and the second sensor 6B are both disposed at a position different from the inner shuttle 83 in the left-right direction, more specifically, to the right of the inner shuttle 83. Moreover, the detection surface 848 of the detection object 84F and the second sensor 6B are disposed at the same position in the left-right direction.

[0076] The second sensor 6B outputs a detection result indicating whether the detection surface 848 of the detection object 84F has approached the sensor head 66 or not.

[0077] <Sensor unit 4> The sensor unit 4 is detachably attached to the frame 7. The sensor unit 4 is attached to the frame 7 and used when adjusting the left-right positional relationship between the sewing needle 31A attached to the needle bar 31 and the point 83C or the needle guard 84C of the movable body 80. On the other hand, the sensor unit 4 is detached when the sewing machine 1 performs a sewing operation. As shown in FIG. 8, the sensor unit 4 has a first sensor 4A and an arm portion 4B.

[0078] The arm portion 4B supports a first sensor 4A, which will be described later, and fixes the first sensor 4A to the frame 7. The arm portion 4B is a bent rectangular column. The arm portion 4B has extensions 451 and 452. The extension portion 451 extends in the left-right direction. The extension portion 452 extends rearward from the left end of the extension portion 451. Holes 461, 462, and 463 are formed in the extension portion 451. The holes 461 to 463 each pass through the extension portion 451 in the up-down direction. The holes 461, 462, and 463 are lined up on the right side in this order.

[0079] The first sensor 4A is supported by an extension 452 of the arm 4B. The first sensor 4A has a support 41, a detection body 42, and a detector 43.

[0080] The support portion 41 is fixed to the right side surface of the extension portion 452 of the arm portion 4B by a screw 411. The detection body 42 is supported on the arm portion 4B by the support portion 41. The detection body 42 has detection portions 42A and 42B facing each other in the front-rear direction. A gap is formed between the detection portions 42A and 42B. The detection portion 42A has a light-emitting portion on the surface facing the detection portion 42B. The detection portion 42B has a light-receiving portion on the surface facing the detection portion 42A. The light-emitting portion emits light toward the light-receiving portion. The light-receiving portion receives the light emitted from the light-emitting portion. The detection body 42 further has a connector 42C on the front side surface of the detection portion 42A. A cable (not shown) is connected to the connector 42C.

[0081] The detector 43 has a base 43A in the form of a long and thin plate. The base 43A is perpendicular to the front-rear direction. The rotation shaft 431 extends forward from the front surface of the base 43A. The tip of the rotation shaft 431 is rotatably supported by a support plate 421 extending forward from the detection unit 42A. The rotation shaft 432 extends backward from the rear surface of the base 43A. The tip of the rotation shaft 432 is rotatably supported by a support plate 422 extending forward from the detection unit 42B. The rotation shafts 431 and 432 are aligned in a straight line in the front-rear direction. The base 43A is rotatable about the rotation shafts 431 and 432. The base 43A extends from the portion where the rotation shafts 431 and 432 are provided to the right end portion, slanting downward.

[0082] A contact surface 433 is provided on a part of the peripheral end of the base 43A. The contact surface 433 has a planar shape perpendicular to the base 43A and extends across the front and rear of the base 43A. The contact surface 433 extends diagonally downward to the right from a position on the peripheral end of the base 43A that is above the rotation axes 431 and 432, curves at the front end of the base 43A, and further extends diagonally downward to the left.

[0083] A restricting portion 434 is provided at a position above the contact surface 433 on the peripheral end of the base 43A. The restricting portion 434 has a planar shape perpendicular to the base 43A and extends across the front and rear of the base 43A. The restricting portion 434 is located above the upper surfaces of the detection portions 42A and 42B. The restricting portion 434 restricts the counterclockwise rotation of the base 43A when viewed from the front by contacting the upper surfaces of the detection portions 42A and 42B. The base 43A can rotate in the clockwise direction from a state in which the counterclockwise rotation is restricted by the restricting portion 434.

[0084] A shielding plate (not shown) is provided in a portion of the base 43A sandwiched between the detection units 42A and 42B. A plurality of slits are formed in the shielding plate. When the base 43A rotates around the rotation shafts 431 and 432, the light emitted from the light emitting unit of the detection unit 42A passes through the slits or is blocked by the shielding plate. The light receiving unit of the detection unit 42B detects the rotational position of the base 43A based on the state of reception of the light emitted from the light emitting unit of the detection unit 42A. The detection body 42 outputs a detection result indicating the detected rotational position via a cable connected to the connector 42C.

