Cut-free yarn upper head-changing mechanism with intermediate yarn clamping and circumferential yarn guide and control method thereof

Abstract

This application relates to the technical field of fiberglass furnace drawing equipment, specifically to a non-cutting yarn upper changing mechanism with intermediate yarn clamping and circumferential yarn guiding, and its control method. The non-cutting yarn upper changing mechanism includes a machine head, an upper changing seat, a yarn pushing mechanism, a yarn clamping mechanism, and a yarn guiding mechanism; the control method includes an air-off state and an air-on state. The non-cutting yarn upper changing mechanism and its control method disclosed in this application not only effectively improve the upper changing efficiency and reduce the number of transition yarns through the intermediate yarn clamping of the yarn clamping mechanism and / or the circumferential yarn guiding of the yarn guiding mechanism, but also provide multiple upper changing working modes, improving the adaptability of the drawing machine.

Description

Technical Field

[0001] This application relates to the technical field of fiberglass furnace drawing equipment, specifically to a non-cutting yarn changing mechanism with intermediate yarn clamping and circumferential yarn guide, and its control method. Background Technology

[0002] Glass fiber, as a composite reinforcing material, has a wide range of applications and varieties, including direct drawing into cylindrical yarn balls by a drawing machine and drawing into horse-shaped yarn balls by a yarn cake drawing machine, etc.

[0003] In the current fiberglass furnace drawing process, the yarn is wound onto the upper wire ring by a V-groove with a wire hook or a threaded groove with a wire hook. This is a superior upper wire ring structure in recent years. However, the yarn left on the upper wire ring is difficult for the robot to remove. It must be manually cut and removed on-site before the robot can complete the yarn removal work. Such human-machine cooperation poses safety hazards and cannot achieve automated continuous production.

[0004] With societal progress, harsh working environments and operational safety have become paramount. In the era of intelligent manufacturing, replacing manual labor with enclosed, fully automated robotic arms in the yarn drawing area, along with energy conservation and improved production efficiency, have become urgent priorities. To address the challenges of increasing the utilization value of waste yarn at the top of the yarn drawing machine and achieving unmanned automation, breakthroughs are needed in cutting and removing yarn remaining on the yarn drawing ring. This will enable upgrades to existing equipment, achieving automated production operations that push out the entire loop of waste yarn at the top of the yarn drawing machine without human intervention. This will improve the overall performance and efficiency of existing yarn drawing machines, significantly enhancing the residual value of waste yarn at the top of the yarn drawing machine and achieving substantial economic benefits.

[0005] Related technical documents:

[0006] Chinese Patent: Automatic Yarn-Pulling Machine and Control Method for Automatic Yarn-Pulling and Transition Yarn-Pulling without Cutting, Application Publication No. CN 118459081 A, which relates to an automatic yarn-pulling and transition scheme using a transition ring.

[0007] Chinese Patent: Automatic Push-out Mechanism for Upper Head Changer Without Cutting and Control Method Thereof with Telescopic Claws and Fixed Claws Arranged in a Cross Pattern, Application Publication No. CN 118545903 A, which relates to the upper head changing yarn pushing assembly seat and the radial telescopic claw mechanism.

[0008] Chinese Patent: A cutting-free top-changing transition ring mechanism that can automatically push out a full circle of yarn, application publication number CN 118459082 A, relates to a yarn pushing transition ring.

[0009] Chinese patent: Slow-pulling automatic yarn feeding online non-cutting transition yarn feeding mechanism, publication number CN211141896U; involving existing yarn feeding hooks and yarn feeding ring grooves, as well as machine head turntables and double machine head configuration schemes; and slow-pulling traction mechanism.

[0010] Chinese Patent: A dual-path air pipe for use on a CNC wire drawing machine (Announcement No.: CN222893107U); relates to a dual-path air distribution pipe on the machine head.

[0011] Chinese Patent: An Automatic Yarn Cutting Mechanism for a Wire Drawing Machine (Announcement No.: CN222138959U); This invention relates to an automatic yarn cutting mechanism.

[0012] Chinese Patent: A Multi-stroke Push Screw Mechanism for a Wire Drawing Machine (Announcement No.: CN222274392U); relates to a push screw mechanism. Summary of the Invention

[0013] In view of this, this application provides a yarn-changing mechanism and its control method for yarn-changing without cutting, with intermediate yarn clamping and circumferential yarn guiding, to solve all or part of the technical problems described in the background section of this application.

[0014] The inventive concept of this application is as follows: 1. The machine head can be fed from either circumferential yarn or from the middle of the machine head, improving the feeding efficiency and quality while minimizing the amount of transition yarn; 2. An upper head-changing seat is set on the machine head, and a yarn guiding mechanism is set on the upper head-changing seat. After the yarn is full, it enters the yarn guiding mechanism, and the yarn is captured and changed by the yarn guiding mechanism and the yarn hook, improving the head-changing efficiency and ensuring that the yarn pushing mechanism can smoothly push out the transition yarn; 3. By setting a yarn-cutting blade and a yarn clamping mechanism on the upper head-changing seat, the traction connection is cut off at the moment the feeding is completed, solving the problem of the machine head spinning yarn.

[0015] The yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding provided in this application to solve its technical problem is as follows:

[0016] A non-cutting yarn changing mechanism with intermediate yarn clamping and circumferential yarn guide, comprising an upper changing seat; characterized in that: it further comprises a yarn guiding mechanism;

[0017] The upper head changing seat is equipped with several yarn guiding piston chambers and corresponding yarn guiding air passages; the yarn guiding air passages are connected to the yarn guiding piston chambers;

[0018] The yarn guiding mechanism includes a yarn guiding piston chamber cover, a yarn guiding piston rod, a push-pull component, a yarn guiding rod, and a yarn guiding return component. The yarn guiding piston chamber cover is fixed to the opening of the yarn guiding piston chamber. The piston part of the yarn guiding piston rod is located inside the yarn guiding piston chamber, and the connecting rod part of the yarn guiding piston rod extends out of the yarn guiding piston chamber cover. The two ends of the push-pull component are respectively hinged to the yarn guiding rod and the extended end of the connecting rod part of the yarn guiding piston rod. The yarn guiding return component is located inside the yarn guiding piston chamber and its two ends abut against the yarn guiding piston chamber cover and the piston part of the yarn guiding piston rod, respectively.

