Fibre bundle gathering device in a spinning machine

Abstract

Provided is a fiber bundle gathering device in a spinning machine that can shorten the distance that a fiber bundle becomes free after being output from a final output roller pair. An upstream end portion (31) of a suction pipe (15) of the fiber bundle gathering device is provided with: an introduction face (31c) that is located at a position on the front portion lower roller (13a) side than a common tangent L at a nip point of the final output roller pair, and that introduces an airflow to a suction slit (27); and a flow path expansion face (31b) that intersects the introduction face (31c) and is located at a position on the outer surface side than an inner surface of the suction pipe (15), and that expands a flow path of the airflow more than at the introduction face (31c). A first angle that a first imaginary line (D1) along the introduction face (31c) makes with the common tangent L is smaller than a second angle (θ2) that a second imaginary line (D2) along the flow path expansion face (31b) makes with the common tangent L.

Description

Technical Field

[0001] This invention relates to a fiber bundle bundling device in a spinning machine. Background Technology

[0002] For example, as disclosed in Patent Document 1, the fiber bundle bundling device is located downstream of the final output roller pair of the drafting device of the spinning machine. The fiber bundle bundling device includes a suction tube and a breathable conveyor belt.

[0003] A suction slit is formed on the suction tube. Furthermore, the suction tube is connected to the suction conduit via a connecting tube. A portion of the breathable conveyor belt is wound around the suction tube. The breathable conveyor belt is, for example, made of a woven fabric capable of ensuring adequate breathability.

[0004] When the spinning machine is running, suction based on the suction pipe acts on the suction pipe via the connecting pipe. Thus, the suction force generated by the suction slit acts on the fiber bundle via the breathable conveyor belt. Consequently, the fiber bundle is attracted to the position on the breathable conveyor belt corresponding to the suction slit, bundled, and transported by the breathable conveyor belt.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-87419

[0006] During the period from when the fiber bundle is output from the final output roller pair until it is adsorbed by the breathable conveyor belt above the suction tube, it is in a free state without being constrained by the roller pair, and therefore, the fibers are prone to disorder. In order to suppress the disorder of the fibers, it is preferable to shorten the distance during which the fiber bundle is in a free state after being output from the final output roller pair.

[0007] The fiber bundle is output along the common tangent at the clamping point of the final output roller pair. Therefore, it is considered to increase the suction force generated by the suction slit by expanding the upstream end of the suction slit downwards from the common tangent to the roller side, thereby shortening the distance by which the fiber bundle is quickly adsorbed onto the breathable conveyor belt and thus freeing the fiber bundle.

[0008] However, if the upstream end of the suction slit is expanded downwards towards the roller side, the airflow flowing along the upstream end tends to form vortices along the inner surface of the suction tube. This generation of vortices slows down the airflow velocity flowing in along the upstream end. If the airflow velocity near the upstream end slows down, the time it takes for the fiber bundle to be adsorbed by the breathable conveyor belt is delayed. Therefore, regardless of whether the upstream end of the suction slit is expanded, the distance the fiber bundle travels to become free remains unchanged. Summary of the Invention

[0009] A fiber bundle bundling device in a spinning machine for solving the above-mentioned problems includes: a suction tube disposed downstream of a final output roller pair having a lower roller and an upper roller, and having a suction slit; and a breathable conveyor belt that rotates while being wound around the suction tube in a manner covering the suction slit to transport the fiber bundle. An airflow flowing into the suction slit causes the fiber bundle to adhere to the breathable conveyor belt and bundle the fiber bundle, and the fiber bundle is then transported in the transport direction via the breathable conveyor belt. The main feature of the fiber bundle bundling device in the spinning machine is that the suction slit is in the transport direction... The upstream end is provided on the curved surface of the suction tube facing the lower roller, and includes: an inlet surface located closer to the lower roller side than the common tangent at the clamping point of the final output roller pair, and introducing the airflow into the suction slit; and a flow path expansion surface intersecting the inlet surface and located at a position closer to the outer surface side than the inner surface of the suction tube, and expanding the flow path of the airflow compared to the flow path at the inlet surface, wherein the size of the first angle between the first imaginary line along the inlet surface and the common tangent is smaller than the second angle between the second imaginary line along the flow path expansion surface and the common tangent.

