distributor

Abstract

Distributor (10), comprising: passage-forming elements (14) arranged in one direction, each passage-forming element (14) having a passage (61, 62) therein; and tubular couplings (81, 82) partially projecting outwardly from the respective passage-forming elements (14), each coupling (81, 82) having a tube insertion hole (97) connected to the passage (61, 62), wherein: the couplings (81, 82) are adjacent to each other in an arrangement direction of the passage-forming elements (14), flexible tubes (80), each having a circular cross-section, are inserted into the corresponding tube insertion holes (97) of the couplings (81, 82), Parts of the couplings (81, 82) which protrude from the passage-forming elements (14) each have the shape of an elongated tube, when each coupling (81, 82) is viewed in an axial direction, a transverse direction of the coupling (81, 82) coincides with the arrangement direction, at least a part of each pipe insertion hole (97) is a stadium-shaped hole (98), each pipe insertion hole (97) having a hole (88) of decreasing diameter, and when each coupling (81, 82) is viewed in the axial direction, a transverse direction of the hole (98) coincides with the transverse direction of the coupling (81, 82).

Description

Technical FieldThe present invention relates to a manifold having couplings into which flexible tubes are inserted, each flexible tube having a circular cross-section.Prior ArtAs disclosed in Patent Document 1, a manifold includes a plurality of manifold blocks, a plurality of electromagnetic valves, and a plurality of couplings. The manifold blocks are arranged in one direction. Each manifold block includes a passage formed therein. An electromagnetic valve is mounted on each manifold block. A tubular coupling projects outwardly from the manifold block. The coupling includes a pipe insertion hole connected to the passage of the manifold block. The couplings are adjacent to one another in the arrangement direction of the distributor blocks. For example, flexible tubes are inserted into the respective tube insertion holes, each flexible tube having a circular cross section.In order to increase the flow rate of a fluid flowing in the passage of the manifold block, a pipe having a large flow cross section is inserted into the pipe insertion hole in some cases. In such a case, the diameter of the pipe insertion hole of the coupling needs to be increased according to the flow cross-sectional area of the pipe. For example, in a case where the pipe insertion hole of the coupling is a circular hole, the outer diameter of the coupling increases as the diameter of the pipe insertion hole is increased. Thus, when the outer diameter of the coupling is excessively increased, the couplings adjacent to each other in the arrangement direction of the manifold blocks are likely to interfere with each other. In such a case, the distance between adjacent manifold blocks may be increased so that the adjacent couplings do not interfere with each other. However, an increase in the distance between the adjacent manifold blocks results in an increase in the size of the manifold in the arrangement direction of the manifold blocks.Prior Art DocumentThe patent specification is incorporated herein by referencePatent Document 1: JP 2002-39 419 ASUMMARY OF THE INVENTIONProblems to be Solved by the InventionIt is an object of the present invention to provide a manifold capable of increasing the flow rate of a fluid flowing in a passage while limiting an increase in size.Means for Achieving the ObjectIn a first aspect of the present invention, a manifold is provided that includes passage forming members and tubular couplings. The passage forming members are arranged in one direction. Each passage forming member has a passage in its interior. The tubular couplings partially project outwardly from the respective passage-forming elements. Each coupling includes a pipe insertion hole connected to the passage. The couplings are adjacent to each other in an arrangement direction of the passage forming members. Flexible tubes each having a circular cross section are inserted into the respective tube insertion holes of the couplings. Portions of the couplings protruding from the passage forming elements each have the shape of an elongated tube. When each coupling is viewed in an axial direction, a transverse direction of the coupling coincides with the arrangement direction. At least a portion of each pipe insertion hole is a stadione-shaped hole, each pipe insertion hole having a decreasing diameter hole. When each coupling is viewed in the axial direction, a transverse direction of the hole coincides with the transverse direction of the coupling.Brief Description of the DrawingsFIG. 1 is a perspective view of an electromagnetic valve manifold according to an embodiment. FIG. 2 is a longitudinal sectional view of the solenoid valve manifold. FIG. 3 is an enlarged longitudinal sectional view of a portion including a first coupling. FIG. 4 is a front view of the first coupling. FIG. 5 is a cross-sectional view taken along line 5- 5 of FIG. 3. FIG. 6 is a front view showing a first coupling according to another embodiment. FIG. 7 is a front view showing a first coupling according to another embodiment. FIG. 8 is a perspective view showing a first coupling according to another embodiment.Embodiments of the InventionA distributor according to an embodiment will now be described with reference to FIGS. 1 to 5. The manifold of the present embodiment is a solenoid valve manifold including a plurality of solenoid valves.As shown in FIG. 1, an electromagnetic valve manifold 10 includes a first end block 11, a second end block 12, a supply / discharge block 13, and a plurality of manifold blocks 14. the first end block 11, the second end block 12, the supply / discharge block 13, and the manifold blocks 14 are arranged in this order in one direction.The supply / discharge block 13 includes a supply coupling 13 aand a discharge coupling 13 b. The supply coupling 13 aincludes a first end connected to a concentrated supply passage (not illustrated) inside the supply / discharge block 13. The supply coupling 13 afurther includes a second end connected to a fluid supply source (not shown), for example, via a piping. The discharge coupling 13 bincludes a first end connected to a concentrated discharge passage (not illustrated) inside the supply / discharge block 13. The discharge coupling 13 bfurther includes a second end that is open to the atmosphere via, for example, a piping.Mounted on each of the manifold blocks 14 is a solenoid valve 20. The solenoid valve manifold 10 further includes a power supply block 15 for supplying power to the solenoid valves 20, and the power supply block 15 is disposed on the opposite side of the first end block 11 from the manifold blocks 14. The first end block 11, the second end block 12, the supply / discharge block 13, the manifold blocks 14, and the power supply block 15 are elongated rectangular blocks. Blocks that are adjacent are coupled to each other while being held in contact with each other.As shown in FIG. 2, each electromagnetic valve 20 includes a valve body 21 shaped like an elongated rectangular block. The valve body 21 is disposed on a placement surface 14 aof the manifold block 14. The valve body 21 includes an elongated rectangular block-shaped body main portion 22, a first coupling block 23 coupled to a first end in the longitudinal direction of the body main portion 22, and a second coupling block 24 coupled to a second end in the longitudinal direction of the body main portion 22. The body main portion 22, the first coupling block 23, and the second coupling block 24 are made of, for example, plastic. The body main portion 22 includes a main portion outer surface 22 afacing the placement surface 14 a. The first coupling block 23 has a first outer surface 23 afacing the placement surface 14 a. The second coupling block 24 includes a second outer surface 24 afacing the placement surface 14 a.The body main portion 22 includes a circular valve hole 26 that receives a valve element 25. The valve hole 26 extends in the longitudinal direction of the body main portion 22, and the valve hole 26 includes a first end that opens in a first end surface in the longitudinal direction of the body main portion 22. The valve hole 26 also includes a second end that opens in a second end surface in the longitudinal direction of the main body portion 22. The valve hole 26 thus extends longitudinally through the body main portion 22, and the valve element 25 is a spool valve element accommodated in the valve hole 26. The valve element 25 can reciprocate in the valve hole 26.The body main