[0019] The yarn guide piston rod can be pushed horizontally by the push-pull component under the action of compressed air; it can also be tilted by the push-pull component under the action of the yarn guide return component.

[0020] When the guide rod is in a horizontal position, it provides space for the transition yarn to be pushed out; when the guide rod is in an inclined position, the fiberglass yarn can be guided by the guide rod to the upper yarn hook and captured by the upper yarn hook.

[0021] Preferably, the yarn guiding mechanism further includes a limiting component; the limiting component is provided with a movable position for the yarn guiding rod; the end of the yarn guiding rod used to hinge the push-pull component is provided with a limiting part; the opening edge of the yarn guiding piston cavity is provided with a receiving groove, and the two sides of the receiving groove are provided with limiting part receiving positions; the limiting component is disposed on the receiving groove, and the yarn guiding rod passes through the movable position of the yarn guiding rod; the limiting part is disposed within the limiting part receiving position and can rotate freely. Further, the limiting part is a circular shaft structure, and the limiting part receiving positions have mutually matching structures and dimensions.

[0022] During the adjustment of the yarn guide rod to a horizontal state or during the tilting of the yarn guide, the limiting part can rotate freely within the limiting part's accommodating position, and the yarn guide rod can move freely within the yarn guide rod's movable position. However, it will not disengage from the accommodating groove and the limiting part's accommodating position under the constraint of the limiting component. When the yarn guide rod of the yarn guide mechanism is in an tilted state, it can guide the glass fiber yarn to the upper yarn hook to facilitate quick head change of the machine head.

[0023] Preferably, the axis of the yarn guide piston cavity is parallel to the axis of the upper head change seat.

[0024] Preferably, the upper head changing seat is also provided with several yarn feeding hooks; when the yarn guide rod is in an inclined state, it can guide the glass fiber yarn to the yarn feeding hooks to facilitate the yarn feeding.

[0025] Preferably, the upper head-changing seat has an inner cavity in the middle part, and a plurality of yarn-pushing channels are provided on the side wall of the upper head-changing seat inner cavity; the yarn-pushing channels are connected to the upper head-changing seat inner cavity. Further, the receiving groove is connected to the head-changing seat inner cavity and the yarn-guide piston cavity.

[0026] Preferably, the yarn-changing mechanism for the non-cutting yarn with intermediate yarn clamping and circumferential yarn guide further includes a yarn clamping mechanism; a yarn clamping piston cavity is provided on the side wall of the inner cavity of the upper head changing seat; the axis of the yarn clamping piston cavity is perpendicular to the axis of the upper head changing seat; a yarn clamping air passage is also provided on the upper head changing seat; the yarn clamping air passage is connected to the yarn clamping piston cavity; the yarn clamping mechanism includes a yarn clamping piston rod, a yarn clamping return component, and a yarn clamping plate; the piston part of the yarn clamping piston rod is located in the yarn clamping piston cavity, and the connecting rod part of the yarn clamping piston rod extends out of the yarn clamping piston cavity; the yarn clamping plate is located at the extended end of the connecting rod part of the yarn clamping piston rod; the yarn clamping return component is located in the yarn clamping piston cavity, and can compress the yarn clamping return component when the yarn clamping piston rod drives the yarn clamping plate to separate to both sides under the action of compressed air.

[0027] Furthermore, the yarn clamping mechanism also includes a yarn clamping piston chamber cover; the yarn clamping piston chamber opens on the outer surface of the upper head changing seat, and the yarn clamping piston chamber cover is disposed on the outer opening of the yarn clamping piston chamber; the two ends of the yarn clamping return member act on the yarn clamping piston chamber cover and the yarn clamping piston rod respectively.

[0028] Furthermore, the yarn clamping mechanism also includes a yarn clamping navigation component; the upper head changing seat is also provided with a yarn clamping navigation hole; one end of the yarn clamping navigation component is fixedly connected to the yarn clamping plate, and the other end of the yarn clamping navigation component is movably assembled in the yarn clamping navigation hole.

[0029] Furthermore, a yarn clamping rod hole is provided in the part of the yarn clamping piston cavity near the inner cavity of the upper changing head, and the connecting rod part of the yarn clamping piston rod extends out of the yarn clamping piston cavity through the yarn clamping rod hole.

[0030] Preferably, it also includes a machine head, with an upper head changing seat disposed on the machine head; further, the machine head is also provided with a front air passage, which is connected to the yarn guiding air passage and the yarn clamping air passage.

[0031] Furthermore, the machine head is equipped with a yarn pushing piston chamber and a yarn pushing air passage; the yarn pushing air passage is connected to the yarn pushing piston chamber.

[0032] Furthermore, the yarn-changing mechanism for the non-cutting yarn with intermediate yarn clamping and circumferential yarn guide also includes a yarn pushing mechanism; the yarn pushing mechanism includes a yarn pushing piston rod, a yarn pushing return component, and an axial yarn pushing rod; the axial yarn pushing rod includes several radial push rods; the piston part of the yarn pushing piston rod is located in the yarn pushing piston cavity, and the connecting rod part of the yarn pushing piston rod extends into the inner cavity of the upper head changing seat; the radial push rods are located in the yarn pushing channel and are fixedly connected to the extended end of the connecting rod part of the yarn pushing piston rod; the yarn pushing return component is located in the yarn pushing piston cavity, and can compress the yarn pushing return component when the yarn pushing piston rod drives the axial yarn pushing rod forward along the axis of the machine head under the action of compressed air.

[0033] When compressed air is connected to the yarn pushing air passage, the yarn pushing piston rod can drive the radial push rod forward along the axis of the machine head to push the transition yarn down the upper head changing seat; when the compressed air is disconnected from the yarn pushing air passage, the yarn pushing piston rod can return to its original position under the action of the yarn pushing return component.

[0034] Furthermore, the axial pusher rod also includes a pusher disc, a radial pusher rod disposed on the pusher disc and extending radially; the pusher disc is fixed to the extended end of the connecting rod portion of the pusher piston rod.

[0035] Furthermore, the yarn pushing mechanism also includes a yarn pushing piston chamber cover; the yarn pushing piston chamber cover is fixedly disposed at the opening of the yarn pushing piston chamber; and the yarn pushing return component is disposed between the yarn pushing piston chamber cover and the piston portion of the yarn pushing piston rod.

