Spinning mechanism of flat seaming machine

Abstract

The invention discloses a needling mechanism of a flat seaming machine, and aims to provide a needling mechanism capable of lifting the highest point position of a machine needle by changing limited parts such as a needle bar crank and a needle bar crankshaft under the condition of not changing the position of a main shaft so as to adapt to the sewing requirement of thicker cloth. The needling mechanism of the flat seaming machine can effectively solve the problem that due to the fact that the lowest point of a machine needle descends, a thick needle handle rolls and damages cloth. The needle comprises a needle rod; a main shaft; the crank connecting rod mechanism comprises a connecting rod, a needle bar crank fixedly connected to the main shaft and a needle bar crankshaft rotationally connected to the needle bar crank; one end of the main shaft bushing is provided with an annular groove distributed around the main shaft, and the center of the annular groove and the main shaft are eccentrically distributed; the sliding block slides along the annular groove; a first eccentric shaft is arranged at one end of the needle bar crankshaft and is rotationally connected with the sliding block; a second eccentric shaft is arranged at the other end of the needle bar crankshaft; the upper end of the connecting rod is rotationally connected with the second eccentric shaft;

Description

Technical Field

[0001] The present invention relates to the technical field of interlock sewing machines, and in particular to a material-piercing mechanism of an interlock sewing machine. Background Art

[0002] The piercing mechanism of current interlock sewing machines typically consists of a needle bar, a main shaft, and a crank-connecting rod mechanism connecting the needle bar and the main shaft. This crank-connecting rod mechanism comprises a connecting rod, a needle bar crank fixedly connected to the main shaft, and a needle bar crankshaft rotatably connected to the needle bar crank. The upper end of the connecting rod is hinged to the needle bar crankshaft, and the lower end of the connecting rod is hinged to the needle bar. The main shaft drives the needle bar up and down through the crank-connecting rod mechanism.

[0003] During actual use, the interlock sewing machine will encounter the working conditions of sewing thicker fabrics. In order to meet the sewing needs of thicker fabrics, the interlock sewing machine needs to raise the presser foot height so that the thick fabric can be easily placed under the presser foot for sewing. When the presser foot height is raised, it will cause the presser foot to interfere with the feed needle of the interlock sewing machine; therefore, the feed needle also needs to be raised. Since the needle tip of the interlock sewing machine needle must be higher than the feed needle thread, otherwise it will cause the feed needle thread to skip stitches, and after the feed needle is raised, the feed needle thread will also be raised accordingly, so the needle height must also be raised. When the needle is at the lowest point, the interlock sewing machine's looper needs to pass through the thread loop formed behind the needle; if the lowest point of the needle is raised, the looper will not be able to pass through the needle thread loop, resulting in skipped stitches.

[0004] That is to say, the highest point of the needle needs to be raised (to adapt to the sewing needs of thicker fabrics); but the lowest point of the needle cannot be raised (otherwise the looper cannot match the needle). In order to achieve this goal, the following solutions are generally used. Solution 1: Without changing the spindle position, an eccentric shaft is installed on the needle bar crankshaft to connect the connecting rod. By adjusting the eccentricity of the eccentric shaft, the needle bar stroke is increased, thereby raising the highest point of the needle and lowering the lowest point of the needle. In this way, although the lowest point of the needle can be kept at the same level to avoid the problem of the bent needle being unable to pass through the needle loop and causing skipped stitches, due to the relatively thick needle shank at the tail of the needle, the lowering of the needle shank may cause the thick needle shank to dig into the fabric when the needle is at its lowest point (damaging the fabric).

[0005] For example, the Chinese patent publication number CN201495386U, the name of the invention is a mechanism with adjustable needle bar stroke of a flat seam sewing machine. This case uses an eccentric shaft to adjust the needle bar stroke, which also has the above-mentioned shortcomings.

[0006] The second option involves adding an eccentric shaft to the needle bar crankshaft to connect it to the connecting rod. Adjusting the eccentricity of the shaft increases the needle bar stroke and simultaneously changes the spindle height to raise the needle's highest point to accommodate sewing thicker fabrics. This maintains the lowest point of the needle to prevent the needle handle from dropping, which could cause the thicker handle to dig into the fabric at its lowest point (damaging the fabric). However, this option requires changing the spindle height, which would require changes to numerous components in the interlock sewing machine, significantly extending the equipment upgrade cycle and increasing production costs. Summary of the Invention

[0007] The purpose of the present invention is to provide a kind of piercing mechanism of a stretch sewing machine which can raise the highest point of the needle to meet the sewing needs of thicker fabrics by changing limited parts such as the needle bar crank and the needle bar crankshaft without changing the position of the main shaft; and can effectively solve the problem of the thicker needle handle crushing the fabric due to the lowering of the lowest point of the needle; thereby effectively shortening the equipment improvement and production cycle and reducing the improvement and production cost.

