Proportional control valve

Abstract

To provide a proportional control valve which is a compact three-way valve having simple structure, and enables the flow volume of gas to be highly accurately controlled.SOLUTION: A proportional control valve 1 comprises: a shaft member 10 including a first passage 6 opened to an end face 11 on one side in the axial direction; a second passage 15; a third passage 17; a fourth passage 19; a valve element 30; a valve seat 65; and forward and backward drive mechanism 50 driving the shaft member 10 forward and backward in the axial direction. The forward and backward drive mechanism 50 can locate the shaft member 10 at a first position where the second passage 15 is not communicated with both the first passage 6 and the third passage 17, and the third passage 17 is not communicated with the first passage 6, at a second position where the second passage 15 is communicated with the third passage 17 and the second passage 15 is not communicated with the first passage 6, and at a third position where the third passage 17 is communicated with the fourth passage 19 via the first passage 6.SELECTED DRAWING: Figure 1

Claims

[Claim 1] A shaft member including a first passage which is an internal passage opening to at least one end face in the axial direction, The second aisle, the third aisle, and the fourth aisle, The valve body and the valve seat, The shaft member comprises a reciprocating drive mechanism that moves the shaft member back and forth in the axial direction, A proportional control valve in which, with the second passage connected to a gas supply source, the forward and backward drive mechanism can position the shaft member in the following positions: a first position in which the second passage does not communicate with both the first and third passages, and the third passage does not communicate with the first passage, with the valve body seated on the valve seat and its end face in contact with the valve body; a second position in which the second passage communicates with the third passage, while the second passage does not communicate with the first passage, with the valve body positioned at a distance from the valve seat and its end face in contact with the valve body; and a third position in which the third passage communicates with the fourth passage via the first passage, with the valve body seated on the valve seat and its end face at a distance from the valve body. [Claim 2] The aforementioned reciprocating drive mechanism, A first coil is positioned radially outward of the shaft member and arranged to surround at least a portion of the shaft member, A second coil is positioned radially outward of the shaft member and is arranged to surround at least a portion of the shaft member, and is spaced apart from the first coil in the axial direction. A permanent magnet is positioned between the axial direction of the first coil and the second coil, and is located radially outward of the shaft member, The shaft member has a large-diameter portion with a larger outer diameter and a small-diameter portion with a smaller outer diameter than the large-diameter portion. The proportional control valve according to claim 1, wherein the shaft member is positioned at the first position by aligning the large-diameter portion with the permanent magnet in the radial direction while the first coil and the second coil are not energized. [Claim 3] The aforementioned reciprocating drive mechanism, A first coil is positioned radially outward of the shaft member and arranged to surround at least a portion of the shaft member, A second coil is positioned radially outward of the shaft member and is arranged to surround at least a portion of the shaft member, and is spaced apart from the first coil in the axial direction. The shaft member has a permanent magnet fixed to its outer circumferential surface, The proportional control valve according to claim 1, wherein the shaft member is positioned at the first position based on the magnetic field generated by the permanent magnet when the first coil and the second coil are not energized. [Claim 4] The proportional control valve according to claim 2 or 3, further comprising one or more first biasing members that bias the shaft member to the first position when the first coil and the second coil are not energized. [Claim 5] The proportional control valve according to claim 2 or 3, further comprising one or more second biasing members for adjusting the radial position of the shaft member. [Claim 6] In the valve body, the portion that contacts the valve seat is made of an elastic material. The valve seat, The first ring-shaped part has approximately the same height at the tip, A proportional control valve according to claim 1 or 2, comprising a second portion which has a lower tip height than the first portion and is located radially outward from the first portion. [Claim 7] The second portion has a flat tip surface extending in a direction perpendicular to the axial direction toward the valve body in the axial direction, The proportional control valve according to claim 6, wherein one or more radially extending grooves are provided on the tip surface. [Claim 8] A proportional control valve according to claim 7, wherein a plurality of radially extending grooves are provided on the tip surface of the second portion, spaced apart in the circumferential direction. [Claim 9] The tip surface of the second portion is provided with one annular groove, or a plurality of annular grooves are provided that are spaced apart in the radial direction. The proportional control valve according to claim 7, wherein the annular groove communicates with a valve body housing chamber in which the valve body is housed via one or more radially extending grooves. [Claim 10] A shaft member including a first passage which is an internal passage opening to at least one end face in the axial direction, The second aisle, the third aisle, and the fourth aisle, The valve body and the valve seat, A reciprocating drive mechanism that moves the shaft member back and forth in the axial direction, The valve body is further comprising a biasing member that biases the valve body to the other side in the axial direction, A proportional control valve in which the forward and backward drive mechanism can position the shaft member in the following positions: a first position in which the valve body is seated on the valve seat and its end face is in contact with the valve body, so that the second passage does not communicate with both the first and third passages and the third passage does not communicate with the first passage; a second position in which the valve body is positioned at a distance from the valve seat and its end face is in contact with the valve body, so that the second passage communicates with the third passage, but the second passage does not communicate with the first passage; and a third position in which the valve body is seated on the valve seat and its end face is positioned at a distance from the valve body, so that the third passage communicates with the fourth passage via the first passage.

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