[0036] Furthermore, the cover of the yarn pusher piston chamber is provided with a cover connecting rod hole; the part of the upper head changer seat used to connect to the machine head is provided with a yarn pusher rod hole, which is connected to the inner cavity of the upper head changer seat; the connecting rod part of the yarn pusher piston rod extends into the inner cavity of the upper head changer seat through the yarn pusher rod hole and the cover connecting rod hole.

[0037] Furthermore, the head-changing mechanism for the non-cutting yarn with intermediate yarn clamping and circumferential yarn guide also includes a dual-path air distribution pipe; the dual-path air distribution pipe is provided with a central air distribution groove, a front air distribution groove, and a central air distribution hole; the central air distribution groove is connected to the central air distribution hole; a central air passage is provided on the machine head, and the central air passage is connected to the yarn pushing piston chamber; the dual-path air distribution pipe is located in the central air passage, the yarn pushing air passage is connected to the central air distribution groove, and the front air passage is connected to the front air distribution groove.

[0038] Compressed air from the yarn pushing air path enters the yarn pushing piston chamber through the central air distribution hole of the dual-path air distribution pipe. Compressed air from the front air path is delivered to the upper head changer via the front air distribution groove to drive the yarn guiding mechanism and the yarn clamping mechanism. The dual-path air distribution pipe simplifies the air path configuration on the machine head, improves the balance of the machine head, and enables the separate delivery of compressed air to achieve independent and precise control of different functional mechanisms or components.

[0039] Preferably, the yarn-changing mechanism with intermediate yarn clamp and circumferential yarn guide also includes several yarn-breaking blades, which are located at the edge of the yarn pushing channel on the upper changing seat. During the upper changing, the yarn-breaking blades can automatically cut the traction connection between the upper changing seat and the slow-pulling traction mechanism by rotating the machine head.

[0040] The control method for the yarn-changing mechanism with intermediate yarn clamping and circumferential yarn guide in this application is as follows:

[0041] A control method for a yarn-changing mechanism without cutting, comprising the following working states:

[0042] In the air-cut state, the yarn clamping piston rod, under the action of the yarn clamping return component, drives the yarn clamping plates to move closer together to complete the yarn clamping action; under the action of the yarn guide return component, the yarn guide piston rod is pulled by the push-pull component to make the yarn guide rod in an inclined state to guide the yarn to the upper hook; at this time, the yarn push piston rod is in the initial unpushed state under the action of the yarn push return component.

[0043] In the ventilated state, the yarn clamping piston rod, under the action of compressed air, drives the yarn clamping plate to separate and return to its original position on both sides, while compressing the yarn clamping return component; the yarn guide piston rod, under the action of compressed air, pushes the yarn guide rod to a horizontal state through the push-pull component, while compressing the yarn guide return component; synchronously or sequentially, the yarn push piston rod, under the action of compressed air, drives the axial yarn push rod forward along the axis of the machine head to complete the yarn push action, while compressing the yarn push return component.

[0044] Beneficial technical effects:

[0045] 1. The yarn-changing mechanism and control method for non-cutting yarn with intermediate yarn clamp and circumferential yarn guide provided in this application can efficiently complete the yarn-changing work on the machine head by setting a yarn pushing channel, a yarn feeding hook and a yarn guiding mechanism on the upper yarn-changing seat, and by using the inclined guiding effect of the yarn guiding mechanism on the glass fiber yarn.

[0046] 2. The yarn-changing mechanism and control method for the non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding provided in this application can improve the traditional method of hooking the yarn from the outer surface of the yarn loop on the machine head to clamping the yarn from inside the upper head seat by setting a yarn pushing channel and a yarn clamping mechanism on the upper head seat. This is beneficial to improving the efficiency of the upper head changing and reducing the number of transition yarns.

[0047] 3. The yarn-changing mechanism and control method for yarn-drawing without cutting provided in this application, which has a middle yarn clamp and a circumferential yarn guide, can complete the yarn-drawing operation by setting a yarn-changing seat, a yarn clamping mechanism, a yarn guiding mechanism and a yarn-drawing hook on the machine head, using either middle yarn feeding or circumferential yarn hooking. This is beneficial to improving the adaptability of the drawing machine and meeting the requirements of complex drawing processes.

[0048] 4. The yarn-changing mechanism and control method with intermediate yarn clamp and circumferential yarn guide provided in this application can automatically cut the traction connection between the upper head changing seat and the slow pull traction mechanism during the upper head changing by setting a yarn-breaking blade on the upper head changing seat, making it possible to automatically change the yarn head and unload the bobbin of the drawing machine.

[0049] 5. The yarn-changing mechanism and control method for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding provided in this application can not only automatically and efficiently complete the yarn-changing work through the cooperation of the yarn clamping mechanism, the yarn guiding mechanism and the yarn pushing mechanism, but also automatically push out and recycle the transition yarn formed during the yarn-changing process.

[0050] The technical solution and technical effects of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0051] Figure 1 : Diagram of gas outage status;

[0052] Figure 2 Front view of the gas supply interruption status;

[0053] Figure 3 : Schematic diagram of ventilation status;

[0054] Figure 4 Front view of ventilation status;

[0055] Figure 5 : Schematic diagram of ventilation and yarn pushing;

[0056] Figure 6Front view of ventilation and yarn pushing;

[0057] Figure 7 First-person perspective structural breakdown diagram;

[0058] Figure 8 Second-person perspective structural decomposition diagram;

[0059] Figure 9 : Schematic diagram of the upper head replacement structure;

[0060] Figure 10 Schematic diagram of the yarn guiding mechanism;

[0061] Figure 11 Schematic diagram of the yarn clamping mechanism;

[0062] Figure 12 Schematic diagram of the yarn pushing mechanism;

[0063] Figure 13 Schematic diagram of dual-path gas distribution pipe structure;

[0064] Figure 14 : Schematic diagram of the yarn breaking process;

[0065] Icon description:

[0066] 1-Machine head, 11-Yarn pusher piston chamber, 12-Yarn pusher air passage, 13-Front end air passage, 14-Central air passage;

