JP2006342952A - Pilot solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pilot solenoid valve capable of reducing water hammer and valve element closing impact by valve opening/closing or closing without disadvantage in aspects of clogging, minimum operating differential pressure, operating stability, main passage stream, electric system, outer size, and valve opening/closing time. <P>SOLUTION: The valve comprises: a communication chamber 1 for allowing a bleed hole 3a and pilot hole 3b to communicate with each other; an orifice 1a for allowing the communication chamber 1 and valve chest 3 to communicate with each other; a valve 2 for throttling the orifice 1a; a groove 2b located in a closing face 2a of the valve 2; and a helical compression spring 12 which prevents the valve 2 from being closed by a force of differential pressure or having a maximum force less than the differential pressure of the valve 2. The effective cross-section area of the orifice 1a less than the area of the bleed hole in throttling is increased to that of the pilot hole 3b or more by opening the valve 2 by a pushing action produced by a reciprocation of valve element 4 or a force of differential pressure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pilot solenoid valve that controls a liquid such as water, a gas-liquid mixed fluid, a vapor, or a gas fluid, and more particularly to a pilot solenoid valve that reduces water hammer and valve body impact impact due to valve opening and closing.

  In the conventional pilot solenoid valve, there is a problem that water hammer is large due to reasons described later and pressure fluctuation, noise, vibration, breakage, etc. occur, and there are various measures for reducing water hammer as described below.

  First, the valve chamber is divided into an outer peripheral chamber that communicates with the bleed hole and an inner peripheral chamber that communicates with the pilot hole, and the valve body speed is reduced by communicating with the throttle of the annular gap, and measures to reduce water hammer due to valve closing are taken. (For example, refer to Patent Document 1).

  In addition, there is one in which the bleed hole is narrowed immediately before the valve is closed to reduce the valve body speed and take measures to reduce water hammer and seating impact due to the valve closing (for example, see Patent Documents 2 to 5).

  In addition, there is a valve body provided with a valve port insertion surface to slow the valve body speed and take measures to reduce water hammer by closing the valve (see, for example, Patent Document 6 and Patent Document 7).

  Further, in the middle of the valve closing process, the plunger or the valve body comes into contact with the speed reducing body to moderate the valve body speed and take measures to reduce water hammer by closing the valve (for example, see Patent Document 8). .

  In addition, the plunger that opens and closes the pilot hole in the needle valve-shaped valve part is held in a half-open state by electricity to hold the valve body in a half-open state, and measures to reduce water hammer by opening and closing the valve are taken (See, for example, Patent Document 9).

Hereinafter, the conventional general pilot solenoid valve of FIG. 7 will be described.
A solenoid valve is roughly divided into a solenoid part and a valve part. In the solenoid portion, a fixed iron core 23 above the guide pipe 22, a plunger 10 that reciprocates, and a return spring 11 that biases the plunger 10 are provided inside. The coil 18 wound around the coil bobbin 19 and the magnetic frame 20 are on the outside.

  In the valve portion, a valve port 5b that communicates the inflow port 5a and the outflow port 5c, a valve body 4 that faces the valve port 5b and opens and closes the valve port 5b, and on the opposite side of the valve port 5b across the valve body 4 A formed valve chamber 3, a bleed hole 3a communicating the inlet 5a and the valve chamber 3, a pilot hole 3b communicating the valve portion 3 and the outlet 5c, and a pilot valve 9 opening and closing the pilot hole 3b And a valve body compression spring 13 for urging the valve body 4. The valve body compression spring 13 may be omitted because the valve opening time and the minimum operating differential pressure increase, but it reduces valve opening trouble or leakage due to the mounting posture and the like, and the valve closing time. When listed in the order of small effective area, the bleed hole 3a, the pilot hole 3b, and the through hole 3c are arranged in this order.

Next, the operation will be described. In the valve opening process, when the coil 18 is energized, a magnetic field is generated, the plunger 10 is attracted against the force of the return spring 11, the pilot hole 3b is opened, and the valve chamber 3 pressure is rapidly reduced. The valve body 4 is raised by the force of the differential pressure, and is blocked by the lid body 6 to open the valve. As the valve body 4 rises, the inlet 5a pressure decreases and the outlet 5c pressure increases.