[0010] Accordingly, the guide surface extends beyond the common tangent and is located on the lower roller side. Therefore, compared to the case where the guide surface extends beyond the common tangent and is located on the upper roller side, the amount of airflow flowing into the suction slit can be increased. Furthermore, the flow path expansion surface expands the flow path of the airflow following the guide surface. Thus, the flow path expansion surface causes the airflow following the guide surface to flow in a direction intersecting the common tangent. This reduces the area where vortices are generated between the inner surface of the suction tube and the airflow. As a result, even if vortices are generated inside the suction tube, the decrease in airflow velocity caused by these vortices can be suppressed. Therefore, even with the upstream end located on the lower roller side (below the common tangent), the fiber bundle is rapidly adsorbed onto the breathable conveyor belt, thus shortening the distance the fiber bundle remains in a free state.

[0011] Alternatively, for a fiber bundle gathering device in a spinning machine, the aforementioned inlet surface is an inclined surface forming the aforementioned upstream end.

[0012] Accordingly, the airflow flows along the inclined surface into the suction slit. Therefore, the inclined surface allows for efficient airflow into the suction slit.

[0013] Alternatively, for the fiber bundle bundling device in a spinning machine, the aforementioned inclined surface can be a flat surface.

[0014] Therefore, airflow can be efficiently introduced into the suction slit.

[0015] Alternatively, for a fiber bundle bundling device in a spinning machine, the aforementioned guide surface extends along the common tangent direction.

[0016] Therefore, the direction of airflow is consistent with the direction of the common tangent, which enables the fiber bundles to be adsorbed onto the breathable conveyor belt more quickly.

[0017] Alternatively, for the fiber bundle gathering device in a spinning machine, the upstream end has an intersecting surface that is orthogonal to the flow path expansion surface and extends from the inner surface of the suction tube toward the flow path expansion surface.

[0018] Therefore, when forming a flow path expansion surface in the suction tube, the inner surface of the suction tube is machined to form the flow path expansion surface. At this time, it is possible to form a cross surface and a flow path expansion surface simultaneously, thus making it easy to form the flow path expansion surface.

[0019] This invention can shorten the distance from the final output roller pair after the fiber bundle becomes free. Attached Figure Description

[0020] Figure 1 This is a partial cross-sectional schematic side view of the fiber bundle bundling device.

[0021] Figure 2 It is a 3D diagram representing a suction tube.

[0022] Figure 3 This is an enlarged view showing the suction slit.

[0023] Figure 4 This is a partially enlarged sectional view of the upstream end.

[0024] Figure 5 It is a schematic diagram showing the clamping point and the upstream end.

[0025] Figure 6 This is an enlarged sectional view of the upstream end.

[0026] Figure 7 This is a schematic diagram showing the clamping point and upstream end in the comparative example.

[0027] Figure 8 This is an enlarged sectional view showing the upstream end of another example.

[0028] Figure 9 This is an enlarged sectional view showing the upstream end of another example.

[0029] Explanation of reference numerals in the attached figures

[0030] θ1...First angle; θ2...Second angle; D1...First imaginary line; D2...Second imaginary line; F...Fiber bundle; L...Common tangent; P1...Clamping point; R...Common tangent direction; 11...Fiber bundle bundling device; 13...Final output roller pair; 13a...Front lower roller; 13b...Front upper roller; 15...Suction tube; 15f...Curved surface; 16...Ventilating conveyor belt; 27...Suction slit; 31...Upstream end; 31a...Intersecting surface; 31b...Flow path expansion surface; 31c...Inlet surface. Detailed Implementation

[0031] The following is based on Figures 1 to 7 An embodiment of the fiber bundle bundling device in a spinning machine as a fiber bundle bundling device in a spinning frame will be described.

[0032] <The complete spinning frame>

[0033] like Figure 1 As shown, the spinning frame includes a fiber bundle bundling device 11 and a drafting device 12. The drafting device 12 includes a final output roller pair 13, which includes a front lower roller 13a as a lower roller and a front upper roller 13b as an upper roller. A gear portion 13c is formed on the front lower roller 13a. The fiber bundle F drafted by the drafting device 12 is output towards the fiber bundle bundling device 11 by the final output roller pair 13.