[0067] 2-Upper head changing seat, 21-Yarn clamping piston cavity, 22-Yarn clamping air passage, 23-Upper head changing seat inner cavity, 24-Yarn pushing channel, 25-Yarn guiding piston cavity, 26-Yarn guiding air passage, 27-Accommodation groove, 28-Limiting part accommodation position, 29-Yarn clamping navigation hole;

[0068] 3- Yarn pushing mechanism, 31- Yarn pushing piston rod, 32- Yarn pushing return component, 33- Axial yarn pushing rod, 331- Yarn pushing disc, 332- Radial push rod, 34- Yarn pushing piston chamber cover;

[0069] 4- Yarn clamping mechanism, 41- Yarn clamping piston rod, 42- Yarn clamping return component, 43- Yarn clamping plate, 44- Yarn clamping piston chamber cover, 45- Yarn clamping navigation component;

[0070] 5-Yarn guiding mechanism, 51-Yarn guiding piston chamber cover, 52-Yarn guiding piston rod, 53-Push-pull component, 54-Yarn guiding rod, 55-Yarn guiding return component, 56-Limiting component, 57-Yarn guiding rod movable position, 58-Limiting part;

[0071] 6-Hook on top;

[0072] 7-Dual gas distribution pipe, 71-Central gas distribution slot, 72-Front end gas distribution slot, 73-Central gas distribution port;

[0073] 8-Broken yarn blade. Detailed Implementation

[0074] Direction convention: The direction of the upper and lower head changing seat on the machine head is the forward direction, and the opposite direction, that is, the direction of the main body of the wire drawing machine, is the backward direction.

[0075] In order to provide a clear and complete explanation of the technical solution of this application, the basic structure and functions of the wire drawing machine will be briefly introduced first.

[0076] Existing yarn drawing machines generally include a frame, a head turntable and its drive mechanism, several heads and their drive mechanisms, a slow-pull traction mechanism, a yarn pusher mechanism, and an automatic yarn cutting mechanism. Among these:

[0077] The head turntable and its drive mechanism are mounted on the frame. The head turntable can rotate under the action of the turntable drive mechanism to realize the rotation of the head.

[0078] The machine head and its drive mechanism are mounted on the machine head turntable. The machine head can rotate freely under the action of its drive mechanism and can rotate synchronously with the machine head turntable.

[0079] The slow-pull traction mechanism is mounted on the frame and is used to pull the yarn during head changes so that the yarn loading loop and yarn loading hook can capture the yarn.

[0080] For details on the machine head turntable, machine head, and slow-pull traction mechanism, please refer to: Slow-pull automatic online yarn feeding mechanism (publication number CN211141896U).

[0081] The pusher screw mechanism is mounted on the frame and is used to adjust the position of the yarn during head changing (e.g., at the head changing seat or the drawing and winding part of the head); please refer to: A multi-stroke pusher screw mechanism for a drawing machine (Announcement No.: CN222274392U).

[0082] The automatic yarn cutting mechanism is used to cut the fiberglass yarn connection between the yarn ball and the upper changing head seat or upper yarn ring. When the fiberglass yarn is pushed or pulled from the upper changing head seat or upper yarn ring to the winding position, a connection will be formed between the upper changing head seat or upper yarn ring and the yarn ball. Without cutting, the automatic unloading of the yarn ball cannot be completed. Please refer to: Chinese Patent: An Automatic Yarn Cutting Mechanism for a Fiber Drawing Machine (Announcement No.: CN222138959U).

[0083] The upper head changing mechanism and its control method for which this application seeks patent protection are technological innovations in the field of drawing machine heads, mainly used to improve the efficiency and quality of upper head changing and minimize the amount of transition yarn.

[0084] The yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding disclosed in this application includes a machine head 1, an upper yarn changing seat 2, a yarn pushing mechanism 3, a yarn clamping mechanism 4, and a yarn guiding mechanism 5.

[0085] Please see Figure 7 , Figure 8 , Figure 13 The machine head 1 is equipped with a yarn pushing piston chamber 11, a yarn pushing air passage 12, a front air passage 13, and a central air passage 14. The central air passage 14 is connected to the yarn pushing piston chamber 11, and the yarn pushing air passage 12 is connected to the central air passage 14. A dual-path air distribution pipe 7 is installed inside the central air passage 14.

[0086] The dual-path air distribution pipe 7 is equipped with a central air distribution groove 71, a front air distribution groove 72, and a central air distribution hole 73; the central air distribution groove 71 is connected to the central air distribution hole 73. The yarn pushing air passage 12 is connected to the central air distribution groove 71, and the front air passage 13 is connected to the front air distribution groove 72.

[0087] Compressed air from the yarn pushing air passage 12 can enter the yarn pushing piston chamber 11 through the central air distribution hole 73 of the dual-path air distribution pipe 7, and compressed air from the front air passage 13 can be delivered to the upper head changing seat 2 through the front air distribution groove 72 to drive the yarn guiding mechanism 5 and the yarn clamping mechanism 4. The use of the dual-path air distribution pipe 1 can simplify the air passage configuration on the machine head 1, improve the balance of the machine head 1, and realize the branch delivery of compressed air to achieve independent and precise control of different functional mechanisms or components.

[0088] Please see Figure 7 , Figure 8 , Figure 9 The upper head changing seat 2 is provided with an upper head changing seat cavity 23. Several yarn pushing channels 24 are on the side wall of the upper head changing seat cavity 23. The yarn pushing channels 24 are connected to the upper head changing seat cavity 23. The yarn pushing channels 24 are used as axial pushing motion channels when pushing out transition yarn, and as clamping channels when the glass fiber yarn is slowly pulled during the upper head changing.

[0089] Please see Figure 14 At least one yarn-pushing channel 24 has a yarn-cutting blade 8 along its edge. When changing the yarn head, the yarn-cutting blade 8 can automatically cut the traction line between the upper head changing seat 2 and the slow-pulling traction mechanism in conjunction with the rotation of the machine head.

[0090] Two yarn clamping piston chambers 21 are also provided on the side wall of the inner cavity 23 of the upper head changing seat. The two yarn clamping piston chambers 21 are arranged opposite each other and their axes are perpendicular to the axis direction of the machine head 1 and the upper head changing seat 2. The yarn clamping piston chambers 21 are used to install the yarn clamping mechanism 4.