portion 22 includes a supply port 27, a first output port 28, a second output port 29, a first discharge port 30, and a second discharge port 31.The first discharge port 30, the first output port 28, the supply port 27, the second output port 29, and the second discharge port 31 are arranged in this order from the first end to the second end of the body main portion 22. The first ends of the supply port 27, the first output port 28, the second output port 29, the first discharge port 30, and the second discharge port 31 are connected to the valve hole 26. The second ends of the supply port 27, the first output port 28, the second output port 29, the first discharge port 30, and the second discharge port 31 open into the main portion facing surface 22 aof the body main portion 22.The inner circumferential surface of the valve hole 26 includes a first valve seat 32 between the supply port 27 and the first output port 28. The inner circumferential surface of the valve hole 26 also includes a second valve seat 33 between the first output port 28 and the first discharge port 30. A fourth valve seat 35 is provided between the second output port 29 and the second discharge port 31. The first valve seat 32, the second valve seat 33, the third valve seat 34, and the fourth valve seat 35 form parts of the inner circumferential surface of the valve hole 26 and are annular.The valve hole 26 also includes a first hole portion 26 a. The first hole portion 26 ais connected to the first discharge port 30 and forms a first end of the valve hole 26 spaced apart from the second valve seat 33. The valve hole 26 further includes a second hole portion 26 b. The second hole portion 26 bis connected to the second discharge port 31 and forms a second end of the valve hole 26 spaced apart from the fourth valve seat 35. The first valve seat 32, the second valve seat 33, the third valve seat 34, the fourth valve seat 35, the first hole portion 26 a, and the second hole portion 26 bhave the same inner diameter.The valve element 25 includes a first valve portion 251, a second valve portion 252, a third valve portion 253, a fourth valve portion 254, a fifth valve portion 255, and a sixth valve portion 256 spaced apart from each other in the axial direction of the valve element 25. The fifth valve portion 255, the second valve portion 252, the first valve portion 251, the third valve portion 253, the fourth valve portion 254, and the sixth valve portion 256 are arranged in this order from the first end to the second end in the axial direction of the valve element 25. The first valve portion 251, the second valve portion 252, the third valve portion 253, the fourth valve portion 254, the fifth valve portion 255, and the sixth valve portion 256 have the same outer diameter.The valve element 25 includes a first shaft portion 25 athat connects the first valve portion 251 and the third valve portion 253 to each other, a second shaft portion 25 bthat connects the first valve portion 251 and the second valve portion 252 to each other, and a third shaft portion 25 cthat connects the third valve portion 253 and the fourth valve portion 254 to each other. The valve element 25 also includes a fourth shaft portion 25 dconnecting the second valve portion 252 and the fifth valve portion 255 to each other, and a fifth shaft portion 25 econnecting the fourth valve portion 254 and the sixth valve portion 256 to each other.The valve element 25 includes a columnar first protruding portion 25 f. The first protruding portion 25 fprotrudes from the end surface of the fifth valve portion 255 that is opposite to the fourth shaft portion 25 d. The first protruding portion 25 fis a first end in the axial direction of the valve element 25, and the valve element 25 further includes a columnar second protruding portion 25 g. The second protruding portion 25 gprotrudes from the end surface of the sixth valve portion 256 that is opposite to the fifth shaft portion 25 e. The second protruding portion 25 gis a second end in the axial direction of the valve element 25.The first shaft portion 25 a, the second shaft portion 25 b, the third shaft portion 25 c, the fourth shaft portion 25 d, the fifth shaft portion 25 e, the first protruding portion 25 f, and the second protruding portion 25 ghave the same outer diameter. The outer diameters of each of the first valve portion 251, the second valve portion 252, the third valve portion 253, the fourth valve portion 254, the fifth valve portion 255, and the sixth valve portion 256 are larger than the outer diameters of each of the first shaft portion 25 a, the second shaft portion 25 b, the third shaft portion 25 c, the fourth shaft portion 25 d, the fifth shaft portion 25 e, the first protruding portion 25 f, and the second protruding portion 25 g.A first slide seal 36 is attached to the outer circumferential surface of the first valve portion 251. The first spool seal 36 serves as a seal between the supply port 27 and the first output port 28 when the first valve portion 251 seats on the first valve seat 32. A second slide seal 37 is attached to the outer circumferential surface of the second valve portion 252. The second slide seal 37 serves as a seal between the first output port 28 and the first discharge port 30 when the second valve portion 252 is seated on the second valve seat 33. A third spool seal 38 is attached to the outer circumferential surface of the third valve portion 253. The third spool seal 38 serves as a seal between the supply port 27 and the second output port 29 when the third valve portion 253 is seated on the third valve seat 34. A fourth slide seal 39 is attached to the outer circumferential surface of the fourth valve portion 254. The fourth spool seal 39 serves as a seal between the second output port 29 and the second discharge port 31 when the fourth valve portion 254 seats on the fourth valve seat 35. The first slide seal 36, the second slide seal 37, the third slide seal 38, and the fourth slide seal 39 are made of rubber and are annular.The first coupling block 23 includes a first piston receiving recess 41 that is a circular hole connected to the first hole portion 26 a. The first protruding portion 25 fof the valve element 25 is formed to selectively enter the first piston receiving recess 41 from the first hole portion 26 aand retract from the first hole portion 26 ainto the first piston receiving recess 41. The first piston receiving recess 41 receives a disk-shaped first piston 42 and the first piston 42 can reciprocate. The first piston 42 is fixed to the distal end of the first protruding portion 25 fof the valve element 25. A first lip seal 43 is attached to the outer circumferential surface of the first piston 42. The first lip seal 43 serves as a seal between the first piston 42 and the inner circumferential surface of the first piston receiving recess 41. the first piston 42 defines a first control pressure chamber 44 within the first piston receiving recess 41. control fluid is supplied to and discharged from the first control pressure chamber 44.The second coupling block 24 includes a second piston receiving recess 45 connected to the second hole portion 26 b. The inner diameter of the second piston receiving recess 45 is smaller than that of the first piston receiving recess 41. the second protruding portion 25 gof the valve element 25 is formed to selectively enter the second piston receiving recess 45 from the second hole portion 26 band retract from the second piston receiving recess 45 into the second hole portion 26 b. The second piston receiving recess 45 receives a disk-shaped second piston 46, and the second piston 46 can move reciprocally. The second piston 46 is fixed to the distal end of the second protruding portion 25 gof the valve element 25. The outer diameter of the second piston 46 is smaller than that of the first piston 42 and a second lip seal 47 is attached to the outer circumferential surface of the second piston 46. The second lip seal 47 serves as a seal between the second piston 46 and the inner circumferential surface of the second piston receiving recess 45. the second piston 46 defines a second control pressure chamber 48 within the second piston receiving recess 45. control fluid is supplied to and discharged from the second control pressure chamber 48.The outer diameter of the second piston 46 is smaller than that of the first piston 42, and accordingly, the pressure receiving area of the second piston 46 that receives the pressure of the control fluid in the second control pressure chamber 48 is smaller than the pressure receiving area of the first piston 42 that receives the pressure of the control pressure in the first control pressure chamber 44.A first seal