Sewing machine

Abstract

The sewing machine (100) is provided with: a sewing needle up-and-down movement mechanism that moves a sewing needle (11) up and down by means of a sewing machine motor (16); the upper feeding mechanism (40) enables the conveying belts (41, 42) to abut against each other from the upper side on the left side and the right side of the needle falling position so as to convey the sewn object on the needle plate (101); detection units (48), (49), (762) for detecting the height of the object to be sewn at the conveying position of the left conveyor belt (41) and the height of the object to be sewn at the conveying position of the right conveyor belt (42), or for detecting the difference between the height of the object to be sewn and the height of the object to be sewn at the conveying position of the left conveyor belt (41) and the height of the object to be sewn at the conveying position of the right conveyor belt (42); and a control device (90) that controls the operation of the needle up-down movement mechanism and the upper feeding mechanism (40). The control device (90) performs control for adjusting the driving of the feed of the left and right conveyor belts (41, 42) of the upper feed mechanism (40) on the basis of the detection by the detection units (48, 49, 762).

Description

Technical Field

[0001] This invention relates to sewing machines. Background Technology

[0002] There is a sewing machine that has upper feed sections on the left and right sides above the needle plate and at the needle drop position, and the workpiece is transported by the conveyor belt of each upper feed section.

[0003] In this sewing machine, the detection arm directly contacts the workpiece on the needle plate from above to detect the thickness of the workpiece (see, for example, Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2006-158497 Summary of the Invention

[0005] In the aforementioned sewing machine, the thickness of the sewn material is measured at only one location. Therefore, if a thickness difference occurs between the two sides of the needle drop position where the left and right feed sections are respectively feeding, the thickness of the sewn material cannot be measured.

[0006] The purpose of this invention is to properly transport the sewn material when there is a height difference between the sewn material and the conveyor belts on the left and right sides of the needle drop position.

[0007] As one aspect of the present invention, a sewing machine has: The needle moving up and down mechanism moves the needle up and down via the sewing machine motor; The top feed mechanism, located on the left and right sides of the needle drop position, causes the conveyor belts to abut from above to transport the workpiece on the needle plate. A detection unit, used to detect the height of the sewn work at the conveying position of the left conveyor belt and the height of the sewn work at the conveying position of the right conveyor belt, or to detect the difference between them; and The control device controls the movement of the needle moving up and down mechanism and the upward feed mechanism. The control device performs control to adjust the drive of the feed of the left and right conveyor belts of the upper feed mechanism based on the detection of the detection unit.

[0008] The effects of the invention

[0009] According to the sewing machine of the present invention, when there is a height difference between the sewn workpieces at each conveying position of the left and right conveyor belts arranged on both sides of the needle drop position, the sewing machine can properly convey the sewn workpieces. Attached Figure Description

[0010] Figure 1 This is a rear view of a sewing machine as an embodiment of the present invention.

[0011] Figure 2 This is a left-side view of the sewing machine.

[0012] Figure 3 This is a perspective view of a sewing machine.

[0013] Figure 4 This is a perspective view of the upper left end of the base of a sewing machine, omitting the presser foot.

[0014] Figure 5 This is a perspective view of the guide frame representing the lower feed mechanism.

[0015] Figure 6 This is a perspective view showing the feeding mechanism with four conveyor belts in a differential feeding state.

[0016] Figure 7 This is a perspective view showing the feeding mechanism with four conveyor belts in a left-right differential feeding state.

[0017] Figure 8 It is a perspective view showing the presser foot mechanism that presses the fabric being sewn onto the needle plate from above and its surrounding area.

[0018] Figure 9 This is a rear view showing the fabric presser foot mechanism and its surroundings.

[0019] Figure 10 This is a right-side view showing the fabric presser foot mechanism and its surroundings.

[0020] Figure 11 This is a block diagram representing the control system of a sewing machine.

[0021] Figure 12 This is a rear view showing the perimeter of a fabric presser foot mechanism, which illustrates an example of a distance sensor used as a detection unit.

[0022] Figure 13 This is a perspective view of the upper surface of the left end of a sewing machine base, showing an example where needle holes are formed directly on the needle plate. Detailed Implementation

[0023] [Summary of Embodiments of the Invention]

[0024] The sewing machine 100, which is an embodiment of the present invention, will now be described in detail.

[0025] Figure 1 This is a rear view of sewing machine 100. Figure 2 This is a left-side view of sewing machine 100. Figure 3 This is a perspective view of sewing machine 100.

[0026] Below, the object to be sewn (refer to) Figure 12 The downstream side of the conveying direction is designated as "front," the upstream side as "rear," the left side as "left," the right side as "right," the vertically above as "up," and the vertically below as "down." These directions are related to... Figures 1 to 13 The relative directions set for the sewing machine 100 shown in the example are: front-back, left-right, and up-down.

[0027] In the following description, the sewing machine 100 is assumed to be set on a horizontal plane, with the front-back and left-right directions being horizontal.

[0028] Examples of sewing machines 100 as embodiments of the present invention include a so-called flat sewing machine.

[0029] like Figures 1 to 3 As shown, the sewing machine 100 includes a sewing machine frame 110, a needle up-and-down movement mechanism, a lower feed mechanism 20 as a feed device, an upper feed mechanism 40 as a feed device, a fabric presser foot mechanism 70 as a presser foot mechanism, a presser foot mechanism, and a positioning scale 50 (see reference). Figure 9 ) and the retreat mechanism 60 (refer to Figure 8 ).

[0030] The needle up-and-down movement mechanism imparts up-and-down movement to the needle 11. Details of the needle up-and-down movement mechanism will be described later.

[0031] The lower feed mechanism 20 provides a conveying action to the workpiece on the needle plate 101 from below.

[0032] The upper feed mechanism 40 provides a conveying action to the workpiece on the needle plate 101 from above.

[0033] The fabric presser foot mechanism 70 applies presser foot pressure to the workpiece on the needle plate 101.

[0034] The vessel mechanism captures the loop of the upper thread from the sewing needle 11 and winds it around the lower thread to form a stitch.

[0035] The positioning scale 50 abuts against the side end of the sewn material to determine the distance from that side end to the stitch, i.e., the width of the welt.

[0036] In order to avoid interference when using the positioning scale 50, the retraction mechanism 60 keeps the conveyor belt guide 44 of the upper feed mechanism 40 in the retraction position.

[0037] In addition, the sewing machine 100 has the various structures of a typical flat sewing machine, such as the thread take-up lever mechanism and the thread adjuster, but since these structures are known, their descriptions are omitted.

[0038] [Sewing machine frame]

[0039] like Figure 1 As shown, the sewing machine frame 110 supports or houses the various structures of the sewing machine 100.

[0040] The sewing machine frame 110 has a sewing machine base 111, a longitudinal body 112, and a sewing machine arm 113.

[0041] The sewing machine base 111 is located at the lower part of the sewing machine 100, along... Figure 1 The sewing machine 100 extends in the left and right directions.

[0042] The longitudinal body section 112 is erected vertically upward from the right end of the sewing machine base section 111.

[0043] The sewing machine arm 113 extends to the left from the upper end of the longitudinal body 112.

[0044] [Needle up-and-down movement mechanism]

[0045] Figure 4 This is a perspective view showing the upper surface of the left end of the sewing machine base 111. Figure 4 The illustration of the presser foot, which will be described later, is omitted in the sewing machine base 111 shown.

[0046] The needle moving mechanism has an upper shaft on the inner side of the sewing machine arm 113, which is configured in a left-right direction along the sewing machine arm 113 and is controlled by the sewing machine motor 16 (see reference). Figure 11 Rotary drive.

[0047] And, as Figures 1 to 4 As shown, the needle moving up and down mechanism includes: a needle bar 12 that holds the needle 11 at its lower end; and a crank mechanism that converts the rotational force of the upper shaft into a reciprocating driving force for up and down movement and transmits it to the needle bar.

[0048] Furthermore, the upper shaft and crank mechanism are well-known structures, so their illustrations are omitted.

[0049] The needle bar 12 extends along the vertical direction of the sewing needle 11 and is supported on the lower left end of the sewing machine arm 113, which can move up and down.

[0050] The sewing needle 11 is held at the lower end of the needle bar 12 and moves up and down together with the needle bar 12. A needle plate 101, which is made of a horizontal flat plate, is provided on the upper surface of the sewing machine base 111 and below the needle bar 12.

[0051] Furthermore, a composite opening 102 is formed at the needle drop position of the sewing needle 11 relative to the needle plate 101. The needle hole component 30 with needle hole 13 and the rear left lower conveyor belt 21, front left lower conveyor belt 22, front right lower conveyor belt 23, and rear right lower conveyor belt 24 of the lower feed mechanism 20 described later are arranged upwardly in the composite opening 102 of the needle plate 101. Hereinafter, the rear left lower conveyor belt 21, front left lower conveyor belt 22, front right lower conveyor belt 23, and rear right lower conveyor belt 24 will also be referred to as lower conveyor belts 21 to 24. That is, the composite opening 102 is an opening formed by integrally combining multiple rectangular openings that expose the needle hole component 30 and each of the lower conveyor belts 21 to 24.

[0052] [Boat Mechanism]

[0053] like Figure 2 and Figure 3 As shown, the vessel mechanism includes: a middle vessel 14 and an outer vessel 15, which are disposed on the underside of the needle hole component 30 of the needle plate 101; and a vessel shaft (not shown) that rotates the outer vessel 15.