[0091] Several yarn guide piston chambers 25 are also provided on the side wall of the inner cavity 23 of the upper head changing seat. The axis of the yarn guide piston chamber 25 is parallel to the axis of the machine head 1 and the upper head changing seat 2. The yarn guide piston chamber 25 is used to assemble the yarn guide mechanism 5.

[0092] The opening edge of the yarn guide piston cavity 25 is provided with a receiving groove 27, which connects to the inner cavity 23 of the upper head changing seat and the yarn guide piston cavity 25; the receiving groove 27 is provided with limit receiving positions 28 on both sides.

[0093] The upper head changing base 2 is also provided with a yarn clamping air passage 22 and a yarn guiding air passage 26; both the yarn clamping air passage 22 and the yarn guiding air passage 26 are connected to the front air passage 13 on the machine head 1. As mentioned earlier, compressed air from the front air passage 13 can be delivered to the yarn clamping air passage 22 and the yarn guiding air passage 26 to drive the yarn clamping mechanism 4 and the yarn guiding mechanism 5.

[0094] Please see Figure 7 , Figure 8 and Figure 10 The yarn guiding mechanism 5 includes a yarn guiding piston chamber cover 51, a yarn guiding piston rod 52, a push-pull component 53, a yarn guiding rod 54, a yarn guiding return component 55, and a limiting component 56.

[0095] The yarn guide piston chamber cover 51 is fixed to the opening of the yarn guide piston chamber 25; the piston part of the yarn guide piston rod 52 is disposed inside the yarn guide piston chamber 25, and the connecting rod part of the yarn guide piston rod 52 extends out of the yarn guide piston chamber cover 51. The two ends of the push-pull component 53 are respectively hinged to the yarn guide rod 54 and the extended end of the connecting rod part of the yarn guide piston rod 52; the yarn guide return component 55 is disposed inside the yarn guide piston chamber 25 and its two ends abut against the yarn guide piston chamber cover 51 and the piston part of the yarn guide piston rod 52 respectively; the yarn guide piston rod 52 can be pushed by the push-pull component 53 under the action of compressed air to keep the yarn guide rod 54 in a horizontal state; it can also be pulled by the push-pull component 53 under the action of the yarn guide return component 55 to keep the yarn guide rod 54 in an inclined state.

[0096] The limiting component 56 is provided with a guide rod movable position 57; the end of the guide rod 54 used to hinge the push-pull component 53 is provided with a limiting part 58; the limiting part 58 is a circular shaft structure, and the limiting part receiving position 28 has a mutually matching structure and size. The limiting component 56 is provided on the receiving groove 27, the guide rod 54 passes through and is received in the guide rod movable position 57, and the limiting part 58 is provided in the limiting part receiving position 28 and can rotate freely.

[0097] During the adjustment of the yarn guide rod 54 to a horizontal state or during the tilting of the yarn guide, the limiting part 58 can rotate freely within the limiting part receiving position 28, and the yarn guide rod 54 can move freely within the yarn guide rod movable position 57. However, it will not disengage from the receiving groove 27 and the limiting part receiving position 28 under the constraint of the limiting part 56. When the yarn guide rod 54 of the yarn guide mechanism 5 is in an tilted state, it can guide the glass fiber yarn to the upper hook 6 to facilitate quick head change of the machine head 1.

[0098] Compressed air is supplied from the yarn guiding air passage 26 into the yarn guiding piston chamber 25, with the air supply point located between the piston portion of the yarn guiding piston rod 52 and the bottom of the yarn guiding piston chamber 25. Under the action of compressed air, the yarn guiding piston rod 52 can be pushed by the push-pull component 53 to keep the yarn guiding rod 54 in a horizontal state. When the compressed air is disconnected, the yarn guiding rod 54 can be tilted by the push-pull component 53 under the action of the yarn guiding return component 55. When the yarn guiding rod 54 is in a horizontal state, it provides space for the transition yarn to be pushed out; when the yarn guiding rod 54 is in a tilted state, the glass fiber yarn can be guided by the yarn guiding rod 54 to the upper yarn hook 6 for quick capture by the upper yarn hook 6.

[0099] Please see Figure 7 , Figure 8 , Figure 11 The yarn clamping mechanism 4 includes a yarn clamping piston rod 41, a yarn clamping return component 42, a yarn clamping plate 43, and a yarn clamping piston chamber cover 44.

[0100] The yarn clamping piston cavity 21 opens on the outer surface of the upper head changing seat 2, and the yarn clamping piston cavity cover 44 is provided on the outer opening of the yarn clamping piston cavity 21; a yarn clamping rod hole is provided in the part of the yarn clamping piston cavity 21 near the inner cavity 23 of the upper head changing seat.

[0101] The piston portion of the yarn clamping piston rod 41 is disposed within the yarn clamping piston cavity 21, and the connecting rod portion of the yarn clamping piston rod 41 extends out of the yarn clamping piston cavity 21 through the yarn clamping rod hole. The yarn clamping plate 43 is disposed at the extended end of the connecting rod portion of the yarn clamping piston rod 41.

[0102] The yarn clamping recovery component 42 is disposed inside the yarn clamping piston cavity 21 and its two ends act on the yarn clamping piston cavity cover 44 and the yarn clamping piston rod 41, respectively. When the yarn clamping piston rod 41 drives the yarn clamping plate 43 to separate to both sides under the action of compressed air, it can compress the yarn clamping recovery component 42.

[0103] Compressed air is supplied into the clamping piston chamber 21 through the clamping air passage 22, so that the air inlet is located between the piston part of the clamping piston rod 41 and the clamping rod hole. Under the action of compressed air, the clamping piston rod 41 can drive the clamping plate 43 to move away from the axis of the machine head 1 so that the clamping plate 43 separates to both sides. When the compressed air is disconnected, the clamping return member 42 can use the elastic restoring force to make the clamping piston rod 41 drive the clamping plate 43 to move towards the axis of the machine head 1 so that they come together and clamp the yarn.

