ELECTROMAGNETIC BEFORE CONTROL VALVE

Abstract

Electromagnetic pilot valve (10) comprising: a housing (11) with ports (17, 18, 19, 20, 21); a spool valve element (15) which is moved back and forth in the housing (11) to switch connections between the ports (17, 18, 19, 20, 21); a first pilot pressure chamber (34) and a second pilot pressure chamber (38) which are provided at opposite ends of the spool valve element (15) in the housing (11); a first pilot valve (41) which supplies pilot fluid to and discharges pilot fluid from the first pilot pressure chamber (34); and a second pilot valve (42) that supplies pilot fluid to the second pilot pressure chamber (38) and discharges pilot fluid from it, wherein the first pilot valve (41) and the second pilot valve (42) are arranged so that they are adjacent to each other and coupled to each other, the first pilot valve (41) and the second pilot valve (42) each have a rectangular block-shaped body (60),wherein the body (60) has a first surface (441) and a second surface (442) located on a side opposite the first surface (441), and each body (60) comprises: a valve chamber (55) in which a pilot valve element (56) is movably received, a supply channel (61) opening into the first surface (441) and the second surface (442) and connected to the valve chamber (55), a first outlet channel (62) opening into the first surface (441) and connected to the valve chamber (55), wherein the first outlet channel (62) is configured to supply pilot fluid to and discharge pilot fluid from the first pilot pressure chamber (34) or the second pilot pressure chamber (38), a second outlet channel (63) opening into the first surface (441), wherein the second outlet channel (63) is configuredthat it supplies input fluid to the first pilot pressure chamber (34) or the second pilot pressure chamber (38) and discharges input fluid from it, and an output channel connection recess (66) provided in a section of the second surface (442) which overlaps with an opening area of ​​the first output channel (62) which opens into the first surface (441), wherein the output channel connection recess (66) is connected to the second output channel (63).

Description

TECHNICAL FIELDThe present invention relates to an electromagnetic pilot valve.PRIOR ARTAn electromagnetic pilot valve includes a housing having ports and a spool valve element that reciprocates within the housing to switch connections between the ports. The housing includes a first pilot pressure chamber and a second pilot pressure chamber at the opposite ends of the spool valve element. The electromagnetic pilot valve also includes a first pilot valve that supplies pilot fluid to and discharges pilot fluid from the first pilot pressure chamber and a second pilot valve that supplies pilot fluid to and discharges pilot fluid from the second pilot pressure chamber. The first pilot valve supplies pilot fluid to and discharges pilot fluid from the first pilot pressure chamber. The second pilot valve supplies pilot fluid to and discharges pilot fluid from the second pilot pressure chamber. This causes the spool valve element to reciprocate to switch the connection between the ports.The first pilot valve and the second pilot valve each include a solenoid. A plug-in structure is known in the art as a wiring structure for supplying power to the solenoids. In the plug-in structure, the first pilot valve and the second pilot valve are installed in a manifold block. In this case, the connecting connections of the first pilot control valve and the connecting connections of the second pilot control valve are connected to the connecting connections of the distributor block, which are connected to a main flow supply. The wires of the plug-in structure having the above-described configuration are not exposed to the outside. The plug-in structure is thus aesthetically advantageous and simplifies the wiring process.For example, as disclosed in Patent Document 1, an electromagnetic pilot valve is known in which a first pilot valve and a second pilot valve are arranged so as to be adjacent to each other and coupled to each other. The electromagnetic pilot valve of Patent Document 1 is a single-sided electromagnetic solenoid valve in which the first pilot valve and the second pilot valve are disposed in the housing toward one side. A single-sided electromagnetic solenoid valve is advantageous in that, when the plug-in structure is used, the power supply structures such as connection ports of the distribution block can be easily aggregated at a location.It is now assumed that, in the single-sided electromagnetic solenoid valve disclosed in Patent Document 1, for example, the second pilot valve is disposed closer to the housing than the first pilot valve. In this case, the body of the first pilot valve has an output passage for supplying pilot fluid to and discharging pilot fluid from the first pilot pressure chamber. The body of the second pilot valve has an output passage for supplying pilot fluid to and discharging pilot fluid from the second pilot pressure chamber, and an additional passage different from the output passage. The additional channel is connected to the output channel of the first pilot valve and serves to supply pilot fluid to the first pilot pressure chamber and to discharge pilot fluid therefrom. As described above, the bodies of the first pilot valve and the second pilot valve have different passage structures. Accordingly, two kinds of bodies are required, resulting in poor production efficiency. Further prior art is described in DE 693 26 156 T2 and DE 10 2005 015 426 A1.PRIOR ART DOCUMENTPatent DocumentPatent Document 1: German Patent Application No. DE 10 2007 040 929 B3SUMMARY OF THE INVENTIONProblems to be Solved by the InventionAccordingly, it is an object of the present invention to provide an electromagnetic pilot valve which improves production efficiency.Means for Solving the ProblemsTo achieve the above objects, and according to a first aspect of the present invention, there is provided an electromagnetic pilot valve including a housing having ports, a spool valve element that reciprocates in the housing to switch connections between the ports, a first pilot pressure chamber and a second pilot pressure chamber provided at opposite ends of the spool valve element in the housing, a first pilot valve that supplies pilot fluid to and discharges pilot fluid from the first pilot pressure chamber, and a second pilot valve that supplies pilot fluid to and discharges pilot fluid from the second pilot pressure chamber. The first pilot valve and the second pilot valve are arranged so as to be adjacent to each other and coupled to each other. The first pilot valve and the second pilot valve each have a rectangular block-shaped body. The body has a first surface and a second surface disposed on a side opposite the first surface. Each body includes a valve chamber in which a pilot valve element is movably accommodated, a supply passage opening into the first surface and the second surface and communicating with the valve chamber, a first output passage, a second output passage, and an output passage communication recess. The first output passage opens into the first surface and is connected to the valve chamber. The first output passage is formed to supply pilot fluid to the first pilot pressure chamber or the second pilot pressure chamber and discharge pilot fluid from the first pilot pressure chamber or the second pilot pressure chamber. The second output channel opens into the first surface. The second output passage is formed to supply pilot fluid to the first pilot pressure chamber or the second pilot pressure chamber and discharge pilot fluid from the first pilot pressure chamber or the second pilot pressure chamber. The output passage communication recess is provided in a portion of the second surface that overlaps with an opening portion of the first output passage that opens into the first surface. The output passage connecting recess is connected to the second output passage.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a cross-sectional view of an electromagnetic valve manifold according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a housing and a manifold block. FIG. 3 is a cross-sectional view showing a first pilot valve and a second pilot valve. FIG. 4 is a perspective view schematically showing the first pilot valve and the second pilot valve. FIG. 5 is a cross-sectional view of a channel-forming block as viewed from the side corresponding to a first surface. FIG. 6 is a cross-sectional view of the channel-forming block as viewed from the side corresponding to a second surface. FIG. 7 is a cross-sectional view of the first pilot valve and the second pilot valve. FIG. 8 is a perspective view of a fastening bracket. FIG. 9 is a perspective view partially showing the first pilot valve and the second pilot valve. FIG. 10 is a perspective view partially showing a state in which the first pilot valve and the second pilot valve are fixed to the housing.MODES FOR CARRYING OUT THE INVENTIONAn electromagnetic pilot valve according to an embodiment will now be described with reference to FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9 to 10. The electromagnetic pilot valve of the present embodiment constitutes an electromagnetic valve manifold together with a manifold block.As shown in FIG. 1, the electromagnetic pilot valve 10 is mounted on a placement surface B 1 of the manifold block MB. The electromagnetic pilot valve 10 includes a main valve unit V 1, a first pilot valve 41, and a second pilot valve 42. the main valve unit V 1 includes a housing 11 that is an elongated rectangular block placed on the placement surface B 1 of the manifold block MB.The housing 11 includes an elongated rectangular block-shaped housing body 12, a first coupling block 13 coupled to a first longitudinal end of the housing body 12, and a second coupling block 14 coupled to a second longitudinal end of the housing body 12. The housing body 12, the first coupling block 13, and the