Weft cutting device of weft knitting machine

Abstract

The utility model relates to the technical field of weft knitting machines, in particular to a weft yarn cutting device of a weft knitting machine. A cutting frame; a stopper; a guide wheel; the vertical guide columns are uniformly, vertically and slidably connected to the inner top wall of the cutting-off cavity of the cutting-off frame and are driven by a sub-driving mechanism arranged in the cutting-off frame; the right pressing block, the cutter and the left pressing block are fixedly connected to the bottom of the vertical guide column in sequence; and the electric driving mechanism is arranged at the top of the cutting frame and is connected with the sub-driving mechanism. The cutting-off precision is high, weft yarn displacement is avoided through the two-way pressing design, notches are smooth, length deviation is controllable, and the follow-up weaving quality is guaranteed; the weft yarn is clamped on a single side after being cut off, loose winding is prevented, rapid butt joint yarn feeding is facilitated, the production efficiency is improved, two sub-drive mechanism model selection is supported, different precision and production scenes are adapted, the cutting length can be manually adjusted, the structure is wear-resistant, maintenance is easy and convenient, abnormal shutdown protection is arranged, equipment loss and weft yarn waste are reduced, and various weft knitting processing requirements are met.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of weft knitting machine especially relates to a weft knitting machine weft yarn cutting device. BACKGROUND

[0002] The weft knitting machine is a kind of knitting machine for producing weft knitted fabric, by yarn is fed into knitting needle along weft and forms loop interlocking, its kind mainly includes round weft knitting machine and flat weft knitting machine, weft knitting machine production process is simple, the yarn used can be directly on machine weaving without preparation process, directly cuts off weft yarn after weaving.

[0003] The patent application file with the publication number CN220468318U discloses a weft knitting machine weft yarn cutting device, the device can adjust cutting length through screw rod, expand the scope of application, but there is key function defect:

[0004] First, lack of weft yarn pressing mechanism in cutting process, only rely on yarn guide block to guide weft yarn, weft yarn is prone to displacement and movement under the action of blade during cutting, resulting in cutting edge skew and length deviation, affecting the continuity of subsequent weaving process and product quality;

[0005] Second, one-side clamping positioning of weft yarn cannot be realized after cutting, two sections of weft yarn after cutting are in free state, which is not conducive to rapid butt joint feeding of subsequent weft yarn, and may cause equipment jam due to loose and winding weft yarn, increase operation process and downtime, difficult to meet the efficient production demand. UTILITY MODEL CONTENTS

[0006] The utility model aims at at least one of the technical problems in the related art to some extent.

[0007] Therefore, the utility model provides a weft knitting machine weft yarn cutting device, the utility model cutting precision is high, two-way pressing design avoids weft yarn displacement, cutting edge is flat, length deviation is controllable, guarantees subsequent weaving quality;Weft yarn is clamped on one side after cutting, prevents loose winding, facilitates rapid butt joint feeding, improves production efficiency, supports two kinds of driven mechanism selection, adapts to different precision and production scene, manual cutting length can also be adjusted, structure is wear-resistant and easy to maintain, sets abnormal stop protection, reduces equipment wear and weft yarn waste, adapts to various weft knitting processing demand.

[0008] To achieve the above object, the utility model provides a weft knitting machine weft yarn cutting device, comprising:

[0009] Mounting frame;

[0010] Cutting frame: horizontally slidingly connected at the top of the mounting frame, driven by the adjusting handle on the mounting frame;

[0011] Limiting block: evenly and symmetrically arranged on the bottom wall of the cutting chamber of the cutting frame;

[0012] Guide wheel: symmetrically arranged on the surface of the cutting frame and corresponding to the position of the limiting block;

[0013] Vertical guide column: evenly and vertically slidingly connected to the top wall of the cutting chamber of the cutting frame and located between the adjacent two groups of limiting blocks, driven by a separate drive mechanism arranged inside the cutting frame;

[0014] Right pressing block, cutting knife and left pressing block: sequentially and fixedly connected to the bottom of the vertical guide column in the direction of yarn travel;

[0015] Electric drive mechanism: arranged on the top of the cutting frame and connected to the separate drive mechanism.

[0016] In addition, the weft cutting device for weft knitting machine according to the above application can also have the following additional technical features:

[0017] Specifically, the electric drive mechanism includes a housing fixedly connected to the top of the cutting frame, a worm rotatably connected to the inner wall of the housing and connected to the output end of a drive reduction integrated mechanism fixedly connected to the inner wall of the housing, and three groups of worms evenly rotatably connected to the inner wall of the housing, wherein the three groups of worms are mutually engaged with the worm, and one end of the separate drive mechanism penetrates into the housing and is connected to the central shaft of the three groups of worms.

[0018] Specifically, the separate drive mechanism includes a transmission seat and a guide shaft, wherein,

[0019] The transmission seat is provided in three groups, the three groups of transmission seats are rotatably connected to the inner wall of the cutting frame, one end of the central shaft of the three groups of transmission seats penetrates into the housing and is connected to the central shaft of the three groups of worms, and the bottom of the three groups of transmission seats is provided with a transmission guide groove;

[0020] The vertical guide column is provided in three groups, one end of the three groups of vertical guide columns penetrates into the cutting frame, and a spring is fixedly connected between the inner wall of the cutting frame and the one end of the three groups of vertical guide columns;

[0021] The guide shaft is fixedly connected to the top of one end of the three groups of vertical guide columns penetrating into the cutting frame and is slidingly connected to the inner wall of the transmission guide groove;

[0022] Among them, the transmission guide groove corresponding to the position of the cutting knife and the left pressing block includes a first downhill section, a first uphill section, a second downhill section and a second uphill section connected in turn;

[0023] The transmission guide groove corresponding to the position of the right pressing block includes a third downhill section, a first parallel section, a third uphill section and a second parallel section connected in turn.