[0104] In a modified embodiment, the yarn clamping mechanism further includes a yarn clamping guide component 45; the upper head changing seat 2 is also provided with a yarn clamping guide hole 29; one end of the yarn clamping guide component 45 is fixedly connected to the yarn clamping plate 43, and the other end of the yarn clamping guide component 45 is movably fitted into the yarn clamping guide hole 29. The sliding fit between the yarn clamping guide component 45 and the yarn clamping guide hole 29 can improve the smoothness of the yarn clamping and return actions.

[0105] Please see Figure 7 , Figure 8 , Figure 12 The yarn-changing mechanism for the non-cutting yarn with intermediate yarn clamping and circumferential yarn guide also includes a yarn pushing mechanism 3; the yarn pushing mechanism 3 includes a yarn pushing piston rod 31, a yarn pushing return component 32, an axial yarn pushing rod 33, and a yarn pushing piston chamber cover 34; the axial yarn pushing rod 33 includes a yarn pushing disc 331 and several radial push rods 332; the radial push rods 332 are arranged on the yarn pushing disc 331 and extend radially.

[0106] The yarn pushing piston chamber cover 34 is fixedly installed at the opening of the yarn pushing piston chamber 11; the yarn pushing piston chamber cover 34 is provided with a cover connecting rod hole; the upper head changing seat 2 is provided with a yarn pushing rod hole at the part used to connect the machine head 1, and the yarn pushing rod hole is connected to the inner cavity 23 of the upper head changing seat.

[0107] The piston portion of the yarn pushing piston rod 31 is located inside the yarn pushing piston chamber 11, and the connecting rod portion of the yarn pushing piston rod 31 extends into the inner cavity 23 of the upper head changing seat through the yarn pushing rod hole and the connecting rod hole of the chamber cover. The yarn pushing disc 331 is fixedly connected to the extended end of the connecting rod portion of the yarn pushing piston rod 31, and the radial push rod 332 is located inside the yarn pushing channel 24; the yarn pushing return member 32 is located inside the yarn pushing piston chamber 11 and between the yarn pushing piston chamber cover 34 and the piston portion of the yarn pushing piston rod 31; when the yarn pushing piston rod 31 drives the axial yarn pushing rod 33 to push forward along the axis of the machine head 1 under the action of compressed air, it can compress the yarn pushing return member 32.

[0108] When compressed air is connected to the yarn pushing air passage 12, the yarn pushing piston rod 31 can drive the radial push rod 332 to push forward along the axis of the machine head 1 to push the transition yarn down the upper head changing seat 2; when the compressed air is disconnected from the yarn pushing air passage 12, the yarn pushing piston rod 31 can retract backward and return to its original position under the action of the yarn pushing return member 32.

[0109] The control method for the above-mentioned head-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guide is described below.

[0110] Mode 1: Yarn clamping mechanism 4 (upper head) + yarn guiding mechanism 5 (head changing or bobbin changing):

[0111] When the front air passage 13 on the machine head 1 is connected, compressed air pushes the yarn clamping piston rod 41, causing the yarn clamping plate 43 to move away from the axis of the machine head 1. The yarn clamping plate 43 separates to both sides, and at the same time, the yarn clamping return member 42 is compressed. Under the action of compressed air, the yarn guide piston rod 52 is pushed by the push-pull member 52 to make the yarn guide rod 53 horizontal, and at the same time, the yarn guide return member 55 is compressed. At this time, the yarn guide operator or robot arm pulls the glass fiber yarn from the yarn pushing channel 24 on the upper head changing seat 2 to the slow pull traction mechanism, so that the glass fiber yarn is located between the two yarn clamping plates 43 on both sides; the situation is as follows. Figure 3 and Figure 4 As shown;

[0112] Then, the compressed air in the front air passage 13 is disconnected, causing the two clamping plates 43 on both sides of the yarn clamping mechanism 4 to move towards each other in the direction of the main shaft axis to clamp the yarn; at the same time, the yarn guide piston rod 52, under the action of the yarn guide return member 55, pulls the yarn guide rod 53 to an inclined state through the push-pull member 53; the situation is as follows. Figure 1 and Figure 2 As shown;

[0113] Then the machine head 1 starts to rotate, and the yarn is stably and firmly wound on the upper head changing seat 2. At the same time, the yarn cutting blade 6 cuts the fiberglass yarn connection between the slow pull traction mechanism and the upper head changing seat 2 to prevent the machine head from throwing the tail yarn. Then the yarn is pushed to the winding station of the machine head 1 by the push rod mechanism for normal drawing and winding production.

[0114] Start the automatic yarn cutting mechanism of the drawing machine to cut the glass fiber connection between the upper head changing seat 2 and the yarn ball;

[0115] The front air passage 13 is opened, causing the yarn clamping plate 43 to separate to both sides, and the yarn guide rod 53 to be in a horizontal state; sequentially or simultaneously, the drive air passage (i.e., the yarn pushing air passage 12) of the yarn pushing mechanism 3 is opened, causing the axial yarn pushing rod 33 to move forward and push the transition yarn down the upper head changing seat 2; the situation is as follows. Figure 5 and Figure 6 As shown;

[0116] Then disconnect the drive air path of the yarn pushing mechanism 3 (i.e., the yarn pushing air path 12) to allow the axial yarn pushing rod 33 to return to its initial unpushed state; as Figure 3 and Figure 4 As shown;

[0117] Once the current die head is full, the pusher screw mechanism will push the fiberglass yarn to the position of the upper head changing seat 2, and the full-bottle die head and the empty-bottle die head will begin to switch positions;

[0118] At this time, the yarn guide piston rod 52 of the empty cylinder head is pulled to an inclined state by the push-pull component 53 under the action of the yarn guide return component 55; the fiberglass yarn is guided to the upper yarn hook 6 and captured by the upper yarn hook;

[0119] The pusher mechanism pushes the fiberglass yarn to the winding position of the empty drum head for continued drawing and winding;

[0120] After the rotation position is changed, the full-bore machine head arrives at the standby station, and the yarn bundle is automatically unloaded by the unloading robot to enter the next process.

[0121] Mode 2: Yarn guiding mechanism 5 (top) + bobbin change:

[0122] The yarn guide or yarn guide robot pulls the fiberglass yarn from the yarn pushing channel 24 on the upper head changing seat 2 or the outer circumferential surface of the yarn guide rod 54 to the slow pull traction mechanism.