[0085] As shown in FIG. 9, the arm 4B is fixed to the frame 7 by inserting the support shafts 751 and 752 of the frame 7 into the holes 462 and 463 from below. A magnet is inserted into the hole 461. When the arm 4B is fixed to the frame 7, the magnet is attracted to an iron plate 753 connected to the frame 7 by magnetic force. The magnet assists the support shafts 751 and 752 in inserting them all the way into the holes 462 and 463 when fixing the arm 4B by magnetic attraction. The magnet also attracts the iron plate 753 to hold the arm 4B so that the sensor unit 4 does not rattle when in use. As shown in FIG. 10, the arm 4B fixed to the frame 7 supports the first sensor 4A to the left and above the movable body 80 (see FIG. 5) of the shuttle unit 8. The detector 43 of the first sensor 4A enters the notch 90A of the shuttle thread guide 90 from the left. The contact surface 433 of the detector 43 is disposed inside the notch 90A.

[0086] <Electrical configuration> The electrical configuration of the sewing machine 1 will be described with reference to FIG. 11. The control unit 110 of the sewing machine 1 includes a CPU 111, a ROM 112, a RAM 113, a storage device 114, an input / output interface (I / O) 115, and drive circuits 121-125. The CPU 111 controls the overall operation of the sewing machine 1. The ROM 112 stores in advance programs and the like for executing various processes. The RAM 113 temporarily stores various pieces of information generated during the execution of various processes. The storage device 114 is non-volatile and stores various setting values.

[0087] The drive circuits 121-125, the encoders 141-143, the switch group 27A, the first sensor 4A, the second sensor 6B, the third sensor 9A, and the fourth sensor 9B are connected to the I / O 115. The drive circuit 121 is connected to a main motor 131, and drives the main motor 131 according to a control command from the CPU 111. The drive circuit 122 is connected to an X motor 132 of a transport mechanism (not shown), and drives the X motor 132 according to a control command from the CPU 111. The drive circuit 123 is connected to a Y motor 133 of the feed mechanism 25, and drives the Y motor 133 according to a control command from the CPU 111. The drive circuit 124 is connected to air cylinders 262L and 262R, and drives the air cylinders 262L and 262R according to a control command from the CPU 111. The drive circuit 125 is connected to the display unit 27B, and displays various information on the display unit 27B according to control commands from the CPU 111. The third sensor 9A directly detects the left-right position of the driver 84 of the movable body 80. The fourth sensor 9B directly detects the left-right position of the shuttle 83. There are no particular limitations on the method of detecting the position in the third sensor 9A and the fourth sensor 9B, and well-known sensors such as optical and magnetic sensors may be used.

[0088] The encoder 141 detects the rotation direction, rotation position, and rotation speed of the output shaft of the main motor 131, and outputs the detection result to the I / O 115. The detection result of the encoder 141 indicates the rotation direction, rotation position, and rotation speed of the main shaft 50 and the shaft body 85 of the shuttle shaft 8B driven by the main motor 131. The encoder 142 detects the rotation position of the output shaft of the X motor 132, and outputs the detection result to the I / O 115. The detection result of the encoder 142 indicates the movement direction, left-right position, and movement speed of the needle bar 31 and the shuttle unit 8. The encoder 143 detects the rotation direction, rotation position, and rotation speed of the output shaft of the Y motor 133, and outputs the detection result to the I / O 115. The detection result of the encoder 143 indicates the movement direction, front-rear position, and movement speed of the holding mechanism 26. The switch group 27A detects various instructions, and outputs the detection result to the I / O 115. The first sensor 4A and the second sensor 6B output the detection results to the I / O 115. The detection result of the first sensor 4A indicates the rotational position of the detector 43. The detection result of the second sensor 6B indicates whether the detection target surface 848 of the detection target 84F has approached the sensor head 66.

[0089] <First adjustment method> 12 to 18, the first adjustment method will be described. The first adjustment method is performed to synchronize the up and down movement of sewing needle 31A attached to needle bar 31 with the rotational movement of movable body 80 by adjusting the rotational position of movable body 80. In addition, the operator puts engaging body 6A into a detached state (see arrow Y11 in FIG. 13).

[0090] As shown in Fig. 12, the operator loosens the fixing screw 842 of the driver 84 using a wrench T (see Fig. 13) passed through the hole 816 to set the release state (S51). The movable body 80 becomes rotatable relative to the shuttle shaft 8B.

[0091] 13, the operator rotates the movable body 80 about the axis C until the engaging extension portion 845 of the engaged body 84E of the driver 84 extends rearward. The extending directions of the engaging body 6A and the engaged body 84E are aligned in a straight line in the axial direction.