second coupling block 14 are made of, for example, plastic. The housing body 12 includes a body facing surface 12 athat faces the placement surface B 1 of the manifold block MB. The first coupling block 13 has a first end surface 13 athat faces the placement surface B 1 of the manifold block MB. The second coupling block 14 has a second end surface 14 athat faces the placement surface B 1 of the manifold block MB.The first coupling block 13 includes a first block body 131 and a first adapter 132. The first block body 131 is coupled to the first end of the housing body 12. The first adapter 132 is coupled to a surface of the first block body 131 on the opposite side to the housing body 12. The second coupling block 14 includes a second block body 141 and a second adapter 142. The second block body 141 is coupled to the second end of the housing body 12. The second adapter 142 is coupled to a surface of the second block body 141 on the opposite side to the housing body 12.As shown in FIG. 2, the housing body 12 has a circular valve hole 16 that receives a spool valve element 15. The valve hole 16 extends in the longitudinal direction of the housing body 12, a first end of the valve hole 16 opens into a first end surface of the housing body 12, a second end of the valve hole 16 opens into a second end surface of the housing body 12, the valve hole 16 thus extends in the longitudinal direction through the housing body 12, and the spool valve element 15 can reciprocate in the valve hole 16.The housing body 12 has a supply port 17, a first output port 18, a second output port 19, a first discharge port 20, and a second discharge port 21. The housing 11 thus has a plurality of terminals. The electromagnetic pilot valve 10 of the present embodiment is a five-port electromagnetic valve.The first discharge port 20, the first output port 18, the supply port 17, the second output port 19, the second discharge port 21 are arranged in this order from the first end toward the second end of the housing body 12. The first ends of the supply port 17, the first output port 18, the second output port 19, the first discharge port 20, and the second discharge port 21 are connected to the valve hole 16. The second ends of the supply port 17, the first output port 18, the second output port 19, the first discharge port 20, and the second discharge port 21 open into the body facing surface 12 aof the housing body 12.The inner circumferential surface of the valve hole 16 includes a first valve seat portion 22 between the supply port 17 and the first output port 18. the inner circumferential surface of the valve hole 16 also includes a second valve seat portion 23 between the first output port 18 and the first discharge port 20. A fourth valve seat portion 25 is provided between the second output port 19 and the second discharge port 21. The first valve seat portion 22, the second valve seat portion 23, the third valve seat portion 24, and the fourth valve seat portion 25 form parts of the inner circumferential surface of the valve hole 16 and are annular.The valve hole 16 also has a first hole portion 16 a. The first hole portion 16 ais connected to the first discharge port 20 and forms a first end of the valve hole 16 spaced apart from the second valve seat portion 23 d. The valve hole 16 further includes a second hole portion 16 b. The second hole portion 16 bis connected to the second discharge port 21 and forms a second end of the valve hole 16 spaced apart from the fourth valve seat portion 25. The first valve seat portion 22, the second valve seat portion 23, the third valve seat portion 24, the fourth valve seat portion 25, the first hole portion 16 a, and the second hole portion 16 bhave the same inner diameter.The spool valve element 15 includes a first valve portion 151, a second valve portion 152, a third valve portion 153, a fourth valve portion 154, a fifth valve portion 155, and a sixth valve portion 156, which are spaced apart from each other in the axial direction of the spool valve element 15 d. The fifth valve portion 155, the second valve portion 152, the first valve portion 151, the third valve portion 153, the fourth valve portion 154, the sixth valve portion 156 are arranged in this order from the first end toward the second end in the axial direction of the spool valve element 15. The first valve portion 151, the second valve portion 152, the third valve portion 153, the fourth valve portion 154, the fifth valve portion 155, and the sixth valve portion 156 have the same outer diameter.The spool valve element 15 includes a first shaft portion 15 athat couples the first valve portion 151 and the third valve portion 153 to each other, a second shaft portion 15 bthat couples the first valve portion 151 and the second valve portion 152 to each other, and a third shaft portion 15 cthat couples the third valve portion 153 and the fourth valve portion 154 to each other. The spool valve element 15 also includes a fourth shaft portion 15 dthat couples the second valve portion 152 and the fifth valve portion 155 together, and a fifth shaft portion 15 ethat couples the fourth valve portion 154 and the sixth valve portion 156 together.The spool valve element 15 includes a columnar first protruding portion 15 f. The first protruding portion 15 fprotrudes from the end surface of the fifth valve portion 155 that is opposite to the fourth shaft portion 15 d. The first protruding portion 15 fis a first end in the axial direction of the spool valve element 15. the spool valve element 15 also includes a columnar second protruding portion 15 g. The second protruding portion 15 gprotrudes from the end surface of the sixth valve portion 156 that is opposite to the fifth shaft portion 15 e. The second protruding portion 15 gis a second end in the axial direction of the spool valve element 15.The first shaft portion 15 a, the second shaft portion 15 b, the third shaft portion 15 c, the fourth shaft portion 15 d, the fifth shaft portion 15 e, the first protruding portion 15 f, and the second protruding portion 15 ghave the same outer diameter. The outer diameter of the first valve portion 151, the second valve portion 152, the third valve portion 153, the fourth valve portion 154, the fifth valve portion 155, and the sixth valve portion 156 is larger than the diameter of the first shaft portion 15 a, the second shaft portion 15 b, the third shaft portion 15 c, the fourth shaft portion 15 d, the fifth shaft portion 15 e, the first protruding portion 15 f, and the second protruding portion 15 g.A first slide seal 26 is attached to the outer circumferential surface of the first valve portion 151. The first slide seal 26 serves as a seal between the supply port 17 and the first output port 18 when the first valve portion 151 is seated on the first valve seat portion 22. A second slide seal 27 is attached to the outer circumferential surface of the second valve portion 152. The second slide seal 27 serves as a seal between the first output port 18 and the first discharge port 20 when the second valve portion 152 is seated on the second valve seat portion 23. A third slide seal 28 is attached to the outer circumferential surface of the third valve portion 153. The third spool seal 28 serves as a seal between the supply port 17 and the second output port 19 when the third valve portion 153 is seated on the third valve seat portion 24. A fourth slide seal 29 is attached to the outer circumferential surface of the fourth valve portion 154. The fourth slide seal 29 serves as a seal between the second output connection 19 and the second discharge connection 21 when the fourth valve section 154 is seated on the fourth valve seat section 25. The first slide seal 26, the second slide seal 27, the third slide seal 28 and the fourth slide seal 29 are made of rubber and are formed annularly.The first coupling block 13 includes a first piston receiving recess 31 that is a circular hole connected to the first hole portion 16 a. The first protruding portion 15 fof the spool valve element 15 is formed to selectively enter the first piston receiving recess 31 from the first hole portion 16 aand retract from the first piston receiving recess 31 into the first hole portion 16 a. The first piston receiving recess 31 receives a disk-shaped first piston 32 while the first piston 32 can reciprocate. The first piston 32 is attached to the distal end of the first protruding portion 15 fof the spool valve element 15 f. A first lip seal 33 is attached to the outer circumferential surface of the first piston 32 f. The first lip seal 33 serves as a seal between the first piston 32 and the inner circumferential surface of the first piston receiving recess 31. the first piston 32 defines a first pilot pressure chamber 34 within the first piston receiving recess 31.The second coupling block 14 includes a second piston receiving recess 35 that is a circular hole connected to the second hole portion 16 b. The inner diameter of the second piston receiving recess 35 is the same as that of the first piston receiving recess 31, and the second protruding portion 15 gof the spool valve element 15 is formed to selectively enter the second piston receiving recess 35 from the second hole portion 16 band retract from the second piston receiving recess 35 into the second hole portion 16 b. The second piston receiving recess 35 receives a disk-shaped second piston 36 while the second piston 36 can reciprocate. The second piston 36 is attached to the distal end of the second protruding portion 15 gof the spool valve element 15. The outer diameter of the second piston 36 is the same as that of the first piston 32 and a second lip seal 37 is attached to the outer circumferential surface of the second piston 36. The second lip seal 37 serves as a seal between the second piston 36 and the inner circumferential surface of the second piston receiving recess 35. the second piston 36 defines a second pilot pressure chamber 38 within the second piston receiving recess 35. The pilot fluid is supplied to and discharged from the second