[0024] Specifically, the split mechanism further comprises a first threaded screw rod, a reciprocating screw rod and a one-way transmission device,

[0025] The first threaded screw rod is provided with two groups, both of which are rotationally connected to the inner wall of the cutting frame and correspond to the positions of the left pressing block and the cutter respectively, one end of both of the first threaded screw rods penetrates into the inside of the shell and is connected to the central shaft of two groups of worm gears, and the other end of both of the first threaded screw rods is threadedly connected to the inner wall of the vertical guide column corresponding to the positions of the left pressing block and the cutter respectively.

[0026] The stroke of the first threaded screw rod is consistent with that of the reciprocating screw rod.

[0027] The one-way transmission device is a ratchet type one-way transmission device.

[0028] Specifically, the second threaded screw rod is threadedly connected to the inner wall of the driving sliding groove of the mounting frame, the bottom of the cutting frame penetrates into the inside of the driving sliding groove and is threadedly connected to the outer surface of the second threaded screw rod, and the bevel gears are arranged on the position corresponding to the end surface of the second threaded screw rod and the end surface of the adjusting handle respectively and are engaged with each other.

[0029] Specifically, the space between the limiting blocks forms a limiting line channel, the width of the limiting line channel is consistent with that of the guide groove of the guide wheel, and the inner walls are on the same horizontal plane.

[0030] The bottom of the right pressing block, the cutter and the left pressing block are on the same horizontal plane.

[0031] The additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present application.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] 1. High cutting precision and high product quality: the right pressing block and the left pressing block press the weft yarn bidirectionally before cutting, and the limiting line channel formed by the limiting blocks effectively avoids the displacement and movement of the weft yarn during cutting, ensures the flatness of the cut, controls the cutting length deviation, and improves the continuity of the subsequent weaving process.

[0034] 2. Single-side clamping positioning, high production efficiency: the right pressure block continuously presses the one end of the weft yarn after cutting to avoid the free loosening of the two sections of weft yarn, facilitate subsequent rapid butt joint yarn feeding, reduce weft yarn winding and equipment jam risk, shorten downtime adjustment time, and adapt to continuous mass production demand;

[0035] 3. Wide structural adaptability and flexible operation: supporting two types of split drive mechanism selection, transmission seat+guide shaft structure adapts to medium and low precision, intermittent production and low-cost transformation scene, first threaded screw rod+reciprocating screw rod+one-way transmission structure adapts to high precision, continuous production and automatic yarn feeding butt joint scene; the cutting length can be manually adjusted through the adjusting handle to adapt to different specifications of weft yarn processing;

[0036] 4. Stable and reliable operation, convenient maintenance: the transmission guide groove is subjected to high-frequency quenching+grinding processing, the surface hardness reaches HRC58-62, and the wear rate is low by cooperating with regular supplement of lubricating grease; the conventional structure has few components and low assembly difficulty, and only the guide groove wear and spring elasticity need to be checked in later maintenance, and the high-precision structure has long wear life;

[0037] 5. Safety protection in place, reduce loss: limit sensors are arranged to deal with abnormal conditions such as weft yarn jam, spring failure, etc., to stop and alarm in time to avoid equipment damage and weft yarn waste; the bottom anti-skid rubber pad of the pressure block and the arc transition design of the transmission guide groove reduce the problems of weft yarn pressure injury and guide shaft jam. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above aspects and / or additional aspects and advantages of the utility model will become apparent and easy to understand from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0039] Figure 1 It is a structure schematic view of the weft knitting machine weft yarn cutting device of the utility model;

[0040] Figure 2 It is a structure schematic view of the electric drive mechanism in the weft knitting machine weft yarn cutting device of the utility model;

[0041] Figure 3 It is a structure schematic view of the split drive mechanism in the weft knitting machine weft yarn cutting device of the utility model;

[0042] Figure 4 It is a structure schematic view of the transmission seat in the weft knitting machine weft yarn cutting device of the utility model;

[0043] Figure 5 It is a first structure schematic view of the transmission guide groove in the weft knitting machine weft yarn cutting device of the utility model;

[0044] Figure 6 It is a second structure schematic view of the transmission guide groove in the weft knitting machine weft yarn cutting device of the utility model;

[0045] Figure 7 It is first threaded lead screw structure schematic view in weft knitting machine weft yarn cutting device of the utility model.

[0046] As shown in the figure:

[0047] 1, mounting frame; 10, driving chute; 11, adjusting handle;

[0048] 2, cutting frame; 21, limit block; 22, guide wheel; 23, vertical guide column; 24, left pressing block; 25, cutter; 26, right pressing block; 27, sub-drive mechanism;

[0049] 3, electric drive mechanism; 31, housing; 32, worm; 33, drive speed reducer integrated machine; 34, worm gear;

[0050] 271, transmission seat; 272, transmission guide groove; 273, spring; 274, guide shaft; 275, first threaded lead screw; 276, reciprocating lead screw; 277, one-way transmission; 100, limit sensor. DETAILED DESCRIPTION

[0051] The embodiments of the utility model are described in detail below, examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the utility model, and cannot be understood as limiting the utility model. On the contrary, the embodiments of the utility model include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

[0052] A weft knitting machine weft yarn cutting device is described below in conjunction with the drawings.