[0034] <Fiber Bundle Bundling Device>

[0035] The fiber bundle gathering device 11 includes a suction pipe 15, a breathable conveyor belt 16, an output section 14, and a guide section 17.

[0036] <Output Department>

[0037] The output section 14 includes a lower clamping roller 18a and an upper clamping roller 19.

[0038] The lower clamping roller 18a is configured to rotate integrally with the rotating shaft 18, which is arranged parallel to and close to the front lower roller 13a of the final output roller pair 13. Furthermore, a gear 22 is provided on the rotating shaft 18 in a manner that allows it to rotate integrally with the rotating shaft 18. Gear section 13c and gear 22 mesh with intermediate gear 25. The torque of the front lower roller 13a is transmitted to the rotating shaft 18 via gear section 13c, intermediate gear 25, and gear 22. This causes the lower clamping roller 18a to rotate.

[0039] The upper clamping roller 19 is pressed against the lower clamping roller 18a via the ventilated conveyor belt 16. The upper clamping roller 19 is supported by a counterweight arm (not shown) via the support member 20.

[0040] <Suction tube>

[0041] The spinning frame is equipped with a suction pipe (not shown) extending along the long side of the machine. The suction pipe 15 is connected to the suction pipe via a connecting pipe 26 while extending parallel to the suction pipe. The suction pipe 15 is located downstream of the final output roller pair 13 of the drafting device 12, and a suction slit 27 is formed in the suction pipe 15.

[0042] The suction tube 15 has a guide surface 28 with a suction slit 27. The breathable conveyor belt 16 rotates with a portion of the breathable conveyor belt 16 partially wound around the suction tube 15 and partially wound around the guide portion 17, covering the suction slit 27. The fiber bundles F adsorbed by the breathable conveyor belt 16 are conveyed along the conveying direction V by the rotation of the breathable conveyor belt 16. The breathable conveyor belt 16 is, for example, formed of a woven fabric that can ensure adequate breathability.

[0043] The suction tube 15 is located downstream of the fiber bundle F in the transport direction V, relative to the clamping point P1 of the final output roller pair 13. Furthermore, the suction tube 15 is located upstream of the fiber bundle F in the transport direction V, relative to the clamping point P2 of the output section 14.

[0044] like Figure 1 and Figure 2 As shown, the suction tube 15 has a guide surface 28 on its outer surface. The guide surface 28 is an arcuate surface with a width in the conveying direction V, which is gently curved along the conveying direction V. The guide surface 28 extends between the clamping points P1 and P2, connecting the clamping point P1 of the final output roller pair 13 and the clamping point P2 of the output section 14. Therefore, the fiber bundle F output from the final output roller pair 13 is guided from the clamping point P1 of the final output roller pair 13 toward the clamping point P2 of the output section 14 by the guide surface 28 formed via the breathable conveyor belt 16.

[0045] In the suction tube 15, the guide surface forming portion 15a that forms the guide surface 28 is a plate-shaped part that is gently curved along the transport direction V of the fiber bundle F. The suction tube 15 has a bottom portion 15b facing the guide surface forming portion 15a. The dimension of the bottom portion 15b in the transport direction V is smaller than the dimension of the guide surface forming portion 15a in the transport direction V.

[0046] The suction tube 15 has a first curved portion 15c that connects the downstream end of the guide surface forming portion 15a in the conveying direction V to the downstream end of the bottom portion 15b in the conveying direction V. The first curved portion 15c is curved in an arc shape along the circumferential surface of the lower clamping roller 18a. The first curved portion 15c faces the circumferential surface of the lower clamping roller 18a.

[0047] The suction tube 15 has a curved section 15f that is continuous with the upstream end of the guide surface forming portion 15a in the conveying direction V, and a second curved portion 15d that connects the curved section 15f to the upstream end of the bottom portion 15b. The second curved portion 15d is curved in an arc shape along the circumferential surface of the front lower roller 13a. The second curved portion 15d faces the circumferential surface of the front lower roller 13a.

[0048] The curved section 15f is disposed downstream of the fiber bundle F in the conveying direction V, relative to the clamping point P1 of the final output roller pair 13. Furthermore, the curved section 15f faces the circumferential surface of the front lower roller 13a of the final output roller pair 13 in the conveying direction V.

