[0001]The present disclosure relates to a process for the production of nonwoven manufacturing apparatus and nonwovens. BACKGROUND [0002]Nonwoven, such as spunbond nonwoven fabric, medical, are widely used in sanitary materials, civil engineering materials and packaging materials and the like. Spunbond nonwoven fabric is cooled process using cooling air of a thermoplastic resin with respect to melt-spun filaments, and after the stretching process using the drawing style, be trapped deposited while diffusing onto the collecting medium It is produced from the web obtained in. [0003] 　Japanese Patent No. 2556953, is cross section in the horizontal direction rectangular, cooling chamber gradually cross section is reduced in the filament travel direction, is connected to the cooling chamber Each stepped recess is formed in the wall of the discharge port stretched nozzle, and has a connection fiber placement machine in the stretching nozzle, apparatus for producing a spun fiber strip of a synthetic resin filaments aerodynamically stretching is disclosed. Patent No. 2556953 No. fiber placement apparatus has a rectangular cross section in the horizontal direction, in the longitudinal direction has the form of a jet pump having Venturi Automobiles annular basin, and the diffuser outlet, the fiber strips placed amount of air sucked from the free air inlet by the intake pipe that is opposed to the diffuser outlet across the filter belt is to be adjusted. [0004] 　Japanese Patent No. 3135498, a nozzle plate having a plurality of nozzles, the processing shaft, has a transport unit and conveyor, the processing shaft and the transport unit process air flows, endless fibers from the nozzle holes of the nozzle plate body the release movement towards the conveyor as air and endless fiber group in the form of a mixture of fibers with the flows are flows during processing shaft, the transport unit is second only to the center of the inflow conduit and its endless fiber groups, up conveyor comprises a elongated to diffuser conduit, releasing motion and fleece forming exercise that overlap with it are forced granted, to produce a spin fleece web from thermoplastic endless fibers above both conduits extending in a direction transverse to the running direction of the conveyor belt apparatus is disclosed. Japanese Patent No. 3135498, inlet conduit and / or a diffuser duct is used for the mixing of air and fibers, circulation for additionally injecting air into the conduit that extends across the running direction of the conveyor belt across the width of the conduit slit-shaped, and comprises a aerodynamic histological like dispensing device in the form of outflow slit for discharging air from the conduit, the flow rate of air to be flow rate and outflow to be additionally feeding an additional supply of air and fibers affect the equal distribution of the fibers in the mixture are to be controlled or adjusted in order. Further, Japanese Patent No. 3135498, the inner surface of the inlet conduit and / or a diffuser conduit comprises a baffle member in the vicinity of the surface of the conduit longitudinal section, so that the spiral region is formed in the rear with respect to the flow direction . [0005] 　Japanese Patent No. 5094588, the spinneret is provided to form the filaments, downstream of the spinneret there is a cooling chamber fed with process air to cool the filaments, stretching unit for stretching the filaments is connected to a cooling chamber and which, being closed connection region between the stretching unit and the cooling chamber, stretching unit has a stretch passage passage wall which are branched on at least a portion of the length of the stretching path, at a stretching unit, branch extending additional air at the upstream end of the passage portion, the filament bundles have been injected into the stretching path by conditions widely formed in the machine direction, deposition apparatus is provided for depositing a spunbond web of filaments, formed from the filament apparatus for producing a spunbond was has been described. [0006] 　Further, Japanese Patent No. 5094588, the downstream drawing unit has a deposition unit comprises deposition unit from the adjacent downstream diffuser and upstream diffuser described to ambient air inlet slit is provided between the upstream diffuser and downstream diffuser is there. Summary of the Invention Problems that the Invention is to Solve [0007] 　Meanwhile, as an important characteristic relating to the quality of the nonwoven fabric, there is uniformity and intensity. For example, in Japanese Patent No. 3135498, although intended to mesh size to obtain a uniform nonwoven fabric, a highly uniform nonwoven entanglement of the filaments is insufficient, strength may be decreased. [0008] 　The present disclosure has been made in view of the above circumstances, aims to provide a method of manufacturing apparatus for and of nonwoven fabric manufacturing nonwoven fabric obtained while suppressing the uniformity is impaired improvement in strength is achieved nonwoven to. Means for Solving the Problems [0009] 　