[0053] As Figures 1-7 shown, the weft knitting machine weft yarn cutting device of the utility model embodiment comprises:

[0054] mounting frame 1;

[0055] cutting frame 2: horizontally slidingly connected at the top of mounting frame 1, driven by adjusting handle 11 on mounting frame 1;

[0056] limit block 21: uniformly and symmetrically arranged in the bottom wall of the cutting cavity of cutting frame 2;

[0057] guide wheel 22: symmetrically arranged on the surface of cutting frame 2 and corresponding to the position of limit block 21;

[0058] vertical guide column 23: uniformly and vertically slidingly connected to the top wall of the cutting cavity of cutting frame 2 and located between the adjacent two groups of limit blocks 21, driven by sub-drive mechanism 27 arranged inside cutting frame 2;

[0059] Right pressing block 26, cutter 25 and left pressing block 24: sequentially fixedly connected at the bottom of vertical guide column 23 in the direction of yarn running;

[0060] Electric drive mechanism 3: provided at the top of cutting frame 2 and connected with sub-drive mechanism 27.

[0061] It should be noted that the mounting frame 1 described in this embodiment is fixedly connected to the surface of the weft knitting machine by bolts.

[0062] It should also be noted that the electric drive mechanism 3 described in this embodiment is connected with the controller of the weft knitting machine through wires to realize data transmission and reception of control instructions.

[0063] It should also be noted that the yarn runs from the right pressing block 26 to the left pressing block 24, and the bottom of the right pressing block 26 and the left pressing block 24 is provided with an anti-skid rubber pad with a friction coefficient ≥0.6 to prevent the weft yarn from slipping when it is pressed tightly.

[0064] It should also be noted that in order to deal with abnormal situations such as weft yarn jamming and spring 273 failure, a limit sensor 100 is provided on the inner wall of the vertical guide column 23 and the cutting frame 2, and the limit sensor 100 is connected with the controller of the weft knitting machine through wires to realize data transmission and reception of control instructions. If the descent and reset stroke is abnormal, the controller triggers a stop alarm to avoid damage to the equipment.

[0065] Specifically, the device realizes a closed-loop working process of synchronous pressing and cutting-single-side clamping-reset readiness through the cooperation of electric drive mechanism 3 and sub-drive mechanism 27, and the specific working principle is as follows:

[0066] Synchronous pressing and cutting: after the weft knitting machine controller issues an instruction, the drive-reduction integrated machine 33 of the electric drive mechanism 3 operates, driving the worm 32 to rotate, and in turn synchronously driving the three sets of meshing worm gears 34 to rotate, the worm gears 34 drive the transmission seat 271 of the sub-drive mechanism 27 to rotate through the center shaft, the transmission guide groove 272 on the transmission seat 271 extrudes the guide shaft 274 at the top of the vertical guide column 23, causing the three sets of vertical guide columns 23 to descend synchronously, respectively driving the right pressing block 26, the cutter 25 and the left pressing block 24 to move downward, and fixing and cutting the weft yarn in the limit line channel formed by the limit block 21 in both directions.

[0067] Single-side clamping: the transmission seat 271 continues to rotate, the guide shaft 274 corresponding to the cutter 25 and the left pressing block 24 moves along the first uphill section of the transmission guide groove 272, the spring 273 drives the vertical guide column 23 to reset, and the cutter 25 and the left pressing block 24 are loosened; the guide shaft 274 corresponding to the right pressing block 26 enters the first parallel section of the transmission guide groove 272, the vertical guide column 23 remains stationary, and the right pressing block 26 continuously presses the weft yarn, realizing single-side clamping at the right end after cutting.

[0068] Reset and threading preparation: when threading or replacing weft is required, the controller instructs the drive speed reducer integrated machine 33 to continue running, the transmission seat 271 rotates by one full circle, during which the cutter 25 and the left pressing block 24 descend-reposition again along the second downhill section, the second uphill section, the right pressing block 26 repositions to the initial position along the third uphill section, the second parallel section, and all components return to the ready state (the weft enters the line limiting channel after being guided by the guide roller 22).

[0069] Cutting length adjustment: rotate the adjustment handle 11 on the mounting rack 1, drive the second threaded rod in the drive sliding groove 10 to rotate through the bevel gear, make the threaded connection of the cutting-off frame 2 move horizontally along the top of the mounting rack 1, combine the scale lines on the surface of the mounting rack 1, accurately adjust the cutting position, and adapt to different cutting length requirements.

[0070] Abnormal protection: the vertical guide column 23 and the inner wall of the cutting-off frame 2 are provided with a limit sensor 100, if the descent and repositioning stroke is abnormal, the controller triggers a stop alarm to avoid damage to the equipment.

[0071] In an embodiment of the utility model, as shown in Figures 1-7 The electric drive mechanism 3 includes a housing 31 fixedly connected to the top of the cutting-off frame 2, a worm 32 rotatably connected to the inner wall of the housing 31, and an output end of a drive speed reducer integrated machine 33 fixedly connected to the inner wall of the housing 31. The inner wall of the housing 31 is uniformly rotatably connected to a worm gear 34, and three groups of worm gears 34 are provided. The three groups of worm gears 34 are mutually engaged with the worm 32. One end of a split drive mechanism 27 penetrates into the inside of the housing 31 and is connected to the central shaft of the three groups of worm gears 34, respectively.