[0092] As shown in Fig. 12, the operator then operates the operating portion 63 of the engaging body 6A to switch the engaging body 6A from the detached state to the engaged state (S53). As shown in Fig. 14, when the engaging body 6A is switched to the engaged state (arrow Y12), the engaging portion 62A of the engaging body 6A enters from the outside and engages with the engaged portion 846 of the engaged body 84E. The movable body 80 is placed in a non-rotatable state.

[0093] Hereinafter, the rotational position of the movable body 80 in a state where the engaging portion 62A of the engaging body 6A is engaged with the engaged portion 846 of the engaged body 84E is referred to as the "engagement rotational position." Note that, with the movable body 80 disposed at the engagement rotational position, the tip 83C of the inner hook 83 can capture the loop formed in the upper thread. In other words, the engagement rotational position corresponds to the rotational position of the movable body 80 at the timing when the tip 83C of the inner hook 83 captures the loop formed in the upper thread.

[0094] Next, the operator operates the rotary knob 51 of the drive unit 5 to rotate the main shaft 50 and the shuttle shaft 8B, and dispose the sewing needle 31A at the meeting position (S55). Note that since the movable body 80 is not connected to the shaft body 85 of the shuttle shaft 8B, it does not rotate even when the shaft body 85 rotates. As shown in FIG. 15, when the sewing needle 31A is disposed at the meeting position (arrow Y13), the tip of the sewing needle 31A enters the notch 90A (see FIG. 4) of the shuttle thread guide 90 from above, and is disposed within the space 810 of the shuttle body 81.

[0095] As shown in Fig. 12, the operator then tightens the fixing screw 842 of the driver 84 using the wrench T (see Fig. 13) passed through the hole 816 to establish a connected state (S57). The movable body 80 is connected to the shaft body 85 of the shuttle shaft 8B (see Fig. 16). Note that the engaging body 6A is maintained in the engaged state, and the engaging portion 62A is engaged with the engaged portion 846 of the engaged body 84E. Therefore, the movable body 80 remains in an unrotatable state.

[0096] Next, the operator switches the engaging body 6A from the engaged state to the disengaged state by operating the operating portion 63 of the engaging body 6A (S59). As shown in Fig. 17, when the engaging body 6A is put into the released state (arrow Y14), the engaging portion 62A disengages from the engaged portion 846 of the engaged body 84E. The movable body 80 becomes rotatable.

[0097] The operator operates the rotary knob 51 of the drive unit 5 to rotate the main motor 131, the main shaft 50, and the shuttle shaft 8B (S61). In response to the rotation of the shuttle shaft 8B, the movable body 80 connected to the shaft body 85 rotates.

[0098] The CPU 111 acquires the detection result output from the second sensor 6B. Based on the acquired detection result, the CPU 111 displays, on the display unit 27B, notification information indicating whether or not the detection target surface 848 of the detection target object 84F has approached the sensor head 66. The operator continues to operate the rotary knob 51 to rotate the movable body 80 until notification information indicating that the detection target surface 848 of the detection target object 84F has approached the sensor head 66 is displayed on the display unit 27B (S63: NO).

[0099] When notification information indicating that the detection target surface 848 of the detection target object 84F approaches the sensor head 66 is displayed on the display unit 27B (S63: YES), the operator stops operating the rotary knob 51. The rotation of the main motor 131, the main shaft 50, and the shuttle shaft 8B stops, and the rotation of the movable body 80 also stops. As shown in FIG. 18, in this state, the detection extension part 847 of the detection target object 84F extends from the axis C toward the sensor head 66 of the second sensor 6B. Hereinafter, the rotation position of the movable body 80 in the state where the approach of the detection target surface 848 of the detection target object 84F is detected by the sensor head 66 of the second sensor 6B is referred to as the "sensor rotation position". The engagement rotation position and the sensor rotation position are different.

[0100] With the movable body 80 disposed at the sensor rotation position, the CPU 111 acquires the detection result output from the encoder 141 of the main motor 131 (S65). The CPU 111 identifies the rotation position of the main shaft 50 based on the acquired detection result (S65). The CPU 111 stores the identified rotation position in the storage device 114 as the needle bar reference position (S67).

[0101] During sewing, CPU 111 acquires the detection result of encoder 141 at the timing when detectable body 84F of movable body 80 is detected by second sensor 6B (i.e., the timing when movable body 80 is located at the sensor rotation position). CPU 111 calculates the difference between the rotational position of main shaft 50 specified by the detection result and the needle bar reference position stored in storage device 114. When the calculated difference becomes larger than a predetermined threshold, CPU 111 displays a notification image indicating that a synchronization error has occurred on display unit 27B.