Apparatus for manufacturing a nonwoven fabric of the present disclosure in order to achieve the above object, comprises a slit-like air guide channel while being placed on the shaft upper side, the filaments with air toward the inlet side of the conductor air passage to the outlet side a first shaft portion to be supplied, are arranged on the shaft lower side, outlet side with the inlet side is communicated with the outlet side of the first shaft portion is arranged opposite the collecting unit for collecting the filaments, the opening width along the inlet side of the machine direction, and a second shaft portion that is widened than the opening width along the machine direction of the first shaft portion, the inlet side of the outlet side of the second shaft portion of the first shaft portion provided at the connection between, configured to include a step portion that connects the inlet side of the outlet side and the second shaft portion of the first shaft portion, and includes a diffusion shaft. [0010] 　Manufacturing method of the nonwoven fabric of the present disclosure includes a slit-like air guide channel while being placed on the shaft upper side, a first shaft portion which the filament with air is supplied toward the inlet side of the conductor air passage to the outlet side , disposed on the shaft bottom side, the inlet side outlet side together are communicated is arranged opposite the collecting unit for collecting the filaments on the outlet side of the first shaft portion, an opening along the machine direction of the inlet side width, the second shaft portion which is widened than the opening width along the machine direction of the first shaft portion, and provided at the connection between the inlet side of the outlet side of the second shaft portion of the first shaft portion, using the spreading shaft with stepped portions for connecting the inlet side of the outlet side and the second shaft portion of the first shaft portion, and supplies the filaments with air from the inlet side of the first shaft portion, the second shea The filaments ejected from the outlet side of the shift portion was collected deposited in the collection unit, generates a web nonwoven fabric is produced, comprises. [0011] 　Apparatus and a method for manufacturing the nonwoven fabric according to the present disclosure, the cooling unit, and a plurality of filaments to cool spinning unit for spinning a plurality of filaments from the molten resin obtained by melting the thermoplastic resin, a plurality of filaments spun It includes a stretching unit for stretching and generates a web was collected deposited in the collecting portion while diffusing the plurality of filaments stretched. Between the collecting unit and the extending portion is diffused shafts provided, is diffused in the machine direction of the air (jet air) passing through the diffusion shaft, by spewing into the collecting unit from the lower side of the opening of the diffusion shaft , highly uniform web is to be produced. [0012] 　Spreading the shaft includes a first shaft portion and the second shaft portion, a second shaft portion, the opening width along the machine direction of the inlet side also widened than the opening width along the exit side of the machine direction of the first shaft portion ing. Further, an outlet side of the first shaft portion and the inlet side of the second shaft portion are connected by the stepped portion. The jet air is introduced from the first shaft portion to the second shaft section, by passing the step portion, it occurs region speed varies the speed fluctuation is accelerated inside increases. A plurality of filaments which are conveyed along the second shaft portion of the diffusion shaft by jetting air is entanglement filaments is accelerated by the speed variation is large area of ​​the ejection wind occur. Accordingly, entanglement of the filaments is large and since webs obtained, a nonwoven fabric produced from the web, the strength is improved by has many tangled filaments. [0013] 　Stepped portion provided on the diffusion shaft, by spreading along the opening width in the machine direction between the first shaft portion and the second shaft section, there in the form capable of promoting the speed variation of the ejection air in the second shaft portion if good, only it needs to be provided on at least one side of the direction opposite to the machine direction side and the machine direction. [0014] 　Further, in the present disclosure, the step portion on each of opposite direction to the machine direction side and the machine direction, may be provided continuously along the machine width direction. [0015] 　Further, in the present disclosure, the step portion includes a first stepped portion provided on the machine direction, and a second step portion provided in the direction opposite to the machine direction, along the machine width direction it may be arranged alternately. [0016] 　Further, the second shaft portion in the present disclosure, may be formed so that the opening width along the machine direction is gradually