[0008] The technical solution of the present invention is: A material-piercing mechanism of a flat sewing machine, comprising: needle bar; spindle; A crank-connecting rod mechanism connecting the needle bar and the main shaft comprises a connecting rod, a needle bar crank fixedly connected to the main shaft, and a needle bar crank shaft rotatably connected to the needle bar crank; A spindle bushing, through which the spindle passes, and an annular groove is provided at one end of the spindle bushing and surrounds the spindle, with the center of the annular groove eccentrically distributed with respect to the spindle; A slider, sliding along the annular groove; A first eccentric shaft is provided at one end of the needle bar crankshaft, and the first eccentric shaft is rotatably connected to the slider; a second eccentric shaft is provided at the other end of the needle bar crankshaft; the upper end of the connecting rod is rotatably connected to the second eccentric shaft, and the lower end of the connecting rod is hinged to the needle bar; When the main shaft drives the needle bar crank to rotate, the center of the second eccentric shaft is always located directly above the center of the needle bar crank.

[0009] Since the center of the annular groove is eccentrically distributed with the main shaft, the first eccentric shaft is eccentrically distributed with the needle crankshaft, and the first eccentric shaft is rotatably connected to the slider, in this way, when the main shaft drives the needle crank to rotate, and the needle crankshaft drives the slider to slide along the annular groove, the needle crankshaft will rotate, so that the relative position of the center of the first eccentric shaft and the center of the needle crankshaft remains unchanged, so that the center of the second eccentric shaft is always located directly above the center of the needle crankshaft. Based on this, it can be obtained that The height H1 of the second eccentric shaft at its highest position is equal to the sum of the height Hz of the main shaft, the distance L1 between the main shaft and the needle bar crankshaft, and the eccentric distance Lp of the second eccentric shaft.

[0010] The height H2 of the second eccentric shaft at the lowest position is equal to the height Hz of the main shaft minus the sum of the distance L1 between the main shaft and the needle bar crankshaft and the eccentric distance Lp of the second eccentric shaft.

[0011] Wherein: Hz is the height of the main shaft; L1 is the distance between the main shaft and the needle crankshaft; Lp is the eccentricity of the second eccentric shaft.

[0012] Assuming the distance between the main shaft and the needle crank of a conventional interlock sewing machine is L, the height Ha of the needle crank at its highest position is equal to the main shaft height Hz plus the distance L between the main shaft and the needle crank (i.e., Hz plus L). The height Hd of the needle crank at its lowest position is equal to the main shaft height Hz minus the distance L between the main shaft and the needle crank (i.e., Hz minus L).

[0013] Without changing the main shaft position (that is, when Hz remains unchanged), it is only necessary to ensure that "L1 is equal to L plus Lp" of this application, that is, H1 of this application is equal to Hz plus L plus 2Lp, and H2 is equal to Hz minus L; that is, compared with the piercing mechanism of the existing interlock sewing machine, the piercing mechanism of this application only needs to change L1 to "L plus Lp" to achieve the height of the highest position of the needle of this application being increased by 2 Lp compared to the highest position of the needle of the existing interlock sewing machine, and at the same time, the height of the lowest position of the needle of this application remains unchanged compared to the lowest position height of the needle of the existing interlock sewing machine.

[0014] Therefore, the present application can achieve the goal of raising the highest point of the needle to meet the sewing requirements of thicker fabrics without changing the position of the main shaft, only by changing the L1 of the needle bar crank, adding eccentric shafts at both ends of the needle bar crank, and setting annular grooves on the main shaft bushing; it can also effectively solve the problem of the thicker needle handle crushing the fabric due to the lowering of the lowest point of the needle; thereby effectively shortening the equipment improvement and production cycle and reducing the improvement and production costs.

[0015] Preferably, the eccentricity between the center of the annular groove and the main shaft is the same as the eccentricity of the first eccentric shaft.

[0016] Preferably, the needle bar crank is provided with a spindle hole, the spindle passes through the spindle hole, and the needle bar crank is further provided with a locking screw, which locks the spindle in the spindle hole, thereby facilitating the installation and production of the needle bar crank.

[0017] Preferably, the needle bar crank is provided with a pin through hole, the pin through hole is parallel to the main shaft, and the needle bar crankshaft is rotatably arranged in the pin through hole. In this way, the installation and production of the needle bar crank and the needle bar crankshaft are facilitated.

[0018] Preferably, the upper end of the connecting rod is provided with an upper shaft hole, and the second eccentric shaft is rotatably connected in the upper shaft hole. In this way, the second eccentric shaft is conveniently connected to the upper end of the connecting rod.

[0019] Preferably, a ball bearing is provided between the second eccentric shaft and the upper shaft hole, so as to effectively reduce the friction between the second eccentric shaft and the upper end of the connecting rod, thereby ensuring that the second eccentric shaft and the upper end of the connecting rod can rotate smoothly.

[0020] Preferably, the machine also includes a casing, the main shaft bushing is fixedly arranged on the casing, and the main shaft is rotatably arranged on the casing.

[0021] Preferably, a needle bar piercing head is provided on the needle bar, and the lower end of the connecting rod is hinged to the needle bar piercing head.

[0022] Preferably, it also includes a lifting block slidably connected to the casing in a vertical direction, the needle bar plucking head includes a plucking head rod extending radially along the needle bar, the lower end of the connecting rod is located between the lifting block and the needle bar, and the lower end of the connecting rod is provided with a lower shaft hole, the plucking head rod passes through the lower shaft hole and is rotatably connected to the lifting block, and the plucking head rod is rotatably connected to the lower shaft hole.

