Fluid control valve and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-12486909-B2
Application number	US-202318142450-A
Country	US
Kind code	B2
Filing date	May 2, 2023
Priority date	May 24, 2022
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A fluid control valve includes a diaphragm assembly including a shaft member joined to an end of a drive shaft on the side near an annular valve seat, a membrane member made of Perfluoro alkoxy Alkane and located in surface contact with the end face of the shaft member on the opposite side to the end joined to the drive shaft, and a weld part formed by laser welding at the interface between the shaft member and the membrane member to join the shaft member and the membrane member. The shaft member is made of fluorine resin with carbon-based additive dispersed.

First claim

What is claimed is:

1 . A fluid control valve comprising:
a flow passage for flowing a control fluid; an annular valve seat provided in the flow passage; a diaphragm assembly configured to contact with or separate from the annular valve seat to control a flow of the control fluid; and a drive shaft that is located coaxially with the annular valve seat and moves the diaphragm assembly in a direction to contact with or separate from the annular valve seat, wherein the diaphragm assembly comprises:
a shaft member coupled on one side to an end of the drive shaft on a side near the annular valve seat;
a membrane member made of perfluoro alkoxy alkane and positioned in surface contact with an end face of the shaft member on an opposite side from the one side coupled to the drive shaft; and
a weld part that is formed in a shape of a string of beads in a cross-section by laser welding, which is performed by irradiating a laser beam onto the membrane member so that the laser beam passes through the membrane member, at an interface between the shaft member and the membrane member and joins the shaft member and the membrane member,
the shaft member is made of fluorine resin containing a carbon-based additive dispersed, the weld part is formed of a weld mark with a diameter gradually increasing from a center of the weld part toward an outer circumferential side, the weld mark is formed such that portions adjacent in a radial direction overlap each other so that a portion of the weld mark, located on the outer circumferential side, overlaps an outer edge of another portion located on an inner circumferential side, the radial direction is perpendicular to the direction in which the diaphragm assembly contacts with or separates from the annular valve seat, the membrane member includes a contact portion in a surface on an opposite side from a side facing the shaft member, and the contact portion will contact with the annular valve seat, and the weld part is located at least on a back side of the contact portion.

2 . The fluid control valve according to claim 1 , wherein the membrane member includes a layer containing a carbon-based additive on a side facing the shaft member.

3 . The fluid control valve according to claim 2 , wherein
the carbon-based additive dispersed in the fluorine resin forming the shaft member is carbon black or carbon nanotube; and the carbon-based additive contained in the layer of the membrane member is carbon black or carbon nanotube.

4 . The fluid control valve according to claim 1 , wherein the carbon-based additive is carbon black or carbon nanotube.

5 . A method for manufacturing a fluid control valve, the fluid control valve comprising:
a flow passage for flowing a control fluid; an annular valve seat provided in the flow passage; a diaphragm assembly configured to contact with or separate from the annular valve seat to control a flow of the control fluid; and a drive shaft that is located coaxial with the annular valve seat and moves the diaphragm assembly in a direction to contact with or separate from the annular valve seat, wherein the method comprises: joining, by laser welding, a shaft member, which is to be coupled on one side to an end of the drive shaft on a side near the annular valve seat, to a membrane member made of perfluoro alkoxy alkane and positioned in surface contact with an end face of the shaft member on an opposite side from the one side to be coupled to the drive shaft to form a weld part in a shape of a string of beads in a cross-section at an interface between the shaft member and the membrane member to produce the diaphragm assembly, the laser welding being performed by irradiating a laser beam onto the membrane member so that the laser beam passes through the membrane member, and wherein the shaft member is made of fluorine resin containing a carbon-based additive dispersed, the weld part is formed of a weld mark with a diameter gradually increasing from a center of the weld part toward an outer circumferential side, the weld mark is formed such that portions adjacent in a radial direction overlap each other so that a portion of the weld mark, located on the outer circumferential side, overlaps an outer edge of another portion located on an inner circumferential side, the radial direction is perpendicular to the direction in which the diaphragm assembly contacts with or separates from the annular valve seat, the membrane member includes a contact portion in a surface on an opposite side from a side facing the shaft member, and the contact portion will contact with the annular valve seat, and the weld part is located at least on a back side of the contact portion.

6 . The method for manufacturing a fluid control valve, according to claim 5 , wherein the membrane member includes a layer containing a carbon-based additive on a side facing the shaft member.

7 . The method for manufacturing a fluid control valve, according to claim 6 , wherein
the carbon-based additive dispersed in the fluorine resin forming the shaft member is carbon black or carbon nanotube; and the carbon-based additive contained in the layer of the membrane member is carbon black or carbon nanotube.

8 . The method for manufacturing a fluid control valve, according to claim 5 , wherein the carbon-based additive is carbon black or carbon nanotube.

Assignees

• Ckd Corp

Inventors

• Murase Hiroyuki
• Tsuneduka Atsushi
• Okada Mayuko

Classifications

• F16K7/16 Primary

  the diaphragm being mechanically actuated, e.g. by screw-spindle or cam · CPC title

• B29C48/255

  Flow control means, e.g. valves (flow dividers B29C48/695) · CPC title

• F16K41/12

  with approximately flat diaphragm · CPC title

• F16K31/1221

  one side of the piston being spring-loaded · CPC title

• B23K26/21

  by welding · CPC title