[0054] The spool shaft is rotatably supported within the sewing machine base 111 with its axial direction in the left-right direction. The spool shaft is fed from the aforementioned upper shaft via a gear mechanism or a belt mechanism, and its rotation around the spool shaft is accelerated to twice that of the upper shaft.

[0055] The middle vessel 14 is housed inside the outer vessel 15. Furthermore, the middle vessel 14 houses a spool (not shown) for supplying the lower wire inside its interior.

[0056] The outer vessel 15 is connected to the left end of the vessel shaft and rotates around the inner vessel 14. The rotation of the inner vessel 14 is restricted so that it does not rotate with the outer vessel 15. The outer vessel 15 has a tip on its outer periphery for capturing the loop of thread from the sewing needle 11. The outer vessel 15 rotates, thereby enabling the loop of thread to be captured by the tip, allowing the lower thread drawn from the inside of the inner vessel 14 to pass through.

[0057] The outer vessel 15 and the middle vessel 14 are arranged in a receiving state inside the generally cylindrical guide frame 29 of the lower feed mechanism 20, which will be described later.

[0058] [Lower feed mechanism]

[0059] Figure 5 This is a perspective view of the guide frame 29 of the lower feed mechanism 20. Figure 6 and Figure 7 This is a perspective view showing the lower feed mechanism 20. Figure 6 and Figure 7 The different installation states of the lower conveyor belts 21 to 24, which will be described later, are shown.

[0060] Below, based on Figures 1 to 7 The lower feed mechanism 20 is described in detail.

[0061] As shown in the figures, the lower feed mechanism 20 includes lower conveyor belts 21 to 24 as conveyor belts, a first motor 25, a second motor 26, rotating shafts 27 and 28, a first pulley 31, and a second pulley 32.

[0062] Furthermore, the lower feeding mechanism 20 includes: a guide frame 29 that guides each of the lower conveyor belts 21 to 24 to contact the lower surface of the workpiece; a first pressurizing mechanism 33; and a second pressurizing mechanism 34.

[0063] Both the first motor 25 and the second motor 26 are motors capable of arbitrarily controlling the amount of motion. The first motor 25 and the second motor 26 are, for example, stepper motors or servo motors. The first motor 25 and the second motor 26 are arranged in a front-to-back configuration on the inside of the right end of the sewing machine base 111, with the output shaft facing to the left.

[0064] The output shaft of the first motor 25 is connected to the first pulley 31 via the rotating shaft 27.

[0065] The output shaft of the second motor 26 is connected to the second pulley 32 via the rotating shaft 28.

[0066] The rotating shafts 27 and 28 are parallel to the left and right directions of the sewing machine base 111 and are rotatably supported inside the sewing machine base 111.

[0067] The first pulley 31 and the second pulley 32 are rotatably supported on the left end of the sewing machine base 111, with their rotation centers centered on the first pulley 31 and the second pulley 32, about axes in the left-right direction of the sewing machine base 111. Furthermore, the first pulley 31 and the second pulley 32 are given rotational action from the first motor 25 and the second motor 26 via rotating shafts 27 and 28, respectively.

[0068] The first pulley 31 and the second pulley 32 are arranged overlapping when viewed from the front-to-back direction. That is, the first pulley 31 and the second pulley 32 are at the same height within the sewing machine base 111 and are at the same position within the sewing machine base 111 in the left-to-right direction. In addition, the first pulley 31 is disposed in front of the second pulley 32 within the sewing machine base 111.

[0069] Figure 6 The diagram shows the state where the front left lower conveyor belt 22 and the front right lower conveyor belt 23, which are fed to the front side of the needle drop position, are mounted on the first pulley 31, and the rear left lower conveyor belt 21 and the rear right lower conveyor belt 24, which are fed to the rear side, are mounted on the second pulley 32. Figure 7The diagram shows the rear left lower conveyor belt 21 and front left lower conveyor belt 22, which feed to the left of the needle drop position, mounted on the first pulley 31, while the front right lower conveyor belt 23 and rear right lower conveyor belt 24 are mounted on the second pulley 32. Figure 6 and Figure 7 As shown, both the first pulley 31 and the second pulley 32 can support all the lower conveyor belts 21, 22, 23, and 24 arranged in the left-right direction.

[0070] That is, the first pulley 31 has the following on its outer circumferential surface: a left groove 311 for supporting the rear left lower conveyor belt 21 or the front left lower conveyor belt 22; and a right groove 312 for supporting the front right lower conveyor belt 23 or the rear right lower conveyor belt 24.

[0071] The second pulley 32 has the following on its outer circumferential surface: a left groove 321 for supporting the rear left lower conveyor belt 21 or the front left lower conveyor belt 22; and a right groove 322 for supporting the front right lower conveyor belt 23 or the rear right lower conveyor belt 24.

[0072] Each of the lower conveyor belts 21 to 24 has the same width, and the left troughs 311 and 321 and the right troughs 312 and 322 each have a width corresponding to that of two conveyor belts.

[0073] Therefore, each of the lower conveyor belts 21 to 24 can be appropriately selected and installed with the first pulley 31 and the second pulley 32.

[0074] Each of the lower conveyor belts 21, 22, 23, and 24 is an endless loop, which is installed between the guide frame 29 and the first pulley 31 or between the guide frame 29 and the second pulley 32.

[0075] In addition, each of the lower conveyor belts 21, 22, 23, and 24... Figure 6 They are arranged sequentially from left to right.

[0076] Guide frame 29 (guide component) is configured as follows: Figure 1 and Figure 2 As shown, it is roughly the same as the first pulley 31 and the second pulley 32 in the left-right direction, as follows: Figure 2 As shown, it is positioned between the first pulley 31 and the second pulley 32 in the front-to-back direction. Furthermore, the guide frame 29 is positioned above the first pulley 31 and the second pulley 32 and directly below the needle plate 101.

[0077] like Figure 5 As shown, the guide frame 29 has: a bracket portion 295 for fixing inside the sewing machine base portion 111; and a cylindrical body portion 296 for guiding each of the lower conveyor belts 21 to 24.

[0078] The guide frame 29 is positioned directly below the needle plate 101 with the central axis of the main body 296 facing the left and right direction of the sewing machine base 111.

[0079] A fitting groove 297 is formed on the outer peripheral surface of the main body 296, at the center of the upper part of the main body 296 in the left-right direction. A plate-shaped needle hole component 30 that is longer in the left-right direction is disposed inside the fitting groove 297. In the needle hole component 30, a needle hole 13 is formed at the needle drop position of the sewing needle 11, which is vertically penetrating through the needle hole component 30.

[0080] The needle hole component 30 is connected to a needle up-and-down movement mechanism (not shown). The needle up-and-down movement mechanism uses the aforementioned sewing machine motor 16 as a drive source to move the needle hole component 30 up and down at the same cycle as the needle 11. The needle hole component 30 moves up and down in the opposite phase to the needle 11 via this mechanism. That is, the forming surface of the needle hole 13 of the needle hole component 30 is at its highest position at the phase that becomes the lower stop point of the needle 11, and at its lowest position at the phase that becomes the upper stop point of the needle 11. The highest position of the forming surface of the needle hole 13 is at the same height as or slightly higher than the upper surface of the needle plate 101. The lowest position of the forming surface of the needle hole 13 is from the lower surface of the needle plate 101 down to its lowest position.

[0081] Furthermore, on the upper part of the outer peripheral surface of the main body 296, the lower conveyor belts 21 to 24 slide in the circumferential direction of the main body 296 to transport the sewn material. Therefore, a first guide section 291, a second guide section 292, a third guide section 293, and a fourth guide section 294 are provided on the upper part of the outer peripheral surface of the main body 296 to guide the lower conveyor belts 21 to 24.

[0082] The first guide part 291 is located to the left rear of the pinhole 13, the second guide part 292 is located to the left front of the pinhole 13, the third guide part 293 is located to the right front of the pinhole 13, and the fourth guide part 294 is located to the right rear of the pinhole 13.

[0083] The first guide section 291 to the fourth guide section 294 are all protruding strips extending in the front-to-back direction, and their width in the left-to-right direction is equal to or slightly wider than that of each of the lower conveyor belts 21 to 24. The rear ends of the first guide section 291 to the fourth guide section 294 are inclined surfaces whose protrusion in the radial direction outward relative to the outer periphery of the main body 296 gradually increases forward. In addition, the front ends of the first guide section 291 to the fourth guide section 294 are inclined surfaces whose protrusion in the radial direction outward relative to the outer periphery of the main body 296 gradually decreases forward.

[0084] The first guide portion 291 is located to the left of the pinhole 13 and extends approximately the entire length, situated behind the center of the pinhole 13.

[0085] Furthermore, the first guide portion 291 has a flat and horizontal guide surface 291a on its front side compared to the maximum protrusion outward in the radial direction towards the main body portion 296. Figure 5 The guide surface 291a and the guide surfaces 292a, 293a and 294a described later are represented by dot patterns. When viewed from above the sewing machine base 111, the guide surface 291a is positioned to face the compound opening 102 of the needle plate 101.

[0086] Furthermore, the guide surface 291a is configured such that the outer side of the rear left lower conveyor belt 21, which slides and contacts on the guide surface 291a, becomes slightly higher than the upper surface of the needle plate 101.