[0023] The beneficial effect of the present invention is as follows: Assuming that the distance between the main shaft and the needle crank of a conventional interlock sewing machine is L, the height Ha of the needle crank at its highest position is equal to the height Hz of the main shaft plus the distance L between the main shaft and the needle crank (i.e., Hz plus L). The height Hd of the needle crank at its lowest position is equal to the height Hz of the main shaft minus the distance L between the main shaft and the needle crank (i.e., Hz minus L).

[0024] Without changing the main shaft position (that is, when Hz remains unchanged), it is only necessary to ensure that "L1 is equal to L plus Lp" of this application, that is, H1 of this application is equal to Hz plus L plus 2Lp, and H2 is equal to Hz minus L; that is, compared with the piercing mechanism of the existing interlock sewing machine, the piercing mechanism of this application only needs to change L1 to "L plus Lp" to achieve the height of the highest position of the needle of this application being increased by 2 Lp compared to the highest position of the needle of the existing interlock sewing machine, and at the same time, the height of the lowest position of the needle of this application remains unchanged compared to the lowest position height of the needle of the existing interlock sewing machine.

[0025] Therefore, the present application can achieve the goal of raising the highest point of the needle to meet the sewing requirements of thicker fabrics without changing the position of the main shaft, only by changing the L1 of the needle bar crank, adding eccentric shafts at both ends of the needle bar crank, and setting annular grooves on the main shaft bushing; it can also effectively solve the problem of the thicker needle handle crushing the fabric due to the lowering of the lowest point of the needle; thereby effectively shortening the equipment improvement and production cycle and reducing the improvement and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1It is a three-dimensional partial structural schematic diagram of a material-piercing mechanism of a flat seam sewing machine of the present invention.

[0027] Figure 2 The present invention is a partial cross-sectional structural diagram of a material-piercing mechanism of a flat seam sewing machine.

[0028] Figure 3 The present invention is a schematic diagram of a cross-sectional structure of a main shaft bushing of a piercing mechanism of a flat sewing machine.

[0029] Figure 4 The present invention is a structural schematic diagram of a needle bar crankshaft of a piercing mechanism of a flat sewing machine.

[0030] Figure 5 The present invention is a diagram of the working principle of a material-piercing mechanism of a flat seam sewing machine.

[0031] In the picture: Needle bar 1, needle bar piercing head 1.1, piercing head bar 1.2; Spindle 2; Spindle bushing 3, annular groove 3.1; Crank-connecting rod mechanism 4, needle bar crank 4.1, connecting rod 4.2, needle bar crankshaft 4.3, first eccentric shaft 4.31, second eccentric shaft 4.32; Lifting block 5; Vertical guide groove 6; Slider 7; a1 refers to the center of the main axis; a2 refers to the center of the annular groove; b1 is the center of the pointer rod crankshaft; b2 refers to the center of the first eccentric shaft. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Specific embodiment 1, as Figure 1 reduce Figure 4 As shown, a piercing mechanism of a flat sewing machine includes a casing, a needle bar 1, a main shaft 2, a main shaft bushing 3, a slider 7 and a crank-connecting rod mechanism 4 connecting the needle bar 1 and the main shaft 2.

[0033] The crank-connecting rod mechanism 4 includes a connecting rod 4.2, a needle crank 4.1 fixedly connected to the main shaft 2, and a needle crankshaft 4.3 rotatably connected to the needle crank 4.1. The needle crankshaft 4.3 is parallel to the main shaft 2. In this embodiment, the main shaft 2 is rotatably mounted on the housing. The main shaft 2 is horizontally arranged. The main shaft bushing 3 is fixedly mounted on the housing. The main shaft 2 passes through the main shaft bushing 3.

[0034] An annular groove 3.1 is formed at one end of the spindle bushing 3, surrounding the spindle 2. In this embodiment, the opening of the annular groove 3.1 faces the needle crank 4.1. The groove 3.1 is offset; specifically, its center is eccentric to the center of the spindle 2. The slider 7 slides along the groove 3.1.

[0035] A first eccentric shaft 4.31 is provided at one end of the needle bar crankshaft 4.3. The first eccentric shaft 4.31 is rotatably connected to the slider 7. A second eccentric shaft 4.32 is provided at the other end of the needle bar crankshaft 4.3. The upper end of the connecting rod 4.2 is rotatably connected to the second eccentric shaft 4.32. The lower end of the connecting rod 4.2 is hinged to the needle bar 1.

[0036] like Figure 5 As shown, when the main shaft 2 drives the needle bar crank 4.1 to rotate, the center of the second eccentric shaft 4.32 is always located directly above the center of the needle bar crank 4.3.

[0037] Since the center of the annular groove 3.1 is eccentrically located with respect to the main shaft 2, the first eccentric shaft 4.31 is eccentrically located with respect to the needle crank 4.3, and the first eccentric shaft 4.31 is rotationally connected to the slider 7, when the main shaft 2 drives the needle crank 4.1 to rotate, causing the needle crank 4.3 to drive the slider 7 to slide along the annular groove 3.1, the needle crank 4.3 will rotate, so that the relative position of the center of the first eccentric shaft 4.31 and the center of the needle crank 4.3 remains unchanged, thereby ensuring that the center of the second eccentric shaft 4.32 is always located directly above the center of the needle crank 4.3. Based on this, it can be obtained that The height H1 of the second eccentric shaft at its highest position is equal to the sum of the main shaft height Hz, the distance L1 between the main shaft and the needle crankshaft, and the eccentric distance Lp of the second eccentric shaft; that is, the height H1 of the second eccentric shaft at its highest position is equal to Hz plus L1 plus Lp.