[0072] It should be noted that the drive speed reducer integrated machine 33 described in this embodiment is equipped with an encoder, which can real-time feedback the rotation angle of the transmission seat 271, and triggers a stop when the rotation angle is 90°, to ensure that the action is accurate and in place.

[0073] It should also be noted that the three groups of worm gears 34 described in this embodiment are arranged on the same side.

[0074] Specifically, the structure and connection relationship of the electric drive mechanism 3 are further described.

[0075] In an embodiment of the utility model, as shown in Figures 1-7 The split drive mechanism 27 includes a transmission seat 271 and a guide shaft 274, wherein,

[0076] The transmission seat 271 is provided in three groups, and the three groups of transmission seats 271 are rotatably connected to the inner wall of the cutting-off frame 2. One end of the central shaft of the three groups of transmission seats 271 penetrates into the inside of the housing 31 and is connected to the central shaft of the three groups of worm gears 34. The bottom of the three groups of transmission seats 271 is provided with a transmission guide groove 272.

[0077] The vertical guide columns 23 are provided in three groups, and one end of each of the three groups of vertical guide columns 23 penetrates into the inside of the cutting frame 2 and is fixedly connected with the inner wall of the cutting frame 2 through a spring 273;

[0078] The guide shafts 274 are fixedly connected at the top of one end of the three groups of vertical guide columns 23 penetrating into the inside of the cutting frame 2 and are in sliding connection with the inner wall of the transmission guide groove 272;

[0079] Among them, the transmission guide groove 272 corresponding to the position of the cutting knife 25 and the left pressing block 24 includes a first downhill section, a first uphill section, a second downhill section and a second uphill section connected in sequence;

[0080] The transmission guide groove 272 corresponding to the position of the right pressing block 26 includes a third downhill section, a first parallel section, a third uphill section and a second parallel section connected in sequence.

[0081] Specifically, the structure and connection relationship of the split drive mechanism 27 are further described;

[0082] Among them, for the transmission guide groove 272 in the transmission seat 271+guide shaft 274 structure, the angle, length, connection mode and other parameters of the segmented structure directly affect the movement stability and action accuracy of the vertical guide column 23, and the specific parameter specifications are as follows:

[0083] 1. Basic matching parameters (matching with guide shaft 274)

[0084] The width of the transmission guide groove 272 needs to be matched with the diameter of the guide shaft 274, and a clearance fit design is adopted, that is, the width of the transmission guide groove 272 = the diameter of the guide shaft 274 + 0.1-0.2mm (for example, when the diameter of the guide shaft 274 is 8mm, the width of the transmission guide groove 272 is 8.1-8.2mm), which can avoid the jamming of the guide shaft 274 and prevent the radial movement from causing the pressing block to deviate;

[0085] The depth of the transmission guide groove 272 is uniformly 10-12mm (the embedding depth of the guide shaft 274 is 5-6mm), which can ensure that the guide shaft 274 will not fall out when moving in the groove, and at the same time, enough space is reserved for the lubricating grease (lithium-based lubricating grease is adopted, and it is supplemented every 200 hours), among them, if the cutting knife 25 needs to be lowered to a depth of >8mm, the groove depth can be increased to 12-15mm, the initial embedding depth is kept at 5-6mm, and 7-10mm of redundant space is reserved to ensure that the guide shaft 274 can realize a downward stroke of 8-10mm, and for extra-thick weft yarn, the height difference of the first downhill section can be increased to 8-10mm to directly match the depth requirement of 8-10mm, thereby reducing the adjustment difficulty of the rotation angle of the transmission seat 271.

[0086] Transmission guide groove 272 surface treatment: high frequency quenching + grinding processing, surface hardness reaches HRC58-62, surface roughness Ra≤0.8μm, reduces the wear rate of guide shaft 274 and transmission guide groove 272, prolongs the service life.

[0087] 2. Transmission guide groove 272 parameters corresponding to cutter 25 and left pressing block 24 (including first downhill section, first uphill section, second downhill section, second uphill section)

[0088]

[0089] 3. Transmission guide groove 272 parameters corresponding to right pressing block 26 (including third downhill section, first parallel section, third uphill section, second parallel section)

[0090]

[0091] 4. Special working condition parameter adjustment suggestion

[0092] When processing thick weft yarn (such as yarn count ≤10S), the downhill section angle can be appropriately increased to 40°-45°, the pressing block descending speed is accelerated, and the incomplete cutting caused by deformation of thick yarn is avoided;

[0093] When processing elastic weft yarn, the parallel section length can be extended to 30-35mm, the single side clamping time is extended, and the subsequent yarn feeding is ensured after the elastic yarn rebound is stable;

[0094] When used in low temperature environment (≤10℃), the guide groove gap can be increased to 0.2-0.3mm, and the jam caused by the increase of lubricating grease viscosity due to low temperature is avoided.

