JP4115436B2 - Solenoid proportional valve - Google Patents

Description

  The present invention relates to an electromagnetic proportional valve having a governor mechanism using a diaphragm.

  In this type of conventional proportional solenoid valve, when the upstream side of the primary chamber is closed and the primary chamber is filled with gas for a long time, the gas leaks to the outside through the diaphragm and the primary chamber has a negative pressure. It may happen. When the pressure in the primary chamber becomes negative, the diaphragm is sucked into the primary chamber and deforms excessively.

When a long time elapses in this excessively deformed state, the diaphragm is plastically deformed, and the subsequent function is hindered. In view of this, there has been known one in which a valve body is provided with a deformation preventing portion that supports the pressure receiving portion of the diaphragm and prevents excessive deformation even when the primary chamber becomes negative pressure (for example, Patent Document 1 and Patent). Reference 2).
JP-A-10-227439 (FIGS. 2 and 3) JP 2001-153350 A (FIGS. 1 to 5)

  In the conventional electromagnetic proportional valve described in the above publication, a deformation preventing portion is provided in the valve body. When the primary pressure fluctuates, the diaphragm receives the pressure fluctuation and quickly moves the valve body to adjust the opening, thereby making the flow rate constant regardless of the change in the primary pressure. However, providing the valve body with the deformation preventing portion increases the weight of the valve body, thereby hindering quick movement of the valve body.

  In addition, a certain gap must be provided between the deformation preventing portion and the main body so that the deformation preventing portion can move together with the valve body. Therefore, the outer peripheral portion of the pressure receiving portion of the diaphragm is not prevented from being deformed by the deformation preventing portion, and is affected by pressure reduction. The outer peripheral portion of the pressure receiving portion is a portion that is most deformed even during normal use, and is a portion that first cracks when the diaphragm deteriorates. Since excessive deformation of the outer peripheral portion cannot be prevented, the effect of extending the life of the diaphragm cannot be expected so much.

  In view of the above problems, an object of the present invention is to provide an electromagnetic proportional valve that can increase the life of a diaphragm without increasing the weight of the valve body.

In order to solve the above problems, an electromagnetic proportional valve according to the present invention extends from a primary chamber through an outlet side opening into a main body in which a primary chamber having a peripheral edge of the outlet side opening as a valve seat is formed. A valve body that contacts the valve seat and closes the outlet side opening, the outer peripheral edge is fixed to the main body, the inner peripheral edge is fixed to the valve body, and between the outer peripheral edge and the inner peripheral edge In an electromagnetic proportional valve having a diaphragm in which the formed pressure receiving portion faces the primary chamber, when the primary chamber is depressurized with the valve body closed, the vicinity of the connecting portion between the pressure receiving portion and the outer peripheral edge is excessively deformed. The deformation prevention portion is provided on the main body side, and a plurality of through holes are formed in the deformation prevention portion so that the pressure in the primary chamber acts on the pressure reception portion while the pressure reception portion is in close contact with the deformation prevention portion. It is characterized by that.

  Among the pressure receiving portions of the diaphragm, the deformation of the connecting portion with the outer periphery is the largest. Therefore, by providing a deformation preventing portion on the main body side, excessive deformation of the portion with the largest deformation amount is prevented. By the way, the valve closed state indicates that the valve body abuts on the peripheral edge of the outlet side opening, that is, the valve seat, and closes the outlet side opening, but only indicates a case where airtightness is strictly guaranteed. Instead, it is a concept that includes a state in which there is a slight leakage between the valve seat portion and the valve body.

  If a stopper portion is provided at the inner peripheral end of the deformation preventing portion that contacts the valve body and prohibits further movement of the valve body in the valve opening direction at the maximum opening state of the valve body, a separate stopper portion is provided. The number of parts can be reduced.

  By the way, the deformation preventing portion may be formed so as to coincide with the shape of the pressure receiving portion in the maximum opening state of the valve body. When the valve element is in the maximum opening state, the deformation of the diaphragm is maximized. If the shape of the deformation preventing portion matches the shape of the pressure receiving portion, the deformation preventing portion supports the entire pressure receiving portion and further deformation is prevented.

  In addition, it is desirable to form a through hole in the deformation preventing portion so that the pressure in the primary chamber acts on the pressure receiving portion in a state where the pressure receiving portion is in close contact with the deformation preventing portion.