[0038] The height H2 of the second eccentric shaft at its lowest position is equal to the height Hz of the main shaft minus the distance L1 between the main shaft and the needle crankshaft and the eccentric distance Lp of the second eccentric shaft. In other words, the height H2 of the second eccentric shaft at its lowest position is equal to Hz minus L1 minus Lp.

[0039] in: Hz is the height of spindle 2; L1 is the distance between the main shaft 2 and the needle crankshaft 4.3; Lp is the eccentricity of the second eccentric shaft 4.32.

[0040] Assuming the distance between the main shaft and the needle crank of a conventional interlock sewing machine is L, the height Ha of the needle crank at its highest position is equal to the main shaft height Hz plus the distance L between the main shaft and the needle crank (i.e., Hz plus L). The height Hd of the needle crank at its lowest position is equal to the main shaft height Hz minus the distance L between the main shaft and the needle crank (i.e., Hz minus L).

[0041] Without changing the position of the main shaft 2 (that is, when Hz remains unchanged), it is only necessary to ensure that "L1 is equal to L plus Lp" of this application, that is, H1 of this application is equal to "Hz plus L plus 2Lp", and H2 is equal to "Hz minus L"; that is, compared with the piercing mechanism of the existing interlock sewing machine, the piercing mechanism of this application only needs to change L1 to "L plus Lp" to achieve the height of the highest position of the needle of this application being increased by 2 Lp compared to the highest position of the needle of the existing interlock sewing machine, and at the same time, the height of the lowest position of the needle of this application remains unchanged compared to the lowest position height of the needle of the existing interlock sewing machine.

[0042] Therefore, the present application can achieve the improvement of the highest point of the needle to meet the sewing requirements of thicker fabrics by changing the L1 of the needle bar crank 4.1, adding eccentric shafts at both ends of the needle bar crank 4.3, and providing an annular groove 3.1 on the main shaft bushing 3 without changing the position of the main shaft 2; it can also effectively solve the problem of the thicker needle handle crushing the fabric due to the lowering of the lowest point of the needle; thereby effectively shortening the equipment improvement and production cycle and reducing the improvement and production cost.

[0043] Specific embodiment 2, as Figure 1 reduce Figure 4 As shown, a needle bar 1 for a flat sewing machine includes a housing, a needle bar 1, a spindle 2, a spindle bushing 3, a slider 7, and a crank-connecting rod mechanism 4 connecting the needle bar 1 and the spindle 2. The needle bar 1 is vertically arranged and can be raised and lowered. The needle of the flat sewing machine is mounted at the lower end of the needle bar 1.

[0044] The crank-connecting rod mechanism 4 includes a connecting rod 4.2, a needle crank 4.1 fixedly connected to the main shaft 2, and a needle crankshaft 4.3 rotatably connected to the needle crank 4.1. The needle crankshaft 4.3 is parallel to the main shaft 2. In this embodiment, the main shaft 2 is rotatably mounted on the housing. The main shaft 2 is arranged horizontally. The main shaft bushing 3 is fixedly mounted on the housing. The main shaft 2 passes through the main shaft bushing 3. The main shaft 2 and the main shaft bushing 3 are arranged coaxially.

[0045] In this embodiment, the needle bar crank 4.1 is fixedly connected to the main shaft 2. Specifically, the needle bar crank 4.1 is provided with a main shaft 2 hole. The main shaft 2 passes through the main shaft 2 hole. The needle bar crank 4.1 is also provided with a locking screw, which locks the main shaft 2 in the main shaft 2 hole. In this embodiment, a connecting screw hole connected to the main shaft 2 hole is provided on the outer surface of the needle bar crank 4.1, and the connecting screw hole extends radially along the main shaft 2 hole. There are one or more connecting screw holes, and the locking screws correspond to the connecting screw holes one by one. The locking screw is threadedly connected in the corresponding connecting screw hole. In this way, the installation and production of the needle bar crank 4.1 are facilitated.

[0046] In this embodiment, the needle crank 4.3 is rotatably connected to the needle crank 4.1. Specifically, the needle crank 4.1 is provided with a pin hole, which is parallel to the main shaft 2, and the needle crank 4.3 is rotatably arranged in the pin hole. This facilitates the installation and production of the needle crank 4.1 and the needle crank 4.3.

[0047] An annular groove 3.1 is formed at one end of the spindle bushing 3, surrounding the spindle 2. In this embodiment, the opening of the annular groove 3.1 faces the needle crank 4.1. The groove 3.1 is offset; specifically, its center is eccentric to the center of the spindle 2. The slider 7 slides along the groove 3.1.

[0048] A first eccentric shaft 4.31 is provided at one end of the needle bar crankshaft 4.3. The first eccentric shaft 4.31 is rotatably connected to the slider 7. A second eccentric shaft 4.32 is provided at the other end of the needle bar crankshaft 4.3. The upper end of the connecting rod 4.2 is rotatably connected to the second eccentric shaft 4.32. The lower end of the connecting rod 4.2 is hinged to the needle bar 1.

