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WE CLAIM:
Claim 1. A pilot-type solenoid valve (10), comprising: a body (14) including a flow path (12) for a pressure 5 fluid in an interior thereof, and a main valve seat (30) disposed at a position facing toward the flow path (12); a pressure chamber (36) connected to the body (14); a main valve element unit (38) including a pilot valve port (68) in communication with the pressure chamber (36) 10 and the flow path (12), and configured to be seated on or
separated away from the main valve seat (30) in an interior of the pressure chamber (36);
a movable iron core (70) in which a pilot valve element (74) is provided and configured to be seated on or separated 15 away from a pilot valve seat (66) of the pilot valve port
(68) at one end portion facing toward the main valve element
unit (38), together with including a groove-shaped
engagement member (78) formed on an outer circumference
thereof;
20 a coil shaped coupling spring (42) connecting the
movable iron core (70) and the main valve element unit (38); and
a solenoid unit (18) configured to drive the movable
iron core (70);
25 wherein the coupling spring (42) comprises:
a first winding part (44) which is formed by being bent
in a polygonal shape, is elastically deformed by the movable
iron core (70) being pressed therein from an opening portion
thereof, and engages with the engagement member (78);
30 a second winding part (46) positioned on an opposite
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side from the first winding part (44), and which is fixed to the main valve element unit (38); and
a third winding part (48) positioned between the first winding part (44) and the second winding part (46).
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Claim 2. The pilot-type solenoid valve (10) according to claim 1, wherein the first winding part (44) is formed by being bent in a triangular shape.
10 Claim 3. The pilot-type solenoid valve (10) according
to claim 1, wherein a diameter (D6) of the movable iron core (70) at a position of the engagement member (78) is less than or equal to a diameter (Dl) of an inscribed circle (Crl) in the opening portion of the first winding part (44).
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Claim 4. The pilot-type solenoid valve (10) according to claim 1, wherein a diameter (D4) of a circumscribed circle (Cr2) of the first winding part (44) is greater than an outer diameter (D5) of the third winding part (48), and a
20 diameter (Dl) of an inscribed circle (Crl) in the opening
portion of the first winding part (44) is less than an inner diameter (D3) of the third winding part (48).
Claim 5. The pilot-type solenoid valve (10) according 25 to claim 1, wherein on a press-fitted portion of the movable iron core (70), a diameter (D7) of an adjacent portion thereof adjacent to the engagement member (78) is greater than a diameter (D6) of the engagement member (78), and the press-fitted portion comprises an umbrella member (80) which 30 is smaller in diameter than the adjacent portion, and is
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formed in a tapered shape tapering toward the main valve element unit (38).
Claim 6. The pilot-type solenoid valve (10) according 5 to claim 5, wherein a diameter (D9) of a distal end part of the umbrella member (80) is less than or equal to a diameter (Dl) of an inscribed circle (Crl) in the opening portion of the first winding part (44).
10 Claim 7. The pilot-type solenoid valve (10) according
to any one of claims 1 to 6, wherein the main valve element
unit (38) further comprises:
a diaphragm (26) configured to be seated on or
separated away from the main valve seat (30);
15 a retaining plate (54) mounted on the diaphragm (26)
and configured to retain the second winding part (46);
an orifice member (56) in which the pilot valve seat
(66) is formed at one end thereof and the pilot valve port
(68) is formed along a central axis, the orifice member (56) 20 being inserted into openings of the diaphragm (26) and the
retaining plate (54); and
a fixing member (58) attached to an outer circumference
of the orifice member (56) on a bottom surface side of the
diaphragm (26), and configured to fix the diaphragm (26), 25 the retaining plate (54), and the second winding part (46)
by being sandwiched between the fixing member (58) and the
orifice member (56).
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