[0095] In an embodiment of the utility model, as shown in Figures 1-7 The split drive mechanism 27 further includes a first threaded lead screw 275, a reciprocating lead screw 276, and a one-way transmission device 277, wherein,

[0096] The first threaded lead screw 275 is provided in two groups, both of which are rotationally connected to the inner wall of the cutting frame 2 and correspond to the positions of the left pressing block 24 and the cutter 25, respectively. One end of each of the two groups of first threaded lead screws 275 penetrates into the inside of the housing 31 and is connected to the central shaft of two groups of worm gears 34. The other end of each of the two groups of first threaded lead screws 275 is threadedly connected to the inner wall of the vertical guide column 23 corresponding to the positions of the left pressing block 24 and the cutter 25, respectively. The reciprocating lead screw 276 is provided in one group and is rotationally connected to the inner wall of the cutting frame 2 and corresponds to the position of the right pressing block 26. One end of the reciprocating lead screw 276 penetrates into the inside of the housing 31 and is connected to the central shaft of the last group of worm gears 34 through the one-way transmission device 277. The other end of the reciprocating lead screw 276 is threadedly connected to the inner wall of the vertical guide column 23 corresponding to the position of the right pressing block 26.

[0097] Wherein, the two sets of first threaded rods 275 are consistent with the reciprocating threaded rod 276 in stroke;

[0098] The one-way driver 277 is a ratchet type one-way driver.

[0099] It should be noted that the reciprocating threaded rod 276 described in this embodiment is a positive and negative thread cross structure, which realizes one-way rotation driving bidirectional reciprocating motion in cooperation with the one-way driver 277.

[0100] It should also be noted that when the transmission seat 271 rotates forward, the one-way driver 277 drives the reciprocating threaded rod 276 to rotate and drive the right pressing block 26 to descend; when the transmission seat 271 rotates reversely, the one-way driver 277 idles, the reciprocating threaded rod 276 does not act, and the right pressing block 26 remains in a pressed state.

[0101] Specifically, another structure and connection relationship of the sub-driving mechanism 27 are further described;

[0102] The structure takes the driving and speed reduction integrated machine 33 as a power source, takes threaded transmission as a core, and takes one-way transmission as a clamping guarantee. Through the forward-reverse rotation cycle of the worm gears 34, the bidirectional pressing and cutting-off-single-side clamping-reset ready closed-loop action is realized in stages, and the specific process is as follows:

[0103] I. Initial state: components are in place and ready to start

[0104] The driving and speed reduction integrated machine 33 is in a shutdown state, and the three sets of worm gears 34 are all at the initial angle (0°). The vertical guide column 23 corresponding to the left pressing block 24 and the cutter 25 is at the initial position of the first threaded rod 275; the vertical guide column 23 corresponding to the right pressing block 26 is at the initial position of the reciprocating threaded rod 276 (the starting point of the positive thread segment); after the weft guide roller 22 guides, the weft yarn passes through the device along the limiting line channel formed by the limiting block 21, and waits for the cutting-off instruction to be triggered.

[0105] II. First stage: forward rotation 90°-bidirectional pressing+precise cutting-off

[0106] Power transmission and action linkage: the weft knitting machine controller issues a cutting-off instruction, the driving and speed reduction integrated machine 33 starts and drives the worm gear 32 to rotate, synchronously meshes the three sets of worm gears 34 to rotate forward by 90°, and further drives the first threaded rod 275 and the reciprocating threaded rod 276 to synchronously rotate forward by 90°.

[0107] Left pressure block 24 and cutter 25 action: the first screw rod 275 connecting left pressure block 24 and cutter 25 rotates forward with worm wheel 34, pushing the corresponding vertical guide column 23 along the inner wall of the cutting frame 2 to vertically descend until the end of the screw rod stroke. During this process, the left pressure block 24 contacts and compresses the weft, and the cutter 25 descends synchronously to accurately cut the weft.

[0108] Right pressure block 26 action: the reciprocating screw rod 276 connecting the right pressure block 26 is linked with the third group of worm wheels 34 through the ratchet one-way transmission 277 (when rotating forward, the one-way transmission 277 engages), and rotates forward with the worm wheel 34. The forward thread segment of the reciprocating screw rod 276 pushes the corresponding vertical guide column 23 to descend to the end of the stroke, and the right pressure block 26 synchronously compresses the right end of the weft, forming a "double-direction fixation" with the left pressure block 24 to avoid weft movement during cutting.

[0109] Three, second stage: reverse rotation 90° - left reset + right pressure (single-sided clamping)

[0110] Power steering and one-way separation: after cutting is completed, the controller instructs the drive reduction machine 33 to operate in reverse, and the worm 32 drives the three groups of worm wheels 34 to rotate 90° in reverse. At this time, the one-way transmission 277 connecting the reciprocating screw rod 276 triggers idling (when rotating in reverse, the ratchet separates), and the reciprocating screw rod 276 is disconnected from the power of the worm wheel 34, remaining in a stationary state.

[0111] Left pressure block 24 and cutter 25 reset: the two groups of first screw rods 275 rotate reversely with the worm wheel 34, pulling the corresponding vertical guide column 23 to vertically ascend, returning to the initial position, the left pressure block 24 releases the left end of the weft, and the cutter 25 disengages from the cutting position, completing the reset.

[0112] Right pressure block 26 pressure holding: the reciprocating screw rod 276 is stationary, and the corresponding vertical guide column 23 remains in a lowered state, the right pressure block 26 continuously compresses the right end of the weft, achieving single-sided clamping with the left end released and the right end fixed, providing stable end positioning (clamping time can be extended as needed through the controller) for subsequent weft butt joint feeding.