member 49a is attached to the outer circumferential surface of the fifth valve portion 255. The first seal member 49a serves as a seal between the fifth valve portion 255 and the first hole portion 26a. The first seal member 49a is annular and made of rubber. The first seal member 49a limits the leakage of fluid from the first discharge port 30 to the first piston receiving recess 41 via the first hole portion 26a.A second seal member 49 bis attached to the outer circumferential surface of the sixth valve portion 256. The second seal member 49 bfunctions as a seal between the sixth valve portion 256 and the second hole portion 26 b. The second seal member 49 bis annular and made of rubber. The second sealing member 49 blimits the leakage of fluid from the second discharge port 31 to the second piston receiving recess 45 via the second hole portion 26 b.Each electromagnetic valve 20 includes a control valve unit 50. the electromagnetic valve 20 is of a single control valve type having a single control valve unit 50. the control valve unit 50 includes a solenoid portion 51. the control valve unit 50 is coupled to an end of the first coupling block 23 on the side opposite to the main body portion 22.Further, the valve body 21 includes a control fluid supply passage 52 connected to the supply port 27 via the valve hole 26. The control fluid supply passage 52 opens in the valve hole 26 at a position connected to the supply port 27 regardless of the position of the valve element 25. The second control pressure chamber 48 is constantly supplied with control fluid from the supply port 27 via the control fluid supply passage 52.The first coupling block 23 includes a control fluid output passage 53 that connects the control valve unit 50 and the first control pressure chamber 44 to each other. Further, the first coupling block 23 includes a valve-side control fluid discharge passage 54 that discharges control fluid. The valve-side control fluid discharge passage 54 includes a first end connected to the control valve unit 50. The valve-side control fluid discharge passage 54 includes a second end that opens into the first outer surface 23 aof the first coupling block 23.Each manifold block 14 includes a supply passage 60, a first output passage 61, a second output passage 62, a first discharge passage 63, and a second discharge passage 64.The supply passage 60, the first output passage 61, the second output passage 62, the first discharge passage 63 and the second discharge passage 64 respectively open into the placement surface 14 a. The end of the supply passage 60 that opens in the placement surface 14 ais connected to the supply port 27. The end of the first output passage 61 that opens in the placement surface 14 ais connected to the first output port 28. The end of the second output passage 62 that opens in the placement surface 14 ais connected to the second output port 29. The end of the first discharge passage 63 that opens in the placement surface 14 ais connected to the first discharge port 30. The end of the second discharge passage 64 that opens in the placement surface 14 ais connected to the second discharge port 31.The end of the supply passage 60 on the opposite side to the placement surface 14 aextends through each manifold block 14 in the arrangement direction of the manifold blocks 14. The end of the first discharge passage 63 located on the opposite side to the placement surface 14 aand the end of the second discharge passage 64 located on the opposite side to the placement surface 14 aextend through each manifold block 14 in the arrangement direction of the manifold blocks 14. The second discharge passages 64 of the adjacent manifold blocks 14 are connected to each other.In the manifold block 14 closest to the first end block 11, the ends of the supply passage 60, the first discharge passage 63 and the second discharge passage 64 are closed by the first end block 11.In the manifold block 14 closest to the supply / discharge block 13, the end of the supply passage 60 is connected to the concentrated supply passage of the supply / discharge block 13. In the manifold block 14 closest to the supply / discharge block 13, the ends of the first discharge passages 63 and the second discharge passage 64 are connected to the concentrated discharge passage of the supply / discharge block 13.Further, each manifold block 14 includes a block-side control fluid discharge passage 65, and the block-side control fluid discharge passage 65 has a first end that opens in the placement surface 14 aat a position facing the first outer surface 23 aof the first coupling block 23, and is connected to the valve-side control fluid discharge passage 54. The block-side control fluid discharge passage 65 has a second end connected to the first discharge passage 63.The solenoid valve manifold 10 includes a seal 70 that serves as a seal between the placement surface 14 aand the valve body 21. The gasket 70 is disposed between the placement surface 14 aand the valve body 21. The electromagnetic valve manifold 10 includes a check valve 71 that blocks the flow of fluid from the block-side control fluid discharge passage 65 to the valve-side control fluid discharge passage 54.When the pressure in the check valve 71 reaches a predetermined pressure, the check valve 71 is opened. The check valve 71 then allows the flow of fluid from the valve-side control fluid discharge passage 54 to the block-side control fluid discharge passage 65, and the fluid that has flowed from the valve-side control fluid discharge passage 54 into the check valve 71 flows out to the block-side control fluid discharge passage 65 via the check valve 71. When the pressure in the check valve 71 is lower than the predetermined pressure, the check valve 71 is closed. The check valve 71 thus blocks the flow of fluid from the block-side control fluid discharge passage 65 to the valve-side control fluid discharge passage 54.The end of the first output passage 61 on the side opposite to the placement surface 14 aopens into a side surface 14 eof each manifold block 14 that is orthogonal to the arrangement direction of the manifold blocks 14. The end of the second output passage 62 on the side opposite from the placement surface 14 aopens into the side surface 14 eof the manifold block 14.Each manifold block 14 includes a tubular first coupling 81 and a tubular second coupling 82, and the first coupling 81 is connected to the end of the first output passage 61 located on the side opposite to the placement surface 14 a. The second coupling 82 is connected to the end of the second output passage 62 on the opposite side to the placement surface 14 a. Thus, the end of the first output passage 61 on the side opposite to the placement surface 14 ais a first coupling connection hole 61 econnected to the first coupling 81. The end of the second output passage 62 on the side opposite to the placement surface 14 ais a second coupling connection hole 62 econnected to the second coupling 82. The inside of the first coupling 81 is connected to the first output passage 61. The interior of the second coupling 82 is connected to the second output passage 62. The first coupling 81 and the second coupling 82 are tubular couplings into which flexible tubes 80 having a circular cross section are inserted.As illustrated in FIG. 1, the first couplings 81 are juxtaposed in the arrangement direction of the manifold blocks 14. The second couplings 82 are arranged in a row in the arrangement direction of the distributor blocks 14. The tubes 80 connected to the first couplings 81 and the second couplings 82 are connected to a fluid pressure device (not shown).The first coupling 81 will now be described with reference to FIGS. 3 and 4. Since the second coupling 82 has the same structure as the first coupling 81, a detailed description of the second coupling 82 will be omitted.As shown in FIG. 3, the first coupling 81 includes a tubular coupling main portion 83 and a pressing ring 84 fixed to the coupling main portion 83. The pressing ring 84 includes an elongated tubular main ring portion 85 and an annular ring flange 86. the annular flange 86 is located on the outer circumferential surface of the main ring portion 85 and protrudes radially outward from a first end in the axial direction of the main ring portion 85.The outer circumferential surface of the ring main portion 85 includes a ring circumferential surface 85 a, a ring engagement surface 85 b, and a ring slant surface 85 c. The ring circumferential surface 85 ais continuous with the ring flange 86 and extends in the axial direction of the ring main portion 85, and the ring engagement surface 85 bprotrudes radially outward from the end of the ring