[0087] The guide surface 291a is formed such that the front end of the guide surface 291a is located slightly behind the center of the pinhole 13, and the rear left lower conveyor belt 21 abuts against the sewn material on the rear side relative to the center of the pinhole 13.

[0088] The second guide portion 292 is located to the left of the pinhole 13 and to the right of the first guide portion 291, and extends approximately the entire length, located in a position slightly forward of the center of the pinhole 13.

[0089] Furthermore, the second guide portion 292 has a flat and horizontal guide surface 292a on its rear side compared to the maximum protrusion in the radial direction outward of the main body portion 296. When viewed from above from the sewing machine base portion 111, the guide surface 292a is configured to face the compound opening portion 102 of the needle plate 101.

[0090] Furthermore, the guide surface 292a is configured such that the outer side of the front left lower conveyor belt 22 that slides on the guide surface 292a becomes slightly higher than the upper surface of the needle plate 101.

[0091] The guide surface 292a is formed such that the rear end of the guide surface 292a is located slightly in front of the center of the needle hole 13, and the front left lower conveyor belt 22 abuts against the sewn material on the front side relative to the center of the needle hole 13.

[0092] The third guide section 293 is located to the right of the pinhole 13 and extends approximately the entire length, positioned slightly forward of the center of the pinhole 13.

[0093] Furthermore, the third guide portion 293 has a flat and horizontal guide surface 293a on its rear side compared to the maximum protrusion in the radial direction outward of the main body portion 296. When viewed from above the sewing machine base portion 111, the guide surface 293a is configured to face the compound opening portion 102 of the needle plate 101.

[0094] Furthermore, the guide surface 293a is configured such that the outer side of the front right lower conveyor belt 23, which slides on the guide surface 293a, becomes slightly higher than the upper surface of the needle plate 101.

[0095] The guide surface 293a is formed such that the rear end of the guide surface 293a is located slightly in front of the center of the needle hole 13, and the front right lower conveyor belt 23 abuts against the sewn material on the front side relative to the center of the needle hole 13.

[0096] The fourth guide portion 294 is located to the right of the pinhole 13 and the third guide portion 293, and is located approximately along the entire length and is positioned to the rear of the center of the pinhole 13.

[0097] Furthermore, the fourth guide portion 294 has a flat and horizontal guide surface 294a on its front side compared to the maximum protrusion in the radial direction outward of the main body portion 296. When viewed from above the sewing machine base portion 111, the guide surface 294a is configured to face the compound opening portion 102 of the needle plate 101.

[0098] Furthermore, the guide surface 294a is configured such that the outer side of the rear right lower conveyor belt 24, which is slidably contacted on the guide surface 294a, becomes slightly higher than the upper surface of the needle plate 101.

[0099] The guide surface 294a is formed such that the front end of the guide surface 294a is located slightly behind the center of the pinhole 13, and the rear right lower conveyor belt 24 abuts against the sewn material on the rear side relative to the center of the pinhole 13.

[0100] Guide surfaces 291a and 294a are positioned rearward relative to the center of needle hole 13, while guide surfaces 292a and 293a are positioned frontward relative to the center of needle hole 13. Therefore, even with speed differences (feed volume differences) between the rear left lower conveyor belt 21 and rear right lower conveyor belt 24 on the rear side and the front left lower conveyor belt 22 and front right lower conveyor belt 23 on the front side, the lower conveyor belts 21 to 24 will not interfere with each other, and the conveying force generated by the front-to-back feed speed difference (feed volume difference) can be applied to the workpiece. Thus, the desired stitch shape in the front-to-back differential feed can be formed, improving sewing quality.

[0101] The first pressurizing mechanism 33 applies tension to all the conveyor belts mounted between the guide frame 29 and the first pulley 31 within each of the lower conveyor belts 21 to 24, thereby suppressing any slack in the mounted lower conveyor belts 21 to 24.

[0102] like Figure 2 , Figure 3 and Figure 6 As shown, the first pressurizing mechanism 33 has a left pressurizing roller 331, a right pressurizing roller 332, a support plate 333 and a base block 334.

[0103] The support plate 333 is a long strip of flat plate along the plane including the front-back and up-down directions of the sewing machine 100, and is supported on the base block 334 with its length direction facing forward and upward.

[0104] Furthermore, the support plate 333 supports the left pressure roller 331 on the left side of its upper end and the right pressure roller 332 on the right side of its upper end in a concentric and rotatable manner. The support plate 333 is configured such that the left pressure roller 331 and the right pressure roller 332 abut against the outer side of the conveyor belt that is mounted between the guide frame 29 and the first pulley 31 from below the rear of the conveyor belt.

[0105] The base block 334 is shared by the second pressure mechanism 34, which will be described later, and supports the structures of the first pressure mechanism 33 and the second pressure mechanism 34. The base block 334 is fixed below the guide frame 29 within the sewing machine base portion 111 and is mounted on the sewing machine base portion 111.

[0106] The support plate 333 has an elongated hole along its length. The support plate 333 is fixed relative to the base block 334 by inserting two bolts through the elongated hole. The length direction of the support plate 333 is oriented approximately orthogonally to the conveyor belt mounted on the first pulley 31. Therefore, by unscrewing the bolts and moving the support plate 333 along the elongated hole, the pressing force of the left pressure roller 331 and the right pressure roller 332 on the conveyor belt can be adjusted. In other words, the tension of the conveyor belt mounted between the guide frame 29 and the first pulley 31 can be adjusted.

[0107] like Figure 6 As shown, the left pressure roller 331 and the right pressure roller 332 have the same outer diameter and are supported by the support plate 333 so as to be rotatable about the same axis in the left-right direction along the lower feed mechanism 20. In addition, the left and right widths of the left pressure roller 331 and the right pressure roller 332 are both twice or more the width of the respective lower conveyor belts 21 to 24.

[0108] Thus, the left pressure roller 331 can abut against either the rear left lower conveyor belt 21 or the front left lower conveyor belt 22, which are mounted between the guide frame 29 and the first pulley 31.

[0109] Similarly, the right pressure roller 332 can abut against either the front right lower conveyor belt 23 or the rear right lower conveyor belt 24 mounted between the guide frame 29 and the first pulley 31.

[0110] The second pressurizing mechanism 34 applies tension to all the conveyor belts mounted between the guide frame 29 and the second pulley 32 within each of the lower conveyor belts 21 to 24, thereby suppressing the slack of each of the lower conveyor belts 21 to 24.

[0111] like Figure 2 , Figure 3 and Figure 6 As shown, the second pressurizing mechanism 34 has a left pressurizing roller 341, a right pressurizing roller 342, a support plate 343 and the aforementioned base block 334.

[0112] The support plate 343 has the same structure as the aforementioned support plate 333, and is supported on the base block 334 with its length direction facing backward and upward.

[0113] Furthermore, the support plate 343 concentrically and rotatably supports the left pressure roller 341 on the left side of its upper end and the right pressure roller 342 on the right side of its upper end. The support plate 343 is configured such that the left pressure roller 341 and the right pressure roller 342 abut against the outer side of the conveyor belt, which is mounted between the guide frame 29 and the second pulley 32, from below the rear of the conveyor belt.

[0114] The support plate 343 also has an elongated hole, allowing it to move along the hole. This allows adjustment of the pressing force of the left pressure roller 341 and right pressure roller 342 on the conveyor belt mounted on the second pulley 32. Therefore, the tension of the conveyor belt mounted between the guide frame 29 and the second pulley 32 can be adjusted.

[0115] like Figure 6 As shown, the left pressure roller 341 and the right pressure roller 342 have the same outer diameter and are supported by the support plate 343 so as to be rotatable about the same axis in the left-right direction along the lower feed mechanism 20. In addition, the left and right widths of the left pressure roller 341 and the right pressure roller 342 are both twice or more the width of the respective lower conveyor belts 21 to 24.

[0116] Thus, the left pressure roller 341 can abut against either the rear left lower conveyor belt 21 or the front left lower conveyor belt 22, which are mounted between the guide frame 29 and the second pulley 32.

[0117] Similarly, the right pressure roller 342 can abut against either the front right lower conveyor belt 23 or the rear right lower conveyor belt 24, which are mounted between the guide frame 29 and the second pulley 32.

[0118] The left pressure roller 331 of the first pressure mechanism 33 and the left pressure roller 341 of the second pressure mechanism 34 can both abut against the rear lower left conveyor belt 21 and the front lower left conveyor belt 22. Similarly, the right pressure roller 332 of the first pressure mechanism 33 and the right pressure roller 342 of the second pressure mechanism 34 can both abut against the front lower right conveyor belt 23 and the rear lower right conveyor belt 24.

[0119] Therefore, regardless of whether the lower conveyor belts 21 to 24 are mounted on the first pulley 31 or the second pulley 32, tension will be applied by either the first pressurizing mechanism 33 or the second pressurizing mechanism 34.

[0120] like Figure 6 and Figure 7 As shown, if the bolts are unscrewed to allow the left pressure roller 331, right pressure roller 332, left pressure roller 341, and right pressure roller 342 to retract, the lower conveyor belts 21 to 24 can be easily removed from the first pulley 31 or the second pulley 32 for replacement.

[0121] Therefore, it is easy to choose and proceed. Figure 6 Sewing in the erected state and Figure 7 Sewing in the erected state.