[0049] In this embodiment, Figure 2 reduce Figure 5 As shown, the eccentricity between the center of the annular groove 3.1 and the center of the main shaft 2 is the same as the eccentricity of the first eccentric shaft 4.31. The eccentricity of the first eccentric shaft 4.31 refers to the distance between the axis of the first eccentric shaft 4.31 and the axis of the needle bar crankshaft 4.3 (i.e., the distance between the center of the first eccentric shaft 4.31 and the center of the needle bar crankshaft 4.3).

[0050] In one example, Figure 2 reduce Figure 5 As shown, the center of the annular groove 3.1 is located directly above the center of the main shaft 2, the axis of the first eccentric shaft 4.31 is located directly above the axis of the needle bar crankshaft 4.3, and the axis of the second eccentric shaft 4.32 is located directly above the axis of the needle bar crankshaft 4.3.

[0051] like Figure 5As shown, when the main shaft 2 drives the needle crank 4.1 to rotate, the center of the second eccentric shaft 4.32 is always directly above the center of the needle crank 4.3. Specifically, when the main shaft 2 drives the needle crank 4.1 to rotate, the center of the first eccentric shaft 4.31 is always directly above the center of the needle crank 4.3, and the center of the second eccentric shaft 4.32 is always directly above the center of the needle crank 4.3.

[0052] Since the center of the annular groove 3.1 is eccentrically distributed with respect to the main shaft 2, the first eccentric shaft 4.31 is eccentrically distributed with respect to the needle bar crankshaft 4.3, and the first eccentric shaft 4.31 is rotatably connected with the slider 7 (such as Figure 5 As shown in the working principle diagram of the piercing mechanism, the center a1 of the main shaft, the center a2 of the annular groove, the center b1 of the needle crankshaft, and the center b2 of the first eccentric shaft form a parallel four-bar mechanism during the movement. Thus, when the main shaft 2 drives the needle crank 4.1 to rotate, and the needle crankshaft 4.3 drives the slider 7 to slide along the annular groove 3.1, the needle crankshaft 4.3 will rotate, so that the relative position of the center of the first eccentric shaft 4.31 and the center of the needle crankshaft 4.3 remains unchanged, so that the center of the second eccentric shaft 4.32 is always located directly above the center of the needle crankshaft 4.3. Based on this, it can be obtained that The height H1 of the second eccentric shaft at its highest point is equal to the sum of the main shaft height Hz, the distance L1 between the main shaft and the needle crankshaft, and the eccentricity Lp of the second eccentric shaft. In other words, the height H1 of the second eccentric shaft at its highest point is equal to "Hz plus L1 plus Lp." The height of the second eccentric shaft at its highest point refers to the height of the center of the second eccentric shaft 4.32 at its highest point.

[0053] The height H2 of the second eccentric shaft at its lowest point is equal to the main shaft height Hz minus the distance L1 between the main shaft and the needle crankshaft plus the eccentricity Lp of the second eccentric shaft. In other words, the height H2 of the second eccentric shaft at its lowest point is equal to "Hz minus L1 minus Lp." The height of the second eccentric shaft at its lowest point refers to the height of the center of the second eccentric shaft 4.32 at its lowest point.

[0054] in: Hz is the height of spindle 2 (i.e., the height of the center of spindle 2); L1 is the distance between the main shaft 2 and the needle crankshaft 4.3 (i.e., L1 is the distance between the axis of the main shaft 2 and the axis of the needle crankshaft 4.3); Lp is the eccentricity of the second eccentric shaft 4.32. The eccentricity of the second eccentric shaft 4.32 refers to the distance between the axis of the second eccentric shaft 4.32 and the axis of the needle crankshaft 4.3 (that is, the distance between the center of the second eccentric shaft 4.32 and the center of the needle crankshaft 4.3).

[0055] Assuming the distance between the main shaft and the needle crank of a conventional interlock sewing machine is L, the height Ha of the needle crank at its highest position is equal to the main shaft height Hz plus the distance L between the main shaft and the needle crank (i.e., Hz plus L). The height Hd of the needle crank at its lowest position is equal to the main shaft height Hz minus the distance L between the main shaft and the needle crank (i.e., Hz minus L).

[0056] Without changing the position of the main shaft 2 (that is, when Hz remains unchanged), it is only necessary to ensure that "L1 is equal to L plus Lp" of this application, that is, H1 of this application is equal to "Hz plus L plus 2Lp", and H2 is equal to "Hz minus L"; that is, compared with the piercing mechanism of the existing interlock sewing machine, the piercing mechanism of this application only needs to change L1 to "L plus Lp" to achieve the height of the highest position of the needle of this application being increased by 2 Lp compared to the highest position of the needle of the existing interlock sewing machine, and at the same time, the height of the lowest position of the needle of this application remains unchanged compared to the lowest position height of the needle of the existing interlock sewing machine.