circumferential surface 85 aon the side opposite to the ring flange 86. The ring engagement surface 85 bis tubular. The outer peripheral edge of the ring engagement surface 85 bis located closer to the axis of the ring main portion 85 than the outer peripheral surface of the ring flange 86 The inclined ring surface 85 cconnects to the outer peripheral edge of the ring engagement surface 85 band extends away from the ring peripheral surface 85 a. At the inclined ring surface 85 c, the outer diameter of the main ring portion 85 decreases as the distance from the circumferential ring surface 85 aincreases. Thus, the end of the pressing ring 84 on the side opposite to the annular flange 86, i.e., the distal end of the pressing ring 84, is shaped like a hook.When the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the outer circumferential surface of the ring flange 86 includes flange planar surfaces 86 aextending in parallel, as shown in FIG. 4. The outer circumferential surface of the annular flange 86 includes a first flange curved surface 86 band a second flange curved surface 86 c. The first flange curved surface 86 bconnects first ends of the flange planar surfaces 86 ato each other, and the second flange curved surface 86 cconnects second ends of the flange planar surfaces 86 ato each other. Therefore, the outer circumferential surface of the annular flange 86 is formed in a stepion shape when the annular flange 86 is viewed in the axial direction of the ring main portion 85.As shown in FIGS. 3 and 4, the ring main portion 85 includes a first insertion hole 87 and a decreasing diameter hole 88. The first insertion hole 87 extends in the axial direction of the ring main portion 85 from the distal end of the ring main portion 85 toward the ring flange 86 As shown in FIG. 4, the inner circumferential surface of the first insertion hole 87 is formed in a step shape when the pressing ring 84 is viewed in the axial direction of the ring main portion 85. The inner circumferential surface of the first insertion hole 87 includes flat surfaces 87 athat extend parallel to each other when the pressing ring 84 is viewed in the axial direction of the ring main portion 85. The inner circumferential surface of the first insertion hole 87 includes a first curved surface 87 band a second curved surface 87 c. The first curved surface 87 bconnects first ends of the planar surfaces 87 ato each other, and the second curved surface 87 cconnects second ends of the planar surfaces 87 ato each other.The planar surfaces 87 aare parallel to the flange planar surfaces 86 awhen the thrust ring 84 is viewed in the axial direction of the ring main portion 85. When the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the first curved surface 87 bextends parallel to the first flange curved surface 86 b, and the second curved surface 87 cextends parallel to the second flange curved surface 86 c. Therefore, when the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the inner circumferential surface of the first insertion hole 87 is formed in a stanation shape and mathematically similar to the outer circumferential surface of the ring flange 86.When the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the direction orthogonal to the planar surfaces 87 ais a transverse direction of the first insertion hole 87, and the direction in which the planar surfaces 87 aextend is a longitudinal direction of the first insertion hole 87.As shown in FIG. 3, the decreasing diameter hole 88 connects an end surface 85 eof the ring main portion 85 to the edge of the first insertion hole 87 located on the opposite side to the distal end of the ring main portion 85. When the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the inner circumferential surface of the decreasing-diameter hole 88 includes guide surfaces 88 aextending in parallel, as shown in FIG. 4. One of the guide surfaces 88 ais continuous with one of the flat surfaces 87 aof the first insertion hole 87; the other of the guide surfaces 88 ais continuous with the other of the flat surfaces 87 aof the first insertion hole 87. The first curved surface 88 bconnects the first ends of the guide surfaces 88 ato each other, and the second curved surface 88 cconnects the second ends of the guide surfaces 88 ato each other. The first curved surface 88 bis continuous with the first curved surface 87 bof the first insertion hole 87. the second curved surface 88 cis continuous with the second curved surface 87 cof the first insertion hole 87.As shown in FIG. 3, the coupling main portion 83 is made of metal. The coupling main portion 83 includes a cylindrical insertion portion 89 and an elongated tubular protruding portion 90. The protruding portion 90 includes a first tubular portion 91 and a second tubular portion 92, and the first tubular portion 91 is formed continuously with the insertion portion 89. The second tubular portion 92 connects to the end of the first tubular portion 91 on the side opposite to the insertion portion 89. The axis of the first tubular portion 91 coincides with the axis of the second tubular portion 92. Therefore, the axes of the insertion portion 89, the first tubular portion 91, and the second tubular portion 92 constitute the axis of the coupling main portion 83.When the coupling main portion 83 is viewed in the axial direction, the outer circumferential surface of the second tubular portion 92 is formed in a stannic shape and extends along the outer circumferential surface of the annular flange 86 of the pressing ring 84 so as to overlap with the outer circumferential surface of the annular flange 86. The outer diameter of the second tubular portion 92 is equal to that of the annular flange 86 The outer circumferential surface of the first tubular portion 91 is formed in a stanation shape, is closer to the axis of the protruding portion 90 than the outer circumferential surface of the second tubular portion 92, and extends along the outer circumferential surface of the second tubular portion 92 Therefore, the outer diameter of the first tubular portion 91 is smaller than the outer diameter of the second tubular portion 92.The protruding portion 90 includes a second insertion hole 90 a, a third insertion hole 90 b, and a fourth insertion hole 90 c. The second insertion hole 90 ais closer to the insertion portion 89 than the third insertion hole 90 band the fourth insertion hole 90 c. As viewed in the axial direction of the coupling main portion 83, the inner circumferential surface of the second insertion hole 90 ais a stepion shape and extends along the inner circumferential surface of the first insertion hole 87 of the pressing ring 84 so as to overlap with the inner circumferential surface of the first insertion hole 87. Therefore, the diameter of the second insertion hole 90a is equal to that of the first insertion hole 87.The third insertion hole 90 bis connected to the second insertion hole 90 a. The inner circumferential surface of the third insertion hole 90 bis formed in a stanation shape, is farther from the axis of the protruding portion 90 than the inner circumferential surface of the second insertion hole 90 a, and extends along the inner circumferential surface of the second insertion hole 90 a. Therefore, the diameter of the third insertion hole 90 bis larger than that of the second insertion hole 90 a.The fourth insertion hole 90 cis connected to the end of the third insertion hole 90 bon the opposite side to the second insertion hole 90 a. The inner circumferential surface of the fourth insertion hole 90 cis formed in a stanation shape, is farther from the axis of the protruding portion 90 than the inner circumferential surface of the third insertion hole 90 b, and extends along the inner circumferential surface of the third insertion hole 90 b. Therefore, the diameter of the fourth insertion hole 90 cis larger than that of the third insertion hole 90 b.The insertion portion 89 includes a connection hole 89 aconnected to the second insertion hole 90 a. The communication hole 89 ais a circular hole. As shown in FIG. 4, the diameter of the connection hole 89 ais equal to the diameter in the transverse direction of the second insertion hole 90 a. That is, the diameter of the communication hole 89 ais equal to the diameter in the transverse direction of the first insertion hole 87 of the pressing ring 84.As shown in FIG. 3, the coupling main portion 83 includes an annular first step surface 831. The first step surface 831 extends in a direction orthogonal to the axial direction of the coupling main portion 83 and connects the inner circumferential surface of the second insertion hole 90 ato the inner circumferential surface of the connection hole 89 a. The coupling