[0122] Figure 6 The lower conveyor belts 21 to 24 are installed in a differential feed configuration. For example, in... Figure 6 In a differential feed state, so-called pleating can be performed. Pleating is a sewing method in which the front side of the needle drop position is fed faster than the back side.

[0123] In addition, in the differential feed mode, the front side of the needle drop position can be fed more slowly than the rear side to perform sewing that applies tension to the workpiece.

[0124] Figure 7 The lower conveyor belts 21 to 24 are in a differential feed configuration. For example, in... Figure 7 In the state of left and right differential feed, if the left side is fed quickly, a right-turning curved stitch can be performed; if the right side is fed quickly, a left-turning curved stitch can be performed.

[0125] Furthermore, since the curvature of the sewing curve can be changed accordingly with the magnitude of the speed difference (the difference in conveying volume) between the left and right sides, a variety of curved sewing can be performed.

[0126] [Fabric presser foot mechanism]

[0127] Figure 8 This is a perspective view of the fabric presser foot mechanism 70, which acts as a presser foot mechanism, pressing the workpiece from above on the needle plate 101, and its surrounding area. Figure 9 This is a rear view showing the fabric presser foot mechanism 70 and its surrounding area. Figure 10 This is a right-side view showing the fabric presser foot mechanism 70 and its surrounding area. Furthermore, in Figure 8 The diagrams of the positioning scale 50 and its support mechanism 53, which will be described later, are omitted.

[0128] The fabric presser foot mechanism 70 includes a presser foot 71, a presser foot bar 72, a mounting platform 74, and a presser foot motor 73 (see reference). Figure 11 ), as a height sensor 762 for the presser foot height detection unit (refer to Figure 11 ).

[0129] like Figure 8 As shown, the presser foot 72 is positioned adjacent to the needle bar 12 in the forward direction and is supported inside the sewing machine arm 113 so as to be able to move up and down in the vertical direction of the fabric presser foot mechanism 70.

[0130] The upper end of the presser foot bar 72 is inside the sewing machine arm 113 and is pressed downward by a presser foot spring (not shown). The extension and retraction of the presser foot spring can be adjusted by a presser foot motor that can arbitrarily control the amount of motion. Therefore, by controlling the presser foot motor, the presser foot pressure of the presser foot 71 can be arbitrarily set.

[0131] In addition, the presser foot motor also controls the lifting action, which switches between the presser foot height (pressing the workpiece on the needle plate 101 with the presser foot 71) and the release height (separating upwards).

[0132] In addition, a height sensor 762 is provided on the presser foot 72 to detect the height of the presser foot 72. Therefore, after the presser foot pressure of the presser foot 71 is set to a predetermined value, when the height of the presser foot 71 changes due to the change in the thickness of the sewn material, the presser foot motor is controlled so that the extension and contraction of the presser foot spring does not change, thereby maintaining the presser foot pressure at a constant set value.

[0133] The presser foot 71 is mounted on the lower end of the presser foot bar 72 via a mounting platform 74. The mounting platform 74 is a block with a horizontal and flat upper and lower surface. The mounting platform 74 is formed by an insertion hole through which the presser foot bar 72 can be inserted, extending from the upper surface to the lower surface. The mounting platform 74 is fixed to the lower end of the presser foot bar 72, for example, by tightening screws.

[0134] Furthermore, the lower end of the connecting rod member 474 of the upper feed mechanism 40, described later, is rotatably connected to the front end of the mounting table 74 about an axis in the left-right direction of the fabric presser foot mechanism 70.

[0135] The presser foot 71 is disposed on the compound opening 102 of the needle plate 101. The presser foot 71 presses down on the workpiece from above, so that the conveying force generated by each of the lower conveyor belts 21 to 24 is properly transmitted to the workpiece. In addition, the presser foot 71 supports the upper left conveyor belt 41 and the upper right conveyor belt 42 of the upper feed mechanism 40 in a conveying manner via the left conveyor belt guide 43 and the right conveyor belt guide 44. Hereinafter, the upper left conveyor belt 41 and the upper right conveyor belt 42 will be referred to as upper conveyor belts 41 and 42, or as left and right upper conveyor belts 41 and 42. Moreover, the presser foot 71 also has the function of pressing down on the workpiece by each of the upper conveyor belts 41 and 42, so that the conveying force of each of the upper conveyor belts 41 and 42 is properly transmitted to the workpiece.

[0136] like Figure 8 and Figure 9 As shown, the presser foot 71 has: a base plate 711 that presses the sewn material from above; and a connecting part 712 that is mounted on the lower end of the presser foot bar 72.

[0137] like Figure 8 As shown, the bottom plate 711 is formed into a so-called boat shape with a smooth bottom surface and the upstream side (rear end of the bottom plate 711) in the fabric conveying direction is curved upward.

[0138] The connecting part 712 is erected on the upper surface of the front end of the base plate 711 and is connected to the base plate 711 by slightly swinging about an axis in the left-right direction. The upper part of the connecting part 712 abuts against the bottom surface of the mounting platform 74 and is fixed to the left side of the mounting platform 74, for example, by screws. In addition, the connecting part 712 can also be joined to the mounting platform 74 by welding or the like, or it can be made of a single piece of material that integrates the connecting part 712 and the mounting platform 74.

[0139] [Upward feed mechanism]

[0140] like Figure 1 , Figure 2 , Figure 8 and Figure 9 As shown, the upper feed mechanism 40 includes: an upper left conveyor belt 41 and an upper right conveyor belt 42 as conveyor belts; the aforementioned left-side conveyor belt guide 43 and right-side conveyor belt guide 44; an upper left motor 45, which serves as the drive source for feeding the upper left conveyor belt 41; an upper right motor 46, which serves as the drive source for feeding the upper right conveyor belt 42; and a guide mechanism 47, which guides each upper conveyor belt 41 and 42 from each upper motor 45, 46 to the presser foot 71.

[0141] The left conveyor belt guide 43 is mounted on the left side of the presser foot 71, and the right conveyor belt guide 44 is mounted on the right side of the presser foot 71.

[0142] The left conveyor belt guide 43 can be rotatably mounted on the left side of the lower part of the connecting part 712 of the presser foot 71 via a support shaft in the left-right direction, and the right conveyor belt guide 44 can be rotatably mounted on the right side of the lower part of the connecting part 712 of the presser foot 71 via a support shaft in the left-right direction.

[0143] like Figure 8 As shown, each conveyor belt guide 43 and 44, when viewed from the side, has the following shape: its front end extends obliquely upwards and forwards, its proximal end at the rear end is closest to the needle plate 101, and its rear end curves obliquely upwards and backwards. Furthermore, the left conveyor belt guide 43 has a feed roller 432 at its rear end, which can rotate via an axis along the left-right direction of the left conveyor belt guide 43. The right conveyor belt guide 44 has a feed roller 442 at its rear end, which can rotate via an axis along the left-right direction of the right conveyor belt guide 44.

[0144] The left-side endless loop upper conveyor belt 41 is guided so that it passes between the left-side conveyor belt guide 43 and the side of the presser foot 71. Similarly, the right-side endless loop upper conveyor belt 42 is guided so that it passes between the right-side conveyor belt guide 44 and the side of the presser foot 71. That is, the left and right upper conveyor belts 41 and 42 fold downwards along the rear outer periphery from the upper part of the feed rollers 432 and 442, respectively. After being guided so that the portion of each conveyor belt guide 43 and 44 closest to the needle plate 101 faces forward, they move forward diagonally upwards. As each upper conveyor belt 41 and 42 travels forward along the portion of each conveyor belt guide 43 and 44 closest to the needle plate 101, it abuts against the workpiece on the needle plate 101 and is conveyed forward.

[0145] Furthermore, when viewed from above, the position where the upper left conveyor belt 41 contacts the workpiece coincides with the position where the lower left conveyor belt 22 contacts the workpiece. The workpiece is conveyed while being held between these conveyor belts.

[0146] Similarly, when viewed from above, the position where the upper right conveyor belt 42 contacts the workpiece coincides with the position where the lower right conveyor belt 23 contacts the workpiece. The workpiece is conveyed while being held between these conveyor belts.

[0147] Furthermore, as described above, each conveyor belt guide 43, 44 is axially supported on the presser foot 71 via a support shaft (not shown) in the left-right direction. Moreover, a tension spring 433, 443 is connected to one end of a shaft portion 434, 444 located at the front end of each conveyor belt guide 43, 44. The other end of the tension spring 433 is connected to a shaft portion 745 located on the left side of the mounting platform 74, applying upward tension to the front end of the left conveyor belt guide 43. The other end of the tension spring 443 is connected to a shaft portion 746 located on the right side of the mounting platform 74, applying upward tension to the front end of the right conveyor belt guide 44.

[0148] Therefore, the rear ends of each conveyor belt guide 43, 44 are subjected to downward rotation, which applies a pressing force toward the needle plate 101 to each upper conveyor belt 41, 42 that travels forward along the part closest to the needle plate 101. Thus, a pressing force is applied to each upper conveyor belt 41, 42 toward the workpiece being sewn on the needle plate 101.

[0149] In addition, the rear ends of each conveyor belt guide 43, 44 are pressed against the sewn material on the needle plate 101. Therefore, corresponding to the change in the thickness of the sewn material, the height of each conveyor belt guide 43, 44 at its rear end changes as it rotates around the support shaft.