[0049] <Suction Slit>

[0050] like Figure 2 and Figure 3 As shown, the width direction of the suction slit 27 is aligned with the long side direction of the suction tube 15. The suction slit 27 includes: an upstream end portion 31 extending linearly along the width direction (the width direction of the suction slit 27), a guide edge portion 29 extending from one of the two ends of the upstream end portion 31 in the width direction, a side edge portion 30 extending from the other end of the upstream end portion 31, and a downstream end portion 32 connected to the guide edge portion 29 and the side edge portion 30.

[0051] The guide edge 29 is an edge for bundling the fiber bundle F. The guide edge 29 includes: a widened portion 29a that is continuous with the upstream end 31; and a downstream portion 29b that is continuous with the widened portion 29a and extends obliquely in a manner that narrows the slit width.

[0052] Here, the direction orthogonal to the long side of the suction tube 15 is defined as the orthogonal direction X. The fiber bundle F output from the final output roller pair 13 travels along the orthogonal direction X near the curved portion 15f of the guide surface 28. Furthermore, the downstream portion 29b of the guide edge 29 is inclined relative to the orthogonal direction X. Moreover, the fiber bundle F traveling along the orthogonal direction X at the guide surface 28 is guided by the guide edge 29 to travel along the widened portion 29a and the downstream portion 29b.

[0053] The side edge portion 30 includes a straight portion 30d extending linearly from the upstream end 31 and a downstream portion 30c continuous with the straight portion 30d. The straight portion 30d extends linearly in a manner parallel to the orthogonal direction X. The downstream portion 30c is inclined relative to the orthogonal direction X.

[0054] From upstream to downstream in the conveying direction V, the slit width of the suction slit 27 gradually widens due to the widening portion 29a and the straight portion 30d, then gradually narrows due to the downstream portion 29b and the straight portion 30d, and finally becomes substantially constant due to the downstream portion 29b of the guide edge portion 29 and the downstream portion 30c of the side edge portion 30.

[0055] Furthermore, the length ratio of the widened portion 29a to the downstream portion 29b of the guide edge 29 of the suction slit 27, the length ratio of the straight portion 30d to the downstream portion 30c of the side edge 30, or the length ratio of the straight portion 30d relative to the entire side edge 30 are appropriately set according to the relationship formed with the inclination of the guide edge 29 or the required quality of the yarn to be spun.

[0056] <Upstream End>

[0057] The upstream end 31 is formed by machining the suction tube 15 with an end mill after the suction slit 27 is formed in the suction tube 15. Specifically, it is formed by moving the end mill along the width direction of the suction slit 27 while keeping it in contact with the upstream end 31.

[0058] like Figure 4 As shown, the upstream end 31 of the suction slit 27 is disposed on the curved surface 15f. The upstream end 31 has a cross surface 31a, a flow path expansion surface 31b, an inlet surface 31c, and an arcuate surface 31f. The cross surface 31a, the flow path expansion surface 31b, the inlet surface 31c, and the arcuate surface 31f extend throughout the entire upstream end 31 in the long side direction of the suction tube 15.

[0059] The inlet surface 31c is smoothly connected to the outer surface of the suction tube 15 via the arc-shaped surface 31f. The inlet surface 31c is a flat inclined surface that slopes downward along the transport direction V of the fiber bundle F from upstream to downstream.

[0060] like Figure 5 and Figure 6 As shown, an imaginary line extending through the guide surface 31c and along the orthogonal direction X is designated as the first imaginary line D1. The first imaginary line D1 is located on the side of the lower roller 13a closer to the common tangent line L at the clamping point P1. Specifically, the first imaginary line D1 is located on the side closer to the bottom 15b of the suction tube 15 than the common tangent line L. Here, if the extension direction of the common tangent line L is set as the common tangent direction R, then the extension direction of the first imaginary line D1 is consistent with the common tangent direction R. Moreover, since the guide surface 31c is located closer to the front lower roller 13a than the common tangent line L, the first imaginary line D1 is located at a position away from the front lower roller 13a from the common tangent line L.