pilot pressure chamber 38.The outer diameter of the first piston 32 is the same as that of the second piston 36, and accordingly, the pressure receiving area of the first piston 32 that receives the pressure of the pilot fluid in the first pilot pressure chamber 34 is the same as the pressure receiving area of the second piston 36 that receives the pressure of the pilot pressure in the second pilot pressure chamber 38.A first seal member 39 ais attached to the outer circumferential surface of the fifth valve portion 155. The first sealing member 39 afunctions as a seal between the fifth valve portion 155 and the first hole portion 16 a. The first seal member 39 ais annular and is made of rubber. The first sealing member 39 alimits leakage of fluid from the first discharge port 20 to the first piston receiving recess 31 via the first hole portion 16 a.A second seal member 39 bis attached to the outer circumferential surface of the sixth valve portion 156. The second sealing member 39 bfunctions as a seal between the sixth valve portion 156 and the second hole portion 16 b. The second seal member 39 bis annular and is made of rubber. The second sealing member 39 blimits leakage of fluid from the second discharge port 21 to the second piston receiving recess 35 via the second hole portion 16 b.As shown in FIG. 3, the first pilot valve 41 and the second pilot valve 42 have the same structure. The first pilot valve 41 and the second pilot valve 42 each have a rectangular block-shaped body 60, and each body 60 includes a solenoid housing 43 shaped like a rectangular tube having a closed end, and a passage-forming block 44 coupled to the solenoid housing 43 and shaped like a rectangular block. The solenoid housing 43 and the passage forming block 44 are made of, for example, plastic. The solenoid housing 43 and the passage forming block 44 are thus made of a non-magnetic material.The solenoid case 43 has a rectangular plate-shaped bottom wall 43 aand a rectangular tubular peripheral wall 43 bextending from the periphery of the bottom wall 43 a. The passage forming block 44 is coupled to the open end of the circumferential wall 43 bof the solenoid housing 43. That is, the channel-forming block 44 is coupled to the end opposite to the bottom wall 43 a. The channel-forming block 44 closes the opening of the peripheral wall 43 b. A magnetic frame 45 made of a magnetic material is fixed to the solenoid case 43. The magnet frame 45 includes a plate-shaped bottom portion 45 aand a tubular extending portion 45 b. The extending portion 45 bextends from the periphery of the bottom portion 45 aand along the inner peripheral surface of the peripheral wall 43 bof the solenoid housing 43.The first pilot valve 41 and the second pilot valve 42 each have a solenoid 46. Each solenoid 46 includes a coil 47, a fixed iron core 48, a plunger 49, and a plunger spring 50. The solenoid case 43 accommodates a tubular bobbin 51 around which the coil 47 is wound. The axis of the bobbin 51 corresponds to the axis of the extending portion 45 bof the magnet frame 45.The fixed iron core 48 is accommodated in the magnet case 43. The fixed iron core 48 has a column shape. The fixed iron core 48 is fixed to the coil 51 during insertion into the coil 51. The axis of the fixed iron core 48 corresponds to the axis of the coil core 51. the length in the axial direction of the fixed iron core 48 is shorter than the length in the axial direction of the coil core 51. the fixed iron core 48 has a flat end surface 48 eon the side opposite to the bottom portion 45 aof the magnet frame 45. The end surface 48 eof the fixed iron core 48 is located inside the bobbin 51.The plunger 49 is in the form of a column inserted into the bobbin 51. The plunger 49 is located between the fixed iron core 48 and the passage-forming block 44. The plunger 49 has a flat end surface 49 efacing the fixed iron core 48. The end surface 49 eof the plunger 49 is formed so as to be held in face contact with the end surface 48 eof the fixed iron core 48. The end of the plunger 49 on the opposite side to the fixed iron core 48 protrudes from the bobbin 51. An annular flange 49f projects from the end of the outer circumferential surface of the plunger 49 on the side opposite to the fixed iron core 48.A tubular magnetic core 52 is disposed in the magnetic frame 45. Specifically, the magnetic core 52 is located inside the end of the extending portion 45 bopposing the bottom portion 45 a. The magnetic core 52 is located between the bobbin 51 and the channel-forming block 44. the outer circumferential surface of the magnetic core 52 contacts the inner circumferential surface of the extending portion 45b of the magnet frame 45. the plunger 49 passes through the interior of the magnetic core 52.The plunger spring 50 is disposed between the magnetic core 52 and the flange 49f of the plunger 49. The plunger spring 50 has a first end supported by an end surface of the magnetic core 52 and a second end supported by the flange 49 fof the plunger 49 f. The plunger spring 50 urges the plunger 49 in a direction in which the end surface 49 eof the plunger 49 separates from the end surface 48 eof the fixed iron core 48.The channel-forming block 44 has a circular receiving hole 44 hhaving a closed end in the end surface opposite to the magnet housing 43. The axis of the receiving hole 44 hcorresponds to the axis of the plunger 49. each body 60 includes a columnar plug 54 attached to the receiving hole 44 h. Each plug 54 is attached to the corresponding receiving hole 44h with sealing members 53. The plug 54 closes the opening of the receiving hole 44 h. The plug 54 cooperates with the receiving hole 44h to define a valve chamber 55 within the passage forming block 44.The valve chamber 55 receives a pilot valve element 56. The end surface of the plug 54 which is disposed within the valve chamber 55 has a first valve seat 57 on which the pilot valve element 56 seats. The bottom surface of the receiving hole 44h has a second valve seat 58 on which the pilot valve element 56 is seated. The pilot valve element 56 is formed to contact and separate from the first valve seat 57 and the second valve seat 58. The pilot valve element 56 is accommodated in the valve chamber 55 while being able to move between the first valve seat 57 and the second valve seat 58. The first valve seat 57 and the second valve seat 58 are arranged to be opposed to each other in the moving direction of the pilot valve element 56 in the valve chamber 55.The valve chamber 55 includes a valve element spring 59 disposed between the pilot valve element 56 and the plug 54. The valve element spring 59 urges the pilot valve element 56 away from the first valve seat 57. The urging force of the valve element spring 59 is smaller than the urging force of the plunger spring 50.The plunger 49 has two elongated plate-shaped valve pressing portions 49a. The valve pressing portions 49a project from the end of the plunger 49 on the side opposite to the fixed iron core 48. The valve pressure portions 49a pass through the passage forming block 44 and project into the valve chamber 55.As shown in FIGS. 3 and 4, each channel-forming block 44 includes a supply channel 61, a first output channel 62, a second output channel 63, a first discharge channel 64, and a second discharge channel 65. The supply channel 61 includes a first hole 611, a second hole 612, a third hole 613, a groove 614, and a through hole 615. The first hole 611 has a first end opening into a first surface 441 of the channel-forming block 44 and a second end opening into the receiving hole 44 h. The first hole 611 extends straight from the first surface 441 of the channel-forming block 44 toward the receiving hole 44 hand passes through the channel-forming block 44. The first end opens into a second surface 442 of the channel-forming block 44 that is opposite the first surface 441. The second end opens into the receiving hole 44h. The first surface 441 and the second surface 442 are parallel to each other. The second hole 612 extends straight from the second surface 442 of the channel forming block 44 toward the receiving hole 44 h, and passes through the channel forming block 44.The groove 614 extends over the entire outer circumferential surface of the plug 54, and the first hole 611 and the second hole 612 are connected to the inside of the groove 614. The through hole 615 is connected to the groove 614 and extends in the radial direction of the plug 54 to pass through the plug 54. The third hole 613 has a first end opening into the through hole 615 and a second end opening into the distal end of the first valve seat 57. The third hole 613 extends straight from the through hole 615 toward the distal end of the first valve seat 57 to pass through the plug 54. The third hole 613 is connected to the valve chamber 55. The supply passage 61 thus opens into the first surface 441 and the second surface 442 of the passage forming block 44 and is connected to the valve chamber 55.The first output passage 62 has a first end opening into a first surface 441 of the passage forming block 44 and a second end opening into the receiving hole 44 h. The second end of the first output passage 62 opens into the receiving hole 44 hat a position between the plug 54 and the bottom surface of the receiving hole 44 h. The first output passage 62 is thus connected to the valve chamber 55.The first discharge passage 64 includes a first hole 641 and a second hole 642. The first hole 641 has a first end that opens into the first surface 441 of the channel forming block 44 and a second end that extends into the interior of the channel forming block 44. The second hole 642 has a first end connected to the second end of the first hole 641 and a second end opened to the distal end of the second valve seat 58. The second hole 642 is connected to the valve chamber 55. The first discharge passage 64 thus opens into the first surface 441 of the passage forming block 44 and is connected to the valve chamber 55.As shown in FIG. 5, the supply passage 61, the first