[0113] Four, third stage: again rotate forward 90° - left secondary compression + right reset (prepare threading)

[0114] Power forward restart and one-way re-engagement: when replacing the weft or threading, the controller instructs the drive reduction machine 33 to operate forward again, and the worm wheel 34 rotates forward 90°. The one-way transmission 277 re-engages, and the reciprocating screw rod 276 rotates forward with the worm wheel 34 (switching to the reverse thread segment).

[0115] The left pressing block 24 and the cutter 25 secondary action: the first threaded lead screw 275 rotates forward again, pushing the vertical guide column 23 down, the left pressing block 24 is pressed again, and the cutter 25 is lowered synchronously.

[0116] Right pressing block 26 reset: reciprocating screw rod 276 pulls the corresponding vertical guide column 23 up through the reverse threaded segment, right pressing block 26 is separated from the weft and returns to the initial position, releasing one-sided clamping, and the staff can smoothly wear new weft.

[0117] Five, the fourth stage: reverse rotation 90° again-all parts reset (ready to cycle)

[0118] The drive speed reducer integrated machine 33 reverses again, the worm gear 34 reverses 90°, and returns to the initial angle:

[0119] The first threaded lead screw 275 reverses, pulling the left pressing block 24 and the cutter 25 corresponding vertical guide column 23 up to reset, and the left pressing block 24 and the cutter 25 return to the initial height synchronously;

[0120] When the one-way transmission 277 reverses with the worm gear 34, it remains idle, the reciprocating screw rod 276 and the right pressing block 26 remain unchanged in the initial position, and thus all parts return to the initial state, the device waits for the next round of cutting instruction, forming a complete working cycle.

[0121] It needs to be added that: travel adjusting nuts (not shown in the figure) can be added to the ends of the first threaded lead screw 275 and the reciprocating screw rod 276, the effective stroke of the screw rod can be changed by rotating the nut (adjustment range 5-10mm), and the pressing depth requirements of different diameter weft (such as 0.1mm ultra-fine denier yarn to 5mm thick yarn) can be adapted without replacing the screw rod.

[0122] It also needs to be added that: a torque limiter (not shown in the figure) can be added between the one-way transmission 277 and the worm gear 34, when the transmission torque exceeds the set value (such as 30N・m), the torque limiter automatically slips to avoid the ratchet from breaking due to overload; At the same time, a rotation angle sensor (not shown in the figure) can be added to the worm gear 34, which triggers the stop when the angle deviation exceeds 5°, preventing the action from being misaligned when the one-way transmission 277 idles.

[0123] It also needs to be added that a micro oil channel (not shown in the figure) can be opened at the bearing seat of the screw rod, connected to the oil storage box at the top of the cutting frame 2, and the lubricating grease is automatically brought into the threaded pair through the centrifugal force when the screw rod rotates, realizing automatic supply once every 500 hours, reducing the workload of manual maintenance, and ensuring the uniformity of lubrication, prolonging the service life of the threaded pair.

[0124] It needs to be understood that the transmission seat 271 + guide shaft 274 of the separate drive mechanism 27 and the first threaded lead screw 275 + reciprocating lead screw 276 + one-way transmission 277 are alternative optional embodiments with consistent core functions (realizing the phased action of the pressing block and the cutter 25), but there are differences in transmission accuracy, working condition adaptability, and cost control. The specific adaptation scenarios and selection logic are as follows:

[0125] Transmission seat 271 + guide shaft 274 structure: conventional working condition priority scheme

[0126] Core features: based on the mechanical transmission logic of the guide groove extrusion guide shaft 274, the profile change of the transmission guide groove 272 when the transmission seat 271 rotates drives the vertical guide column 23 to move up and down, and cooperates with the spring 273 to realize reset. The structure is simple, the number of parts is small, the assembly difficulty is low, and the later maintenance only needs to regularly check the wear of the transmission guide groove 272 and the elasticity of the spring 273.

[0127] Applicable scenarios:

[0128] Low-precision weft knitting processing: such as weft cutting of ordinary knitted fabrics (such as T-shirt fabrics, home textile fabrics), which has higher tolerance for cutting length deviation (allowing ±0.5mm deviation) and does not require extreme action synchronization;

[0129] High-frequency intermittent operation: such as small-batch multi-variety production, the equipment needs to be frequently started and stopped to switch specifications. This structure has fast response speed (from instruction issuance to pressing block contact with weft yarn only 0.3-0.5s) and is not prone to transmission jamming due to frequent start-stop;

[0130] Low-cost demand scenarios: such as the transformation of old weft knitting machines in small and medium-sized textile enterprises. The manufacturing cost of this structure is 30%-40% lower than that of the threaded transmission scheme, which can control the transformation budget.

[0131] Limitations: transmission accuracy is greatly affected by guide groove machining precision (such as surface roughness and segmented connection smoothness). The wear of the guide shaft 274 and the transmission guide groove 272 after long-term use may cause the pressing block to drop the stroke deviation (cumulative deviation ≤0.8mm), which is not suitable for high-precision knitted products (such as medical knitted fabrics, precision filter knitted fabrics).

[0132] First threaded lead screw 275 + reciprocating lead screw 276 + one-way transmission 277 structure: high-precision working condition exclusive scheme

[0133] Core features: Thread engagement transmission replaces guide slot extrusion transmission. Through the rotation of the first threaded screw rod 275 (driving the left pressing block 24 and the cutter 25) and the reciprocating screw rod 276 (driving the right pressing block 26), the rotary motion is converted into the linear motion of the vertical guide column 23. The one-way holding of the right pressing block 26 is realized by the ratchet type one-way transmission device 277. The transmission accuracy is determined by the thread lead accuracy (such as lead deviation ≤0.05mm). The action repeatability error can be controlled within ±0.1mm.