[0061] The angle between the first imaginary line D1 and the common tangent L is defined as the first angle θ1. Furthermore, in this embodiment, the first angle θ1 is 0 degrees; therefore, in... Figure 5 and Figure 6The first angle θ1 is not illustrated. As the first angle θ1 increases, the inlet surface 31c reaches the inner surface of the suction tube 15, therefore, the flow path expansion surface 31b and the intersection surface 31a cannot be formed. Therefore, the maximum value of the first angle θ1 is set to the angle that can form the intersection surface 31a and the flow path expansion surface 31b.

[0062] Furthermore, as the first angle θ1 decreases, at its minimum value of 0 degrees, the first imaginary line D1 is parallel to the common tangent line L. If the first angle θ1 becomes 0 degrees, the direction of airflow along the guide surface 31c is consistent with the direction of the common tangent line R. This allows the airflow to flow along the transport direction V of the fiber bundle F output from the clamping point P1, which is therefore preferable. Therefore, in this embodiment, the first angle θ1 is 0 degrees.

[0063] The flow path expansion surface 31b is a flat surface that intersects the inlet surface 31c at an angle relative to it. Furthermore, the flow path expansion surface 31b is formed on the outer surface side of the inner surface of the suction tube 15. Since the inlet surface 31c is located closer to the front lower roller 13a than the common tangent line L, the flow path expansion surface 31b, which connects to the inlet surface 31c, is also located closer to the front lower roller 13a than the common tangent line L. Moreover, the flow path expansion surface 31b extends away from the common tangent line L, with the boundary between it and the inlet surface 31c as its starting point.

[0064] The imaginary line extending through the flow path expansion surface 31b and along the orthogonal direction X is designated as the second imaginary line D2. The extension direction of the second imaginary line D2 intersects the common tangent direction R. The angle between the second imaginary line D2 and the common tangent L is designated as the second angle θ2. The magnitude of the second angle θ2 is greater than the magnitude of the first angle θ1. In other words, the magnitude of the first angle θ1 is less than the magnitude of the second angle θ2.

[0065] As the second angle θ2 decreases, it becomes impossible to form the cross surface 31a. Therefore, the minimum value of the second angle θ2 is the angle at which the cross surface 31a can be formed. As the second angle θ2 increases, the cross surface 31a approaches the outer surface side of the suction tube 15. Therefore, a portion recessed towards the outer surface side of the suction tube 15 is formed between the flow path expansion surface 31b and the cross surface 31a. This easily generates vortices in the recessed portion, which is therefore undesirable. Therefore, it is preferable to set the second angle θ2 such that the cross surface 31a is orthogonal to the flow path expansion surface 31b.

[0066] The intersecting surface 31a is a surface that intersects the inner surface of the suction tube 15. The intersecting surface 31a is a flat surface orthogonal to the flow path expansion surface 31b. Therefore, the intersecting surface 31a is orthogonal to the flow path expansion surface 31b and extends from the inner surface of the suction tube 15 toward the flow path expansion surface 31b. Furthermore, a step is formed on the inner surface of the curved portion 15f of the suction tube 15 through the intersecting surface 31a and the flow path expansion surface 31b.

[0067] <The Role of the Implementation Method>

[0068] If the spinning frame is running, the fiber bundle F, after being drafted by the drafting device 12, is output from the final output roller pair 13 toward the fiber bundle bundling device 11. At this time, if... Figure 5 As shown, fiber bundle F is output from the final output roller pair 13 along the common tangent L. Furthermore, fiber bundle F is drawn in by the suction tube 15 and attracted by the breathable conveyor belt 16, causing fiber bundle F to move from the clamping point P1 of the final output roller pair 13 towards the clamping point P2 of the output section 14. Subsequently, fiber bundle F is guided by the guide surface 28 via the breathable conveyor belt 16 and conveyed by the breathable conveyor belt 16 in the conveying direction V.

[0069] <Comparative Example>

[0070] Here, the upstream end 71 of the comparative example will be described.