output passage 62, and the first discharge passage 64 are arranged in this order in the moving direction of the pilot valve element 56. The opening of the supply passage 61 in the first surface 441 and the opening of the first discharge passage 64 in the first surface 441 are disposed on the opposite sides of the opening of the first output passage 62 in the first surface 441 when viewed in the moving direction of the pilot valve element 56.As shown in FIGS. 4 and 5, the second output channel 63 includes a first end that opens into the first surface 441 of the channel-forming block 44 and a second end that extends toward the second surface 442 of the channel-forming block 44. The second output channel 63 extends straight from the first surface 441 to the second surface 442. That is, the second output channel 63 extends in a direction orthogonal to the first surface 441 and the second surface 442. As shown in FIG. 5, the second output passage 63 is disposed between the first discharge passage 64 and one of the opposite side surfaces 443 of the passage forming block 44 as viewed in a direction orthogonal to the moving direction of the pilot valve element 56. The opposite side surfaces 443 of the passage forming block 44 are a pair of surfaces that connect the first surface 441 and the second surface 442 to each other.As shown in FIGS. 4 and 5, the second discharge passage 65 includes a first end that opens into the first surface 441 of the passage forming block 44 and a second end that extends toward the second surface 442 of the passage forming block 44. The second discharge passage 65 extends straight from the first surface 441 toward the second surface 442. That is, the second discharge passage 65 extends in a direction orthogonal to the first surface 441 and the second surface 442. The second discharge channel 65 and the second output channel 63 extend parallel to each other. As shown in FIG. 5, the second discharge passage 65 is disposed between the first discharge passage 64 and the other of the opposing side surfaces 443.As shown in FIGS. 4, 6, and 7, each channel-forming block 44 includes an output channel connection recess 66. The output passage communication groove 66 is provided in a region including a portion overlapping with an opening area Z 1 of the first output passage 62 opening into the first surface 441 and a portion overlapping with the second output passage 63. The output passage connecting recess 66 is connected to one end of the second output passage 63.The passage forming block 44 includes a discharge passage connecting recess 67, and the discharge passage connecting recess 67 is also formed in the second surface 442 of the passage forming block 44. The discharge passage communication groove 67 is provided in a region including a portion overlapping with an opening area Z 2 of the first discharge passage 64 opening into the first surface 441 and a portion overlapping with the second discharge passage 65. The discharge passage connecting recess 67 is connected to the second end of the second discharge passage 65.As shown in FIG. 3, the first pilot valve 41 is installed in the housing 11 and is disposed adjacent to the second pilot valve 42. The second pilot valve 42 is disposed between the first pilot valve 41 and the first coupling block 13 of the housing 11. The first pilot valve 41 and the second pilot valve 42 are disposed at an end of the first coupling block 13 opposite to the case body 12. The electromagnetic pilot valve 10 of the present embodiment is a solenoid-type one-sided electromagnetic valve in which the first pilot valve 41 and the second pilot valve 42 are disposed toward one side in the housing 11.The first surface 441 of the passage forming block 44 of the second pilot valve 42 is held in contact with the surface of the first adapter 132 located on the opposite side to the housing body 12. The first surface 441 of the passage forming block 44 of the first pilot valve 41 is held in contact with the second surface 442 of the passage forming block 44 of the second pilot valve 42.As shown in FIG. 4, the supply passage 61 of the first pilot valve 41 and the supply passage 61 of the second pilot valve 42 are connected to each other. Further, the output passage communication groove 66 of the passage forming block 44 of the second pilot valve 42 is connected to the first output passage 62 of the first pilot valve 41. Thus, the first output passage 62 of the first pilot valve 41 is connected to the second output passage 63 of the second pilot valve 42 via the output passage communication recess 66 of the second pilot valve 42. In addition, the discharge passage communication groove 67 of the passage forming block 44 of the second pilot valve 42 is connected to the first discharge passage 64 of the first pilot valve 41. Thus, the first discharge passage 64 of the first pilot valve 41 is connected to the second discharge passage 65 of the second pilot valve 42 via the discharge passage connection recess 67 of the second pilot valve 42.As shown in FIG. 3, in the first pilot valve 41, the opening of the supply passage 61 in the second surface 442, the discharge passage communication recess 66, and the discharge passage communication recess 67 are closed by a fixing bracket 70.Fig. 8 shows the mounting bracket 70 made of metal. The fastening bracket 70 includes two extending portions 70 aand a coupling portion 70 b. The extending portions 70a are thin elongated plates extending parallel to each other. The coupling portion 70 bis a thin elongated plate that couples ends of the extending portions 70 ato each other in the longitudinal direction. The coupling portion 70 bextends in a direction orthogonal to the extending direction of the extending portions 70 a. In a plan view, the coupling portion 70 bhas the same shape as the second surface 442 of the channel-forming block 44. Each extending portion 70a has an engaging hole 70h in the end on the side opposite to the coupling portion 70b. The engagement hole 70 hpass through the extending portion 70 ain the thickness direction. The engaging hole 70 his rectangular.As shown in FIG. 9, each channel-forming block 44 has a first guide groove 71 ain each of the side surfaces 443. The two first guide grooves 71a extend parallel to each other. The first guide grooves 71 aextend from the first surface 441 to the second surface 442. The first adapter 132 has a second guide groove 71 bconnected to the first guide grooves 71 aon each of side surfaces connected to the side surfaces 443 of the channel forming block 44. Each first guide groove 71 aand the corresponding second guide groove 71 bare located in the same plane. Each second guide groove 71b has an engaging protrusion 71f which is engaged with the corresponding engaging hole 70h. As shown in FIG. 5, the first guide grooves 71 aare disposed on the opposite sides of the opening of the supply passage 61 in the first surface 441 and on the opposite sides of the opening of the first output passage 62 in the first surface 441 as viewed from the first surface 441.FIG. 10 illustrates a state in which the first pilot valve 41 and the second pilot valve 42 are adjacent to each other. In this state, the extending portions 70a are guided to the second guide grooves 71b by the first guide grooves 71a, and the engaging holes 70h are engaged with the engaging protrusions 71f. In this manner, the engaging holes 70 hengage with the engaging protrusions 71 f, so that the extending portions 70 aare fixed to the first adapter 132. Thereby, the fixing bracket 70 is fixed to the first adapter 132. As shown in FIG. 5, the two extending portions 70 aare disposed on the opposite sides of the opening of the supply passage 61 in the first surface 441 and on the opposite sides of the opening of the first output passage 62 in the first surface 441, as viewed from the first surface 441.As shown in FIG. 3, the coupling portion 70 bof the fixing bracket 70 is held in contact with the entire second surface 442 of the passage forming block 44 of the first pilot valve 41. The coupling portion 70 bshakes the supply passage 61, the output passage communication recess 66, and the discharge passage communication recess 67 open into the second surface 442 of the passage forming block 44 of the first pilot valve 41. Since the extending portions 70a are fixed to the first adapter 132, the first pilot valve 41 and the second pilot valve 42 are fixed to the first adapter 132 while being held between the coupling portion 70b of the fixing bracket 70 and the first adapter 132. Therefore, the fixing bracket 70 fixes the first pilot valve 41 and the second pilot valve 42 to the housing 11.A seal 72 is disposed on the second surface 442 of the passage forming block 44 of the first pilot valve 41. Another seal 72 is disposed between the first surface 441 of the passage forming block 44 of the first pilot valve 41 and the second surface 442 of the passage forming block 44 of the second pilot valve 42. In addition, a seal 72 is provided between the first surface 441 of the passage forming block 44 of the second pilot valve 42 and the housing 11.The packing 72 disposed on the second surface 442 of the passage forming block 44 of the first pilot valve 41 is pressed against the passage forming block 44 of the first pilot valve 41 by the coupling portion 70 bof the fixing bracket 70. Thus, the surface of the coupling portion 70 bof the fixing bracket 70 that is close to the extending portions 70 a, that is, the inner surface of the fixing bracket 70, serves as a pressing surface 70 fthat presses the packing 72 against the passage forming block 44 of the first pilot valve 41.As shown in FIGS. 5 and 6, each seal 72 includes a first seal hole 72 a, a second seal hole 72 b, a third seal hole 72 c, a fourth seal hole 72 d, and a fifth seal hole 72 e. In a plan view of the first surface 441, the first seal hole 72 asurrounds the opening of the supply passage 61. in a plan view of the first surface 441, the second seal hole 72 bsurrounds the opening of the first output passage 62. in a