In the valve closing process, the magnetic field disappears when deenergized, the plunger 10 is lowered by the return spring 11, the pilot hole 3 b is closed, the valve chamber 3 pressure is increased, and the valve body is compressed by the force of the differential pressure and the force of the valve body compression spring 13. 4 descends and the valve closes. As the valve body 4 descends, the inlet 5a pressure increases and the outlet 5c pressure decreases.

Next, the difference between the conventional general pilot solenoid valve of FIG. 8 and FIG. 7 will be described. The valve body tension spring 14 is hooked on the plunger 10 having the pilot valve 9 and the valve body 4 having the pilot hole 3b. For this reason, in the valve opening process, the plunger 10 suction helps the valve body 4 to rise through the valve body tension spring 14, so that the minimum operating differential pressure is reduced. In the valve closing process, the valve body 4 is lowered by the pressure difference of the valve body 4 and the force of the return spring 11 to close the valve.

Japanese Utility Model Publication No. 4-97186 Japanese Patent Laid-Open No. 4-327083 Japanese Patent Laid-Open No. 7-119863 JP-A-7-229580 JP 2002-106748 A JP-A-8-145226 Japanese Patent Laid-Open No. 2002-286158 JP 2004-308885 A Japanese Patent Laid-Open No. 11-2356

  In the conventional pilot solenoid valve described above, in the valve opening process, when the pilot hole is opened, the valve chamber pressure is drastically reduced. In the initial stage, the differential pressure between the inlet and the valve chamber is large, and the valve body is accelerated rapidly. It is blocked by the body and leads to valve opening. For this reason, fluctuations in the pressure drop on the inflow side and the pressure increase on the outflow side are large. In particular, a gas-liquid mixed fluid has a large water hammer due to a collision of a staying liquid, a burst of a gas reservoir, interference between the two, and the like, and pressure fluctuation, noise, vibration, breakage, and the like occur.

  In the valve closing process, since the differential pressure between the inlet, the outlet, and the valve chamber is smaller in the initial stage, the valve body moves with low acceleration. As the valve body approaches the valve seat, the pressure at the inlet and the valve chamber increases and the pressure at the outlet decreases, so that the valve body gradually accelerates. Maximum speed. For this reason, the pressure rises at the inflow side in an accelerating manner. The gas-liquid mixed fluid and the liquid are likely to cause water hammer due to their large kinetic energy, and in particular, the liquid is incompressible so that the water hammer is large. In addition, due to the kinetic energy of the outflow side fluid, the outflow side may drop in pressure and a water hammer called liquid column separation may occur.

  In recent years, quietness has been demanded in the living environment. Noise, damage to the valve body, and the like occur due to the impact that the valve body is stopped by the valve opening lid and the seating impact that the valve body is stopped by the valve seat that is closed. In particular, gas and gas-liquid mixed fluids are likely to deteriorate due to the high flow rate.

  In addition, the clogging problem is important from the viewpoint of the expansion and maintenance of fluids used such as agricultural water, but the method of reducing the diameter of the bleed hole and reducing the bleed hole immediately before closing the valve to reduce water hammer is the valve closing time. As the bleed hole clogging increases, the diameter reduction is particularly limited, and the method of squeezing tends to be unstable due to the flow of the main flow path, making the operation and reduction of water hammer unstable, both of which are caused by valve opening. Does not reduce water hammer.

  In addition, the valve chamber is divided into an outer peripheral chamber that communicates with the bleed hole and an inner peripheral chamber that communicates with the pilot hole. The valve opening / closing time increases and the water hammer due to valve opening does not decrease.

  In addition, the method by providing the valve port insertion surface on the valve body interacts with the flow of the main flow path, and pressure loss and vibration are likely to increase due to the flow obstruction and vortex. Water hammer due to valve opening is not reduced.