[0123] Disconnecting the front air passage 13 of the machine head 1, the yarn guide piston rod 52, under the action of the yarn guide return member 55, pulls the yarn guide rod 54 to an inclined yarn guide state through the pulling member 53, and the yarn is guided to the yarn feeding hook 6; Figure 1 and Figure 2 As shown;

[0124] As the machine head 1 begins to rotate, the fiberglass yarn is hooked by the upper wire hook 6 and firmly wound onto the upper head changing seat 2. At the same time, the yarn-breaking blade 8 cuts the fiberglass yarn connection between the slow-pulling traction mechanism and the upper head changing seat 2.

[0125] Start the pusher screw mechanism to push the fiberglass yarn to the winding station on the machine head 1 for normal drawing and winding production to complete the top yarn production;

[0126] Start the automatic yarn cutting mechanism of the drawing machine to cut the glass fiber connection between the upper head changing seat 2 and the yarn ball;

[0127] The air passage 13 at the front end of the machine head 1 is opened, and the yarn guide piston rod 52, under the action of compressed air, pushes the yarn guide rod 54 to a horizontal state through the pulling component 53; at the same time, the yarn clamping plate 43 moves away from the axis of the machine head 1 under the action of compressed air, and the yarn clamping plate 43 separates to both sides; Figure 3 and Figure 4 As shown;

[0128] Sequentially or synchronously, the drive air passage of the yarn pushing mechanism 3 (i.e., the yarn pushing air passage 12) is activated, causing the axial yarn pushing rod 33 to advance forward and push the transition yarn down the upper head changing seat 2; the situation is as follows. Figure 5 and Figure 6 As shown;

[0129] Then disconnect the drive air path of the yarn pushing mechanism 3 (i.e., the yarn pushing air path 12), and let the axial yarn pushing rod 33 return to its initial unpushed state; as Figure 3 and Figure 4 As shown;

[0130] Once the current machine head is full, the pusher screw mechanism will push the yarn to the position of the upper head changing seat 2, and the full-bore machine head and the empty-bore machine head will begin to switch positions;

[0131] At this time, the yarn guide piston rod 52 of the empty cylinder head is pulled to an inclined state by the push-pull component 53 under the action of the yarn guide return component 55; the fiberglass yarn is guided to the upper yarn hook 6 and captured by the upper yarn hook;

[0132] The pusher mechanism pushes the fiberglass yarn to the winding position of the empty drum head for continued drawing and winding;

[0133] After the rotation position is changed, the full-bore machine head arrives at the standby station, and the yarn bundle is automatically unloaded by the unloading robot to enter the next process.

[0134] The above examples illustrate feasible control methods for the non-cutting yarn changing mechanism with intermediate yarn clamping and circumferential yarn guiding. Other implementation schemes can be adopted in specific applications. As can be seen from the above changing steps, the non-cutting yarn changing mechanism with intermediate yarn clamping and circumferential yarn guiding disclosed in this application can complete the changing operation independently through the yarn guiding mechanism 5 (corresponding to mode 2), or it can complete the changing operation jointly through the cooperation of the yarn guiding mechanism 5 and the yarn clamping mechanism 4 (corresponding to mode 1). This allows it to flexibly adapt to different production needs and complete different production tasks in specific production environments. Furthermore, the intermediate yarn clamping of the yarn clamping mechanism 4 and / or the circumferential yarn guiding of the yarn guiding mechanism 5 can effectively improve the changing efficiency and reduce the number of transition yarns.

[0135] As can be seen from the above description of the head-changing step, the control method of the head-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding involved in this application includes the following two characteristic working states:

[0136] In the air-cut state, the yarn clamping piston rod 41, under the action of the yarn clamping return member 42, drives the yarn clamping plates 43 to move closer together to complete the yarn clamping action; the yarn guide piston rod 52, under the action of the yarn guide return member 55, causes the yarn guide rod 54 to be in an inclined state by the pull of the push-pull member 53 to guide the yarn to the upper hook 6; at this time, the yarn push piston rod 31 is in the initial unpushed state under the action of the yarn push return member 32.

[0137] In the ventilated state, the yarn clamping piston rod 41, under the action of compressed air, drives the yarn clamping plate 43 to separate and return to its original position on both sides, while compressing the yarn clamping return member 42; the yarn guide piston rod 52, under the action of compressed air, pushes the yarn guide rod 54 to a horizontal state through the push-pull member 53, while compressing the yarn guide return member 55; synchronously or sequentially, the yarn push piston rod 31, under the action of compressed air, drives the axial yarn push rod 33 to move forward along the axis of the machine head 1 to complete the yarn push action, while compressing the yarn push return member 32.

[0138] The technical solutions and effects of this application have been described in detail above with reference to the accompanying drawings and specific embodiments. It should be noted that those skilled in the art can develop other embodiments based on this. Any simple modifications and equivalent substitutions that do not depart from the innovative concept of this application are covered by this application and fall within the protection scope of this patent.

Claims

1. A yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guide, comprising an upper yarn-changing seat (2); characterized in that: It also includes a yarn guiding mechanism (5); The upper head changing seat (2) is provided with a plurality of yarn guiding piston chambers (25) and corresponding yarn guiding air passages (26); the yarn guiding air passages (26) are connected to the yarn guiding piston chambers (25). The yarn guiding mechanism (5) includes a yarn guiding piston chamber cover (51), a yarn guiding piston rod (52), a push-pull component (53), a yarn guiding rod (54), and a yarn guiding return component (55). The yarn guide piston chamber cover (51) is fixed to the opening of the yarn guide piston chamber (25); The piston portion of the yarn guide piston rod (52) is disposed inside the yarn guide piston cavity (25), and the connecting rod portion of the yarn guide piston rod (52) extends out of the yarn guide piston cavity cover (51). The two ends of the push-pull component (53) are respectively hinged to the extension ends of the connecting rod of the yarn guide rod (54) and the yarn guide piston rod (52); The yarn guide return component (55) is disposed in the yarn guide piston cavity (25) and its two ends act on the piston portion of the yarn guide piston cavity cover (51) and the yarn guide piston rod (52), respectively. The yarn guide piston rod (52) can be pushed by the push-pull component (53) under the action of compressed air to make the yarn guide rod (54) in a horizontal state; it can also be pulled by the push-pull component (53) under the action of the yarn guide return component (55) to make the yarn guide rod (54) in an inclined state.