plan view of the first surface 441, the third seal hole 72 csurrounds the opening of the first discharge passage 64. in a plan view of the first surface 441, the fourth seal hole 72 dsurrounds the opening of the second output passage 63. in a plan view of the first surface 441, the fifth seal hole 72 esurrounds the opening of the second discharge passage 65.The seal 72 interposed between the first surface 441 of the passage forming block 44 of the second pilot valve 42 and the housing 11 serves as a seal on the first surface 441 between the supply passage 61, the first output passage 62, the second output passage 63, the first discharge passage 64, and the second discharge passage 65 of the second pilot valve 42, The seal 72 interposed between the second surface 442 of the passage forming block 44 of the first pilot valve 41 and the coupling portion 70 bof the fixing bracket 70 serves as a seal on the second surface 442 between the supply passage 61, the output passage connecting recess 66, and the discharge passage connecting recess 67 of the first pilot valve 41.As shown in FIG. 1, the housing 11 has a pilot fluid supply passage 73 connected to the supply port 17 via the valve hole 16. The pilot fluid supply passage 73 opens into the valve hole 16 at a position connected to the supply port 17 regardless of the position of the spool valve element 15.The housing 11 further includes a pilot fluid output passage 74 that connects the first output passage 62 of the second pilot valve 42 and the second pilot pressure chamber 38 to each other. The specific path of the pilot fluid output passage 74 is not shown. Further, the housing 11 has a pilot fluid discharge passage 75 connected to the first discharge passage 64 of the second pilot valve 42. The portion of the pilot fluid discharge passage 75 located on the opposite side to the second pilot valve 42 is divided into a portion opening into the end surface of the first coupling block 13 corresponding to the housing body 12 and a portion opening into the first end surface 13 aof the first coupling block 13.As shown in FIGS. 1 and 7, the housing 11 has a pilot fluid output passage 76 that connects the second output passage 63 of the second pilot valve 42 and the first pilot pressure chamber 34 to each other. Further, the housing 11 has a pilot fluid discharge passage 77 connected to the second discharge passage 65 of the second pilot valve 42. The end of the pilot fluid discharge passage 77, which is located on the opposite side to the second discharge passage 65 of the second pilot valve 42, is connected to the pilot fluid discharge passage 75. The specific paths of the pilot fluid output passage 76 and the pilot fluid discharge passage 77 are not illustrated.As shown in FIG. 1, the second coupling block 14 of the housing 11 has a pilot fluid discharge passage 78. The pilot fluid discharge passage 78 is divided into a portion opening into the end surface of the second coupling block 14 corresponding to the housing body 12 and a portion opening into the second end surface 14 aof the second coupling block 14. For example, when the first pilot valve 41 and the second pilot valve 42 are disposed closer to the opposite side to the case body 12 with respect to the second coupling block 14 and the second pilot valve 42 is disposed between the first pilot valve 41 and the second coupling block 14, the pilot fluid discharge passage 78 is connected to the first discharge passage 64 of the second pilot valve 42.As shown in FIGS. 1 and 2, the manifold block MB includes a block supply channel 81, a first block discharge channel 82, a second block discharge channel 83, a first block discharge channel 84, and a second block discharge channel 85. the block supply channel 81, the first block discharge channel 82, the second block discharge channel 83, the block discharge channel 84, and the second block discharge channel 85 open into the placement surface B 1. The end of the ingot supply channel 81 that opens into the placement surface B 1 is connected to the supply port 17. The end of the first block output channel 82 that opens into the placement surface B 1 is connected to the first output terminal 18. The end of the second block output channel 83 opening into the placement surface B 1 is connected to the second output terminal 19. The end of the first block discharge passage 84 that opens into the placement surface B 1 is connected to the first discharge port 20. The end of the second block discharge passage 85 that opens into the placement surface B 1 is connected to the second discharge port 21.The end of the ingot supply channel 81 located on the side opposite to the placement surface B 1 is connected to a fluid supply source (not shown) via piping and the like. The end of the first block discharge passage 82 located on the side opposite to the placement surface B 1 and the end of the second block discharge passage 83 located on the side opposite to the placement surface B 1 are connected to a fluid pressure device (not shown) via piping and the like. The end of the first block discharge passage 84 located on the side opposite to the placement surface B 1 and the end of the second block discharge passage 85 located on the side opposite to the placement surface B 1 are connected to the atmosphere via piping and the like.The manifold block MB further includes a first block-side pilot fluid discharge passage 86 and a second block-side pilot fluid discharge passage 87. the first block-side pilot fluid discharge passage 86 has a first end that opens into the placement surface B 1 at a position opposite to the first facing end surface 13 aof the first coupling block 13 and is connected to the pilot fluid discharge passage 75. The first block-side pilot fluid discharge passage 86 has a second end connected to the first block discharge passage 84. The second block-side pilot fluid discharge passage 87 has a first end that opens into the placement surface B 1 at a position opposite to the second end surface 14 aof the second coupling block 14 and is connected to the pilot fluid discharge passage 78. The second block-side pilot fluid discharge passage 87 has a second end connected to the second block discharge passage 85.The block-side gasket 88 is provided between the placement surface B 1 of the manifold block MB and the housing body 12. The block-side gasket 88 serves as a seal between the placement surface B 1 of the manifold block MB and the case body 12.A first check valve 89a is attached to the first end of the first block-side control fluid discharge passage 86. The first check valve 89 aopens when the pressure in the first check valve 89 areaches a predetermined pressure, whereby the fluid can flow from the pilot fluid discharge passage 75 toward the first block-side pilot fluid discharge passage 86. The first check valve 89 alosure when the pressure in the first check valve 89 ais lower than the predetermined pressure, thereby preventing fluid from flowing from the first block-side pilot fluid discharge passage 86 to the pilot fluid discharge passage 75.A second check valve 89 bis attached to the first end of the second block-side control fluid discharge passage 87. The second check valve 89 bopens when the pressure in the second check valve 89 breaches a predetermined pressure, thereby allowing the fluid to flow from the pilot fluid discharge passage 78 toward the second block-side pilot fluid discharge passage 87. The second check valve 89 bshorts when the pressure in the second check valve 89 bis lower than the predetermined pressure, thereby preventing fluid from flowing from the second block-side pilot fluid discharge passage 87 to the pilot fluid discharge passage 78.As shown in FIG. 1, the first pilot valve 41 includes a first connection port 91. the first connection port 91 is electrically connected to the coil 47 of the solenoid 46 of the first pilot valve 41. The first communication port 91 protrudes from an end surface of the solenoid housing 43 of the first pilot valve 41 that is on the side opposite to the passage forming block 44. The second pilot valve 42 also includes a second connection port 92, and the second connection port 92 is electrically connected to the coil 47 of the solenoid 46 of the second pilot valve 42. The second communication port 92 protrudes from an end surface of the solenoid housing 43 of the second pilot valve 42 that is on the side opposite to the passage forming block 44.The distribution block MB includes a circuit board 93, a first terminal 94, and a second terminal 95. the circuit board 93 receives power from an external controller such as a programmable logic controller (PLC). The first terminal 94 and the second terminal 95 are electrically connected to the circuit board 93. The first connection port 91 is connected to the first port 94 when the electromagnetic pilot valve 10 is simultaneously mounted on the placement surface B 1 of the manifold block MB. The second connection port 92 is connected to the second port 95 when the electromagnetic pilot valve 10 is simultaneously mounted on the placement surface B 1 of the manifold block MB. The electromagnetic valve distributor of the present embodiment has a plug-in structure in which, simultaneously with the mounting of the first pilot valve 41 and the second pilot valve 42 in the distributor block MB, the first connection port 91 of the first pilot valve 41 and the second connection port 92 of the second pilot valve 42 are connected to the first port 94 and the second port 95 of the distributor block MB, respectively.An operation of the present embodiment will now be described.It is assumed that, as shown in FIG. 3, the power supply from the circuit board 93 shown in FIG. 1 to the coil 47 of the solenoid 46 of the first pilot valve 41 via the first port 94 and the first connection port 91 is cut off, and that power is supplied from the circuit board 93 via the second port 95 and the second connection port 92 to the coil 47 of the solenoid 46 of the second pilot valve 42.In this case, the coil 47 of the second pilot