[0150] like Figures 9 to 11 As shown, in the sewing machine 100, the inter-axial distance between the shaft portions 434, 444 and shaft portions 745, 746 at both ends of the tension springs 433, 443 located at the two ends of each conveyor belt guide 43, 44 is detected by left and right potentiometers 48, 49. By detecting these left and right potentiometers 48, 49, the change in the height (vertical position) of the rear end caused by the rotation of each conveyor belt guide 43, 44 can be detected.

[0151] The upper left motor 45 and the upper right motor 46 are motors whose speed can be controlled, such as DC motors, AC motors, stepper motors, etc.

[0152] Furthermore, with its output shaft facing to the left, the upper left motor 45 is supported on the front side of the left end of the sewing machine arm 113 via the motor bracket 451.

[0153] In addition, with the output shaft facing to the left, the upper right motor 46 is supported above the upper left motor 45 on the front side of the left end of the sewing machine arm 113 via the motor bracket 451.

[0154] Furthermore, a motor pulley 452 is mounted on the output shaft of the upper left motor 45. One end of the upper left conveyor belt 41 is wound around the motor pulley 452.

[0155] Additionally, a motor pulley 462 is mounted on the output shaft of the upper right motor 46. One end of the upper right conveyor belt 42 is wound around this motor pulley 462.

[0156] The upper left conveyor belt 41 is an endless loop. One end of the upper left conveyor belt 41, after being stretched, is mounted on the motor pulley 452 of the upper left motor 45, and the other end is mounted on the feed roller 432 of the conveyor belt guide 43.

[0157] The upper right conveyor belt 42 is also an endless loop. One end of the upper right conveyor belt 42, after being stretched, is mounted on the motor pulley 462 of the upper right motor 46, and the other end is mounted on the feed roller 442 at the rear end of the aforementioned conveyor belt guide 44.

[0158] Furthermore, the paths from the motor pulley 452 to the feed roller 432 in the upper left conveyor belt 41 and from the motor pulley 462 to the feed roller 442 in the upper right conveyor belt 42 overlap when viewed from the left and right directions, except for the periphery of the motor pulleys 452 and 462. In addition, the upper right conveyor belt 42 is positioned on the right side relative to the upper left conveyor belt 41.

[0159] like Figure 2 As shown, the guiding mechanism 47 guides the upper left conveyor belt 41 and the upper right conveyor belt 42 along their respective paths.

[0160] The guiding mechanism 47 includes: a pair of first tension rollers 471 arranged left and right; a pair of second tension rollers 472 arranged left and right; a guide arm 475 composed of upper and lower connecting rods 473 and 474; and a plurality of guide rollers 476 rotatably disposed on each part of the path of each upper conveyor belt 41 and 42.

[0161] A pair of first tension rollers 471 are positioned below the motor pulley 452. Additionally, a pair of second tension rollers 472 are positioned between the motor pulley 452 and the pair of first tension rollers 471.

[0162] The pair of first tension rollers 471 are tension rollers that are rotatable about an axis in the left-right direction of the sewing machine 100 and have a wide axial width. Moreover, the pair of first tension rollers 471 press the upper left conveyor belt 41 and the upper right conveyor belt 42 from the outside, and apply inward tension to each of the upper conveyor belts 41, 42.

[0163] The pair of second tension rollers 472 are tension rollers that are rotatable about an axis in the left-right direction of the sewing machine 100 and have a narrow axial width. Moreover, the pair of second tension rollers 472 presses the upper right conveyor belt 42 from the inside, giving the upper right conveyor belt 42 an outward tension.

[0164] In addition, the upper right conveyor belt 42 is extended forward and backward by a pair of second tension rollers 472, thus avoiding interference with the motor pulley 452 located in the middle of the path.

[0165] One end of the connecting rod member 473 constituting the upper side of the guide arm 475 is connected to the lower end of the motor bracket 451, and at this connection point, it can rotate about an axis in the left-right direction of the sewing machine 100. In addition, the other end of the connecting rod member 473 is connected to one end of the lower connecting rod member 474, and at this connection point, it can rotate about an axis in the left-right direction of the sewing machine 100.

[0166] Furthermore, as described above, the other end of the lower connecting rod component 474 is connected to the front end of the mounting platform 74, and at this connection point, it can rotate about an axis in the left-right direction of the sewing machine 100.

[0167] The connecting part between the upper connecting rod member 473 and the lower connecting rod member 474 is provided with: a guide roller 476, which abuts against the endless annular upper left conveyor belt 41 and upper right conveyor belt 42 from the front side of the sewing machine 100 on the inner side of the ring; and a guide roller (not shown), which abuts against the front side of the sewing machine 100 on the outer side of the ring.

[0168] Thus, the left and right upper conveyor belts 41 and 42 are conveyed along the path of the upper connecting rod member 473 and the path of the lower connecting rod member 474.

[0169] Therefore, even if the bending angles of the upper connecting rod member 473 and the lower connecting rod member 474 change due to variations in the thickness of the sewn material or the lifting and lowering of the presser foot 71 caused by unevenness, the left and right upper conveyor belts 41 and 42 will maintain their paths along the upper connecting rod member 473 and the lower connecting rod member 474, respectively. Thus, the path lengths of each upper conveyor belt 41 and 42 are kept constant, suppressing variations in the tension of each upper conveyor belt 41 and 42.

[0170] [Positioning scale]

[0171] Figure 9 The number 50 indicates the positioning scale, and the number 53 indicates its support mechanism.

[0172] The positioning ruler 50 is used to position the side end of the sewn object in the left and right directions when sewing, maintaining a certain distance (the width of the welt) from the needle drop position.

[0173] The positioning scale 50 includes: an abutment plate 51 that abuts against the side end (right end in this embodiment) of the workpiece on the needle plate 101; and a connecting portion 52 that connects the abutment plate 51 to the support mechanism 53. The abutment plate 51 is a flat plate with a plane along the front-back direction and the up-down direction of the upper feed mechanism 40, so that the right end of the workpiece abuts against its left side to position the workpiece.

[0174] The support mechanism 53 includes a retaining shaft 54, a cylindrical body 55, a cylinder, and a position adjustment motor 57 (see reference). Figure 11 The retaining shaft 54 ​​holds the positioning scale 50. The cylindrical body 55 holds the retaining shaft 54 ​​in place when inserted through it. The cylinder raises and lowers the positioning scale 50, switching between the used position on the needle plate 101 and the non-used position where the positioning scale 50 is retracted upwards. The position adjusting motor 57 moves the positioning scale 50 left and right via the retaining shaft 54 ​​for positioning.

[0175] [Retreat Agency]

[0176] Figures 8 to 10 The reference numeral 60 shown is a retraction mechanism used to maintain the right-side conveyor belt guide 44 in the retraction position when using the positioning scale 50.

[0177] When the adjusted welt width is small, the abutment plate 51 is positioned close to the needle drop position. In this case, the rear end of the right conveyor belt guide 44 may interfere with the abutment plate 51, so the conveyor belt guide 44 is rotated around the support shaft, causing the rear end to retract upward.

[0178] The retraction mechanism 60 is a mechanism that holds the rear end of the conveyor belt guide 44 in an upward retraction state.

[0179] The retraction mechanism 60 has a retaining member 61, which is supported at its upper end by a pivot 62 in the left-right direction on a connecting rod member 474. The retaining member 61 has a recess 611 at its lower end, and an operating portion 612 for rotating the retaining member 61 is formed near the recess 611. Operating the operating portion 612 of the retaining member 61 causes it to rotate, thereby allowing the recess 611 of the retaining member 61 to engage and retain the shaft portion 444 on the front end side, which moves downwards when the rear end of the conveyor belt guide 44 is retracted upwards.

[0180] Thus, the retaining member 61 of the retraction mechanism 60 can retain the rear end of the conveyor belt guide 44 in an upward retraction state.

[0181] Furthermore, reference numeral 63 is a torsion coil spring. The torsion coil spring 63 applies force to the retaining member 61 in a direction that rotates forward at the lower end of the retaining member 61. When the retaining member 61 is not retaining the conveyor belt guide 44, the torsion coil spring 63 causes the retaining member 61 to retract forward, so that the lower end of the retaining member 61 does not interfere with the conveyor belt guide 44.

[0182] [Using a sewing machine]

[0183] The sewing machine 100 with the above structure is capable of performing sewing with both upper and lower belt feeds.

[0184] In this case, the lower feed mechanism 20 feeds each of the lower conveyor belts 21 to 24 by... Figure 6 The device is set up in a way that allows for sewing at different speeds on the front and back sides of the needle hole 13.

[0185] In addition, the lower feed mechanism 20 feeds each of the lower conveyor belts 21 to 24 by... Figure 7 The device is set up in a way that allows for sewing at different speeds on the left and right sides of the needle hole 13.

[0186] On the other hand, when weft stitching is performed along the right end of the sewn material, the front end of the right conveyor belt guide 44 is pressed down, and the material moves from the conveying position to the retraction position, which is maintained by the retraction mechanism 60.

[0187] Furthermore, the actuator of the support mechanism 53 of the positioning scale 50 is driven to move the positioning scale 50 from the non-use position to the use position.