[0134] Applicable scenarios:

[0135] High-precision weft knitting processing: such as cutting of superfine denier weft yarn (single wire diameter ≤0.05mm) and elastic weft yarn (such as spandex blended yarn). Such weft yarns are prone to stretch deformation due to uneven pressing block pressure or stroke deviation. This structure can accurately control the pressing block descent depth through thread (such as pressing block and weft yarn contact pressure error ≤5N), avoiding yarn damage;

[0136] Continuous mass production: such as 24-hour continuous operation of large-scale knitted fabric factories. The wear-resistant life of the threaded transmission pair (using high-strength alloy steel and nitrogen treatment) can be 2-3 times that of the "transmission seat 271 + guide shaft 274" structure (cumulative operation of 10000 hours without obvious wear), reducing the number of downtime maintenance;

[0137] Scenarios with high single-sided clamping stability requirements: such as automatic yarn feeding mechanism directly connected after weft yarn cutting. The right pressing block 26 needs to maintain constant clamping force (such as 10-15N) and no displacement. This structure uses the thread self-locking feature of the reciprocating screw rod 276 (lead angle ≤3°, meeting the self-locking condition), which can avoid the clamping force fluctuation caused by spring 273 reset, ensuring that the success rate of yarn feeding connection is ≥99.5%.

[0138] Limitations: complex structure (including 3 sets of threaded shafts and 1 set of one-way transmission device 277). During assembly, the coaxiality of the threaded shaft and the vertical guide column 23 (≤0.02mm) needs to be ensured, otherwise the threaded jamming may occur; the start response speed is relatively slow (from the issuance of the instruction to the pressing block contacting the weft yarn, it takes 0.6-0.8s), which is not suitable for frequent start-stop small batch production.

[0139] Selection priority recommendation

[0140] When the weft knitting machine processing product precision requirement is ≤±0.3mm and the production mode is intermittent, the transmission seat 271 + guide shaft 274 structure is preferred;

[0141] When the processing precision requirement is ≤±0.1mm and the production mode is continuous mass production or automatic yarn feeding system connection, the first threaded screw rod 275 + reciprocating screw rod 276 + one-way transmission device 277 structure must be selected;

[0142] Two structures cannot be assembled at the same time (transmission path conflict), and the structure needs to be replaced simultaneously with the corresponding transmission assembly of the split drive mechanism 27 (such as replacing the transmission seat 271 with a threaded shaft, and adjusting the connection mode of the vertical guide column 23), and the relative position of the pressing block and the cutter 25 needs to be recalibrated.

[0143] In an embodiment of the present application, as shown in Figures 1-7 The inner wall of the driving sliding groove 10 of the mounting frame 1 is threadedly connected with a second threaded lead screw, the bottom of the cutting frame 2 penetrates into the inside of the driving sliding groove 10, and is threadedly connected to the outer surface of the second threaded lead screw. The end surface of the adjusting handle 11 penetrating into the inside of the driving sliding groove 10 corresponds to the position of the end surface of the second threaded lead screw, and a bevel gear is arranged at each position and meshes with each other.

[0144] It should be noted that the second threaded lead screw and the bevel gear described in this embodiment are not shown in the figure.

[0145] It should be further noted that the mounting frame 1 in this embodiment is provided with scale lines (not shown in the figure).

[0146] Specifically, the adjusting handle 11 is rotated to drive the second threaded lead screw to rotate, and the second threaded lead screw rotates synchronously to drive the cutting frame 2 to move horizontally along the top of the mounting frame 1. The specific movement data can be obtained by observing the position of the scale line.

[0147] In an embodiment of the present application, as shown in Figures 1-7 The space between the limiting blocks 21 forms a limiting line channel, the limiting line channel has the same width as the guide groove of the guide wheel 22, and the inner walls are on the same horizontal plane.

[0148] The bottoms of the right pressing block 26, the cutter 25 and the left pressing block 24 are on the same horizontal plane.

[0149] Specifically, the limiting line channel formed by the limiting block 21 has the same width as the guide groove of the guide wheel 22, and the inner walls are coplanar, which can allow the weft yarn to pass smoothly along the horizontal path without deviation or jamming, and can accurately position the subsequent cutting. The bottoms of the right pressing block 26, the cutter 25 and the left pressing block 24 are on the same plane, and can move synchronously when descending: the pressing block simultaneously presses the weft yarn, the cutter 25 simultaneously cuts, and the weft yarn is not displaced or cut inaccurately due to height difference, thereby ensuring the cutting quality.

[0150] In conclusion, the weft yarn cutting device of the weft knitting machine has high cutting precision, avoids weft yarn displacement through bidirectional pressing design, has controllable flat cut and length deviation, guarantees subsequent knitting quality, clamps the weft yarn on one side after cutting, prevents loose winding, facilitates quick butt joint yarn feeding, improves production efficiency, supports two kinds of selection of the two drive mechanisms 27, is suitable for different precision and production scenes, can manually adjust the cutting length, has wear-resistant structure and convenient maintenance, is provided with abnormal stop protection, reduces equipment loss and weft yarn waste, and is suitable for various weft knitting processing requirements.