valve 42 is energized so that magnetic fluxes passing through the magnetic frame 45, the fixed iron core 48, the plunger 49, and the magnetic core 52 are generated around the coil 47. Energization of the coil 47 generates an attractive force in the fixed iron core 48, and accordingly, the plunger 49 is attracted to the fixed iron core 48 against the urging force of the plunger spring 50. The urging force of the valve element spring 59 thus moves the pilot valve element 56 of the second pilot valve 42 away from the first valve seat 57, so that the pilot valve element 56 seats on the second valve seat 58.As a result, the supply passage 61 of the second pilot valve 42 and the first output passage 62 are communicated with each other via the valve chamber 55, and the communication between the first output passage 62 and the first discharge passage 64 via the valve chamber 55 is blocked. Compressed fluid from the fluid supply source is supplied as pilot fluid to the second pilot pressure chamber 38 via the pilot fluid supply passage 73, the supply passage 61 of the second pilot valve 42, the valve chamber 55, the first output passage 62, and the pilot fluid output passage 74.On the other hand, since no power is supplied to the coil 47 of the solenoid 46 of the first pilot valve 41, no attractive force is generated in the fixed iron core 48 due to energization of the coil 47. Accordingly, the plunger 49 is moved away from the fixed iron core 48 by the urging force of the plunger spring 50. Therefore, the valve pressing portions 49a of the plunger 49 press the pilot valve element 56 of the first pilot valve 41 toward the first valve seat 57 against the pressing force of the valve element spring 59 so that the pilot valve element 56 is seated on the first valve seat 57.As a result, the first output passage 62 and the first discharge passage 64 of the first pilot valve 41 are communicated with each other via the valve chamber 55, and the communication between the supply passage 61 and the first output passage 62 via the valve chamber 55 is blocked. The pilot fluid in the first pilot pressure chamber 34 is discharged to the pilot fluid discharge passage 77 via the pilot fluid output passage 76, the second output passage 63 of the second pilot valve 42, the output passage communication recess 66, the first output passage 62 of the first pilot valve 41, the valve chamber 55, the first discharge passage 64, the discharge passage communication recess 67 of the second pilot valve 42, and the second discharge passage 65. The pilot fluid discharged to the pilot fluid discharge passage 77 is discharged to the atmosphere through the pilot fluid discharge passage 75, the first check valve 89 a, the first block-side pilot fluid discharge passage 86, and the first block discharge passage 84.In this way, the discharge of pilot fluid from the first pilot pressure chamber 34 through the first pilot valve 41 and the supply of pilot fluid to the second pilot pressure chamber 38 through the second pilot valve 42 are performed, so that the spool valve element 15 moves toward the first piston receiving recess 31. This allows the supply port 17 and the second output port 19 to be connected to each other, and the first output port 18 and the first discharge port 20 to be connected to each other. In addition, the first slide seal 26 of the first valve portion 151 serves as a seal between the supply port 17 and the first output port 18, and the fourth slide seal 29 of the fourth valve portion 154 serves as a seal between the second output port 19 and the second discharge port 21.When the spool valve element 15 moves toward the first piston receiving recess 31, the fluid in the pilot fluid discharge passage 75 flows into the space in the first piston receiving recess 31 located on the opposite side of the first piston 32 to the first pilot pressure chamber 34 via the space between the first coupling block 13 and the housing body 12. In addition, when the spool valve element 15 moves toward the first piston receiving recess 31, the fluid in the space in the second piston receiving recess 35 located on the opposite side of the second piston 36 from the second pilot pressure chamber 38 flows into the pilot fluid discharge passage 78 via the space between the second coupling block 14 and the housing body 12.Then, the fluid is supplied from the fluid supply source to the fluid pressure device via the block supply passage 81, the supply port 17, the second output port 19, and the second block output passage 83. In addition, the fluid is discharged from the fluid pressure device to the atmosphere through the first block discharge passage 82, the first output port 18, the first discharge port 20, and the first block discharge passage 84.For example, assume that power is supplied from the circuit board 93 shown in FIG. 1 to the coil 47 of the solenoid 46 of the first pilot valve 41 via the first port 94 and the first connection port 91, and that the power supply from the circuit board 93 to the coil 47 of the solenoid 46 of the second pilot valve 42 is cut off via the second port 95 and the second connection port 92.In this case, the coil 47 of the first pilot valve 41 is energized so that magnetic fluxes passing through the magnetic frame 45, the fixed iron core 48, the plunger 49, and the magnetic core 52 are generated around the coil 47. Energization of the coil 47 generates an attractive force in the fixed iron core 48, and accordingly, the plunger 49 is attracted to the fixed iron core 48 against the urging force of the plunger spring 50. The urging force of the valve element spring 59 thus moves the pilot valve element 56 of the first pilot valve 41 away from the first valve seat 57, so that the pilot valve element 56 seats on the second valve seat 58.As a result, the supply passage 61 of the first pilot valve 41 and the first output passage 62 are communicated with each other via the valve chamber 55, and the communication between the first output passage 62 and the first discharge passage 64 via the valve chamber 55 is blocked. Then, the compressed fluid is supplied from the fluid supply source as pilot fluid to the first pilot pressure chamber 34 via the pilot fluid supply passage 73, the supply passage 61 of the second pilot valve 42, the supply passage 61 of the first pilot valve 41, the valve chamber 55, the first output passage 62, the output passage communication recess 66 of the second pilot valve 42, the second output passage 63, and the pilot fluid output passage 76.On the other hand, since no power is supplied to the coil 47 of the solenoid 46 of the second pilot valve 42, no attractive force is generated in the fixed iron core 48 due to energization of the coil 47. Accordingly, the plunger 49 is moved away from the fixed iron core 48 by the urging force of the plunger spring 50. Therefore, the valve pressing portions 49a of the plunger 49 press the pilot valve element 56 of the second pilot valve 42 toward the first valve seat 57 against the pressing force of the valve element spring 59 so that the pilot valve element 56 is seated on the first valve seat 57.As a result, the first output passage 62 and the first discharge passage 64 of the second pilot valve 42 are communicated with each other via the valve chamber 55, and the communication between the supply passage 61 and the first output passage 62 via the valve chamber 55 is blocked. The pilot fluid in the second pilot pressure chamber 38 is discharged to the atmosphere through the pilot fluid output passage 74, the first output passage 62 of the second pilot valve 42, the valve chamber 55, the first discharge passage 64, the pilot fluid discharge passage 75, the first check valve 89 a, the first block-side pilot fluid discharge passage 86, and the first block discharge passage 84.In this way, the supply of pilot fluid to the first pilot pressure chamber 34 through the first pilot valve 41 and the discharge of pilot fluid from the second pilot pressure chamber 38 through the second pilot valve 42 are performed, so that the spool valve element 15 moves toward the second piston receiving recess 35. This allows the supply port 17 and the first output port 18 to be connected to each other, and the second output port 19 and the second discharge port 21 to be connected to each other. In addition, the third spool seal 28 of the third valve portion 153 serves as a seal between the supply port 17 and the second output port 19, and the second spool seal 27 of the second valve portion 152 serves as a seal between the first output port 18 and the first discharge port 20.When the spool valve element 15 moves toward the second piston receiving recess 35, the fluid in the space in the first piston receiving recess 31 located on the opposite side of the first piston 32 to the first pilot pressure chamber 34 flows into the pilot fluid discharge passage 75 via the space between the first coupling block 13 and the housing body 12, and when the spool valve element 15 moves toward the second piston receiving recess 35, the fluid in the pilot fluid discharge passage 78 also flows into the space in the second piston receiving recess 35 located on the opposite side of the second piston 36 to the second pilot pressure chamber 38 via the space between the second coupling block 14 and the housing body 12.Then, the fluid is supplied from the fluid supply source to the fluid pressure device via the block supply passage 81, the supply port 17, the first output port 18, and the first block output passage 82. In addition, the fluid is discharged from the fluid pressure device to the atmosphere through the second block discharge passage 83, the second output port 19, the second discharge port 21, and the second block discharge passage 85.As described above, the first pilot valve 41 supplies pilot fluid to and discharges pilot fluid from the first pilot pressure chamber 34. The second pilot valve 42 supplies pilot fluid to and discharges pilot fluid from the second pilot pressure chamber 38. The first output passage 62 and the second output passage 63 supply or discharge pilot fluid to or from the first pilot pressure chamber 34 or the second pilot pressure chamber 38. The first discharge passage 64 and the second discharge passage 65 discharge pilot fluid in the first pilot pressure chamber 34 or the second pilot pressure chamber 38.The electromagnetic pilot valve 10 of the present embodiment is of an internal pilot type in which a part of the fluid supplied to the supply port 17 is supplied to the first pilot pressure chamber 34 and the second pilot pressure chamber 38. In the electromagnetic pilot valve 10, the spool valve element 15 is reciprocated in the housing 11 by the pilot fluid so that connections of the ports are switched.The above-described embodiment provides the following advantages.