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US-20260126119-A1 - REGULATOR

US20260126119A1US 20260126119 A1US20260126119 A1US 20260126119A1US-20260126119-A1

Abstract

In a regulator, a receiving portion of a diaphragm member, which receiving portion receives a tip surface of a shaft portion of a valve element, includes, in a part thereof facing the tip surface, a concave spherical surface formed with a first radius, centered on a central axis of the shaft portion. In this regulator, the first radius is a value equal to or greater than a value obtained by subtracting 20% of the value of a diameter of the shaft portion from the value of the diameter; and the part of the tip surface that faces the concave spherical surface is a convex spherical surface formed with a second radius obtained by subtracting 2 to 5% of the value of the first radius from the value of the first radius.

Inventors

  • Tatsushi NABEI
  • Kyomi YAMADA

Assignees

  • CKD CORPORATION

Dates

Publication Date
20260507
Application Date
20230830
Priority Date
20221123

Claims (10)

  1. 1 . A regulator comprising: an upstream fluid chamber in which a valve element is housed; a downstream fluid chamber located downstream of the upstream fluid chamber; a valve hole allowing communication between the upstream fluid chamber and the downstream fluid chamber; an annular valve seat provided along an outer circumference of the valve hole and configured to allow contact and separation of the valve element; and a diaphragm member housed in the downstream fluid chamber and configured to vary its position in a contact and separation direction depending on a pressure of operation air, the valve element including a shaft portion that has a columnar shape and extends from the upstream fluid chamber into the downstream fluid chamber through the valve hole in the contact and separation direction, the shaft portion separably and loosely fitting in a receiving portion of the diaphragm member that receives a distal end face of the shaft portion, a biasing means being placed on a side of the valve element, opposite the diaphragm member, to apply a biasing force to the valve element in a direction to contact with the annular valve seat, and the regulator being configured to adjust an opening degree of the valve element by a balance between the pressure of the operation air and the biasing force, wherein the receiving portion is provided with a concave spherical surface in a portion facing the distal end face, the concave spherical surface being centered on a central axis of the shaft portion and formed with a first radius, the first radius is equal to or larger than a value obtained by subtracting 20% of a value of a diameter of the shaft portion from the value of the diameter, and a portion of the distal end face facing the concave spherical surface has a convex spherical surface formed with a second radius that is a value obtained by subtracting 2% to 5% of a value of the first radius from the value of the first radius.
  2. 2 . The regulator described in claim 1 , wherein the first radius is equal to or less than a value obtained by adding 20% of the value of the diameter of the shaft portion to the value of the diameter.
  3. 3 . The regulator described in claim 2 , wherein the first radius is equal to larger than a value obtained by subtracting 10% of the value of the diameter of the shaft portion from the value of the diameter and further equal to or less than a value obtained by adding 10% of the value of the diameter of the shaft portion to the value of the diameter.
  4. 4 . The regulator described in claim 1 , wherein the second radius is a value obtained by subtracting 3% to 4% of the value of the first radius from the value of the first radius.
  5. 5 . The regulator described in claim 1 , wherein the receiving portion includes a concave curved surface tangentially continuous to the concave spherical surface, the concave curved surface being formed with a radius smaller than the first radius on an outer circumference of the concave spherical surface, and the distal end face includes a convex curved surface tangentially continuous to the convex spherical surface, the convex curved surface being formed with a radius smaller than the second radius on an outer circumference of the convex spherical surface and in a portion facing the concave curved surface.
  6. 6 . The regulator described in claim 1 , wherein the receiving portion includes a first flat surface on a tangent line of the concave spherical surface and on an outer circumference of the concave spherical surface, and the distal end face includes a second flat surface on a tangent line of the convex spherical surface on an outer circumference of the convex spherical surface and in a portion facing the first flat surface.
  7. 7 . The regulator described in claim 1 , wherein the receiving portion includes a cylindrical wall facing an outer peripheral surface of the shaft portion, a gap is provided between the cylindrical wall and the outer peripheral surface of the shaft portion, and the gap has a magnitude corresponding to 3% to 5% of the value of the diameter of the shaft portion.
  8. 8 . The regulator described in claim 1 , wherein the convex spherical surface has a top portion provided with a non-contact portion that is located coaxially with the shaft portion and does not contact with the concave spherical surface, and the non-contact portion has a diameter not exceeding 1/20 of the value of the diameter of the shaft portion.