[0102] <Second adjustment method> The second adjustment method will be described with reference to Figs. 19 to 22. The first adjustment method is performed to adjust the left-right positional relationship between the sewing needle 31A attached to the needle bar 31 and the point 83C or the needle guard 84C of the movable body 80. Note that the operator performs the first adjustment method before starting the second adjustment method, and then tightens the fixing screw 842 of the driver 84 to connect the movable body 80 and the shaft body 85 of the shuttle shaft 8B. In addition, the operator detaches the sensor unit 4 from the frame 7.

[0103] As shown in Fig. 19, the operator operates the rotary knob 51 of the drive unit 5 that drives the needle bar 31 to place the sewing needle 31A at the meeting position (S11). The meeting position is the position of the sewing needle 31A at the timing when the point 83C of the inner shuttle 83 captures the loop formed in the upper thread. As shown in Fig. 10, the tip of the sewing needle 31A placed at the meeting position enters the notch 90A of the shuttle thread guide 90 from above. The point 83C of the inner shuttle 83 and the needle receiver 84C of the driver 84 are positioned to the right of the sewing needle 31A placed at the meeting position.

[0104] As shown in FIG. 19, next, the worker mounts and fixes the sensor unit 4 on the frame 7 of the sewing machine 1 (S13). The worker connects a cable to the connector 42C of the sensor unit 4. The detector 43 of the first sensor 4A enters the notch 90A of the shuttle thread guide 90 from the left. The contact surface 433 of the detector 43 comes into contact with the sewing needle 31A from the left. When the sewing needle 31A comes into contact with the detector 43, the detector 43 rotates clockwise around the rotation shafts 431, 432 as viewed from the front. The first sensor 4A detects the rotation position of the detector 43 by the detector 42, and outputs the detected position to the cable via the connector 42C.

[0105] The CPU 111 acquires the detection result output from the first sensor 4A. The CPU 111 stores the rotational position of the detector 43 indicated by the acquired detection result in the storage device 114 as a first initial reference position (S15).

[0106] The operator rotates the head 88B of the position adjustment mechanism 8C with a screwdriver or the like. This causes the body 88A of the position adjustment mechanism 8C to also rotate, and the shuttle shaft 8B moves leftward relative to the frame 7. At this time, the screwdriver 84 connected to the shaft body 85 of the shuttle shaft 8B also moves leftward (S17). Note that since the position adjustment mechanism 8D is not rotating, the inner shuttle 83 does not move. The needle guard 84C of the screwdriver 84 approaches the sewing needle 31A from the right.

[0107] The first sensor 4A detects the rotational position of the detector 43 by the detector 42 periodically or in response to an operation of the position adjustment mechanism 8C by an operator, and outputs the detection result. The CPU 111 acquires the detection result output from the first sensor 4A. The CPU 111 calculates the rotation angle of the detector 43 based on the difference between the rotational position indicated by the acquired detection result and the first initial reference position. Furthermore, the CPU 111 calculates the amount of displacement of the sewing needle 31A in the left-right direction based on the calculated rotation angle (S19). The CPU 111 displays the calculated amount of displacement on the display unit 27B.

[0108] The detector 43 of the first sensor 4A does not rotate until the needle guard 84C of the driver 84 comes into contact with the sewing needle 31A. Therefore, the rotational position indicated by the detection result output from the first sensor 4A remains at the first initial reference position. In this case, the calculated displacement amount of the sewing needle 31A is "0".

[0109] On the other hand, as shown in Figure 21, when the needle guard 84C of the driver 84 comes into contact with the sewing needle 31A, the sewing needle 31A receives a leftward force from the needle guard 84C and bends. The detector 43 of the first sensor 4A rotates as the sewing needle 31A bends and displaces. The rotational position detected by the detector 42 of the first sensor 4A changes. The CPU 111 calculates the amount of displacement of the sewing needle 31A based on the difference between the rotational position indicated by the detection result output from the first sensor 4A and the first initial reference position (S19). The CPU 111 displays the calculated amount of displacement on the display unit 27B.

[0110] The worker determines whether the amount of displacement displayed on the display unit 27B has reached 0.01 mm (S21). If the amount of displacement displayed on the display unit 27B is less than 0.01 mm (S21: NO), the worker continues the operation of the position adjustment mechanism 8C to move the screwdriver 84 to the left. If the amount of displacement displayed on the display unit 27B has reached 0.01 mm (S21: YES), the worker stops operating the position adjustment mechanism 8C. This also stops the movement of the screwdriver 84 to the left.