  Further, the method in which the plunger or the valve body comes into contact with the speed reducer from the middle of the valve closing process does not reduce the water hammer due to the valve opening.

  In addition, the method of holding the plunger that opens and closes the pilot hole with the needle valve-shaped valve portion in the half-open state is an electromagnetic valve driving device that changes the electric power step by step to hold the plunger in the half-open state. Is required.

  The present invention is intended to solve the problems of such a conventional configuration, such as clogging, minimum operating differential pressure, operation stability, main flow path, electrical system, and external dimensions. The pilot solenoid valve reduces water hammer and valve body impact shock due to valve opening and closing, and does not adversely affect the valve opening and closing time. The purpose is to obtain a pilot solenoid valve that further reduces the impact and impact of the valve body.

  In order to achieve the above object, the present invention achieves the above-described object by a reason described later, a valve port that communicates the inlet and the outlet, a valve body that faces the valve port and opens and closes the valve port, and a valve port that sandwiches the valve body. A pilot solenoid valve having a valve chamber formed on the opposite side, a bleed hole that communicates with the inlet, a pilot hole that communicates with the outlet, and a pilot valve that opens and closes the pilot hole by reciprocating movement of the plunger. A communication chamber that communicates with the pilot hole, and an orifice that communicates with the communication chamber and the valve chamber and has an effective cross-sectional area less than the bleed hole may be provided.

  Furthermore, in order to further reduce water hammer and valve element impact impact due to valve opening and closing, for the reasons described later, a guide hole provided in the communication chamber of the lid and a valve provided in the valve element by sliding in the guide hole are provided. The body sliding portion is cylindrical, and when the valve body is opened, the valve body sliding portion may restrict only the bleed hole outlet to less than the effective area of the bleed hole.

Furthermore, in order to further reduce water hammer and valve element impact impact due to valve opening and closing, a diaphragm in which an orifice, which is an annular gap between the guide hole and the valve body sliding part, is sandwiched and fixed for the reason described later. It is preferable that the groove provided in the guide hole and the groove provided in the valve body sliding portion fit each other at a slight opening degree or more of the valve body and increase beyond the effective area of the pilot hole. In addition, a communication hole that connects the communication chamber and the valve chamber, a valve 2 that opens and closes the communication hole, a compression coil spring that suppresses the opening of the valve 2 due to the force of the differential pressure, and a slight opening degree of the valve body As described above, when the valve is pushed by the reciprocating motion of the valve body and the valve is opened, the communication hole may be larger than the effective area of the pilot hole. Further, the communication hole having an effective area greater than or equal to the pilot hole may be formed on the inner peripheral side of the attachment surface of the lid so that it is closed by the diaphragm of the valve body with a slight opening.

Furthermore, when reducing only the water hammer or valve body impact impact due to valve closing due to the difference in fluid, the communication hole has an effective cross-sectional area of the pilot hole other than a slight opening in the valve closing process for the same reason as described later. It is good to be above. For this reason, the valve is on the side of the communication chamber, and the compression coil spring is preferably less than the force of the differential pressure of the valve 2 instead of suppressing the opening of the valve 2 due to the force of the differential pressure .

Furthermore, the narrow orifice instead of communicating holes eliminates the communication hole, so that the orifice aperture at the orifice is less than the bleed hole effective area, it may be recessed grooves in the closed chain surface or seating surface. Accumulated debris in the groove when the orifice is squeezed out and removed immediately after the chain is opened, reducing clogging. Reducing the amount of clogging reduction and further reducing the cross-sectional area of the groove do not make the clogging more disadvantageous, and further reduce water hammer and valve body impact impact due to valve opening / closing or valve closing.

  Next, the operation will be described. The flow path that connects the communication chamber and the valve chamber has a drastic reduction in flow rate when the valve is opened, removal of accumulated dust by alternating backflow of the valve opening process and valve closing process, and removal of garbage by the bleed hole. It is hard to clog and can be squeezed more than the bleed hole. Furthermore, the valve body speed depends on the flow rate of the flow in and out of the valve chamber, and the flow rate depends on the effective sectional area and the differential pressure. For this reason, if the valve chamber is less than the effective cross-sectional area of the bleed hole and the valve chamber communicates with only the communication chamber, the valve body speed can be moderated, and the water hammer and valve body impact impact caused by opening and closing the valve can be reduced.