  As is apparent from the above description, the present invention has the deformation preventing portion provided on the main body side, so that the deformation preventing portion can prevent excessive deformation of the diaphragm having the largest deformation amount. As a result, the lifetime of the diaphragm can be greatly extended. Further, since the deformation preventing portion is not provided on the valve body, the weight of the valve body does not increase, and the responsiveness of the valve body to the fluctuation of the primary pressure is not impaired.

  Referring to FIG. 1, reference numeral 1 denotes an electromagnetic proportional valve according to the present invention, which is provided with a solenoid portion 3 on an upper portion of a hollow main body 2. This solenoid part 3 is provided with a plunger 31 that is movable in the vertical direction, so that the electromagnetic force in the direction of pushing the plunger 31 downward increases in proportion to the magnitude of the direct current that flows through the solenoid coil 32. It is configured.

  The main body 2 is provided with an inflow port 21 and an outflow port 22, and the flow rate of the gas flowing into the main body 2 from the inflow port 21 is controlled by the amount of depression of the valve body 4 pushed down by the plunger 31 described above. It is configured to flow out of. A valve body sheet 5 made of sheet metal is fitted into the main body 2.

  The valve seat 5 has a substantially cylindrical shape, and a valve seat 51 is formed at the lower end. When the valve body 4 rises, the valve body portion 41 formed at the lower portion of the valve body 4 comes into contact with the valve seat portion 51 over the entire circumference to close the valve, and stops the outflow of gas from the outlet 22. However, in this embodiment, since the sealing member made of rubber or the like is not provided in the valve body portion 41, it is not guaranteed that the outlet 22 is completely closed.

  Further, when the valve body 41 is moved away from the valve seat 51 by opening the valve body 4 with the plunger 31 and the valve is opened, the gas flows through the gap between them to the lower side of the valve body 41, and the outlet 22 Out of the gas.

  A diaphragm 6 is fixed to the upper portion of the valve body 4. The diaphragm 6 is made of rubber having flexibility, and has a thick attachment portion 61 at the center and a thick attachment portion 62 at the outer peripheral portion, and is sandwiched between the attachment portions 61 and 62. Thus, a thin pressure receiving portion 63 is formed.

  The diaphragm 6 is fixed to the valve body 4 by a mounting portion 61 on the center side, and is positioned so that the center axis of the diaphragm 6 and the center axis of the valve body 4 do not shift. On the other hand, a positioning part 52 rising upward is formed in the vicinity of the state part of the valve body seat 5, and the mounting part 62 on the outer peripheral side of the diaphragm 6 is in contact with the positioning part 52 and positioned. As a result, the valve body 4 is similarly positioned by the positioning portion 52.

  The valve seat portion 51 is a part of the valve body sheet 5 like the positioning portion 52, and is formed so that the central axes of both coincide with each other by forming the valve seat portion 51 and the positioning portion 52 by machining at the same time. ing. Therefore, the central axis of the valve body 4 positioned by the positioning portion 52 coincides with the central axis of the valve seat portion 51 at the same time. For this reason, the valve body 4 is pushed down by a very small distance from the closed state, and a very narrow gap G is formed between the valve body portion 41 and the valve seat portion 51, so that the gas corresponding to the minimum flow rate from the outlet port 22. When the amount flows out, the width of the narrow gap G becomes uniform over the entire circumference, and the amount of gas flowing out from the outflow port 22 is stabilized without causing individual differences in the electromagnetic proportional valve 1. Reference numeral 11 denotes a spring that urges the valve body 4 upward, so that the valve body 4 moves downward by its own weight and the valve body part 41 does not leave the valve seat part 51 when the solenoid coil 32 is not energized. It will function.

  By the way, in this Embodiment, the deformation | transformation prevention member 7 was attached so that the valve body 4 might be surrounded. Referring to FIGS. 2 and 3 together, when the valve body 4 is largely pushed down, the valve body 4 comes into contact with the stopper portion 71 formed on the inner peripheral portion of the deformation preventing member 7, and the lowered position of the valve body 4 is reached. Was regulated at a predetermined position.

  The diaphragm 6 functions as a governor, and when the primary pressure of the gas flowing in from the inlet 21 fluctuates when the valve body 4 is pushed down by a predetermined amount to be opened, the pressure fluctuation is changed. In response, the position of the valve body 4 is automatically adjusted to function to stabilize the outflow amount of gas from the outlet 22.

  FIG. 2 shows a state in which the valve body 4 is restricted from further descending by the stopper portion 71, that is, a fully opened state. In this state, the diaphragm 6 contacts the upper surface 72 of the deformation preventing member 7. Therefore, the shape of the upper surface 72 is matched with the shape of the pressure receiving portion 63 of the diaphragm 6 so that the pressure receiving portion 63 is not deformed.