(1) The passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 respectively include the supply passage 61 that opens into the first surface 441 and the second surface 442 and is connected to the valve chamber 55, the first output passage 62 that opens into the first surface 441 and is connected to the valve chamber 55, and the second output passage 63 that opens into the first surface 441. Further, the passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 each include the output passage communication groove 66. the output passage communication groove 66 is provided in a portion of the second surface 442 that overlaps with the opening area Z 1 of the first output passage 62 that opens into the first surface 441 and is connected to the second output passage 63.For example, the first pilot valve 41 and the second pilot valve 42 are arranged such that the first surface 441 of the passage forming block 44 of the first pilot valve 41 and the second surface 442 of the passage forming block 44 of the second pilot valve 42 abut each other, so that the first output passage 62 of the first pilot valve 41 and the output passage communication recess 66 of the second pilot valve 42 are communicated with each other. In this case, the first output passage 62 of the first pilot valve 41 is connected to the second output passage 63 of the second pilot valve 42 via the output passage connection recess 66 of the second pilot valve 42.Further, for example, the first pilot valve 41 and the second pilot valve 42 are arranged such that the second surface 442 of the passage forming block 44 of the first pilot valve 41 and the first surface 441 of the passage forming block 44 of the second pilot valve 42 abut each other, so that the first output passage 62 of the second pilot valve 42 and the output passage communication recess 66 of the first pilot valve 41 are communicated with each other. In this case, the first output passage 62 of the second pilot valve 42 is connected to the second output passage 63 of the first pilot valve 41 via the output passage communication recess 66 of the first pilot valve 41.Thus, although the passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 have the same passage structure, it is possible to supply pilot fluid to and discharge pilot fluid from the first pilot pressure chamber 34 of the first pilot valve 41 and supply pilot fluid to and discharge pilot fluid from the second pilot pressure chamber 38 of the second pilot valve 42. It is therefore not necessary to manufacture two kinds of passage forming blocks having different structures to perform the supply of control fluid to and the discharge of control fluid from the first control pressure chamber 34 and to perform the supply of control fluid to and the discharge of control fluid from the second control pressure chamber 38. This improves the production efficiency.(2) The passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 respectively include the first discharge passage 64 opening into the first surface 441 and connected to the valve chamber 55, and the second discharge passage 65 opening into the first surface 441. Further, the passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 each include the discharge passage communication recess 67 provided in a portion of the second surface 442 that overlaps with the opening area Z 2 of the first discharge passage 64 that opens into the first surface 441 and is connected to the second discharge passage 65.For example, the first pilot valve 41 and the second pilot valve 42 are arranged such that the first surface 441 of the passage forming block 44 of the first pilot valve 41 and the second surface 442 of the passage forming block 44 of the second pilot valve 42 abut each other, so that the first discharge passage 64 of the first pilot valve 41 and the discharge passage communication recess 67 of the second pilot valve 42 are communicated with each other. In this case, the first discharge passage 64 of the first pilot valve 41 is connected to the second discharge passage 65 of the second pilot valve 42 via the discharge passage connection recess 67 of the second pilot valve 42.Further, for example, the first pilot valve 41 and the second pilot valve 42 are arranged such that the second surface 442 of the passage forming block 44 of the first pilot valve 41 and the first surface 441 of the passage forming block 44 of the second pilot valve 42 abut each other, so that the first discharge passage 64 of the second pilot valve 42 and the discharge passage communication recess 67 of the first pilot valve 41 are communicated with each other. In this case, the first discharge passage 64 of the second pilot valve 42 is connected to the second discharge passage 65 of the first pilot valve 41 via the discharge passage connection recess 67 of the first pilot valve 41.Although the passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 have the same passage structure, it is possible to use different passages to supply pilot fluid to and discharge pilot fluid from the first pilot pressure chamber 34 and supply pilot fluid to and discharge pilot fluid from the second pilot pressure chamber 38 of the second pilot valve 42. Therefore, for example, when pilot fluid is discharged from the first pilot pressure chamber 34, the pilot fluid discharged from the first pilot pressure chamber 34 is prevented from flowing into the valve chamber 55 of the second pilot valve 42. The second pilot valve 42 is thus prevented from malfunction.(3) The gaskets 72 are respectively disposed on the second surface 442 of the passage forming block 44 of the first pilot valve 41, between the first surface 441 of the passage forming block 44 of the first pilot valve 41 and the second surface 442 of the passage forming block 44 of the second pilot valve 42, and between the first surface 441 of the passage forming block 44 of the second pilot valve 42 and the housing 11. On the first surface 441, the gasket 72 serves as a seal between the supply passage 61, the first output passage 62, the second output passage 63, the first discharge passage 64, and the second discharge passage 65, and on the second surface 442, the gasket 72 serves as a seal between the supply passage 61, the output passage communication recess 66, and the discharge passage communication recess 67, The gaskets 72 of the same type may be respectively disposed on the second surface 442 of the passage forming block 44 of the first pilot valve 41, between the first surface 441 of the passage forming block 44 of the first pilot valve 41 and the second surface 442 of the passage forming block 44 of the second pilot valve 42, and between the first surface 441 of the passage forming block 44 of the second pilot valve 42 and the housing 11. This improves the production efficiency.(4) The first pilot valve 41 and the second pilot valve 42 are fixed to the housing 11 by the fixing bracket 70. This configuration eliminates the need for bolt insertion holes, unlike a case where the first pilot valve 41 and the second pilot valve 42 are fastened to the housing 11 by bolts. Therefore, the channel-forming block 44 does not need to have spaces for forming screw insertion holes. Thereby, the sizes of the first pilot valve 41 and the second pilot valve 42 can be reduced. Since the passage forming block 44 does not need to have spaces for forming screw insertion holes, the flow cross-sectional areas of the passages can be increased.(5) The coupling portion 70 bshates the supply passage 61 that opens into the second surface 442 of the passage forming block 44 of the first pilot valve 41, the discharge passage communication recess 66, and the discharge passage communication recess 67. Thus, no component other than the fixing bracket 70 is required to close the supply passage 61, the discharge passage communication recess 66, and the discharge passage communication recess 67 that open in the second surface 442 of the passage forming block 44 of the first pilot valve 41. This reduces the number of components, thereby improving production efficiency.The body 60 of each of the first pilot valve 41 and the second pilot valve 42 has the first valve seat 57 and the second valve seat 58 which are arranged to oppose each other in the moving direction of the pilot valve element 56 in the valve chamber 55. When the pilot valve element 56 is seated on the first valve seat 57, the supply passage 61 and the first output passage 62 are separated from each other. When the pilot valve element 56 is seated on the second valve seat 58, the first output passage 62 and the first discharge passage 64 are separated from each other. The supply passage 61, the first output passage 62, and the first discharge passage 64 are arranged in this order in the moving direction of the pilot valve element 56. The second output passage 63 is disposed between the first discharge passage 64 and one of the opposite side surfaces 443. The second discharge passage 65 is disposed between the first discharge passage 64 and the other of the opposing side surfaces 443. As viewed from the first surface 441, the two extending portions 70 aare disposed on the opposite sides of the opening of the supply passage 61 in the first surface 441 and on the opposite sides of the opening of the first output passage 62 in the first surface 441. These structures are advantageous in reducing the size of the first pilot valve 41 and the second pilot valve 42 each including the first valve seat 57 and the second valve seat 58 arranged to oppose each other in the moving direction of the pilot valve element 56 in the valve chamber 55.Since the passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 are common parts, the electromagnetic pilot valve 10 is easy to assemble. This eliminates the need for machine adjustment during maintenance, improving the efficiency of maintenance.