  In addition, when the valve slide part is opened, only the bleed hole outlet is restricted to less than the effective area of the bleed hole, so that the flow rate of the bleed hole is reduced and clogging of the orifice, bleed hole, pilot hole, etc. is reduced. . By reducing this reduction and further narrowing the orifice, bleed hole, or pilot hole, the valve body speed becomes slower, clogging, and water hammer and valve body impact impact due to valve opening and closing are further reduced. To do.

  Furthermore, the closer the valve body is to the valve seat, the more the valve opening and closing time is, the more it affects the water hammer and the valve body impact shock. When the cross-sectional area is passed, the valve opening / closing time and orifice clogging are significantly reduced, and the increase in water hammer and valve impact resistance due to valve opening and valve closing is small. By reducing the amount of this reduction and making the valve chamber more tightly squeezed, with less than a slight opening of the valve body, there is no disadvantage in terms of valve opening / closing time and clogging. The impact and impact of the valve body are further reduced.

  Further, similarly, if the communication chambers communicate with each other with a pilot hole effective cross-sectional area larger than the slight opening in the valve closing process, the valve opening time and orifice clogging are further reduced. By reducing this reduction and making the communication chambers more restrictive between just before the valve closes, there is no disadvantage in terms of valve opening time and clogging, and water hammer or valve body impact shock due to valve closing occurs. Reduce more.

  The pilot solenoid valve of the present invention as described above has the following effects.

  Providing a communication chamber that communicates the bleed hole and the pilot hole, and an orifice that communicates the communication chamber and the valve chamber with an area less than the effective cross-sectional area of the bleed hole is not disadvantageous in terms of clogging due to the above reasons. It can reduce water hammer and valve element impact shock due to valve opening and closing.

  In addition, since the valve chamber communicates with the communication chamber that communicates the bleed hole and the pilot hole and becomes equal pressure immediately after the valve is opened, there is no disadvantage in terms of the minimum operating differential pressure. In addition, the orifice is less likely to be clogged, and the present mechanism is inside and hardly affected by the flow of the main flow path, so there is no disadvantage in terms of operation stability. Further, since it is not necessary to provide a valve port insertion surface in the valve body, there is no disadvantage in terms of the flow of the main flow path such as pressure loss and vibration. Moreover, since it does not depend on the electric system, there is no disadvantage in terms of the electric system. Further, the communication chamber only needs to be larger than the effective sectional area of the pilot hole and can be made small, so that there is no disadvantage in terms of the external dimensions.

  Further, the guide hole provided in the communication chamber of the lid body and the valve body sliding portion provided in the valve body which slides in the guide hole are cylindrical, and the valve body sliding portion is a bleed hole when the valve is opened. By restricting only the outlet to less than the effective cross-sectional area of the bleed hole, clogging, water hammer due to valve opening and valve closing, and valve body impact impact can be further reduced for the reasons described above. In addition, the communication chamber pressure and the valve chamber pressure are reduced due to the restriction of the bleed hole when the valve is opened, so the minimum operating differential pressure is reduced, the plunger required suction force is reduced by the pilot hole diameter reduction, and the flow coefficient is increased by the valve body lift amount. Increase in size or downsizing due to the reduced diameter of the valve body.

  An orifice, which is an annular gap between the guide hole and the valve body sliding portion, is a slight opening degree or more of the diaphragm valve body sandwiched and fixed at the periphery, and a groove provided in the guide hole and a groove provided in the valve body sliding portion Therefore, the increase in the pilot hole effective cross-sectional area is not disadvantageous in terms of valve opening / closing time and clogging. Can be reduced.