main portion 83 also includes an annular second step surface 832. The second step surface 832 extends in a direction orthogonal to the axial direction of the coupling main portion 83 and connects the inner circumferential surface of the second insertion hole 90 ato the inner circumferential surface of the third insertion hole 90 b. Further, the coupling main portion 83 includes an annular third step surface 833. The third step surface 833 extends in a direction orthogonal to the axial direction of the coupling main portion 83 and connects the inner circumferential surface of the third insertion hole 90 bto the inner circumferential surface of the fourth insertion hole 90 c.The first coupling 81 includes an annular sealing member 93. the sealing member 93 is attached to the inner circumferential surface of the third insertion hole 90 b. The seal member 93 is made of rubber. The first coupling 81 includes an annular holding member 94. the holding member 94 is mounted in the inner circumferential surface of the fourth insertion hole 90 cwhile being held in contact with the third step surface 833. The inner circumferential surface of the holding member 94 is closer to the axis of the coupling main portion 83 than the inner circumferential surface of the third insertion hole 90 band is farther from the axis of the coupling main portion 83 than the inner circumferential surface of the second insertion hole 90 a. The seal member 93 is held between the second step surface 832 and the holding member 94 so as to be fixed to the inner circumferential surface of the third insertion hole 90 bwhile being positioned at the inner side of the third insertion hole 90 b. The holding member 94 prevents the sealing member 93 from being removed from the third insertion hole 90 b.The first coupling 81 includes a jig 95. the jig 95 is located in the fourth insertion hole 90 c. The tensioner 95 includes an annular tensioner main portion 95a and clamping tongues 95b. The tension tongues 95b project from the inner circumferential surface of the tensioner main portion 95a. The tension tongues 95b are arranged at equal intervals in the circumferential direction of the tensioner main portion 95a. The tension tongues 95b are thin plates bent to be closer to the axis of the tensioner main portion 95a as the distance from the inner circumferential surface of the tensioner main portion 95a increases.The first coupling 81 includes a tubular collar member 96. the collar member 96 is inserted into the fourth insertion hole 90 c. The collar member 96 includes a tubular collar main portion 96a and an annular collar engaging portion 96b. The collar engagement portion 96 bprotrudes radially inward from one end in the axial direction of the collar main portion 96 a. The outer circumferential surface of the collar main portion 96 aextends along the inner circumferential surface of the fourth insertion hole 90 c. The outer circumferential surface of the collar main portion 96 ais fitted into the inner circumferential surface of the fourth insertion hole 90 c. The collar member 96 is thus fixed to the fourth insertion hole 90 c. As viewed in the axial direction of the coupling main portion 83, the inner circumferential surface of the collar main portion 96 ais a stadione shape and extends along the inner circumferential surface of the third insertion hole 90 bto overlap the inner circumferential surface of the third insertion hole 90 b.The end of the collar main portion 96 aon the opposite side to the collar engagement portion 96 band the holding member 94 hold the outer periphery of the jig main portion 95 aof the jig 95 therebetween. Since the jig main portion 95 ais held between the holding member 94 and the collar main portion 96 a, the jig 95 is fixed in the fourth insertion hole 90 c. The tension tongues 95b are disposed in the fourth insertion hole 90c so as to be bent toward the seal member 93. The distal ends of the tension tongues 95b are arranged on the inside of the holding element 94. FIG. 4 shows a state before the resilient deformation of the tension tongues 95b. When viewed in the axial direction of the coupling main portion 83, the distal ends of the tension tongues 95 bin the state shown in FIG. 4 are closer to the axis of the coupling main portion 83 than the inner circumferential surface of the second insertion hole 90 a.As shown in FIG. 3, the inner diameter of the collar engagement portion 96 bis larger than the outer diameter of the ring circumferential surface 85 aof the pressing ring 84 and smaller than the outer diameter of the outer circumferential edge of the ring engagement surface 85 b. When the ring main portion 85 of the pressing ring 84 is forcibly pressed into the collar member 96, the ring slant surface 85 cpass the collar engagement portion 96 bsuch that the ring circumferential surface 85 ais located on the inner side of the collar engagement portion 96 b. In this way, the pressing ring 84 is fixed to the coupling main portion 83 by the collar member 96.In a state where the pressing ring 84 is fixed to the coupling main portion 83, the distal end of the ring main portion 85 in the axial direction of the coupling main portion 83 faces the clamping tongues 95 b. The ring engagement surface 85 bcontacts the collar engagement portion 96 b,so that the coupling main portion 83 is prevented from being removed from the pressing ring 84. The pressing ring 84 is inserted into the coupling main portion 83 until the annular flange 86 contacts the collar member 96.In a state where the ring engagement surface 85 bis in contact with the collar engagement portion 96 b, the distal end of the ring main portion 85 is separated from the tension tongues 95 b. When the push ring 84 is pushed until the annular flange 86 contacts the collar member 96, the distal end of the ring main portion 85 contacts the tension tongues 95b. The tension tongues 95b contact the inclined annular surface 85c and are elastically deformed so that the distal ends of the tension tongues 95b are moved away from the axis of the coupling main portion 83.The first coupling 81 is connected to the first coupling connection hole 61 eby inserting the insertion portion 89 of the coupling main portion 83 into the first coupling connection hole 61 e. The protruding portion 90, the collar member 96, and the pressing ring 84 of the coupling main portion 83 form an elongated tubular portion protruding from the side surface 14 eof the manifold block 14. Thus, the first couplings 81 partially protrude outwardly from the manifold block 14. The portion of each of the first couplings 81 protruding from the manifold block 14 is in the form of an elongated tube.A part of the tube 80 is located in the decreasing diameter hole 88, the first insertion hole 87, the fourth insertion hole 90 c, the third insertion hole 90 b, and the second insertion hole 90 a. Thus, the decreasing diameter hole 88, the first insertion hole 87, the fourth insertion hole 90 c, the third insertion hole 90 b, and the second insertion hole 90 aform a pipe insertion hole 97 into which the pipe 80 is inserted. The pipe insertion hole 97 is connected to the first output passage 61 via the communication hole 89 a. The pipe insertion hole 97 is thus connected to the passage inside the manifold block 14.The imaginary circle C 1 in FIG. 4 represents the outer circumferential surface of the pipe 80 before being deformed. As shown in FIG. 4, the longitudinal extension of the first insertion hole 87 and the longitudinal extension of the second insertion hole 90 aare larger than the outer diameter of the tube 80 before being deformed. The transverse diameter of the first insertion hole 87 and the transverse diameter of the second insertion hole 90 aare smaller than the outer diameter of the tube 80 before deformation. Thus, the first insertion hole 87 and the second insertion hole 90 aform a hole 98 that is a step-shaped hole having a transverse direction diameter smaller than the outer diameter of the tube 80 before being deformed. Therefore, a portion of the pipe insertion hole 97 is the hole 98 which is a stadione-shaped hole.The open edge of the decreasing diameter hole 88 is the open edge of the pipe insertion hole 97. Thus, the pipe insertion hole 97 has the decreasing diameter hole 88. The decreasing diameter hole 88 connects the open edge of the pipe insertion hole 97 to the hole 98. in addition, the outer diameter of the decreasing diameter hole 88 decreases from the open edge of the pipe insertion hole 97 toward the hole 98. The open edge of the pipe insertion hole 97 is a stadia hole that is mathematically similar to the hole 98.As shown in FIG. 3, the communication hole 89 aconnects the inside of the pipe 80 inserted