  9. 9 . The regulator described in claim 2 , wherein the second radius is a value obtained by subtracting 3% to 4% of the value of the first radius from the value of the first radius.
  10. 10 . The regulator described in claim 3 , wherein the second radius is a value obtained by subtracting 3% to 4% of the value of the first radius from the value of the first radius.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is a US national phase application based on the PCT International Patent Application No. PCT/JP 2023/031550 filed on Aug. 30, 2023, and claiming the priority to Japanese Patent Application No. 2022-186980 filed on Nov. 23, 2022, the entire contents of which are incorporated by reference herein. TECHNICAL FIELD The invention relates to a regulator. BACKGROUND ART In a conventional semiconductor manufacturing process, for example, a regulator disclosed in Patent Document 1 is used to control the pressure of a control fluid, such as pure water and a chemical solution, which are used in a film forming process for wafers. The regulator in a conventional art will be described with reference to FIG. 28. FIG. 28 is a cross-sectional view of a regulator 50 in the conventional art. The regulator 50 is formed, in the order from an upstream side, with an input port 59, an upstream fluid chamber 52, a valve hole 54, a downstream fluid chamber 53, and an output port 60 to form a series of flow paths. The upstream fluid chamber 52 houses therein a valve element 51. This valve element 51 can move in the vertical direction in the figure to contact with and separate from an annular valve seat 55 provided along the outer circumference of the valve hole 54. A compression coil spring 58 is placed on the lower end side of the valve element 51 in the figure. The biasing force of this compression coil spring 58 biases the valve element 51 in a direction to contact with the annular valve seat 55 (in a closing direction). Further, the valve element 51 is provided with a shaft portion 511 having a columnar shape and extending, in the direction to contact and separate from the upstream fluid chamber 52, into the downstream fluid chamber 53 through the valve hole 54. A distal end face 512 of this shaft portion 511 is formed as a convex spherical surface with the diameter substantially equal to the diameter of the shaft portion 511. This shaft portion 511 fits loosely, i.e., with play, in a separable manner, in a receiving portion 571 of the diaphragm member 57 placed in the downstream fluid chamber 53. The receiving portion 571 of the diaphragm member 57 is formed as a concave spherical surface with the diameter substantially equal to the diameter of the shaft portion 511. The diaphragm member 57 can vary its position in the contact and separation direction depending on the pressure of operation air supplied to a pressure acting chamber 56. The regulator 50 configured as above can adjust the distance (i.e., the opening degree) of the valve element 51 with respect to the annular valve seat 55 by the balance of the pressure of operation air supplied to the pressure acting chamber 56 and the biasing force of the compression coil spring 58. Here, the configuration that the valve element 51 separably, loosely fits in the diaphragm member 57 will be described in detail. For instance, when the pressure in the downstream fluid chamber 53 rapidly rises upon receiving the back pressure via the output port 60, the diaphragm member 57 is pushed upward in the figure (i.e., in the closing direction). At that time, if the valve element 51 and the diaphragm member 57 are inseparably connected, the valve element 51 may move together in the closing direction as the diaphragm member 57 is pushed up in the closing direction, causing excessive interference to the annular valve seat 55. The excessive interference between the valve element 51 and the annular valve seat 55 is not preferable because it may cause the generation of particles due to wear or the like. Therefore, when the valve element 51 and the diaphragm member 57 are separable, even if the pressure in the downstream fluid chamber 53 rapidly rises, pushing up the diaphragm member 57 in the closing direction, the diaphragm member 57 moves in the closing direction separately and independently from the valve element 51. Accordingly, the valve element 51 is not moved in the closing direction, and can prevent the excessive interference with the annular valve seat 55. The valve element 51 and the diaphragm member 57 are components to be exposed to a control fluid and thus made of fluorinated synthetic resin (e.g., PTFE, PFA, etc.) having high corrosion resistance. RELATED ART DOCUMENTS Patent Documents Patent Document 1: Japanese unexamined patent application publication No. 2021-89070 SUMMARY OF INVENTION Problems to be Solved by the Invention However, the above-described regulator has the following problems. If the valve element 51 loosely fits in the diaphragm member 57 in a separable manner as described above, the distal end face 512 of the shaft portion 511 and the receiving portion 571 of the diaphragm member 57 repeatedly make contact with and separation from each other, which may generate dusts. This dust generation is considered to be caused by the excessive stress that occurs in the contact surface of the distal end face 512 and the contact surface