[0111] The operator performs an input operation via the switch group 27A to notify the sewing machine 1 that the movement of the screwdriver 84 has been stopped. The CPU 111 accepts the input operation. The CPU 111 determines the rotational position of the detector 43 in this state as the first zero point position (S23). The CPU 111 stores the determined first zero point position in the storage device 114 (S23). The CPU 111 calculates the amount of displacement of the screwdriver 84 relative to the first zero point position based on the difference between the rotational position indicated by the detection result obtained from the first sensor 4A and the first zero point position. The CPU 111 displays the calculated amount of displacement on the display unit 27B. Furthermore, the CPU 111 displays the detection result by the third sensor 9A on the display unit 27B as the left-right position of the screwdriver 84.

[0112] The sewing machine 1 determines the detection result of the third sensor 9A at the first zero point position detected by the first sensor 4A as the reference position in the left-right direction of the driver 84 (hereinafter referred to as the "first reference position") and stores it in the storage device 114 (S24). In other words, the first sensor 4A is used as a sensor for identifying the reference position of the third sensor 9A. The CPU 111 displays the difference between the detection result of the third sensor 9A and the first reference position on the display unit 27B.

[0113] The operator rotates the position adjustment mechanism 8C with a screwdriver or the like to move the screwdriver 84 in the left-right direction. The operator moves the screwdriver 84 in the left-right direction until the operation setting value of the screwdriver 84 recommended for the sewing machine 1 (hereinafter referred to as the "first operation setting value") matches the difference displayed on the display unit 27B (S25). When the first operation setting value matches the difference displayed on the display unit 27B, the operator ends the operation of the position adjustment mechanism 8C and stops the movement of the screwdriver 84. The CPU 111 stores the rotation position indicated by the detection result obtained from the third sensor 9A at this time in the storage device 114 as the needle receiver reference position (S25). With the above, the adjustment of the left-right positional relationship between the needle receiver 84C of the screwdriver 84 and the sewing needle 31A is completed.

[0114] As shown in FIG. 20, the CPU 111 stores the rotational position indicated by the detection result currently obtained from the first sensor 4A in the storage device 114 as the second initial reference position (S27).

[0115] The operator rotates the head 89B of the position adjustment mechanism 8D with a screwdriver or the like. This causes the body 89A of the position adjustment mechanism 8D to rotate as well, and the inner shuttle 83 moves leftward relative to the frame 7. At this time, the inner shuttle 83 also moves leftward (S29). The tip 83C of the inner shuttle 83 approaches the notch 30 (see FIG. 3) of the sewing needle 31A from the right.

[0116] The first sensor 4A continuously detects the rotation angle of the detector 43 by the detector 42 and outputs the detection result. The CPU 111 acquires the detection result output from the first sensor 4A. The CPU 111 calculates the amount of displacement in the left-right direction of the sewing needle 31A based on the difference between the rotation position indicated by the acquired detection result and the second initial reference position (S31). The CPU 111 displays the calculated amount of displacement on the display unit 27B.

[0117] The detector 43 of the first sensor 4A does not rotate until the tip 83C of the inner hook 83 comes into contact with the sewing needle 31A. Therefore, the rotational position indicated by the detection result output from the first sensor 4A remains at the second initial reference position. In this case, the calculated displacement of the sewing needle 31A becomes "0".

[0118] On the other hand, as shown in Figure 22, when the tip 83C of the hook 83 comes into contact with the sewing needle 31A, the sewing needle 31A receives a leftward force from the tip 83C and bends. The detector 43 of the first sensor 4A rotates as the sewing needle 31A bends and displaces. The rotational position detected by the detector 42 of the first sensor 4A changes. The CPU 111 calculates the amount of displacement of the sewing needle 31A based on the difference between the rotational position indicated by the detection result output from the first sensor 4A and the second initial reference position (S31). The CPU 111 displays the calculated amount of displacement on the display unit 27B.

[0119] The operator determines whether the amount of displacement displayed on the display unit 27B has reached 0.01 mm (S33). If the amount of displacement displayed on the display unit 27B is less than 0.01 mm (S33: NO), the operator continues the operation of the position adjustment mechanism 8D to move the inner shuttle 83 to the left. If the amount of displacement displayed on the display unit 27B has reached 0.01 mm (S33: YES), the operator stops the operation of the position adjustment mechanism 8D. This also stops the movement of the inner shuttle 83 to the left.

[0120] The operator performs an input operation via the switch group 27A to notify the sewing machine 1 that the movement of the inner hook 83 has been stopped. The CPU 111 accepts the input operation. The CPU 111 determines the rotational position of the detector 43 in this state as the second zero point position (S35). The CPU 111 stores the determined second zero point position in the storage device 114 (S35). The CPU 111 calculates the amount of displacement of the inner hook 83 relative to the second zero point position based on the difference between the rotational position indicated by the detection result obtained from the first sensor 4A and the second zero point position. The CPU 111 displays the calculated amount of displacement on the display unit 27B. Furthermore, the CPU 111 displays the detection result by the fourth sensor 9B on the display unit 27B as the left-right position of the inner hook 83.