2. The yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding as described in claim 1, characterized in that: The yarn guiding mechanism (5) also includes a limiting component (56); The limiting component (56) is provided with a guide rod movable position (57). The end of the yarn guide rod (54) used to hinge the push-pull component (53) is provided with a limiting part (58). The opening edge of the yarn guide piston cavity (25) is provided with a receiving groove (27), and the two sides of the receiving groove (27) are provided with limiting receiving positions (28). The limiting component (56) is disposed on the receiving groove (27), the yarn guide rod (54) passes through the moving part (57) of the yarn guide rod, and the limiting part (58) is disposed in the receiving part (28) of the limiting part and can rotate freely.

3. The yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding as described in claim 1, characterized in that: The upper head changing seat (2) has an inner cavity (23) in the middle part, and several yarn pushing channels (24) are provided on the side wall of the inner cavity (23). The yarn pushing channel (24) is connected to the inner cavity (23) of the upper head changing seat.

4. The yarn-changing mechanism with intermediate yarn clamp and circumferential yarn guide as described in claim 3, characterized in that: It also includes a yarn clamping mechanism (4); A yarn-clamping piston cavity (21) is provided on the side wall of the inner cavity (23) of the upper head changing seat. The axis of the yarn clamping piston cavity (21) is perpendicular to the axis of the upper head changing seat (2); The upper head changing seat (2) is also provided with a yarn clamping air passage (22); The yarn clamping air passage (22) is connected to the yarn clamping piston chamber (21). The yarn clamping mechanism (4) includes a yarn clamping piston rod (41), a yarn clamping return piece (42), and a yarn clamping plate (43). The piston portion of the yarn clamping piston rod (41) is disposed in the yarn clamping piston cavity (21), and the connecting rod portion of the yarn clamping piston rod (41) extends out of the yarn clamping piston cavity (21). The yarn clamping plate (43) is disposed at the extended end of the connecting rod portion of the yarn clamping piston rod (41); The yarn clamping recovery component (42) is disposed in the yarn clamping piston cavity (21). When the yarn clamping piston rod (41) drives the yarn clamping plate (43) to separate to both sides under the action of compressed air, it can compress the yarn clamping recovery component (42).

5. The yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding as described in claim 4, characterized in that: The yarn clamping mechanism (4) also includes a yarn clamping piston chamber cover (44). The yarn clamping piston cavity (21) opens onto the outer surface of the upper head changing seat (2), and the yarn clamping piston cavity cover (44) is disposed on the outer opening of the yarn clamping piston cavity (21); The two ends of the yarn clamping recovery component (42) act on the yarn clamping piston chamber cover (44) and the yarn clamping piston rod (41), respectively.

6. The yarn-changing mechanism with intermediate yarn clamp and circumferential yarn guide as described in claim 3, characterized in that: The non-cutting yarn upper changing mechanism with intermediate yarn clamp and circumferential yarn guide also includes a machine head (1); the upper changing seat (2) is fixedly installed on the machine head (1); The machine head (1) is provided with a yarn pushing piston chamber (11) and a yarn pushing air passage (12); the yarn pushing air passage (12) is connected to the yarn pushing piston chamber (11). The yarn-changing mechanism for the non-cutting yarn with intermediate clamping and circumferential guide also includes a yarn pushing mechanism (3). The yarn pushing mechanism (3) includes a yarn pushing piston rod (31), a yarn pushing return component (32), and an axial yarn pushing rod (33). The axial push rod (33) includes a plurality of radial push rods (332); The piston part of the yarn pushing piston rod (31) is disposed in the yarn pushing piston cavity (11), and the connecting rod part of the yarn pushing piston rod (31) extends into the inner cavity (23) of the upper head changing seat. The radial push rod (332) is disposed in the yarn pushing channel (24) and fixedly connected to the protruding end of the connecting rod of the yarn pushing piston rod (31); The yarn pusher return member (32) is disposed in the yarn pusher piston cavity (11). When the yarn pusher piston rod (31) drives the axial yarn pusher rod (33) to push forward along the axial direction of the machine head (1) under the action of compressed air, it can compress the yarn pusher return member (32).

7. The yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding as described in claim 6, characterized in that: The axial pusher rod (33) also includes a pusher disc (331). The radial push rod (332) is disposed on the yarn pusher (331) and extends radially; The yarn pusher disc (331) is fixedly installed at the extended end of the connecting rod portion of the yarn pusher piston rod (31).

8. The yarn-changing mechanism without cutting, with intermediate yarn clamping and circumferential yarn guiding as described in claim 7, is characterized in that: The yarn pushing mechanism (3) also includes a yarn pushing piston chamber cover (34). The yarn pushing piston chamber cover (34) is fixedly installed at the opening of the yarn pushing piston chamber (11); The yarn pushing return component (32) is disposed between the yarn pushing piston chamber cover (34) and the piston portion of the yarn pushing piston rod (31).

9. The yarn-changing mechanism without cutting, with intermediate yarn clamping and circumferential yarn guiding as described in claim 3, is characterized in that: The yarn-changing mechanism with intermediate yarn clamp and circumferential yarn guide also includes a yarn-breaking blade (8). The yarn-breaking blade (8) is located at the edge of the yarn-pushing channel (24) on the upper head changing seat (2).

10. A control method for a yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding, applied to the yarn-changing mechanism for non-cutting yarn with intermediate yarn clamping and circumferential yarn guiding as described in claim 1; comprising the following working states: In the air-cut state, the yarn clamping piston rod (41) drives the yarn clamping plates (43) to move closer together under the action of the yarn clamping return member (42) to complete the yarn clamping action; the yarn guide piston rod (52) is pulled by the push-pull member (53) under the action of the yarn guide return member (55) to make the yarn guide rod (54) in an inclined state so as to guide the yarn to the upper yarn hook (6). In the ventilation state, the yarn clamping piston rod (41) drives the yarn clamping plate (43) to separate and return to its original position on both sides under the action of compressed air, and at the same time compresses the yarn clamping return piece (42); the yarn guide piston rod (52) is pushed by the push-pull component (53) under the action of compressed air to make the yarn guide rod (54) in a horizontal state, and at the same time compresses the yarn guide return piece (55).

Images