In addition, a communication hole that communicates the communication chamber and the valve chamber, a valve 2 that opens and closes the communication hole, a compression coil spring that prevents the valve 2 from being opened by the force of the differential pressure, and a slight opening of the valve body are provided. When the valve 2 is pushed by the reciprocating motion of the valve body and the valve 2 opens, the communication hole is larger than the effective area of the pilot hole. For the above reasons, the valve opening / closing time and clogging are not disadvantageous. , Water hammer and valve impact shock due to valve opening and closing can be further reduced.

Further, the valve 2 is in the communication chamber side, a compression coil spring, instead of suppressing the valve 2 open-chain by the force of the pressure difference, by less than the force of the differential pressure valve 2, the valve opening process, Due to the sudden decrease in the communication chamber pressure, the valve 2 is opened by the force of the differential pressure of the valve 2 before being pushed. Therefore, for the reasons described above, the valve opening time and clogging are not adversely affected. Water hammer and valve impact resistance can be further reduced.

In addition, the valve opening process is performed by drilling the communication hole that is equal to or larger than the pilot hole effective cross-sectional area on the inner peripheral side of the mounting surface of the lid so that it is closed to the diaphragm of the valve body with a slight opening degree. Due to the sudden decrease in the communication chamber pressure, the diaphragm bends toward the valve chamber and the communication hole closes , and the valve speed is initially slower than before . In the valve closing process, the inlet pressure is higher than the valve chamber pressure, and as the differential pressure increases, the diaphragm bends toward the valve chamber, and the communication hole is closed by the diaphragm immediately before the valve is closed . Except under small quantity Kana opening, to open the communication hole, the orifice clogging is further reduced. By reducing this reduced amount and further narrowing the orifice , water hammer and valve element impact can be further reduced without causing a disadvantage in terms of clogging. In addition, the number of parts is small and the cost can be reduced.

Further, the squeeze orifice instead of communicating holes eliminates the communication hole, so that the orifice aperture at the orifice is less than the bleed hole effective area, be recessed grooves in the closed chain surface or seating surface is by the In addition, it is possible to further reduce water hammer and valve body impact shock due to valve opening / closing or valve closing without causing further disadvantage in terms of clogging.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The drawings including the conventional examples of FIGS. 7 and 8 have many common parts, and the common parts are denoted by the same reference numerals. The present invention is not limited to the open type when energized, and can also be applied to a closed pilot solenoid valve when energized.

  The solenoid part of FIGS. 1-4 has the fixed iron core 23 of the guide pipe 22 upper part, the plunger 10 which reciprocates, and the return spring 11 which urges | biases the plunger 10 inside. The coil 18 wound around the coil bobbin 19 and the magnetic frame 20 are on the outside, and are the same as those in FIGS.

  1 to 4 includes a valve port 5b that communicates the inflow port 5a and the outflow port 5c, a valve body 4 that faces the valve port 5b and opens and closes the valve port 5b, and a valve member 4 sandwiching the valve body 4 therebetween. A valve chamber 3 formed on the opposite side of the port 5b, a bleed hole 3a communicating with the inflow port 5a, a pilot hole 3b communicating with the outflow port 5c, a pilot valve 9 for opening and closing the pilot hole 3b, a bleed hole 3a and a pilot There is a communication chamber 1 that communicates with the hole 3b, and an orifice 1a that communicates the communication chamber 1 and the valve chamber 3. When listed in order of small effective area, the bleed hole 3a, the pilot hole 3b, and the communication chamber 1 are arranged in this order.

Orifice 1a of FIG. 1, when the throttle groove 2b in the closed chain surface 2a is closed Ru valve 2, chromatic Kodan area is less than the bleed hole 3a.
2, with the orifice 1a is less than the bleed hole 3a effective area, the communication hole 1b communicating with the communication chamber 1 and the valve chamber 3 there.
FIG. 3 shows that the lid body 6 includes a flow rate adjusting screw 16 that throttles the orifice 1a having an effective cross-sectional area less than the bleed hole 3a and externally adjusts the valve closing time, water hammer and valve body impact, and the communication hole 1b. .
The orifice 1a in FIG. 4 is an annular gap between the guide hole 6a and the valve body sliding portion 4a, and the groove 6b of the guide hole 6a and the groove 4b of the valve body sliding portion 4a exceed a slight opening degree of the valve body 4. The effective sectional area increases from less than the bleed hole 3a.