[0057] Therefore, the present application can achieve the improvement of the highest point of the needle to meet the sewing requirements of thicker fabrics by changing the L1 of the needle bar crank 4.1, adding eccentric shafts at both ends of the needle bar crank 4.3, and providing an annular groove 3.1 on the main shaft bushing 3 without changing the position of the main shaft 2; it can also effectively solve the problem of the thicker needle handle crushing the fabric due to the lowering of the lowest point of the needle; thereby effectively shortening the equipment improvement and production cycle and reducing the improvement and production cost.

[0058] Specifically, a piercing mechanism of a flat seam sewing machine further includes a drive mechanism for driving a main shaft 2. The drive mechanism includes a drive motor (not shown). The drive motor directly drives the main shaft 2 to rotate, or the drive motor drives the main shaft 2 to rotate via a transmission mechanism. For example, the drive motor drives the main shaft 2 via a synchronous belt transmission mechanism.

[0059] Furthermore, an upper shaft hole is provided at the upper end of the connecting rod 4.2, and the second eccentric shaft 4.32 is rotatably connected in the upper shaft hole. In this way, the rotatable connection between the second eccentric shaft 4.32 and the upper end of the connecting rod 4.2 is facilitated.

[0060] In this embodiment, a ball bearing is provided between the second eccentric shaft 4.32 and the upper shaft hole. This effectively reduces friction between the second eccentric shaft 4.32 and the upper end of the connecting rod 4.2, ensuring smooth rotation of the second eccentric shaft 4.32 and the upper end of the connecting rod 4.2. Of course, it should be noted that a bearing may not be provided between the second eccentric shaft 4.32 and the upper shaft hole, or another bearing may be provided.

[0061] Further, such as Figure 1 、 Figure 2As shown, the needle bar 1 is provided with a needle bar piercing head 1.1, which is fixedly connected to the needle bar 1. The lower end of the connecting rod 4.2 is hinged to the needle bar piercing head 1.1.

[0062] In this embodiment, a material-stitching mechanism of a flat sewing machine further includes a lifting block 5 slidably connected to the housing in a vertical direction. Specifically, a vertical guide groove 6 is provided on the housing, and the lifting block 5 slides along the vertical guide groove 6. The needle bar plucking head 1.1 includes a plucking head rod 1.2 extending radially along the needle bar 1. The lower end of the connecting rod 4.2 is located between the lifting block 5 and the needle bar 1. A lower shaft hole is provided at the lower end of the connecting rod 4.2. The plucking head rod 1.2 passes through the lower shaft hole and is rotatably connected to the lifting block 5. The plucking head rod 1.2 is rotatably connected to the lower shaft hole.

[0063] Specific embodiment three, as Figure 1 reduce Figure 4 As shown, a needle bar 1 for a flat sewing machine includes a housing, a needle bar 1, a spindle 2, a spindle bushing 3, a slider 7, and a crank-connecting rod mechanism 4 connecting the needle bar 1 and the spindle 2. The needle bar 1 is vertically arranged and can be raised and lowered. The needle of the flat sewing machine is mounted at the lower end of the needle bar 1.

[0064] The crank-connecting rod mechanism 4 includes a connecting rod 4.2, a needle crank 4.1 fixedly connected to the main shaft 2, and a needle crankshaft 4.3 rotatably connected to the needle crank 4.1. The needle crankshaft 4.3 is parallel to the main shaft 2. In this embodiment, the needle crank 4.1 and the main shaft 2 are integrally formed so that the needle crank 4.1 is fixedly connected to the main shaft 2.

[0065] In this embodiment, the main shaft 2 is rotatably mounted on the housing. The main shaft 2 is horizontally disposed. The main shaft bushing 3 is fixedly mounted on the housing. The main shaft 2 passes through the main shaft bushing 3. The main shaft 2 and the main shaft bushing 3 are coaxially disposed.

[0066] In this embodiment, the needle crank 4.3 is rotatably connected to the needle crank 4.1. Specifically, the needle crank 4.1 is provided with a pin hole, which is parallel to the main shaft 2, and the needle crank 4.3 is rotatably arranged in the pin hole. This facilitates the installation and production of the needle crank 4.1 and the needle crank 4.3.

[0067] An annular groove 3.1 is formed at one end of the spindle bushing 3, surrounding the spindle 2. In this embodiment, the opening of the annular groove 3.1 faces the needle crank 4.1. The groove 3.1 is offset; specifically, its center is eccentric to the center of the spindle 2. The slider 7 slides along the groove 3.1.

[0068] A first eccentric shaft 4.31 is provided at one end of the needle bar crankshaft 4.3. The first eccentric shaft 4.31 is rotatably connected to the slider 7. A second eccentric shaft 4.32 is provided at the other end of the needle bar crankshaft 4.3. The upper end of the connecting rod 4.2 is rotatably connected to the second eccentric shaft 4.32. The lower end of the connecting rod 4.2 is hinged to the needle bar 1.

[0069] In this embodiment, Figure 2 reduce Figure 5 As shown, the eccentricity between the center of the annular groove 3.1 and the center of the main shaft 2 is the same as the eccentricity of the first eccentric shaft 4.31. The eccentricity of the first eccentric shaft 4.31 refers to the distance between the axis of the first eccentric shaft 4.31 and the axis of the needle bar crankshaft 4.3 (i.e., the distance between the center of the first eccentric shaft 4.31 and the center of the needle bar crankshaft 4.3).