[0188] Thus, while the workpiece is being conveyed, sewing is performed in such a way that the right end of the workpiece is always in contact with the left side of the abutment plate 51 of the positioning scale 50, thereby sewing with the target along the stitch width.

[0189] [Sewing machine control system]

[0190] Figure 11 This is a block diagram representing the control system of the sewing machine 100.

[0191] like Figure 11 As shown, the sewing machine 100 has a control device 90 for controlling the movement of each structure. Furthermore, the sewing machine motor 16, presser foot motor 73, first motor 25, second motor 26, upper left motor 45, upper right motor 46, and position adjustment motor 57 are connected to the control device 90 via their respective motor drive circuits 16a, 73a, 25a, 26a, 45a, 46a, and 57a.

[0192] In addition, the sewing machine motor 16, presser foot motor 73, first motor 25, second motor 26, upper left motor 45, upper right motor 46, and position adjustment motor 57 are equipped with encoders 161, 732, 251, 261, 453, 461, and 571 to detect their rotational speed. These encoders 161, 732, 251, 261, 453, 461, and 571 are also connected to the control device 90 via motor drive circuits 16a, 73a, 25a, 26a, 45a, 46a, and 57a.

[0193] In addition, the solenoid valve 58, which operates the position switching cylinder that switches the positioning scale 50 between the used position and the non-used position, is connected to the control device 90 via the drive circuit 58a.

[0194] The control device 90 has a CPU 91, ROM 92, RAM 93, and data storage 94, and performs various action controls as described later.

[0195] The ROM 92 contains the system program that forms the basis for the motion control of the sewing machine 100.

[0196] In addition, the data memory 94 stores various data, programs, etc., which will be described later. Furthermore, the data memory 94 is composed of non-volatile semiconductor memory such as flash memory, EEPROM, or EPROM, but it may also utilize storage devices such as HDDs.

[0197] The CPU 91 executes various programs stored in the ROM 92 and data memory 94. The RAM 93 is the memory that serves as the operating area for the CPU 91.

[0198] In addition, the operation input unit 96, which serves as a setting input device, is connected to the control device 90 via an interface (I / F) 96a.

[0199] The operation input unit 96 includes a display unit 961. The display unit 961 displays information required for inputting various settings. The display unit 961 is configured to include an input screen. This operation input unit 96 is configured as a so-called touch panel or touchscreen, in which a touch sensor is provided on the display unit 961, which serves as the input screen. However, the display screen and the operation input unit can also be separate structures.

[0200] Additionally, the pedal 95 is connected to the control device 90 via interface 95a. The pedal 95 is used to input commands such as starting and stopping the sewing, increasing or decreasing the sewing speed, and other instructions.

[0201] Additionally, the height sensor 762 and the left and right potentiometers 48 and 49 are connected to the control device 90 via interfaces 762a, 48a, and 49a. The height sensor 762 detects the height of the presser foot 71.

[0202] [Control implemented based on the detection of the height of the conveying position of the left and right upper conveyor belts]

[0203] The controls described below apply to situations where the lower conveyor belts 21 to 24 of the lower feed mechanism 20 are fed according to... Figure 7 The device is set up in a way that allows for sewing by conveying the needle at different speeds on the left and right sides of the needle hole 13.

[0204] The height sensor 762, which detects the height of the presser foot 71, and the left and right potentiometers 48 and 49 detect the height of the workpiece at the conveying position of the upper left conveyor belt 41 and the conveying position of the workpiece at the conveying position of the upper right conveyor belt 42, with the needle plate as a reference. As described above, the height sensor 762 and the left and right potentiometers 48 and 49 function as a detection unit for detecting the height with the needle plate as a reference.

[0205] In addition, the potentiometers 48 and 49 on the left and right function as detection units, which detect the height of the sewn item at the conveying position of the upper left conveyor belt 41 and the conveying position of the upper right conveyor belt 42, with the presser foot as the reference.

[0206] In addition, the potentiometers 48 and 49 on the left and right sides function as detection units, which detect the difference between the height of the sewn item at the conveying position of the upper left conveyor belt 41 and the height of the sewn item at the conveying position of the upper right conveyor belt 42.

[0207] Furthermore, "the height of the workpiece at the conveying position" refers to the height near the rear ends of the left and right conveyor belt guides 43 and 44, at the point where the upper left and right conveyor belts 41 and 42 contact the workpiece. The conveyor belt guides 43 and 44 press the workpiece at this position, so by determining the height of this position, the height of the workpiece can be obtained.

[0208] In addition, "the height of the sewn object at the conveying position" can also be described as the height observed from the presser foot 71, which serves as a support component and supports the left and right conveyor belt guides 43 and 44.

[0209] However, the height of the sewn item at the conveying position of the left and right upper conveyor belts 41 and 42 is not limited to the example above. For example, the height of the sewn item at the conveying position can also be the height measured from the upper surface of the needle plate 101.

[0210] As described above, the left and right potentiometers 48 and 49 detect the inter-axis distance between the shaft portions 434 and 444 located at the front ends of each conveyor belt guide 43 and 44, and the shaft portions 745 and 746 opposite to the shaft portions 434 and 444 on the rear slope. This inter-axis distance is correlated with the height of the sewn material at the conveying position of the left and right upper conveyor belts 41 and 42. Therefore, a height table 941 representing this correlation is stored in the data memory 94.

[0211] The CPU 91 of the control device 90 can obtain the height of the sewn item at the conveying position of the left and right upper conveyor belts 41 and 42 by referring to the detection values ​​of each potentiometer 48 and 49 and the height table 941.

[0212] (1) The CPU 91 of the control device 90 can obtain the "height of the workpiece at the conveying position of the left and right upper conveyor belts 41 and 42" based on the detection values ​​of each potentiometer 48 and 49. In the use of the sewing machine 100 in this example, the "height of the workpiece at the conveying position of the left and right upper conveyor belts 41 and 42" in this case is set as "the height of the left and right upper conveyor belts 41 and 42 based on the presser foot".

[0213] (2) In addition, the CPU 91 can obtain the difference in height of the sewn material at the conveying position of the left and right upper conveyor belts 41 and 42 based on the difference in the upper movement of the left and right conveyor belt guides 43 and 44.

[0214] (3) Furthermore, the CPU 91 can obtain the height of the presser foot 71 from the upper surface of the needle plate based on the detection value of the height sensor 762. Therefore, by adding the height of the workpiece at the conveying position of the left and right upper conveyor belts 41, 42 to the height of the presser foot 71 from the upper surface of the needle plate, the height of the workpiece at the conveying position of the left and right upper conveyor belts 41, 42 as observed from the needle plate 101 can be obtained. In the use of the sewing machine 100 in this example, the height of the workpiece at the conveying position of the left and right upper conveyor belts 41, 42 in this case is set as the height of the left and right upper conveyor belts 41, 42 relative to the needle plate.

[0215] The upper conveyor belts 41 and 42 on the left and right sides are respectively set with feed intervals. The upper motors 45 and 46 on the left and right sides control the movement of the upper conveyor belts to intermittently convey the set feed interval for each stitch.

[0216] In contrast, CPU 91 calculates the value of any one of the following: (1) "the height of the left and right upper conveyor belts 41 and 42 relative to the presser foot", (2) "the difference in height of the sewn material at the conveying position of the left and right upper conveyor belts 41 and 42", and (3) "the height of the left and right upper conveyor belts 41 and 42 relative to the needle plate". Based on this value, it performs motion control to correct the drive of the left and right upper motors 45 and 46.

[0217] After obtaining (1) "the height of the left and right upper conveyor belts 41 and 42 with the presser foot as the reference", the CPU 91 performs the following action control on the left and right upper motors 45 and 46.

[0218] When the upward movement of the conveyor position caused by the rotation of the conveyor belt guides 43 and 44 increases, the tension of the tension springs 433 and 443 increases, and the pressure generated during pressing by the conveyor belt guides 43 and 44 increases. Simultaneously, the conveying resistance of the left and right upper conveyor belts 41 and 42 increases. Therefore, while maintaining a constant amount of motion corresponding to one feed interval for the upper motors 45 and 46, corrections are made by increasing the feed speed or increasing the torque during drive.

[0219] In this case, a conveyor table 942, which specifies the correspondence between the speed correction values ​​or torque correction values ​​of the upper motors 45 and 46 and the height of the left and right upper conveyor belts 41 and 42 relative to the presser foot, is stored in the data memory 94. The speed correction values ​​and torque correction values ​​can be, for example, values ​​of speed increase / decrease ratios or torque increase / decrease ratios.

[0220] Furthermore, if the CPU 91 obtains the height of the left and right upper conveyor belts 41 and 42 based on the presser foot, respectively, it refers to the conveyor table 942 and performs motion control to correct the feed speed or torque of the left and right upper motors 45 and 46.

[0221] In addition, after obtaining (2) "the difference in height of the sewn material at the conveying position of the left and right upper conveyor belts 41 and 42", the CPU 91 performs the following action control on the left and right upper motors 45 and 46.

[0222] Between the left and right conveyor belt guides 43 and 44, when the height difference between their respective upper conveyor belts 41 and 42 increases, the tension of either of the tension springs 433 and 443 increases, and the pressure generated by either of the corresponding conveyor belt guides 43 and 44 during pressing increases, thus increasing the resistance to conveying.