into the hole 98 and the first output passage 61 to each other. The first step surface 831 serves as a stopper surface that contacts the distal end of the tube 80 inserted into the second insertion hole 90 a.The transverse direction of the first insertion hole 87 and the second insertion hole 90 ais the transverse direction of the first coupling 81, The longitudinal direction of the first insertion hole 87 and the second insertion hole 90 ais the longitudinal direction of the first coupling 81, and thus, when the first coupling 81 is viewed in the axial direction, the transverse direction of the hole 98 coincides with the transverse direction of the first coupling 81.As shown in FIG. 1, the first couplings 81 are arranged such that the transverse direction of each first coupling 81 coincides with the arrangement direction of the manifold blocks 14, as viewed in the axial direction. The second couplings 82 are arranged such that the transverse direction of each second coupling 82 coincides with the arrangement direction of the manifold blocks 14, as viewed in the axial direction.An operation of the present embodiment will now be described.It is now assumed that a pipe 80 having an outer diameter larger than the transverse diameter of the hole 98 is inserted into the pipe insertion hole 97 of each first coupling 81. In this case, when the pipe 80 is inserted from the open edge of the pipe insertion hole 97, it is inserted into the first insertion hole 87 while being guided by the guide surfaces 88 aof the decreasing diameter hole 88.As shown in FIG. 5, the pipe 80 inserted into the first insertion hole 87 is pressed and deformed by the planar surfaces 87 ain the inner circumferential surface of the first insertion hole 87. The planar surfaces 87 aare located on the opposite sides in the lateral direction of the first insertion hole 87; the tube 80 is inserted while being deformed into the first insertion hole 87 toward the space near the first curved surface 87 bto the space near the second curved surface 87 c. The first and second curved surfaces 87 b, 87 care located on the opposite sides in the longitudinal direction of the first insertion hole 87, and as a result, the tube 80 is elastically deformed by fitting to the inner circumferential surface of the first insertion hole 87.As shown in FIG. 3, the tube 80 contacts the clamping tongues 95b and passes the inside of the chuck 95 while pushing away the clamping tongues 95b. At this time, the pipe 80 passes the inside of the seal member 93 while contacting the inner circumferential surface of the seal member 93. The tube 80 is inserted into the second insertion hole 90 auntil the distal end contacts the first step surface 831. Accordingly, the inside of the pipe 80 is connected to the first output passage 61 via the communication hole 89 a. A pipe 80 is inserted into the pipe insertion holes 97 of each second coupling 82 in the same manner as the pipe 80 inserted into the pipe insertion hole 97 of each first coupling 81. That is, the tube 80 is inserted into the second insertion hole 90 auntil the distal end contacts the first step surface 831. Accordingly, the inside of the pipe 80 is connected to the second output passage 62 via the communication hole 89 a.The outer circumferential surface of the seal member 93 is in close contact with the inner circumferential surface of the third insertion hole 90 b. The inner circumferential surface of the seal member 93 is in close contact with the outer circumferential surface of the tube 80. The seal member 93 thus limits leakage of fluid to the outside through the gap between the outer circumferential surface of the tube 80 and the tube insertion hole 97. When the tube 80 is inserted into the tube insertion hole 97 until the distal end contacts the first step surface 831, the tension tongues 95b return to their original shape before being pushed away from the tube 80, so that the distal ends of the tension tongues 95b enter the outer circumferential surface of the tube 80. This prevents the pipe 80 from being removed from the pipe insertion hole 97.When removing the pipe 80 from the pipe insertion hole 97, the pressing ring 84 is pressed toward the inside of the coupling main portion 83 until the annular flange 86 contacts the collar member 96. When the distal end of the ring main portion 85 contacts the tension tongues 95b, the tension tongues 95b are elastically deformed so that the distal ends of the tension tongues 95b are separated from the outer circumferential surface of the tube 80. This cancels the "bite" of the distal end of the tension tongues 95b into the outer circumferential surface of the tube 80. The pipe 80 can thus be pulled out of the pipe insertion hole 97.As shown in FIG. 2, when power is supplied to the solenoid portion 51, the control valve unit 50 connects the control fluid supply passage 52 and the control fluid output passage 53 to each other, and separates the control fluid output passage 53 and the valve-side control fluid discharge passage 54 from each other. Then, the fluid from the fluid supply source flows in from the supply coupling 13 avia a piping, and is supplied as control fluid to the first control pressure chamber 44 via the concentrated supply passage of the supply / discharge block 13, the supply passage 60, the supply port 27, the control fluid supply passage 52, and the control fluid output passage 53.At this time, the pressure receiving area of the second piston 46 receiving the pressure of the control fluid in the second control pressure chamber 48 is smaller than the pressure receiving area of the first piston 42 receiving the pressure of the control pressure in the first control pressure chamber 44. As a result, the valve element 25 is moved in the direction of the second piston receiving recess 45. Thereby, the supply port 27 and the first output port 28, and the second output port 29 and the second discharge port 31 can be connected to each other. In addition, the third spool seal 38 of the third valve portion 253 serves as a seal between the supply port 27 and the second output port 29, and the second spool seal 37 of the second valve portion 252 serves as a seal between the first output port 28 and the first discharge port 30.Then, the fluid from the fluid supply source flows in from the supply coupling 13 avia a piping, and is supplied to the fluid pressure device via the concentrated supply passage of the supply / discharge block 13, the supply passage 60, the supply port 27, the first output port 28, the first output passage 61, the communication hole 89 aof the first coupling 81, and the pipe 80 connected to the first coupling 81. In addition, the fluid is discharged from the fluid pressure device to the atmosphere via the pipe 80 connected to the second coupling 82, the communication hole 89 aof the second coupling 82, the second output passage 62, the second output port 29, the second discharge port 31, the second discharge passage 64, the concentrated discharge passage of the supply / discharge block 13, the discharge coupling 13 b, and the piping.When the supply of power to the solenoid portion 51 is stopped, the control valve unit 50 connects the control fluid output passage 53 and the valve-side control fluid discharge passage 54 to each other, and disconnects the control fluid supply passage 52 and the control fluid output passage 53 from each other. Thereby, the fluid supply from the fluid supply source to the first control pressure chamber 44 via the pipings, the supply coupling 13 a, the concentrated supply passage of the supply / discharge block 13, the supply passage 60, the supply port 27, the control fluid supply passage 52, and the control fluid output passage 53 is cut off. Then, the fluid in the first control pressure chamber 44 is discharged to the atmosphere via the control fluid output passage 53, the valve-side control fluid discharge passage 54, the block-side control fluid discharge passage 65, the first discharge passage 63, the concentrated discharge passage of the supply / discharge block 13, the discharge coupling 13 b, and the piping. Accordingly, the valve element 25 is moved toward the first piston receiving recess 41. Thereby, the supply port 27 and the second output port 29 can be connected to each other, and the first output port 28 and the first discharge port 30 can be connected to each other. In addition, the first slide seal 36 of the first valve portion 251 serves as a seal between the supply port 27 and the first output port 28, and the fourth slide seal 39 of the fourth valve portion 254 serves as a seal between the second output port 29 and the second discharge port 31.Then, the fluid from the fluid supply source flows in from the