[0071] like Figure 7 As indicated by arrow Y, due to the suction effect of the suction pipe, an airflow is generated flowing towards the upstream end 71 of the suction slit 27. In the comparative example, the upstream end 71 has a plane 71a extending from the outer surface to the inner surface of the suction pipe 15. The plane 71a of the upstream end 71 extends beyond the common tangent L and is located on the front lower roller 13a side, but it does not have a flow path expansion surface 31b or a cross surface 31a. Therefore, in the comparative example, at the upstream end 71, the airflow following the flow along the plane 71a continues to flow in the common tangent direction R. This generates a vortex in the region W between the inner surface of the suction pipe 15 and the airflow. In the comparative example, this vortex causes a decrease in the airflow velocity near the inner surface of the suction pipe 15. Furthermore, in the comparative example, the fiber bundle F output from the final output roller pair 13 is adsorbed by the breathable conveyor belt 16 on the side of the upper roller 13b, which is further forward than the common tangent L.

[0072] Next, the function of the upstream end 31 in the implementation method will be explained in comparison with a comparative example.

[0073] like Figure 6As indicated by arrow Y, the suction effect of the suction pipe generates an airflow that flows towards the upstream end 31 of the suction slit 27. The inlet surface 31c of the upstream end 31 extends beyond the common tangent L and is located on the front lower roller 13a side. Therefore, compared to the case where the inlet surface 31c extends beyond the common tangent L and is located on the front upper roller 13b side, the amount of airflow flowing towards the suction slit 27 can be increased.

[0074] Furthermore, the flow path of the airflow following the inlet surface 31c is expanded by the flow path expansion surface 31b. Therefore, the airflow following the inlet surface 31c flows away from the common tangent L by the flow path expansion surface 31b. In other words, the flow path of the airflow following the inlet surface 31c is expanded. Moreover, although a vortex is generated between the airflow after flow path expansion and the inner surface of the suction tube 15, the area W where this vortex is generated is smaller than in the comparative example. As a result, even if a vortex is generated inside the suction tube 15, the decrease in airflow velocity caused by this vortex can be suppressed. Therefore, the fiber bundle F output from the final output roller pair 13 is adsorbed by the breathable conveyor belt 16 near the intersection of the common tangent L and the second imaginary line D2. As a result, compared to the case in the comparative example where the fiber bundle F is adsorbed by the breathable conveyor belt 16 on the side of the upper roller 13b further forward of the common tangent L, the fiber bundle F output from the final output roller pair 13 can be rapidly adsorbed by the breathable conveyor belt 16. As a result, the distance from the final output roller to the 13th output of the fiber bundle F to become free is shortened.

[0075] According to the above implementation method, the following effects can be obtained.

[0076] (1) By using the guide surface 31c located on the side of the lower roller 13a, which is ahead of the common tangent line L, the amount of airflow flowing into the suction slit 27 can be increased. Furthermore, by using the flow path expansion surface 31b, the region W of the vortex generated along the inner surface of the suction tube 15 can be reduced. As a result, by using the upstream end 31, the amount of airflow drawn by the suction slit 27 can be increased, and the decrease in flow velocity caused by the vortex can also be suppressed. Therefore, the fiber bundle F can be quickly adsorbed onto the breathable conveyor belt 16. Therefore, the free state of the fiber bundle F from the output of the final output roller pair 13 to the adsorption by the breathable conveyor belt 16 can be shortened, thus suppressing fiber disorder of the fiber bundle F.

[0077] (2) Through the inlet surface 31c, the airflow flowing along the common tangential direction R can be kept in its original state and introduced into the suction slit 27. Compared with the case where the inlet surface 31c is not formed, the amount of airflow flowing into the suction slit 27 can be increased. As a result, the fiber bundle F can be adsorbed onto the breathable conveyor belt 16 more quickly than when the inlet surface 31c is not formed, and the fiber bundle F can be easily bundled. In addition, through the flow path expansion surface 31b, the area W where vortices are generated can be reduced. According to the above, the fiber bundle F can be adsorbed quickly and a suction force capable of bundling can be generated without increasing power consumption.

[0078] (3) The fiber bundle F output from the final output roller pair 13 can be quickly adsorbed onto the breathable conveyor belt 16 via the upstream end 31. As a result, the quality of the yarn made from the fiber bundle F can be stabilized.