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 remain technically consistent with each other.The first discharge passage 64 of each of the first pilot valve 41 and the second pilot valve 42 may be provided with a check valve that allows the fluid discharged from the valve chambers 55 to flow while blocking the fluid from flowing to the valve chambers 55. This further effectively prevents the pilot fluid discharged from the first pilot pressure chamber 34 from entering the valve chamber 55 of the second pilot valve 42 and prevents the pilot fluid discharged from the second pilot pressure chamber 38 from flowing into the valve chamber 55 of the first pilot valve 41.The first discharge passages 64, the second discharge passages 65, and the discharge passage connection recesses 67 may be omitted from the passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42. The passage forming blocks 44 of the first pilot valve 41 and the second pilot valve 42 may each be provided with a discharge passage that opens into the first surface 441 and the second surface 442 and is connected to the valve chamber 55.The seal disposed on the second surface 442 of the passage forming block 44 of the first pilot valve 41 may have a shape different from that of the seal 72 provided between the first surface 441 of the passage forming block 44 of the first pilot valve 41 and the second surface 442 of the passage forming block 44 of the second pilot valve 42. In short, the seal provided on the second surface 442 of the passage forming block 44 of the first pilot valve 41 is only intended to serve as a seal on the second surface 442 between the supply passage 61, the output passage communication recess 66, and the discharge passage communication recess 67.The fastening bracket 70 may be made of plastic.Between the coupling portion 70 bof the fixing bracket 70 and the second surface 442 of the passage forming block 44 of the first pilot valve 41, a plate member closing the supply passage 61, the output passage communication recess 66, and the discharge passage communication recess 67 opening into the second surface 442 of the passage forming block 44 of the first pilot valve 41 may be provided.The first pilot valve 41 and the second pilot valve 42 may be mounted to the housing 11 by bolts. In this case, a plate member that closes the supply passage 61, the output passage communication groove 66, and the discharge passage communication groove 67 opening into the second surface 442 of the passage forming block 44 of the first pilot valve 41 needs to be fixed to the second surface 442 of the passage forming block 44 of the first pilot valve 41.The main valve unit V 1 of the electromagnetic pilot valve 10 may be a three-port double directional control valve that receives two spool valve elements in a valve bore 16. In this case, the two spool valve elements are operated independently of each other by supplying pilot fluid to and discharging pilot fluid from the first pilot pressure chamber 34 of the first pilot valve 41 and by supplying pilot fluid to and discharging pilot fluid from the second pilot pressure chamber 38 of the second pilot valve 42.

Claims

An electromagnetic pilot valve (10) comprising: a housing (11) having ports (17, 18, 19, 20, 21); a spool valve element (15) reciprocated in the housing (11) to switch connections between the ports (17, 18, 19, 20, 21); a first pilot pressure chamber (34) and a second pilot pressure chamber (38) provided at opposite ends of the spool valve element (15) in the housing (11); a first pilot valve (41) supplying pilot fluid to and discharging pilot fluid from the first pilot pressure chamber (34); and a second pilot valve (42) supplying pilot fluid to and discharging pilot fluid from the second pilot pressure chamber (38), wherein the first pilot valve (41) and the second pilot valve (42) are arranged to be adjacent to and coupled to each other, the first pilot valve (41) and the second pilot valve (42) each have a rectangular block-shaped body (60), the body (60) having a first surface (441) and a second surface (442) located on a side opposite to the first surface (441), and each body (60) comprises: a valve chamber (55) in which a pilot valve element (56) is movably accommodated; a supply passage (61) opening into the first surface (441) and the second surface (442) and connected to the valve chamber (55); a first output passage (62) opening into the first surface (441) and connected to the valve chamber (55), the first output passage (62) being configured to:, in order to supply pilot fluid to and discharge pilot fluid from the first pilot pressure chamber (34) or the second pilot pressure chamber (38), a second output passage (63) that opens into the first surface (441), the second output passage (63) being configured to supply pilot fluid to and discharge pilot fluid from the first pilot pressure chamber (34) or the second pilot pressure chamber (38), and an output passage communication recess (66) provided in a portion of the second surface (442) that overlaps with an opening area of the first output passage (62) that opens into the first surface (441), the output passage communication recess (66) being connected to the second output passage (63).The electromagnetic pilot valve (10) according to claim 1, wherein each body (60) comprises: a first discharge passage (64) that opens into the first surface (441) and is connected to the valve chamber (55), the first discharge passage (64) being configured to discharge pilot fluid from the first pilot pressure chamber (34) or the second pilot pressure chamber (38); a second discharge passage (65) that opens into the first surface (441); the second discharge passage (65) being configured to discharge pilot fluid from the first pilot pressure chamber (34) or the second pilot pressure chamber (38); and a discharge passage communication recess (67) is provided in a portion of the second surface (442) that overlaps with an opening area of the first discharge passage (64) that opens into the first surface (441), wherein the discharge passage connecting recess (67) is connected to the second discharge passage (65).The electromagnetic pilot valve (10) according to claim 2, further comprising seals (72), each seal (72) serving on the first surface (441) as a seal between the supply passage (61), the first output passage (62), the second output passage (63), the first discharge passage (64), and the second discharge passage (65), and serving on the second surface (442) as a seal between the supply passage (61), the output passage communication recess (66), and the discharge passage communication recess (67), and the gaskets (72) are respectively provided on the second surface (442) of the body (60) of the first pilot valve (41) between the first surface (441) of the body (60) of the first pilot valve (41) and the second surface (442) of the body (60) of the second pilot valve (42) and between the first surface (441) of the body (60) of the second pilot valve (42) and the housing (11).The electromagnetic pilot valve (10) according to claim 3, further comprising: a fixing bracket (70) fixing the first pilot valve (41) and the second pilot valve (42) to the housing (11), wherein the fixing bracket (70) comprises: two plate-shaped extending portions (70a) fixed to the housing (11), and a coupling portion (70b) coupling the extending portions (70a) to each other, and the first pilot valve (41) and the second pilot valve (42) are fixed to the housing (11) by fixing the extending portions (70a) to the housing (11) so that the first pilot valve (41) and the second pilot valve (42) are held between the coupling portion (70b) and the housing (11).The electromagnetic pilot valve (10) according to claim 4, wherein the coupling portion (70b) closes the supply passage (61), the output passage communication recess (66), and the discharge passage communication recess (67) opening into the second surface (442) of the body (60) of the first pilot valve (41).The electromagnetic pilot valve (10) according to claim 4 or 5, wherein each body (60) includes a first valve seat (57) and a second valve seat (58) arranged to oppose each other in a moving direction of the pilot valve element (56) in the valve chamber (55) when the pilot valve element (56) is seated on the first valve seat (57), the supply passage (61) and the first output passage (62) are separated from each other when the pilot valve element (56) is seated on the second valve seat (58), the first output passage (62) and the first discharge passage (64) are separated from each other, the supply passage (61), the first output passage (62) and the first discharge passage (64) are arranged in this order in the moving direction of the pilot valve element (56), when viewed in a direction orthogonal to the moving direction of the pilot valve element (56), the second discharge passage (63) is disposed between the first discharge passage (64) and one of two side surfaces (443) connecting the first surface (441) and the second surface (442) to each other, the second discharge passage (65) is disposed between the first discharge passage (64) and the other of the side surfaces (443), and when viewed from the first surface (441), the extending portions (70a) are disposed on opposite sides of an opening of the supply passage (61) in the first surface (441) and on opposite sides of an opening of the first discharge passage (62) in the first surface (441).

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