[0070] In one example, Figure 2 reduce Figure 5 As shown, the center of the annular groove 3.1 is located directly above the center of the main shaft 2, the axis of the first eccentric shaft 4.31 is located directly above the axis of the needle bar crankshaft 4.3, and the axis of the second eccentric shaft 4.32 is located directly above the axis of the needle bar crankshaft 4.3.

[0071] like Figure 5 As shown, when the main shaft 2 drives the needle crank 4.1 to rotate, the center of the second eccentric shaft 4.32 is always directly above the center of the needle crank 4.3. Specifically, when the main shaft 2 drives the needle crank 4.1 to rotate, the center of the first eccentric shaft 4.31 is always directly above the center of the needle crank 4.3, and the center of the second eccentric shaft 4.32 is always directly above the center of the needle crank 4.3.

[0072] Since the center of the annular groove 3.1 is eccentrically distributed with respect to the main shaft 2, the first eccentric shaft 4.31 is eccentrically distributed with respect to the needle bar crankshaft 4.3, and the first eccentric shaft 4.31 is rotatably connected with the slider 7 (such as Figure 5 As shown in the working principle diagram of the piercing mechanism, the center a1 of the main shaft, the center a2 of the annular groove, the center b1 of the needle crankshaft, and the center b2 of the first eccentric shaft form a parallel four-bar mechanism during the movement. Thus, when the main shaft 2 drives the needle crank 4.1 to rotate, and the needle crankshaft 4.3 drives the slider 7 to slide along the annular groove 3.1, the needle crankshaft 4.3 will rotate, so that the relative position of the center of the first eccentric shaft 4.31 and the center of the needle crankshaft 4.3 remains unchanged, so that the center of the second eccentric shaft 4.32 is always located directly above the center of the needle crankshaft 4.3. Based on this, it can be obtained that The height H1 of the second eccentric shaft at its highest point is equal to the sum of the main shaft height Hz, the distance L1 between the main shaft and the needle crankshaft, and the eccentricity Lp of the second eccentric shaft. In other words, the height H1 of the second eccentric shaft at its highest point is equal to "Hz plus L1 plus Lp." The height of the second eccentric shaft at its highest point refers to the height of the center of the second eccentric shaft 4.32 at its highest point.

[0073] The height H2 of the second eccentric shaft at its lowest point is equal to the main shaft height Hz minus the sum of the spacing L1 between the main shaft and the needle crankshaft and the eccentricity Lp of the second eccentric shaft. In other words, the height H2 of the second eccentric shaft at its lowest point is equal to "Hz minus L1 minus Lp." The height of the second eccentric shaft at its lowest point refers to the height of the center of the second eccentric shaft 4.32 at its lowest point.

[0074] in: Hz is the height of spindle 2 (i.e., the height of the center of spindle 2); L1 is the distance between the main shaft 2 and the needle crankshaft 4.3 (i.e., L1 is the distance between the axis of the main shaft 2 and the axis of the needle crankshaft 4.3); Lp is the eccentricity of the second eccentric shaft 4.32. The eccentricity of the second eccentric shaft 4.32 refers to the distance between the axis of the second eccentric shaft 4.32 and the axis of the needle crankshaft 4.3 (that is, the distance between the center of the second eccentric shaft 4.32 and the center of the needle crankshaft 4.3).

[0075] Assuming that the distance between the main shaft 2 and the needle crank 4.3 of the existing interlock sewing machine is L, the height Ha of the highest position of the needle crank 4.1 is Hz plus L. The height Hd of the lowest position of the needle crank 4.1 is Hz minus L.

[0076] Without changing the position of the main shaft 2 (that is, when Hz remains unchanged), it is only necessary to ensure that "L1 is equal to L plus Lp" of this application, that is, H1 of this application is equal to "Hz plus L plus 2Lp", and H2 is equal to "Hz minus L"; that is, compared with the piercing mechanism of the existing interlock sewing machine, the piercing mechanism of this application only needs to change L1 to "L plus Lp" to achieve the height of the highest position of the needle of this application being increased by 2 Lp compared to the highest position of the needle of the existing interlock sewing machine, and at the same time, the height of the lowest position of the needle of this application remains unchanged compared to the lowest position height of the needle of the existing interlock sewing machine.

[0077] Therefore, the present application can achieve the improvement of the highest point of the needle to meet the sewing requirements of thicker fabrics by changing the L1 of the needle bar crank 4.1, adding eccentric shafts at both ends of the needle bar crank 4.3, and providing an annular groove 3.1 on the main shaft bushing 3 without changing the position of the main shaft 2; it can also effectively solve the problem of the thicker needle handle crushing the fabric due to the lowering of the lowest point of the needle; thereby effectively shortening the equipment improvement and production cycle and reducing the improvement and production cost.

[0078] Specifically, a piercing mechanism of a flat seam sewing machine further includes a drive mechanism for driving a main shaft 2. The drive mechanism includes a drive motor (not shown). The drive motor directly drives the main shaft 2 to rotate, or the drive motor drives the main shaft 2 to rotate via a transmission mechanism. For example, the drive motor drives the main shaft 2 via a synchronous belt transmission mechanism.