[0079] (4) In order to quickly adsorb the fiber bundle F output from the final output roller pair 13 onto the breathable conveyor belt 16, it is advisable to bring the suction pipe 15 close to the front lower roller 13a. However, there is a limit to how close the suction pipe 15 can be to the front lower roller 13a in order to prevent the fiber bundle F from getting clogging when it gets wrapped around the front lower roller 13a. However, by forming an inlet surface 31c and a flow path expansion surface 31b at the upstream end 31, it is possible to quickly adsorb the fiber bundle F output from the final output roller pair 13 onto the breathable conveyor belt 16 without bringing the suction pipe 15 close to the front lower roller 13a.

[0080] (5) The inlet surface 31c is an inclined surface that intersects with the flow path expansion surface 31b. Therefore, airflow can be efficiently introduced into the suction slit 27 through the inlet surface 31c.

[0081] (6) The inlet surface 31c is a flat inclined surface. For example, compared with the case where the inlet surface 31c is a curved inclined surface, airflow can be efficiently introduced into the suction slit 27.

[0082] This embodiment can be modified as follows. This embodiment and the following modifications can be combined and implemented to the extent that they do not contradict each other technically.

[0083] The shape of the upstream end 31 of the suction slit 27 is not limited to a straight shape extending along the long side of the suction tube 15. For example, it can also be a shape that extends obliquely relative to the orthogonal direction X.

[0084] ○ It can also replace the case where the breathable conveyor belt 16 is formed by making many holes in the rubber or elastic resin belt body instead of the case where the belt is made of woven or knitted fabric.

[0085] ○ For example Figure 8As shown, the guide surface 31c can also be formed by defining the inner surface of the through hole 33 that extends through the curved surface 15f along the thickness direction.

[0086] ○ For example Figure 9 As shown, regarding the first angle θ1 formed by the common tangent L and the first imaginary line D1, as long as it is smaller than the second angle θ2, it can also be greater than 0 degrees.

[0087] The size of the second angle θ2 can be appropriately changed as long as it is larger than the first angle θ1.

[0088] Alternatively, in the upstream end 31, there is no intersection surface 31a that intersects with the inner surface of the suction tube 15. In this case, the flow path expansion surface 31b is formed along the inner surface of the suction tube 15.

[0089] ○ The flow path expansion surface 31b and the intersection surface 31a can be non-orthogonal as long as they intersect.

Claims

1. A fiber bundle bundling device for a spinning machine, comprising: A suction tube, located downstream of the final output roller pair comprising a lower roller and an upper roller, and having a suction slit; and A breathable conveyor belt, which rotates while being wound around the suction tube in a manner covering the suction slit, transports fiber bundles. The fiber bundles are attracted to the breathable conveyor belt and bundled by the airflow flowing into the suction slit, and then conveyed in the conveying direction by the breathable conveyor belt. The fiber bundle bundling device in the spinning machine is characterized in that... With respect to the upstream end of the suction slit in the conveying direction, The upstream end is located on the curved section of the suction tube facing the lower roller. Furthermore, the upstream end has: The inlet surface, located on the lower roller side closer to the common tangent at the clamping point of the final output roller pair, guides the airflow into the suction slit; and A flow path expansion surface, which intersects the inlet surface and is located on the outer surface side of the inner surface of the suction tube, expands the flow path of the airflow compared to the flow path at the inlet surface. An imaginary line extending through the inlet surface and in a direction orthogonal to the long side of the suction tube is designated as the first imaginary line, and an imaginary line extending through the flow path expansion surface and in the orthogonal direction is designated as the second imaginary line. The first angle between the first imaginary line and the common tangent is smaller than the second angle between the second imaginary line and the common tangent.

2. The fiber bundle bundling device in a spinning machine according to claim 1, characterized in that, The inlet surface is an inclined surface that forms the upstream end.

3. The fiber bundle bundling device in a spinning machine according to claim 2, characterized in that, The inclined surface is a flat surface.

4. The fiber bundle bundling device in a spinning machine according to claim 1 or 2, characterized in that, The inlet surface extends along the common tangent direction.

5. The fiber bundle bundling device in a spinning machine according to claim 1 or 2, characterized in that, The upstream end has an intersecting surface that is orthogonal to the flow path expansion surface and extends from the inner surface of the suction tube toward the flow path expansion surface.

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