wider toward the inlet side to the outlet side. Effect of the invention [0017] 　According to the present disclosure described above, it is possible to facilitate the entanglement occurs filaments being conveyed within the spreading shaft by the air to be jetted air, it is possible to obtain the nonwoven fabric strength is increased by entangling the filaments , there is an effect that. Therefore, according to the present disclosure, it is possible to provide a method of manufacturing apparatus for and of nonwoven fabric manufacturing nonwoven fabric obtained while suppressing the uniformity is impaired improvement in strength is achieved nonwoven. BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIG. 1 is a schematic diagram of a non-woven fabric manufacturing apparatus according to the present embodiment. FIG. 2 is a schematic perspective view showing a diffusion shaft of the spreading unit according to the present embodiment. [FIG 3A] is a schematic sectional view of a diffusion shaft according to the present embodiment. [FIG 3B] is a schematic sectional view of a diffusion shaft being compared. [FIG 4A] is a schematic perspective view showing an example of the other spreading shaft. [FIG. 4B] is a schematic perspective view showing an example of the other spreading shaft. [FIG. 4C] is a schematic perspective view showing an example of the other spreading shaft. 5 is a schematic sectional view showing another example of the spreading shaft. DESCRIPTION OF THE INVENTION [0019] 　Hereinafter, with reference to the drawings illustrating an example embodiment of the present disclosure in detail. FIG 1 shows a main part of the manufacturing apparatus 10 of the nonwoven fabric according to the present embodiment. Manufacturing apparatus 10 according to the present embodiment is used in the manufacture of spunbonded nonwoven fabric. In the following description, MD (machine direction) direction indicates the machine direction, CD (cross machine direction) direction indicates a width direction crossing the MD direction (machine width direction), UP direction, the vertical direction It shows the upper. [0020] 　Manufacturing apparatus 10 includes spinning unit 12 for generating a filament by spinning the molten resin thermoplastic resin used in the spunbond nonwoven is fused, the cooling unit 14 for cooling processing for the filament, and drawing with respect to the filament comprising a stretching unit 16 for processing. The manufacturing apparatus 10 is to collect the cooling process and the stretching filaments, provided with a collecting portion 18 spreading unit 20 spewing filaments toward, and into the collecting portion 18 to obtain a web composed of a non-woven fabric. [0021] 　Spinning unit 12 includes a spinneret 22 having a plurality of spinning nozzles are arranged, the molten resin introducing pipe 24 is connected to a spinneret 22. The spinning unit 12 is spun filaments from a plurality of spinning nozzle by the molten resin is introduced into a spinneret 22 from the molten resin introducing pipe 24. Thus, spinning unit 12 derives a plurality of filaments arranged in the CD direction. Cooling unit 14 is provided with a cooling chamber 26 in which a plurality of filaments spun is introduced, the cooling air supply duct 28 is connected to the cooling chamber 26. Cooling section 14, a plurality of filaments is introduced into the cooling chamber 26 is cooled by cooling air supplied from the cooling air supply duct 28. [0022] 　Stretching unit 16 (in FIG. 1, the paper front and back direction) opening cross section CD direction comprises stretching shaft 30 extending in the vertical direction is shorter narrow width longer MD direction. Stretching the shaft 30 of the extension part 16 has a plurality of filaments is introduced from the cooling unit 14. Stretching unit 16, the air air supplied separately from the stretching shaft 30 and the cooling air or cooling air is introduced together with a plurality of filaments and stretching air is derived while stretching the filaments introduced from the cooling unit 14. [0023] 　Collecting section 18 is provided with suction means (not shown) provided below the transfer zone 32, and transporting zone 32 of the collection medium which is formed by a mesh or a punching metal. The diffusion section 20 is provided with a diffusion shaft 36. Spreading shaft 36, opening of the upper side is directed to the opening of the lower side of the drawing shaft 30 of the extension part 16, the opening of the lower side is directed onto a collecting surface 32A of the transfer zone 32 of the collecting portion 18 ing. [0024] 　The diffusion shaft 36, a plurality of filaments which are cooled and stretched is introduced from the drawing the shaft 30. Spreading unit 20, an air wind introduced into the diffusion shaft 36 separately from the plurality of drawn air or drawing air is introduced into the diffusion shaft 36 from stretching shaft 30 with filaments and jetted air, conveying a plurality of filaments by jetting air and, spewing toward the lower side of the opening of the diffusion shaft 36 filaments