[0121] The sewing machine 1 determines the detection result of the fourth sensor 9B at the second zero point position detected by the first sensor 4A as the reference position in the left-right direction of the inner hook 83 (hereinafter referred to as the "second reference position") and stores it in the storage device 114 (S36). In other words, the first sensor 4A is used as a sensor for specifying the reference position of the fourth sensor 9B. The CPU 111 displays the difference between the detection result of the fourth sensor 9B and the second reference position on the display unit 27B.

[0122] The operator rotates the position adjustment mechanism 8D with a screwdriver or the like to move the hook 83 in the left-right direction. The operator moves the hook 83 in the left-right direction until the operation setting value of the hook 83 recommended for the sewing machine 1 (hereinafter referred to as the "second operation setting value") matches the difference displayed on the display unit 27B (S37). When the second operation setting value matches the difference displayed on the display unit 27B, the operator ends the operation of the position adjustment mechanism 8D and stops the movement of the hook 83. The CPU 111 stores the rotation position indicated by the detection result obtained from the fourth sensor 9B at this time in the storage device 114 as the tip reference position (S37). With the above, the adjustment of the left-right positional relationship between the tip 83C of the hook 83 and the sewing needle 31A is completed.

[0123] <Actions and Effects of the Present Embodiment> The sewing machine 1 is capable of mounting a sensor unit 4 including a first sensor 4A on the frame 7. When the needle 31A is displaced as a result of the tip 83C or needle guard 84C of the movable body 80 coming into contact with the needle 31A, the sewing machine 1 can detect the amount of displacement using the first sensor 4A. An operator of the sewing machine 1 can confirm the left-right positional relationship between the tip 83C or needle guard 84C of the movable body 80 and the needle 31A based on the amount of displacement of the needle 31A detected by the first sensor 4A. Therefore, the operator can accurately adjust the left-right positional relationship between the needle 31A and the movable body 80 based on the confirmed positional relationship.

[0124] Specifically, for example, based on the amount of displacement of the sewing needle 31A detected by the first sensor 4A, the operator can easily adjust the left-right position of the inner hook 83 using the position adjustment mechanism 8D so that the positional relationship between the sewing needle 31A and the point 83C is the recommended one in the sewing machine 1. Also, for example, based on the amount of displacement of the sewing needle 31A detected by the first sensor 4A, the operator can easily adjust the left-right position of the driver 84 using the position adjustment mechanism 8C so that the positional relationship between the sewing needle 31A and the needle guard 84C is the recommended one in the sewing machine 1.

[0125] The display unit 27B of the sewing machine 1 displays the amount of displacement of the sewing needle 31A detected by the first sensor 4A. The amount of displacement of the sewing needle 31A changes depending on the left-right positional relationship between the tip 83C or needle guard 84C of the movable body 80 and the sewing needle 31A. Therefore, the operator can confirm the left-right positional relationship between the tip 83C and needle guard 84C and the sewing needle 31A by visually checking the display unit 27B. Therefore, the operator can easily adjust the left-right positional relationship between the sewing needle 31A and the movable body 80 while checking the display unit 27B.

[0126] The first sensor 4A has a detection body 42 and a detector 43 having a contact surface 433. The first sensor 4A detects the rotational position of the detector 43 when the sewing needle 31A comes into contact with the contact surface 433 and rotates. In this case, the first sensor 4A can detect the amount of displacement of the sewing needle 31A with high accuracy regardless of the size or shape of the sewing needle 31A, compared to when the amount of displacement of the sewing needle 31A is directly detected by a position sensor or the like.

[0127] When determining the left-right positional relationship between the sewing needle 31A and the movable body 80 based on the amount of displacement of the sewing needle 31A, it is preferable that the amount of displacement is detected near a portion of the sewing needle 31A that contacts the tip 83C or the needle guard 84C of the movable body 80. In contrast, the detector 43 of the first sensor 4A extends obliquely downward toward the right from the rotation axes 431, 432. This allows the first sensor 4A to bring the contact surface 433 of the detector 43 into contact with the portion of the sewing needle 31A that contacts the tip 83C and the needle guard 84C of the movable body 80. Therefore, the first sensor 4A can accurately detect the amount of displacement of the sewing needle 31A, and therefore can more accurately detect the left-right positional relationship between the sewing needle 31A and the movable body 80.