supply coupling 13 avia the piping, and is supplied to the fluid pressure device via the concentrated supply passage of the supply / discharge block 13, the supply passage 60, the supply port 27, the second output port 29, the second output passage 62, the communication hole 89 aof the second coupling 82, and the pipe 80 connected to the second coupling 82. In addition, the fluid is discharged to the atmosphere from the fluid pressure device to the atmosphere via the pipe 80 connected to the first coupling 81, the communication hole 89 aof the first coupling 81, the first output passage 61, the first output port 28, the first discharge port 30, the first discharge passage 63, the concentrated discharge passage of the supply / discharge block 13, the discharge coupling 13 b, and the piping.The electromagnetic valve 20 is an internal control valve in which a part of the fluid supplied to the supply port 27 is supplied to the first control pressure chamber 44 and the second control pressure chamber 48. The valve element 25 is reciprocated in the valve hole 26 by the control fluid so that connections of the ports are switched.A similar exemplary case assumes that the pipe insertion holes 97 are circular holes and the diameter of each of the pipe insertion holes 97 is equal to the diameter in the transverse direction of each of the holes 98. As compared with this case, the electromagnetic valves 20 maximize the flow cross-sectional area of the pipe 80 inserted into the pipe insertion hole 97. Accordingly, the flow rate of the fluid flowing in the manifold block 14 is increased. Thereby, the amount of fluid supplied to the fluid pressure device and the amount of fluid discharged from the fluid pressure device are increased, thereby improving the responsiveness of the fluid pressure device.The above-described embodiment has the following advantages.(1) The portions of the first coupling 81 and the second coupling 82 protruding from the manifold block 14 are each in the form of an elongated tube. When the first coupling 81 and the second coupling 82 are viewed in the axial direction, the transverse direction of the first coupling 81 and the second coupling 82 coincides with the arrangement direction of the manifold blocks 14. A portion of the pipe insertion hole 97 is the hole 98, which is a dione-shaped hole. When the first coupling 81 and the second coupling 82 are viewed in the axial direction, the transverse direction of the hole 98 coincides with the transverse direction of the first coupling 81 and the second coupling 82.It is now assumed that a pipe 80 having an outer diameter larger than the transverse diameter of the hole 98 is inserted into the pipe insertion hole 97. In this case, the pipe 80 is pushed and deformed by the portions of the inner circumferential surface of the hole 98 on the opposite sides in the transverse direction of the hole 98. The tube 80 is inserted into the hole 98 while being deformed into the spaces on the opposite sides in the longitudinal direction of the hole 98. Therefore, the pipe 80 can be inserted into the pipe insertion holes 97 even when the outer diameter of the pipe 80 is larger than the transverse diameter of the hole 98In of the exemplary comparative case, it is considered that the pipe insertion holes 97 are circular and the diameter of each of the pipe insertion holes 97 is equal to the transverse diameter of each of the holes 98. Compared with this case, the flow area of the pipe 80 inserted into the pipe insertion hole 97 is maximized in the above-described embodiment. The pipe 80 having a maximized flow cross-sectional area can be inserted into the pipe insertion hole 97 without having to increase the outer diameter of the portions of the first coupling 81 and the second coupling 82 protruding from the manifold block 14 in the arrangement direction of the manifold blocks 14. Thus, it is not necessary to increase the distance between adjacent manifold blocks 14 in order to prevent the first couplings 81 and the second couplings 82 that are adjacent to each other in the arrangement direction of the manifold blocks 14 from interfering with each other. Therefore, it is possible to increase the flow rate of the fluid flowing in the passages while limiting an increase in the size of the solenoid valve manifold 10.(2) The pipe insertion hole 97 has the decreasing diameter hole 88. The decreasing diameter hole 88 connects the open edge of the pipe insertion hole 97 to the hole 98. in addition, the outer diameter of the decreasing diameter hole 88 decreases from the open edge of the pipe insertion hole 97 toward the hole 98. This configuration allows the pipe 80 inserted from the open edge into the pipe insertion hole 97 to be easily insertable toward the hole 98 while passing through the diameter decreasing hole 88. Accordingly, the tube 80 is easily inserted into the hole 98.(3) The open edge of the pipe insertion hole 97 is a stadia hole that is mathematically similar to the hole 98. A similar exemplary case assumes that the open edge of the pipe insertion hole 97 is a circular hole having a diameter equal to the diameter in the longitudinal direction of the hole 98. Compared with this case, the above-described embodiment increases the thickness of the portions located on the opposite lateral sides of the first coupling 81 or the second coupling 82. Thereby, the strength of the first coupling 81 and the second coupling 82 is easily secured.(4) The flow rate of the fluid flowing in the distributor block 14 is increased. Thereby, the amount of fluid supplied to the fluid pressure device and the amount of fluid discharged from the fluid pressure device are increased, thereby improving the responsiveness of the fluid pressure device.(5) The flow area maximized pipe 80 may be inserted into the pipe insertion hole 97 without increasing the distance between the adjacent manifold blocks 14. As a result, the size of the electromagnetic valve distributor 10 is not increased and the space requirement of the electromagnetic valve distributor 10 is thus reduced.(6) The flow rate of the fluid flowing in the passage of the manifold block 14 can be increased by the use of a tube 80 having a circular cross section. Therefore, the shape of the pipe 80 does not need to be changed to increase the flow cross-sectional area of the pipe 80. Thus, an already existing pipe 80 with a round cross-section can be used.The above-described embodiment may be modified as follows. The above-described embodiment and the following modifications may be combined as long as the combined modifications are technically consistent with each other.As shown in FIG. 6, the communication hole 89 amay be formed in a stadione shape. When the first coupling 81 is viewed in the axial direction, the transverse direction of the communication hole 89a coincides with the transverse direction of the hole 98. The transverse direction diameter of the communication hole 89 ais equal to the transverse direction diameter of the hole 98, the longitudinal direction extension of the communication hole 89 ais smaller than the longitudinal direction extension of the hole 98. Compared with this case, the modification increases the flow cross-sectional area of the communication hole 89 a. As a result, the flow rate of the fluid flowing in the distributor block 14 is further increased.The pipe insertion hole 97 need not include the decreasing diameter hole 88. For example, the edge of the first insertion hole 87 near the annular flange 86 may serve as an open edge of the pipe insertion hole 97.The entire pipe insertion hole 97 may be the stadione-shaped hole 98. In short, it is sufficient that at least a portion of the pipe insertion hole 97 is a stadione-shaped hole.The open edge of the pipe insertion hole 97 may be a stadia hole that is mathematically non-similar to the hole 98.For example, the open edge of the pipe insertion hole 97 may be a circular hole having a diameter larger than the diameter in the longitudinal direction of the hole 98, as shown in FIG. 7. When the open edge of the pipe insertion hole 97 is a circular hole, the diameter of the open edge is larger than the outer diameter of the pipe 80 before being deformed.Therefore, when the annular flange 86 is viewed in the axial direction of the ring main portion 85, the outer circumferential surface of the annular flange 86 may have an elliptical shape without the flange planar surfaces 86 a. Also, the outer circumferential surface of the annular flange 86 may be rectangular when the annular flange 86 is viewed in the axial direction of the ring main portion 85. In a case where the outer circumferential surface of the annular flange 86 is rectangular, when the annular flange 86 is viewed