Next, the basic operation of FIGS. 1 to 4 will be described. In the valve opening process, when the coil 18 is energized, a magnetic field is generated, the plunger 10 is attracted against the force of the return spring 11, the pilot hole 3b is opened, and the communication chamber 1 pressure is drastically reduced. The pressure in the valve chamber 3 is also reduced by the orifice 1a and the communication hole 1b (only in FIGS. 2 and 3), and the valve body 4 is raised by the force of the differential pressure, and is blocked by the lid body 6 to open the valve. As the valve body 4 rises, the inlet 5a pressure decreases and the outlet 5c pressure increases.

When the valve is not energized in the valve closing process, the magnetic field disappears, the plunger 10 is lowered by the force of the return spring 11, the pilot hole 3b is closed, and the communication chamber 1 pressure is increased. The valve chamber 3 pressure is also increased by the orifice 1a and the communication hole 1b (FIGS. 2 and 3 only), and the valve element 4 is lowered by the force of the differential pressure and the valve is closed. As the valve body 4 descends, the inlet 5a pressure increases and the outlet 5c pressure decreases.

The valve body compression spring 13 of FIGS. 1 to 3 is not necessary because the valve opening time and the minimum operating differential pressure increase, but it reduces valve opening trouble or leakage due to the mounting posture and the like, and the valve closing time. .
In FIG. 4, the valve body tension spring 14 that is latched to the valve shaft 4 f of the valve body 4 and the plunger 10 may be omitted, but the force of the valve body tension spring 14 is generated by the suction of the plunger 10 in the valve opening process. However, since the valve body 4 is lifted, the minimum operating differential pressure is lowered. When the valve is closed, the return spring 11 pushes the valve body 4 against the valve seat 5d, so that the mounting posture of the electromagnetic valve is free.

1-4, and the communication hole 1b shown in FIGS. 2 and 3, drastic reduction of the flow rate when the valve is opened, removal of accumulated debris by alternating backflow between the valve opening process and the valve closing process, and the bleed hole 3a. It is hard to be clogged by removing garbage. For this reason, the effective cross-sectional area of the bleed hole 3a can be reduced by restricting the valve 2 (FIG. 1), closing the valve 2 (FIG. 2), closing the communication hole 1b (FIG. 3), or separating the groove 4b and the groove 6 (FIG. 4). Since the valve chamber 3 communicates only with the communication chamber 1 with the orifice 1a less than that, the speed of the valve body becomes slow, there is no disadvantage in terms of clogging, and water hammer or valve body impact shock due to valve opening and closing Is reduced.

  In addition, since the valve chamber 3 communicates with the communication chamber 1 that communicates the bleed hole 3a and the pilot hole 3b and becomes equal pressure immediately after the valve is opened, there is no disadvantage in terms of the minimum operating differential pressure. Further, the orifice 1a and the communication hole 1b are not easily clogged as described above, and the mechanism is inside and hardly affected by the flow of the main flow path, so that there is no disadvantage in terms of operation stability. Further, since the valve body 4 has no insertion surface for the valve port 5b, there is no disadvantage in terms of the flow of the main flow path such as pressure loss and vibration. Moreover, since the electric system is not changed, there is no disadvantage in terms of the electric system. Further, in terms of the outer dimensions, there is no disadvantage so that FIGS. 1 to 3 and 4 are equal to FIGS. 7 and 8 of the conventional example.