[0128] The shuttle thread guide 90, which covers the upper part of the movable body 80, has a notch 90A extending rightward from the left end. The detector 43 of the first sensor 4A enters the notch 90A from the left. In this case, the detector 43 of the first sensor 4A is prevented from contacting the shuttle thread guide 90, and the contact surface 433 can be brought into contact with the vicinity of the portion of the sewing needle 31A that contacts the movable body 80.

[0129] The tip 83C and the needle guard 84C can come into contact with the sewing needle 31A from the right. Meanwhile, the contact surface 433 of the detector 43 of the first sensor 4A comes into contact with the sewing needle 31A from the left. Therefore, when the sewing needle 31A is bent to the left in response to the movable body 80 coming into contact with the sewing needle 31A from the right, the first sensor 4A can accurately detect the amount of bending as the amount of displacement.

[0130] <Modification> The present invention is not limited to the above embodiment, and various modifications are possible. The shuttle mechanism 8A of the sewing machine 1 may be a horizontal shuttle in which the bobbin is set horizontally. The shuttle mechanism 8A may be a full rotary shuttle in which the inner shuttle 83 and the driver 84 are not separate but are connected together. The first sensor 4A may be provided in an undetachable manner on the sewing machine 1. In this case, the first sensor 4A may be supported by a movable arm that can be moved between a close position where the detector 43 is close to the sewing needle 31A and a distant position where the detector 43 is distant from the sewing needle 31A.

[0131] The sewing machine 1 may have a speaker. When the displacement amount of the sewing needle 31A reaches 0.01 mm, the sewing machine 1 may notify the operator by outputting a notification sound from the speaker (S21, S33).

[0132] When moving the shuttle 83 or the driver 84 in the steps S21 and S33, the operator does not have to stop the movement of the shuttle 83 or the driver 84 at a position where the displacement of the sewing needle 31A is exactly 0.01 mm. For example, the operator may constantly monitor the displacement displayed on the display unit 27B while moving the shuttle 83 or the driver 84. The operator may move the shuttle 83 or the driver 84 from a state where the sewing needle 31A is not in contact with the shuttle 83 or the driver 84 until the sewing needle 31A is bent by 0.01 mm or more, and when the displacement reaches 0.01 mm during that time, the CPU 111 may automatically set the rotational position of the detector 43 to the first zero point position or the second zero point position and store it in the storage device 114.

[0133] The first sensor 4A may use the state in which the sewing needle 31A is not in contact with the detector 43 and is not rotating, i.e., the state in which the regulating portion 434 is in contact with the upper surface of the detection body 42, as a reference, and detect the amount of rotation from this state as a displacement amount using the detection body 42.

[0134] In the above embodiment, the first sensor 4A of the sensor unit 4 optically detects the rotational position of the detector 43 that rotates in response to the displacement of the sewing needle 31A and outputs the detection result. The first sensor 4A may detect the amount of displacement of the sewing needle 31A using a different method and output the detection result. For example, the first sensor 4A may detect the amount of displacement of the sewing needle 31A by detecting the rotational position of the detector 43 that rotates in response to the displacement of the sewing needle 31A as a change in capacitance, magnetic flux, or resistance value. Also, the amount of displacement of the sewing needle 31A may be detected by using a detector that slides in the axial direction in response to the displacement of the sewing needle 31A and detecting the amount of sliding of the detector as a change in optical, capacitance, magnetic flux, or resistance value.

[0135] The detector 43 has been described as having a shape in which the contact surface 433 that contacts the sewing needle 31A extends diagonally downward to the right, but the base 43A of the detector 43 may have a different shape. For example, the detector 43 may have a fan shape when viewed from the front. The detector 43 may also have a shape extending diagonally upward to the right by arranging the above-mentioned configuration upside down. The arm 4B is not limited to a bent rectangular column, and may have a different shape as long as it supports the first sensor 4A and can fix the first sensor 4A to the frame 7. For example, the extension 451 may not be provided, and the extension 452 extending in the front-rear direction may have a hole through which a support shaft provided in the frame 7 passes or a hole through which a magnet that is attracted to the frame 7 is inserted.

[0136] The shuttle thread guide 90 may be removed from the shuttle mechanism 8A when performing the second adjusting method. In this case, the shuttle thread guide 90 does not need to be provided with the notch 90A.

[0137] In the second adjustment method, only the steps S11 to S25 may be performed, and the steps S27 to S37 may not be performed. Alternatively, in the second adjustment method, only the steps S27 to S37 may be performed, and the steps S11 to S25 may not be performed. The first zero point position and the second zero point position may be determined by calculating the detector 43 of the first sensor 4A when the displacement amount of the sewing needle 31A is 0 mm.