[0223] Therefore, while maintaining the same amount of motion corresponding to one feed interval, the CPU 91, within the upper motors 45 and 46, corrects by increasing the feed speed or increasing the driving torque for the side with a higher conveying position, and corrects by decreasing the feed speed or decreasing the driving torque for the side with a lower conveying position.

[0224] In this case, a transport table 942, which specifies the correspondence between the speed increase / decrease or torque increase / decrease of the upper motors 45 and 46 and the height difference of the transport position, is stored in the data memory 94. The speed increase / decrease or torque increase / decrease value can be, for example, a speed increase / decrease ratio or a torque increase / decrease ratio.

[0225] Furthermore, if the CPU 91 obtains the height difference between the conveying positions of the upper conveyor belts 41 and 42 of the left and right conveyor belt guides 43 and 44, it refers to the conveying table 942 and performs motion control to increase or decrease the speed or torque of the upper motors 45 and 46 of the left and right sides.

[0226] Furthermore, in this case, regarding the speed or torque of the upper motors 45 and 46, it is exemplified that one is increased and the other is decreased, but it is also possible to increase the speed or torque only for the side where the height of the conveying position of the upper conveyor belts 41 and 42 increases, and not to make correction for the side where the height of the conveying position decreases.

[0227] After obtaining (3) "the height of the left and right upper conveyor belts 41 and 42 relative to the needle plate", the CPU 91 performs the following motion control on the left and right upper motors 45 and 46.

[0228] "The height of the upper conveyor belts 41 and 42 on the left and right sides, relative to the needle plate" indicates the thickness of the workpiece being sewn. When the thickness of the workpiece increases, it is related to the material of the workpiece. For example, when the workpiece is soft, the feed rate of the workpiece may decrease.

[0229] Therefore, when the thickness of the sewn material increases, the feed amount is adjusted to compensate for the single feed interval set for the upper motor 45 or 46.

[0230] In this case, a feed table 942, which specifies the correspondence between the sum of the feed amounts of the upper motors 45 and 46 and the height of the left and right upper conveyor belts 41 and 42 relative to the needle plate, is stored in the data memory 94. The sum of the feed amounts is, for example, the value of the feed amount increase factor.

[0231] Furthermore, if the CPU 91 obtains the "height of the left and right upper conveyor belts 41 and 42 based on the needle plate" for the left and right conveyor belt guides 43 and 44, it refers to the conveyor table 942 and performs motion control to drive the left and right upper motors 45 and 46 to correct the set feed interval.

[0232] In addition, the sewing machine 100 may be configured to obtain only one of the following: (1) "the height of the left and right upper conveyor belts 41, 42 based on the presser foot", (2) "the difference in height of the workpiece at the conveying position of the left and right upper conveyor belts 41, 42", or (3) "the height of the left and right upper conveyor belts 41, 42 based on the needle plate", and perform the corresponding left and right upper motors 45, 46 motion control.

[0233] Alternatively, while achieving (1) to (3) above, it is also possible to configure the operation control corresponding to them to only perform the portion selected from the operation input unit 96. In this case, the operation input unit 96 functions as a selection setting unit.

[0234] Furthermore, it can also be configured to obtain two or more of the above (1) to (3) and perform all the operation control of the corresponding left and right upper motors 45 and 46.

[0235] Furthermore, having obtained (1) the "height of the left and right upper conveyor belts 41, 42 relative to the presser foot", the left and right upper motors 45, 46 can be corrected by increasing the feed speed or increasing the torque during drive. However, the drive motion control can also be performed in place of them or in parallel with them to increase the set feed interval. In this case, a feed table specifying the correspondence between the sum of the feed amounts of the upper motors 45, 46 and the "height of the left and right upper conveyor belts 41, 42 relative to the presser foot" can be stored in the data memory 94. In this case, the sum of the feed amounts can be, for example, a value representing the increase factor of the feed amount.

[0236] Furthermore, having obtained (2) the "difference in height of the sewn material at the conveying positions of the left and right upper conveyor belts 41 and 42", the left and right upper motors 45 and 46 can be corrected by increasing the feed speed or increasing the torque during drive. However, they can also be used in place of them or in parallel to perform the drive control by increasing the set feed interval. In this case, a feed table specifying the correspondence between the sum of the feed amounts of the upper motors 45 and 46 and the "difference in height of the sewn material at the conveying positions of the left and right upper conveyor belts 41 and 42" can be stored in the data memory 94. In this case, the sum of the feed amounts can be, for example, a value representing an increase multiple of the feed amount.

[0237] Furthermore, having obtained (3) the "height of the left and right upper conveyor belts 41, 42 relative to the needle plate" as observed from the needle plate 101, the left and right upper motors 45, 46 are driven by adjusting the feed interval. However, they can also be adjusted by increasing the feed speed or increasing the torque during drive, either in place of them or in parallel with them. In this case, a feed table specifying the correspondence between the speed adjustment value or torque adjustment value of the upper motors 45, 46 and the "height of the left and right upper conveyor belts 41, 42 relative to the needle plate" can be stored in the data memory 94. In this case, the speed adjustment value can also be a value of the speed increase / decrease ratio. In addition, the torque adjustment value can also be a value of the torque increase ratio.

[0238] Furthermore, in any of the above situations, various tables used for calibrating the drive of the left and right upper motors 45 and 46 corresponding to (1) to (3) above can be created through input from the operation input unit 96. In this case, the operation input unit 96 functions as a numerical setting unit.

[0239] In addition, when the CPU 91 obtains (1) "the height of the left and right upper conveyor belts 41 and 42 based on the presser foot", (2) "the difference in height of the sewn material at the conveying position of the left and right upper conveyor belts 41 and 42", and (3) "the height of the left and right upper conveyor belts 41 and 42 based on the needle plate", it performs corrections to increase the feed speed, increase the torque during driving, or add the feed amount for the left upper motor 45 or right upper motor 46 that drives the left upper conveyor belt 41 or right upper conveyor belt 42 which has a higher conveying position. However, the corrections of the present invention are not limited to the above examples.

[0240] For example, depending on the type of material being sewn or the support structure of the upper conveyor belts 41 and 42, adjustments can be made to the upper left motor 45 or the upper right motor 46 that drives the upper left conveyor belt 41 or the upper right conveyor belt 42, which have a lower conveying position, such as increasing the feed speed, increasing the torque during drive, or adding a feed amount adjustment. In these cases, it is preferable to store the required tables in the data memory 94.

[0241] Furthermore, the sewing machine 100 can be configured such that, in any case where the height of the conveying position increases or decreases, it is possible to select whether to increase the feed speed, increase the torque during drive, or increase the feed amount.

[0242] [Technical Effects of Embodiments of the Invention]

[0243] The sewing machine 100 described above has left and right potentiometers 48 and 49 and a height sensor 762 as detection units. Based on the detection of these detection units, the control device 90 performs control to adjust the drive of the feed of the conveyor belts 41 and 42 implemented by the left and right upper motors 45 and 46 of the upper feed mechanism 40.

[0244] Therefore, when a thickness difference occurs between the left and right sides of the sewn material at the needle drop position, the conveying action implemented by the upper feed mechanism 40 can be adjusted to ensure proper conveying of the sewn material.

[0245] Furthermore, the control device 90 performs control to adjust the feed amount (feed pitch) of one or both of the upper left conveyor belt 41 and the upper right conveyor belt 42 based on the detection of the aforementioned detection unit. Thus, in the event of fluctuations in the left and right feed amounts due to height differences, such fluctuations can be suppressed through adjustment.

[0246] In particular, the control device 90 controls the feed amount of the side with the higher height of the sewn material at the conveying position between the left and right upper conveyor belts 41 and 42 to increase the feed amount, thereby suppressing the possible decrease in feed amount due to the increase in the thickness of the sewn material.

[0247] In addition, the control device 90 controls the feed amount of the side with the lower height of the sewn material at the conveying position in the left and right upper conveyor belts 41 and 42 to increase, thereby suppressing the reduction in feed amount that may sometimes occur due to the decrease in the thickness of the sewn material, depending on the type of sewn material.

[0248] Furthermore, the control device 90 performs control to adjust the feed speed of one or both of the upper left conveyor belt 41 and the upper right conveyor belt 42 based on the detection of the aforementioned detection unit. Therefore, in the event of fluctuations in the left and right feed speeds due to height differences, such fluctuations can be suppressed through adjustment.

[0249] In particular, the control device 90 controls the feed speed of the side with the higher height of the sewn material at the conveying position between the left and right upper conveyor belts 41 and 42 to increase the feed speed, thereby suppressing the possible decrease in feed speed due to the increase in the thickness of the sewn material.

[0250] In addition, the control device 90 performs control to increase the feed speed of the side with lower height of the sewn material at the conveying position in the left and right upper conveyor belts 41 and 42, thereby suppressing the possible decrease in feed speed due to the decrease in the thickness of the sewn material, which may sometimes occur depending on the type of sewn material.

[0251] Furthermore, based on the detection by the aforementioned detection unit, the control device 90 performs control to adjust the torque of one or both of the left and right upper motors 45 and 46 that feed the upper left conveyor belt 41 and feed the upper right conveyor belt 42. Thus, in the event of fluctuations in the torque of the left and right conveyors due to height differences, such fluctuations can be suppressed through adjustment.

