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CN-121993616-A - Pilot-operated control valve

CN121993616ACN 121993616 ACN121993616 ACN 121993616ACN-121993616-A

Abstract

A valve member is made of a material having high elasticity such as rubber, which prevents deterioration of the operating characteristics of a control valve, and can improve the valve leakage characteristics. In a pilot control valve having a main valve body for opening and closing a main valve port and having a pilot valve seat, the main valve body includes a rubber main valve member for opening and closing the main valve port, a rubber valve port member for contacting and separating the pilot valve port from the pilot valve shaft, and a metal case member for restricting elastic deformation of the main valve member and the valve port member, the case member includes an outer case member for covering the main valve member and the valve port member from an outer peripheral side, and an inner case member disposed in the outer case member, the inner case member has a trunk portion having a center hole serving as a pilot passage, and a flange portion extending outward from the trunk portion, an outer peripheral surface of the trunk portion is in contact with inner peripheral surfaces of the main valve member and the valve port member, and an upper surface of the flange portion is in contact with a lower surface of the valve port member, and a lower surface of the flange portion is in contact with an upper surface of the main valve port member.

Inventors

  • KIBUNE NISHI

Assignees

  • 株式会社不二工机

Dates

Publication Date
20260508
Application Date
20251031
Priority Date
20241101

Claims (10)

  1. 1. A pilot control valve includes: A valve body having a main valve chamber and a pilot valve chamber inside, the valve body having an inflow path through which fluid flows into the main valve chamber and an outflow path through which the fluid flows out of the main valve chamber, an end portion of the outflow path on the main valve chamber side being a main valve port; A main valve element that moves forward and backward with respect to the main valve opening; a pilot passage penetrating the main valve body and selectively communicating the pilot valve chamber and the outflow passage; A pressure equalizing passage that communicates the main valve chamber and the pilot valve chamber; A pilot valve port formed at an end portion of the pilot passage on a pilot valve chamber side; a pilot valve shaft which opens and closes the pilot passage by advancing and retreating relative to the pilot valve port and has a tip end portion inserted into the pilot valve port when closing the valve, and A driving device that drives the pilot valve shaft, It is characterized in that the method comprises the steps of, The pilot valve shaft, the main valve spool, and the main valve port are arranged in this order along an axial direction, and when the axial direction is set to be an "up-down direction", a direction from the main valve spool toward the pilot valve shaft is set to be an "up" direction, and a direction from the main valve spool toward the main valve port is set to be a "down" direction, In the valve body, a main valve seat is provided around the main valve port, The main valve seat is a part for the main valve core to be abutted, The main valve core has: an annular main valve member made of an elastic material and configured to be in contact with and separated from the main valve seat to open and close the main valve port; An annular pilot valve port member made of an elastic material, including the pilot valve port, and being in contact with and separated from the pilot valve shaft, and A case member which is made of a material having a higher rigidity than the main valve member and the pilot valve port member and which restricts elastic deformation of the main valve member and the pilot valve port member, The shell member includes: a housing member covering the main valve member and the pilot valve port member from an outer peripheral side, and An inner shell member disposed inside the outer shell member, The inner shell member has: A cylindrical body part having a central hole extending in the vertical direction and serving as the pilot passage, and A plate-shaped flange portion extending outward from the trunk portion, The outer peripheral surface of the trunk portion is in contact with the inner peripheral surface of the main valve member and the inner peripheral surface of the pilot valve port member, The upper surface of the flange portion abuts against the lower surface of the pilot valve port member, and the lower surface of the flange portion abuts against the upper surface of the main valve member.
  2. 2. The pilot-operated valve of claim 1, wherein, The main valve spool further includes a valve shaft stopper made of a material having higher rigidity than the pilot valve port member, and is brought into contact with the pilot valve shaft during a valve closing operation, thereby restricting downward movement of the pilot valve shaft.
  3. 3. The pilot-operated valve of claim 2, wherein, The tip end portion of the pilot valve shaft has a shape of a reverse taper or a reverse truncated cone, The valve shaft stopper has a restriction hole that is inserted into the distal end portion of the pilot valve shaft at the time of valve closing operation, and abuts against the distal end portion to restrict further downward movement of the pilot valve shaft, The limiting hole is arranged above the pilot valve port, The restricting hole has an inner diameter larger than an inner diameter of the pilot valve port and smaller than a maximum diameter of the tip end portion of the pilot valve shaft.
  4. 4. The pilot-operated valve of claim 1, wherein, The elastic material constituting the main valve member and the pilot valve port member is rubber.
  5. 5. The pilot-operated valve as claimed in any one of claims 1 to 4, wherein, The main valve spool has a sealing portion that prevents the fluid from flowing between the main valve chamber and the main valve port through a gap between the housing member and the main valve member when the valve is closed, The sealing portion is formed at a position outside the main valve seat.
  6. 6. The pilot-operated valve of claim 5, wherein, The valve body has an annular protruding portion, the inside of which becomes the main valve port, and which protrudes upward with respect to the periphery, The protruding part is provided with the main valve seat, The seal portion is formed at a position outside the protruding portion.
  7. 7. The pilot-operated valve of claim 5 or 6, wherein, The valve is provided with a low-pressure introduction path which is at least a part of a flow path that communicates with the main valve port when the valve is closed, introduces a low pressure on the outflow path side to the sealing portion side of the main valve member, and reaches the sealing portion from the outflow path.
  8. 8. The pilot-operated valve of claim 7, wherein, The low pressure introduction path includes: An annular path extending annularly along a circumferential direction of the main valve member on an upper surface of an outer peripheral portion of the main valve member, and And a communication path that communicates the annular path and the main valve port.
  9. 9. The pilot-operated valve of claim 8, wherein, The communication path includes: one or more vertical paths extending in the up-down direction along the inner peripheral surface of the main valve member, and And one or more horizontal paths extending from an upper end portion of the vertical path along an upper surface of the main valve member in a radial direction of the main valve member.
  10. 10. The pilot-operated valve as claimed in any one of claims 1 to 4, wherein, The flange portion has at least one through hole which communicates between a space on an upper side of the flange portion and a space on a lower side of the flange portion, The main valve member and the pilot valve port member are integrally formed by a connecting portion formed of the elastic material disposed in the through hole.