to the collecting surface 32A of the transfer zone 32. Collecting section 18, the filaments expelled in collecting surface 32A of the transfer zone 32, was collected on a suction while collecting surface 32A by suction means, for generating a web comprising a nonwoven fabric. [0025] 　The diffusion shaft 36, a slit-shaped air guide passage is formed. Air guide path of diffusion shaft 36, inside the opening width (opening width along the MD direction) is formed so as to extend downward, ejection air passing through the diffusion shaft 36 spreads along the MD direction (diffusion ) it is way. Thus, in the manufacturing apparatus 10, it is diffused when multiple filaments passing through the diffusion shaft 36 of the spreading unit 20, are deposited is sprayed onto the collecting surface 32A of the collecting portion 18. The manufacturing apparatus 10 is in the range of up to the lower end and one hundred mm distance from several tens of mm of the collecting surface 32A of the transfer zone 32 of the diffusion shaft 36, the filament is more than necessary after being blown from the spreading shaft 36 so that is prevented from diffusing into. The manufacturing apparatus 10 is capable of applying a known configuration by spinning molten resin to produce a plurality of filaments, collecting the plurality of filaments generated cooling treatment and drawing treatment to. [0026] 　2 and 3A show the spreading shaft 36 of the spreading unit 20. As shown in FIGS. 1 to 3A, spreading shaft 36 includes an upper shaft 38 and lower shaft 40 as a second shaft portion of the first shaft portion. Further, the spreading shaft 36, the stepped portion 42 is provided in the connection portion between the upper shaft 38 and lower shaft 40. Spreading shaft 36, than the upper shaft 38 are long length direction of the lower shaft 40 along the vertical direction, the step portion 42 is formed on the upper side than the middle portion of the vertical diffusion shaft 36 there. [0027] 　As shown in FIG. 2, the upper shaft 38 has a wall portion 44A and the wall portion 44B are arranged in pairs along the MD direction, a pair of side wall portions 44C are disposed in the CD direction. The top shaft 38, forming wall portion 44A, the 44B and the pair of side wall portions 44C, the opening cross section of the opening 38A and the lower end of the opening 38B of the upper end, narrower in the MD direction, the longer the long rectangular tube body shape in the CD direction It is. [0028] 　As shown in FIGS. 2 and 3A, the upper shaft 38, the opening width of the upper end of the opening 38A (opening width along the MD direction) and the opening length (aperture length along the CD direction), stretching the shaft 30 (FIG. aligned with the opening (not shown) of the lower end portion of the first reference), a plurality of filaments derived from stretching shaft 30 is introduced. The upper shaft 38, the wall portion 44A, 44B are well be parallel to each other, the opening width toward the opening 38A into the opening 38B may be slightly inclined so as to gradually increase. In this embodiment, the wall portion 44A such that the opening width gradually increases toward the opening 38A into the opening 38B, 44B and is inclined, thereby, the upper shaft 38, the opening width of the lower end of the opening 38B It is slightly larger than the opening width of the upper end of the opening 38A. [0029] 　As shown in FIG. 2, the lower shaft 40, the wall portion 46A and the wall portion 46B are arranged in pairs along the MD direction, the pair of side wall portions 46C (FIG. 2 in the CD direction, only one shown ) are arranged. Lower shaft 40, forming wall portion 46A, the 46B and the pair of side wall portions 46C, the opening cross section of the opening 40A and the lower end of the opening 40B of the upper end, narrower in the MD direction, the longer the long rectangular tube body shape in the CD direction It is. [0030] 　The lower shaft 40 has an opening 40A of the upper end is opposite to the opening 38B of the upper shaft 38, an opening 40B of the lower end is opposed to the transfer zone 32 of the collecting portion 18. Further, as shown in FIGS. 2 and 3A, the lower shaft 40, the wall portion 46A such that the opening width gradually increases toward the opening 40A to 40B, 46B are inclined. Thus, the lower shaft 40 is the opening width gradually increases toward the opening 40A of the upper end to the lower end of the opening 40B, the opening width of the lower end of the opening 40B is greater than the opening width of the upper end of the opening 40A . The lower shaft 40 may if not the opening width towards at least the upper end of the opening 40A to the lower end of the opening 40B is narrow, the lower shaft 40, an opening width changes from the opening 40A of the upper end to the lower end of the opening 40B it may be a non configuration. [0031] 　On the other hand, as shown in FIG. 3A, spreading shaft 36, the opening width Wd of the upper end of the opening 40A of the lower shaft 40 is larger than the opening width Wu of the lower end of the opening 38B of the upper shaft 38 (Wu