[0252] Specifically, the control device 90 controls the increase of torque of the upper motor 45 or 46 feeding the upper conveyor belt 41 or 42 on the side with the higher height of the workpiece at the conveying position, thereby suppressing the possible decrease in feed torque due to the increase in the thickness of the workpiece.

[0253] In addition, the control device 90 controls the increase of torque of the upper motor 45 or 46 that feeds the upper conveyor belt 41 or 42 on the side with the lower height of the sewn item at the conveying position between the left and right upper conveyor belts 41 and 42. This can suppress the decrease in conveying torque that may sometimes occur due to the reduction in the thickness of the sewn item, depending on the type of sewn item.

[0254] [other]

[0255] The various embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above. For example, in the embodiments, a structural element integrally formed by a single component can be replaced by a structural element divided into multiple components that are connected or fixed to each other. In addition, a structural element composed of multiple components connected together can be replaced by a structural element integrally formed by a single component. Apart from this, the details shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

[0256] For example, the conveying position where the detection unit performs the detection is not limited to the position where the upper conveyor belts 41 and 42 of the left and right conveyor belt guides 43 and 44 abut, but also includes the surrounding area, such as the upstream or downstream side of the abutting position, which is a range that will not produce a large difference in the detection value (considered to be substantially the same range).

[0257] Furthermore, the detection unit that detects the height of the sewn item at the conveying position of the left and right upper conveyor belts 41 and 42 is not limited to the above structure, and any detection unit capable of detecting the height of the sewn item at the conveying position can be used.

[0258] For example, Figure 12As shown, optical distance sensors 48A and 49A can also be used. In this case, it is preferable to use distance sensors 48A and 49A to detect the distance from above to the immediate upstream side of the position where the left and right upper conveyor belts 41 and 42 abut in the sewn work. Each distance sensor 48A and 49A is preferably located at a position where its height does not change during sewing, such as above the detection position and below the sewing machine arm 113.

[0259] In this case, each distance sensor 48A and 49A can individually detect the height of the sewn material at the conveying position of the left and right upper conveyor belts 41 and 42 as referenced by the needle plate 101, and can obtain the thickness of the sewn material at each detection position.

[0260] Alternatively, instead of potentiometers 48 and 49 that detect the interaxial distance between the left and right conveyor belt guides 43 and 44, a linear sensor or magnetic sensor that detects the interaxial distance can be used as the detection unit.

[0261] Alternatively, as a detection unit, a rotary potentiometer or encoder can be used to detect the angle of the left and right conveyor belt guides 43 and 44 around the support shaft 431.

[0262] In addition, such as Figure 4 As shown, an example is illustrated in the sewing machine 100 described above, where the needle hole 13 is disposed in the needle hole component 30, which moves up and down relative to the needle plate 101 at the same cycle as the sewing needle 11, but is not limited to this. For example, as Figure 13 As shown, a needle hole 13 can also be formed by directly penetrating the needle plate 101 relative to the needle plate 101, and the needle hole 13 can be fixedly set in a component that does not move up or down.

[0263] The present invention includes the following methods.

[0264] Project 1

[0265] A sewing machine having: The needle moving up and down mechanism moves the needle up and down via the sewing machine motor; The top feed mechanism, located on the left and right sides of the needle drop position, causes the conveyor belts to abut from above to transport the workpiece on the needle plate. A detection unit, used to detect the height of the sewn work at the conveying position of the left conveyor belt and the height of the sewn work at the conveying position of the right conveyor belt, or to detect the difference between them; and The control device controls the movement of the needle moving up and down mechanism and the upward feed mechanism. The control device performs control to adjust the drive of the feed of the left and right conveyor belts of the upper feed mechanism based on the detection of the detection unit.

[0266] Project 2

[0267] According to the sewing machine described in Project 1, among which, The control device performs control to adjust the feed rate of one or both of the left and right conveyor belts based on the detection of the detection unit.

[0268] Project 3

[0269] According to the sewing machine described in Project 1 or Project 2, among which, The control device performs the following control: among the left and right conveyor belts, the feed amount of the conveyor belt with the higher height of the sewn object at the conveying position is relatively increased.

[0270] Project 4

[0271] According to the sewing machine described in Project 1 or Project 2, among which, The control device performs the following control: relatively increasing the feed amount of the conveyor belt on the side with the lower height of the sewn object at the conveying position, between the left and right conveyor belts.

[0272] Project 5

[0273] According to any of the sewing machines described in Items 1 through 4, among which, The control device performs control to adjust the feed speed of one or both of the left and right conveyor belts based on the detection of the detection unit.

[0274] Project 6

[0275] According to any of the sewing machines described in Items 1 through 5, among which, The control device performs the following control: the feed speed of the conveyor belt with the higher height of the sewn object at the conveying position is relatively increased between the left and right conveyor belts.

[0276] Project 7

[0277] According to any of the sewing machines described in Items 1 through 5, among which, The control device performs the following control: the feed speed of the conveyor belt on the side with the lower height of the sewn object at the conveying position is relatively increased between the left and right conveyor belts.

[0278] Project 8

[0279] According to any of the sewing machines described in Items 1 through 7, among which, The control device performs the following control based on the detection of the detection unit: adjusting the torque of one or both of the motors feeding the left conveyor belt and the motors feeding the right conveyor belt.

[0280] Project 9

[0281] According to any of the sewing machines described in Items 1 through 8, among which, The control device performs the following control: it relatively increases the torque of the motor that feeds the conveyor belt of the left and right conveyor belts, on the side with the higher height of the sewn object at the conveying position.

[0282] Project 10

[0283] According to any of the sewing machines described in Items 1 through 8, among which, The control device performs the following control: it relatively increases the torque of the motor that feeds the conveyor belt of the left and right conveyor belts on the side where the height of the sewn object at the conveying position is lower.

[0284] Project 11

[0285] According to any of the items 1 through 10, the sewing machine described therein, The detection unit can detect the height relative to the presser foot and the height relative to the needle plate, which are the heights of the workpiece at the conveyor position on the left and right sides of the conveyor belt. The control device has a selection setting unit that selects whether to adjust the drive of the feed of the left and right conveyor belts of the upper feed mechanism based on any one of the height based on the presser foot, the height based on the needle plate, and the difference between the heights.

[0286] Project 12

[0287] According to any of the items 1 to 11, the sewing machine described therein, The control device has a value setting unit that sets the value of the object to be adjusted.

[0288] This application is based on Japanese Patent Application No. 2023-152063, filed on September 20, 2023, the contents of which are incorporated herein by reference.

Claims

1. A sewing machine, comprising: The needle moving up and down mechanism moves the needle up and down via the sewing machine motor; The top feed mechanism, located on the left and right sides of the needle drop position, causes the conveyor belts to abut from above to transport the workpiece on the needle plate. A detection unit, used to detect the height of the sewn work at the conveying position of the left conveyor belt and the height of the sewn work at the conveying position of the right conveyor belt, or to detect the difference between them; and The control device controls the movement of the needle moving up and down mechanism and the upward feed mechanism. The control device performs control to adjust the drive of the feed of the left and right conveyor belts of the upper feed mechanism based on the detection of the detection unit.

2. The sewing machine according to claim 1, wherein, The control device performs control to adjust the feed rate of one or both of the left and right conveyor belts based on the detection of the detection unit.

3. The sewing machine according to claim 2, wherein, The control device performs the following control: among the left and right conveyor belts, the feed amount of the conveyor belt with the higher height of the sewn object at the conveying position is relatively increased.

4. The sewing machine according to claim 2, wherein, The control device performs the following control: relatively increasing the feed amount of the conveyor belt on the side with the lower height of the sewn object at the conveying position, between the left and right conveyor belts.

5. The sewing machine according to claim 1, wherein, The control device performs control to adjust the feed speed of one or both of the left and right conveyor belts based on the detection of the detection unit.

6. The sewing machine according to claim 5, wherein, The control device performs the following control: the feed speed of the conveyor belt with the higher height of the sewn object at the conveying position is relatively increased between the left and right conveyor belts.

7. The sewing machine according to claim 5, wherein, The control device performs the following control: the feed speed of the conveyor belt on the side with the lower height of the sewn object at the conveying position is relatively increased between the left and right conveyor belts.

8. The sewing machine according to claim 1, wherein, The control device performs the following control based on the detection of the detection unit: adjusting the torque of one or both of the motors feeding the left conveyor belt and the motors feeding the right conveyor belt.

9. The sewing machine according to claim 8, wherein, The control device performs the following control: it relatively increases the torque of the motor that feeds the conveyor belt of the left and right conveyor belts, on the side with the higher height of the sewn object at the conveying position.

10. The sewing machine according to claim 8, wherein, The control device performs the following control: it relatively increases the torque of the motor that feeds the conveyor belt of the left and right conveyor belts on the side where the height of the sewn object at the conveying position is lower.

11. The sewing machine according to any one of claims 1 to 10, wherein, The detection unit can detect the height relative to the presser foot and the height relative to the needle plate, which are the heights of the workpiece at the conveyor position on the left and right sides of the conveyor belt. The control device has a selection setting unit that selects whether to adjust the drive of the feed of the left and right conveyor belts of the upper feed mechanism based on any one of the height based on the presser foot, the height based on the needle plate, and the difference between the heights.

12. The sewing machine according to claim 2, 5 or 8, wherein, The control device has a value setting unit that sets the value of the object to be adjusted.

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