[0079] Furthermore, an upper shaft hole is provided at the upper end of the connecting rod 4.2, and the second eccentric shaft 4.32 is rotatably connected in the upper shaft hole. In this way, the rotatable connection between the second eccentric shaft 4.32 and the upper end of the connecting rod 4.2 is facilitated.

[0080] In this embodiment, a ball bearing is provided between the second eccentric shaft 4.32 and the upper shaft hole. This effectively reduces friction between the second eccentric shaft 4.32 and the upper end of the connecting rod 4.2, ensuring smooth rotation of the second eccentric shaft 4.32 and the upper end of the connecting rod 4.2. Of course, it should be noted that a bearing may not be provided between the second eccentric shaft 4.32 and the upper shaft hole, or another bearing may be provided.

[0081] Further, such as Figure 1 、 Figure 2 As shown, the needle bar 1 is provided with a needle bar piercing head 1.1, which is fixedly connected to the needle bar 1. The lower end of the connecting rod 4.2 is hinged to the needle bar piercing head 1.1.

[0082] In this embodiment, a material-stitching mechanism of a flat sewing machine further includes a lifting block 5 slidably connected to the housing in a vertical direction. Specifically, a vertical guide groove 6 is provided on the housing, and the lifting block 5 slides along the vertical guide groove 6. The needle bar plucking head 1.1 includes a plucking head rod 1.2 extending radially along the needle bar 1. The lower end of the connecting rod 4.2 is located between the lifting block 5 and the needle bar 1. A lower shaft hole is provided at the lower end of the connecting rod 4.2. The plucking head rod 1.2 passes through the lower shaft hole and is rotatably connected to the lifting block 5. The plucking head rod 1.2 is rotatably connected to the lower shaft hole.

[0083] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A material-piercing mechanism of a flat seam sewing machine, comprising: needle bar; spindle; The crank-connecting rod mechanism connecting the needle bar and the main shaft comprises a connecting rod, a needle bar crank fixedly connected to the main shaft, and a needle bar crank shaft rotatably connected to the needle bar crank; the crank mechanism is characterized by further comprising: A spindle bushing, through which the spindle passes, and an annular groove is provided at one end of the spindle bushing and surrounds the spindle, with the center of the annular groove eccentrically distributed with respect to the spindle; A slider, sliding along the annular groove; A first eccentric shaft is provided at one end of the needle bar crankshaft, and the first eccentric shaft is rotatably connected to the slider; a second eccentric shaft is provided at the other end of the needle bar crankshaft; the upper end of the connecting rod is rotatably connected to the second eccentric shaft, and the lower end of the connecting rod is hinged to the needle bar; When the main shaft drives the needle bar crank to rotate, the center of the second eccentric shaft is always located directly above the center of the needle bar crank.

2. The material-piercing mechanism of a flat seam sewing machine according to claim 1, wherein: The height H1 of the second eccentric shaft at the highest position is equal to the sum of the height Hz of the main shaft, the distance L1 between the main shaft and the needle bar crankshaft, and the eccentricity Lp of the second eccentric shaft; the height H2 of the second eccentric shaft at the lowest position is equal to the height Hz of the main shaft minus the sum of the distance L1 between the main shaft and the needle bar crankshaft and the eccentricity Lp of the second eccentric shaft.

3. The material-piercing mechanism of a flat seam sewing machine according to claim 1, wherein: The eccentricity between the center of the annular groove and the main shaft is the same as the eccentricity of the first eccentric shaft.

4. A material-piercing mechanism for a flat seam sewing machine according to claim 1, 2 or 3, characterized in that: The needle bar crank is provided with a spindle hole, and the spindle passes through the spindle hole. The needle bar crank is also provided with a locking screw, and the locking screw locks and fixes the spindle in the spindle hole.

5. A material-piercing mechanism for a flat seam sewing machine according to claim 1, 2 or 3, characterized in that: The needle bar crank is provided with a pin through hole, the pin through hole is parallel to the main shaft, and the needle bar crankshaft is rotatably arranged in the pin through hole.

6. A material-piercing mechanism for a flat seam sewing machine according to claim 1, 2 or 3, characterized in that: An upper shaft hole is provided at the upper end of the connecting rod, and the second eccentric shaft is rotatably connected in the upper shaft hole.

7. The material-piercing mechanism of a flat seam sewing machine according to claim 6, wherein: A ball bearing is provided between the second eccentric shaft and the upper shaft hole.

8. A material-piercing mechanism for a flat seam sewing machine according to claim 1, 2 or 3, characterized in that: The machine also includes a casing, the main shaft bushing is fixedly arranged on the casing, and the main shaft is rotatably arranged on the casing.

9. The material-piercing mechanism of a flat seam sewing machine according to claim 8, wherein: The needle bar is provided with a needle bar piercing head, and the lower end of the connecting rod is hinged to the needle bar piercing head.

10. The material-piercing mechanism of a flat seam sewing machine according to claim 9, wherein: It also includes a lifting block slidably connected to the casing in a vertical direction, the needle bar plucking head includes a plucking head rod extending radially along the needle bar, the lower end of the connecting rod is located between the lifting block and the needle bar, and the lower end of the connecting rod is provided with a lower shaft hole, the plucking head rod passes through the lower shaft hole and is rotatably connected to the lifting block, and the plucking head rod is rotatably connected to the lower shaft hole.

Images