in the axial direction of the ring main portion 85, the four corners of the annular flange 86 may be rounded or chamfered. In addition, when the coupling main portion 83 is viewed in the axial direction, the outer circumferential surface of the second tubular portion 92 may have an elliptical or rectangular shape and extend along the outer circumferential surface of the annular flange 86 so as to overlap with the outer circumferential surface of the annular flange 86.Further, when the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the inner circumferential surface of the first insertion hole 87 may have an elliptical shape without the planar surfaces 87 a. When the pressing ring 84 is viewed in the axial direction of the ring main portion 85, the inner circumferential surface of the first insertion hole 87 may be rectangular. In a case where the inner circumferential surface of the first insertion hole 87 is rectangular, the four corners of the pressing ring 84 may be rounded or chamfered. In addition, as viewed in the axial direction of the coupling main portion 83, the inner circumferential surface of the second insertion hole 90 amay have an elliptical or rectangular shape and extend along the inner circumferential surface of the first insertion hole 87 so as to overlap with the inner circumferential surface of the first insertion hole 87 of the pressing ring 84.In short, it is sufficient that the hole 98 is a dione-shaped hole and the transverse direction of the hole 98 coincides with the transverse direction of a coupling when viewed in the axial direction of the coupling. It is also sufficient if parts of couplings which protrude from the distributor block 14 each have the shape of an elongate tube.As shown in FIG. 8, the insertion portion 89 of the coupling main portion 83 may have the shape of an elongated tube. In this case, the outer circumferential surface of the insertion portion 89 is closer to the axis of the protruding portion 90 than the outer circumferential surface of the first tubular portion 91 and extends along the outer circumferential surface of the first tubular portion 91. therefore, the outer diameter of the insertion portion 89 is smaller than the outer diameter of the first tubular portion 91. In this case, the first coupling connection hole 61 eand the second coupling connection hole 62 e, into which the insertion portion 89 is inserted, are respectively a dione-shaped hole corresponding to the outer circumferential surface of the insertion portion 89. As a result, the flow cross-sectional area of the communication hole 89 aincreases without the outer diameter of the insertion portion 89 increasing in the arrangement direction of the manifold blocks 14. Accordingly, the amount of fluid flowing in the passage in the port block 14 is further increased, while the size of the solenoid valve manifold 10 is not increased. In addition, the outer circumferential surface of the insertion portion 89 may have an elliptical or rectangular shape as viewed in the axial direction.The thrust ring 84 may be made of metal.The coupling main portion 83 may be made of resin.Some of the couplings may be formed such that the valve bodies 21 of the electromagnetic valves 20 project outward, each of the tube insertion holes 97 being connected to a corresponding passage formed inside the valve bodies 21. In this case, the valve bodies 21 of the electromagnetic valves 20 correspond to the passage forming members arranged in one direction, each valve body 21 having a passage inside.The electromagnetic valve 20 may be, for example, an electromagnetic three-way valve.The electromagnetic valve 20 may be formed such that the outer diameter of the first piston 42 and the outer diameter of the second piston 46 are the same, and a compression spring that presses the valve element 25 toward the first piston receiving recess 41 may be accommodated in the second piston receiving recess 45. In addition, the electromagnetic valve 20 may be configured such that the pressure in the first control pressure chamber 44 acts against the pressing force of the compression spring so that the valve element 25 is moved toward the second piston receiving recess 45.In the above-described embodiment, the electromagnetic valve 20 is of an internal control type. However, the electromagnetic valve 20 may be of an external control type that supplies the first control pressure chamber 44 and the second control pressure chamber 48 with fluid supplied from the outside, not from the supply port 27.The solenoid valve 20 may be of a dual control type having two control valve units 50.Not all of the manifold blocks 14 need include the solenoid valve 20. The manifold is not limited to the solenoid valve manifold 10 including the solenoid valve 20. However, any type of manifold may be used as long as it includes passage forming members arranged in one direction and each having a passage inside. Various changes in form and details may be made to the above examples without departing from the spirit and scope of the claims and their equivalents. The examples are for description only and not for limitation. Descriptions of features in each example are to be considered applicable to similar features or aspects in other examples. Suitable results may be achieved when operations are performed in a different order and / or when components in a described system, architecture, device, or circuit are combined differently and / or replaced or supplemented by other components or their equivalents. The scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents. All variations within the scope of the claims and their equivalents are included in the present disclosure.

Claims

A manifold (10) comprising: passage forming members (14) arranged in one direction, each passage forming member (14) having a passage (61, 62) inside; and tubular couplings (81, 82) partially protruding outward from the respective passage forming members (14), each coupling (81, 82) having a pipe insertion hole (97) connected to the passage (61, 62), wherein: the couplings (81, 82) are adjacent to each other in an arrangement direction of the passage forming members (14), flexible pipes (80) each having a circular cross section are inserted into the respective pipe insertion holes (97) of the couplings (81, 82), parts of the couplings (81, 82) protruding from the passage forming members (14) each have the shape of an elongated pipe when each coupling (81, 81, 82 ) in an axial direction, a transverse direction of the coupling (81, 82) coincides with the arrangement direction, at least a part of each pipe insertion hole (97) is a dione-shaped hole (98), each pipe insertion hole (97) having a decreasing diameter hole (88), and when each coupling (81, 82) is viewed in the axial direction, a transverse direction of the hole (98) coincides with the transverse direction of the coupling (81, 82).The manifold (10) of claim 1, wherein the decreasing diameter hole (88) connects an open edge of the pipe insertion hole (97) to the hole (98), and an outer diameter of the decreasing diameter hole (88) decreases from the open edge toward the hole (98).The manifold (10) of claim 2, wherein the open edge is a stadione-shaped hole mathematically similar to the hole (98).The manifold (10) according to any one of claims 1 to 3, wherein each coupling (81, 82) comprises: a communication hole (89a) connecting the passage (61, 62) to an inner space of the pipe (80) inserted into the hole (98); and a stopper surface (831) connecting the hole (98) and the communication hole (89a) to each other, a distal end of the pipe (80) inserted into the hole (98) contacts the stopper surface (831), the communication hole (89a) being a dione-shaped hole, wherein when each coupling (81, 82) is viewed in the axial direction, a transverse direction of the communication hole (89a) coincides with the transverse direction of the hole (98), a diameter in the transverse direction of the communication hole (89a) being equal to a diameter in the transverse direction of the hole (98), and an extension in a longitudinal direction of the communication hole (89a) is smaller than an extension in a longitudinal direction of the hole (98)The manifold (10) according to claim 4, wherein each coupling (81, 82) has an insertion portion (89) that has the communication hole (89a) and is inserted into a coupling communication hole (61e, 62e) of the passage forming member (14), the insertion portion (89) has the shape of an elongated tube, and when the insertion portion (89) is viewed in an axial direction, a transverse direction of the insertion portion (89) coincides with the arrangement direction.

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