Further, referring also to FIG. 4, since the deformation preventing member 7 is formed with a plurality of window holes 73, which are through-holes penetrating vertically, the gas can be obtained even when the diaphragm 6 is in close contact with the deformation preventing member 7. The deformation preventing member 7 does not hinder the primary pressure of the above acting on the diaphragm 6.

  By the way, the diaphragm 6 is generally formed of rubber because it requires flexibility. On the other hand, the gas contains a large amount of organic gas such as butane. This organic gas melts in the rubber constituting the diaphragm 6. The upper surface of the diaphragm 6 is in contact with the atmosphere, but such an organic gas is hardly contained in the atmosphere. Therefore, the partial pressure of the organic gas across the diaphragm 6 is very high on the lower surface side with respect to the upper surface side.

  When the valve body 4 is closed, the valve body 4 is pulled upward by the primary pressure received by the pressure receiving portion 63 and the elastic force of the diaphragm 6 itself. When a long time elapses in this state, the organic gas melts in the diaphragm 6 and is released into the atmosphere having a low partial pressure. For this reason, the organic gas passes through the diaphragm 6 and flows out from the inside of the electromagnetic proportional valve 1 into the atmosphere.

  When the organic gas flows out from the primary chamber in this way, the pressure in the primary chamber decreases. However, since the partial pressure of the organic gas is still much higher than the partial pressure in the atmosphere, the organic gas continues to flow out even when the pressure on the lower surface side of the diaphragm 6, that is, the pressure in the primary chamber becomes negative.

  As a result, the diaphragm 6 is sucked toward the primary chamber as shown in FIG. However, since the deformation preventing member 7 is attached to the main body 2 side as described above, the outer peripheral portion of the pressure receiving portion 63, that is, the boundary portion with the attaching portion 62 is supported by the upper surface 72 of the deformation preventing member 7. As described above, it is prevented from being excessively deformed by preventing it from being sucked into the primary chamber side.

  When a new gas is supplied into the primary chamber, the pressure receiving portion 63 receives the primary pressure of the new gas, and the shape of the pressure receiving portion 63 is restored to the original shape shown in FIG.

  In addition, when using what was shown in this Embodiment upside down, since the valve body 4 will always be urged | biased by the dead weight in the valve closing direction, when using it in such a posture. May omit the spring 11. Further, the gas flow out to the outlet 22 side may be completely stopped in a state where a seal member is attached to the valve body 41 and the valve body 41 is seated on the valve seat 51.

  In the above embodiment, the deformation preventing member 7 is a single component. However, the deformation preventing member 7 may be formed integrally with the valve body sheet 5 or may be formed integrally with the main body 2 in a type that does not use the valve body sheet 5. It may be formed.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

Diagram showing the closed state Diagram showing fully open state Diagram showing details of the vicinity of the diaphragm The figure which shows the shape of a deformation | transformation prevention member

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solenoid proportional valve 3 Solenoid part 4 Valve body 5 Valve body sheet | seat 6 Diaphragm 7 Deformation prevention member 8 Holder 21 Inlet 22 Outlet 41 Valve body part 51 Valve seat part 71 Stopper part

Claims (3)

The main body is formed with a primary chamber in which the peripheral edge of the outlet side opening serves as a valve seat, extends from the primary chamber through the outlet side opening, contacts the valve seat and closes the outlet side opening. A valve body is provided, and an outer peripheral edge is fixed to the main body, an inner peripheral edge is fixed to the valve body, and a pressure receiving portion formed between the outer peripheral edge and the inner peripheral edge faces the primary chamber. in the proportional solenoid valve, when the valve body is primary chamber is reduced in pressure by closed, it provided the deformation preventing portion which prevents the connecting portion near the said pressure receiving portion and the outer circumferential edge from being excessively deformed body, pressure An electromagnetic proportional valve characterized in that a plurality of through holes are formed in the deformation preventing portion so that the pressure in the primary chamber acts on the pressure receiving portion in a state where the portion is in close contact with the deformation preventing portion .   In the maximum opening state of the valve body, a stopper portion that contacts the valve body and prohibits further movement in the valve opening direction is provided at the inner peripheral end of the deformation prevention portion. The electromagnetic proportional valve according to claim 1.   The electromagnetic proportional valve according to claim 1 or 2, wherein the deformation preventing portion is formed so as to coincide with the shape of the pressure receiving portion in the maximum opening degree of the valve body.

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