Description

Pilot-operated control valve Technical Field The present invention relates to a pilot control valve, and more particularly to a structure of a main valve body having a pilot valve seat. Background In a refrigeration cycle apparatus including a refrigerant circuit such as an air conditioner, a refrigeration apparatus, and a freezing apparatus, a pilot control valve is used that opens and closes a pilot valve using an electric drive device such as a solenoid or a motor, and opens and closes a main valve in accordance with the opening and closing of the pilot valve. Fig. 14 and 15 show an example of a conventional pilot control valve. As shown in these drawings, the control valve 51 includes a valve body 12 having a main valve chamber 13 and a pilot valve chamber 19 inside, and having an inflow passage 14 through which fluid flows into the main valve chamber 13 and an outflow passage 15 through which fluid flows out of the main valve chamber 13, a main valve port 16 formed at an end portion of the outflow passage 15 on the main valve chamber 13 side, a main valve spool 18 opening and closing the outflow passage 15 by advancing and retreating the main valve spool 18, a pilot passage 21 penetrating the main valve spool 18 and selectively communicating the pilot valve chamber 19 and the outflow passage 15, a pressure equalizing passage 23 communicating the main valve chamber 13 and the pilot valve chamber 19, a pilot valve port 22 formed at an upper end portion of the pilot passage 21, a pilot valve shaft 20 opening and closing the pilot valve passage 21 by coming into contact with (abutting and separating from) an upper edge (pilot valve seat) of the pilot valve port 22, and a driving device 24 driving the pilot valve shaft 20. The pilot valve shaft 20 has a tip end portion of a needle shape (a rounded cone shape or a rounded truncated cone shape) inserted into the pilot valve port 22 when the valve is closed. On the other hand, the main spool 18 includes a valve member 52 and a housing member 34, the valve member 52 opens and closes the main valve port 16 by coming into contact with and separating from the main valve seat 17, the pilot passage 21 penetrates a center portion of the valve member 52 in the up-down direction, and the housing member 34 covers the valve member 52 from the outer peripheral surface side. The outer peripheral surface of the housing member 34 slidably contacts the inner peripheral surface of the main valve chamber 13, and the main valve body 18 is supported in the main valve chamber 13 so as to be movable up and down. In order to improve the sealability (the fluid blocking property at the time of valve closing) of the main port 16 and the pilot port 22, the valve member 52 is made of a resin material. Further, as a document that discloses such a pilot control valve, the following patent document 1 is known. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2023-104598. Technical problem to be solved by the invention However, in recent years, in order to improve the performance and reliability of air conditioning units, further improvement in valve leakage characteristics (i.e., blocking of fluid at the time of valve closing) has been demanded. Therefore, as a material constituting the valve member 52, a material having a higher elasticity (for example, rubber) may be used instead of the resin. However, if such a material having a large elasticity is used, although the valve leakage characteristic can be improved, the inner diameter of the pilot passage 21 is changed by the differential pressure load applied to the valve member 52 at the time of closing the valve, and thus the intended operation characteristic of the control valve 51 may not be obtained. In addition, the valve member 52 is likely to be detached from the case member 34. Disclosure of Invention Accordingly, an object of the present invention is to provide a new main valve spool structure having excellent valve leakage characteristics, which can eliminate the above-mentioned problems. Technical means for solving the technical problems In order to solve the above-described problems and achieve the object, a pilot control valve (sometimes simply referred to as a "control valve" in the present application) according to the present application includes a valve body having a main valve chamber and a pilot valve chamber inside, the valve body having an inflow path through which a fluid (for example, a refrigerant, hereinafter the same) flows into the main valve chamber and an outflow path through which the fluid flows out of the main valve chamber, and having a main valve port formed at an end portion of the outflow path on the main valve chamber side, a main spool that moves forward and backward with respect to the main valve port, a pilot passage that penetrates the main spool and selectively communicates the pilot valve chamber and the outflow path, a pressure equalizing passage