[0138] The value "0.01 mm" used as the reference value for judgment in S21 and S33 is an example, and other values ​​may be used. For example, in S21, the displacement amount may be compared with a first operation set value. For example, in S33, the displacement amount may be compared with a second operation set value.

[0139] <Other> The shaft body 85 is an example of a "shaft" of the present invention. The first sensor 4A is an example of a "sensor" of the present invention. The left-right direction is an example of an "axial direction" of the present invention. The right side is an example of a "one side in the axial direction" of the present invention. The left side is an example of a "other side in the axial direction" of the present invention. The hook thread guide 90 is an example of a "plate" of the present invention. S11 is an example of a "first step" of the present invention. S13 is an example of a "second step" of the present invention. S17 and S29 are examples of a "third step" of the present invention. S19 and S31 are examples of a "fourth step" of the present invention. S23, S24, S35, and S36 are examples of a "fifth step" of the present invention. [Explanation of symbols]

[0140] 1: Sewing machine 4A: First sensor 4B: Arm section 7: Frame 8A: Hook mechanism 8B: Hook shaft 8C, 8D: Position adjustment mechanism 31: Needle bar 31A: Sewing needle 43: Detector 80: Movable body 83: Medium pot 83C: Sword tip 84: Driver 84C: Needle holder 85: Shaft body 90: Kettle thread guide 90A: Notch 433: Contact surface C: Axis

Claims

1. A needle bar that can be moved in the vertical direction and has a sewing needle attached to its tip; a hook mechanism including a movable body having a needle point that catches an upper thread that is inserted into the sewing needle attached to the needle bar and a needle receiver that comes into contact with and guides the sewing needle; a hook shaft having an axis extending in a direction intersecting the vertical direction and rotating the movable body in a rotation direction around the axis; a position adjustment mechanism capable of adjusting a position of the movable body in an axial direction of the shuttle shaft; a frame that accommodates the shuttle mechanism, the shuttle shaft, and the position adjustment mechanism; a sensor having a contact surface that comes into contact with the sewing needle from one side in the axial direction, the sewing needle being positioned at a meeting position that is the position of the sewing needle when the point captures the loop formed in the upper thread, and for detecting an amount of displacement of the sewing needle in the axial direction; an arm portion supporting the sensor and fixed to the frame; A sewing machine comprising:

2. 2. The sewing machine according to claim 1, further comprising a display unit which displays information based on the amount of displacement of the sewing needle detected by the sensor.

3. The sensor includes: a detector that is rotatable about a rotation axis that intersects with the axial direction and has the contact surface; a detection unit that detects a rotational position of the detector that rotates around the rotation axis when the sewing needle comes into contact with the contact surface; 2. The sewing machine according to claim 1, further comprising:

4. A plate covering an upper portion of the movable body is provided, The plate is The detector extends from one end in the axial direction to the other end and has a notch into which the detector enters from the one end in the axial direction.

4. The sewing machine according to claim 3.

5. The sword tip and the needle holder are 2. The sewing machine according to claim 1, wherein the sewing needle is accessible from the other side in the axial direction.

6. 6. A method for adjusting a position of the movable body relative to the sewing needle in the sewing machine according to claim 1, comprising: a first step of positioning the sewing needle at the meeting position; a second step of fixing a sensor unit having the sensor and the arm portion to the frame; a third step of moving the movable body from the other side in the axial direction toward the sewing needle after the sewing needle is disposed at the meeting position in the first step and the sensor unit is fixed to the frame in the second step; a fourth step of detecting a displacement amount of the sewing needle by the sensor when the movable body moved by the third step comes into contact with the sewing needle and is bent; a fifth step of determining a reference position for adjusting the axial position of the movable body by the position adjustment mechanism based on the displacement amount of the sewing needle detected in the fourth step; An adjustment method comprising:

7. a shuttle mechanism including a movable body having a needle bar movable in an up-down direction and capable of mounting a sewing needle at its tip, a point for capturing an upper thread passed through the sewing needle mounted on the needle bar, and a needle guard for contacting and guiding the sewing needle; a shuttle shaft having an axis extending in a direction intersecting the up-down direction and for driving and rotating the movable body in a rotational direction about the axis; a position adjustment mechanism for adjusting the position of the movable body in the axial direction of the shuttle shaft; and a frame for accommodating the shuttle mechanism, the shuttle shaft, and the position adjustment mechanism, a sensor having a contact surface that contacts the sewing needle from one side in the axial direction and capable of detecting an amount of displacement of the sewing needle in the axial direction; an arm portion that supports the sensor and is fixable to the frame; A sensor unit comprising:

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