[0151] In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0152] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0153] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and the ordinary skilled in the art can change, modify, replace and deform the above embodiments within the scope of the present application.

Claims

1. A weft yarn cutting device for a weft knitting machine, characterized in that, Include: Mounting frame (1); Cutting frame (2): horizontally slidingly connected at the top of the mounting frame (1), driven by the adjusting handle (11) on the mounting frame (1); Limiting block (21): evenly and symmetrically arranged on the inner bottom wall of the cutting cavity of the cutting frame (2); Guide wheel (22): symmetrically arranged on the surface of the cutting frame (2) and corresponding to the position of the limiting block (21); Vertical guide column (23): evenly and vertically slidingly connected to the inner top wall of the cutting cavity of the cutting frame (2) and located between the adjacent two groups of limiting blocks (21), driven by the sub-drive mechanism (27) arranged inside the cutting frame (2); Right pressing block (26), cutting knife (25) and left pressing block (24): sequentially fixedly connected to the bottom of the vertical guide column (23) in the direction of yarn running; Electric drive mechanism (3): arranged on the top of the cutting frame (2) and connected with the sub-drive mechanism (27).

2. The weft machine weft thread cutting device according to claim 1, characterized in that The electric drive mechanism (3) comprises a housing (31) fixedly connected to the top of the cutting frame (2), a worm (32) rotatably connected to the inner wall of the housing (31) and connected with the output end of a drive reduction integrated machine (33) fixedly connected to the inner wall of the housing (31), and three groups of worm gears (34) rotatably connected to the inner wall of the housing (31), wherein the three groups of worm gears (34) are all meshed with the worm (32), and one end of the sub-drive mechanism (27) penetrates into the inside of the housing (31) and is connected with the central shaft of the three groups of worm gears (34) respectively.

3. The weft machine weft thread cutting device according to claim 2, characterized in that The sub-drive mechanism (27) comprises a transmission seat (271) and a guide shaft (274), wherein, The transmission seat (271) is provided in three groups, the three groups of transmission seats (271) are all rotatably connected to the inner wall of the cutting frame (2), one end of the central shaft of the three groups of transmission seats (271) penetrates into the inside of the housing (31) and is connected with the central shaft of the three groups of worm gears (34), and the bottom of the three groups of transmission seats (271) is provided with a transmission guide groove (272); The vertical guide column (23) is provided in three groups, one end of the three groups of vertical guide columns (23) penetrates into the inside of the cutting frame (2), and a spring (273) is fixedly connected between the inner wall of the cutting frame (2) and the vertical guide column (23); The guide shaft (274) is fixedly connected to the top of one end of the three groups of vertical guide columns (23) penetrating into the inside of the cutting frame (2) respectively, and is slidingly connected with the inner wall of the transmission guide groove (272); Among them, the transmission guide groove (272) corresponding to the positions of the cutting knife (25) and the left pressing block (24) comprises a first downhill section, a first uphill section, a second downhill section and a second uphill section connected in sequence; The transmission guide groove (272) corresponding to the position of the right pressing block (26) comprises a third downhill section, a first parallel section, a third uphill section and a second parallel section connected in sequence.

4. The weft machine weft thread cutting device according to claim 2, characterized in that The sub-drive mechanism (27) further comprises a first threaded lead screw (275), a reciprocating lead screw (276) and a one-way transmission device (277), wherein, The first threaded screw rod (275) is provided with two groups, both of which are rotationally connected to the inner wall of the cutting frame (2) and correspond to the positions of the left pressing block (24) and the cutter (25) respectively, one end of both of the first threaded screw rods (275) penetrates into the inside of the shell (31) and is connected to the central shaft of two groups of worm gears (34), and the other end of both of the first threaded screw rods (275) is threadedly connected to the inner wall of the vertical guide column (23) corresponding to the positions of the left pressing block (24) and the cutter (25) respectively, the reciprocating screw rod (276) is provided with one group, which is rotationally connected to the inner wall of the cutting frame (2) and corresponds to the position of the right pressing block (26), one end of the reciprocating screw rod (276) penetrates into the inside of the shell (31) and is connected to the central shaft of the last group of worm gears (34) through the one-way transmission device (277), and the other end of the reciprocating screw rod (276) is threadedly connected to the inner wall of the vertical guide column (23) corresponding to the position of the right pressing block (26). The stroke of the two groups of first threaded screw rods (275) is consistent with that of the reciprocating screw rod (276). The one-way transmission device (277) is a ratchet type one-way transmission device.

5. The weft machine weft thread cutting device according to claim 1, characterized in that The inner wall of the driving sliding groove (10) of the mounting frame (1) is threadedly connected with a second threaded screw rod, the bottom of the cutting frame (2) penetrates into the inside of the driving sliding groove (10) and is threadedly connected to the outer surface of the second threaded screw rod, and the end surface of the adjusting handle (11) penetrating into the inside of the driving sliding groove (10) corresponds to the position of one end surface of the second threaded screw rod and is provided with a bevel gear at the corresponding position and is engaged with each other.

6. The weft machine weft thread cutting device according to claim 1, characterized in that The space between the limiting blocks (21) forms a limiting line channel, the width of the limiting line channel is consistent with that of the guide groove of the guide wheel (22), and the inner walls are on the same horizontal plane. The bottom of the right pressing block (26), the cutter (25) and the left pressing block (24) are on the same horizontal plane.

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