  Further, in FIGS. 2 and 4, the guide hole 6 a provided in the communication chamber 1 of the lid body 6 and the valve body sliding portion 4 a that slides in the valve body 4 and is provided in the valve body 4 are cylindrical. When opened, the valve body sliding portion 4a restricts only the outlet of the bleed hole 3a to less than the effective sectional area of the bleed hole 3a. 2 is not divided by the through holes 3d. For this reason, the flow rate of the bleed hole 3a is reduced, and clogging of the orifice 1a, the bleed hole 3a, and the pilot hole 3b is reduced. By reducing this reduced amount and further narrowing down the orifice 1a, the valve body speed is made gentler, and clogging, water hammer and valve body impact impact due to valve opening and closing are further reduced. The smaller the diameter of the guide hole 6a, the larger the pressure receiving area of the valve chamber 3 and the slower the valve body speed. Further, when the valve is opened, the communication chamber 1 pressure and the valve chamber 3 pressure are reduced as described above, so that the minimum operating differential pressure is reduced, the required suction force of the plunger 10 is reduced by the diameter of the pilot hole 3b, and the lift amount of the valve body 4 is increased. It is possible to increase the flow coefficient by reducing the size by reducing the diameter of the valve body 4 or the like.

  Further, FIG. 4 shows a groove provided in the guide hole 6a so that the orifice 1a, which is an annular gap between the guide hole 6a and the valve body sliding portion 4a, is more than a slight opening degree of the diaphragm valve body 4 sandwiched and fixed at the periphery. 6b and the groove 4b provided in the valve body sliding part 4a are fitted, and the pilot hole 3b has an effective sectional area or more. The closer the valve body 4 is to the valve seat 5d, the opposite of the valve opening / closing time and the influence of the water hammer and the valve body impact impact, the increase in the effective sectional area of the orifice 1a above the slight opening of the valve body 4 is The valve opening / closing time and the clogging of the orifice 1a are greatly reduced, and the water hammer and valve body impact impact due to the valve opening and closing are slight. By reducing this reduced amount and further narrowing the orifice 1a below the slight opening of the valve body 4, there is no disadvantage in terms of valve opening / closing time and clogging, and water hammer and valve body impact by valve opening and valve closing are avoided. Reduces stop impact more. In addition, the groove 6b of the guide hole 6a and the groove 4b of the valve body sliding part 4a are recessed in the axial direction with a semicircular cross section, and are attached so as to fit in the circumferential direction (FIG. 6).

Further, FIGS. 1 and 2 are provided with an orifice 1a that connects the communication chamber 1 and the valve chamber 3, a valve 2 of the orifice 1a , and a compression coil spring 12 that suppresses opening of the valve 2 due to the force of differential pressure . . In FIG. 1, the valve 2 and the valve body 4 are slightly separated, and in FIG. 2, the valve 2 and the pin 15 are slightly separated. For this reason, when the valve 2 is opened by being reciprocated by the valve body 4 at a slight opening degree or more of the valve body 4, the orifice 1a becomes larger than the effective sectional area of the pilot hole 3b. The above reasons, a valve opening and closing times, and a groove 2b clogging with greatly reduced at a slight angle less than the valve element 4, the increase in water hammer and the valve body衝止impact by the valve opening and valve closing There are few. By reducing this reduction amount and reducing the cross-sectional area of the groove 2b, the water hammer and valve body impact impact due to valve opening and closing are further reduced without adversely affecting the valve opening / closing time and clogging. Further, since the valve 2 protrudes from the lid body 6, it can cope with the wobbling of the unguided diaphragm valve body 4 of FIG. The urging force of the compression coil spring 12 is equal to or greater than the force of the differential pressure of the valve 2 at the maximum operating differential pressure. Further, in FIG. 1, the plug 7 is provided and the valve 2 is changed, so that the valve opening / closing time and the water hammer and the valve body impact impact can be easily adjusted. Further, the valve 2 in FIG. 2 is a steel ball, so there is no galling, and it is inexpensive because it is a commercial product together with the parallel pin 15.

Further, in FIG. 1, when the compression spring 12 is replaced with a compression coil spring 12 having a pressure less than the differential pressure of the valve 2, the valve 2 is on the communication chamber 1 side. Is opened by the force of differential pressure before being pushed. For this reason, valve opening time and clogging of the orifice 1a are reduced. Reduce the amount of decrease, the squeezing more grooves 2b with a small opening less than the valve element 4, without being disadvantageous in terms of the valve opening time and clogging, water by valve closing hammer and the valve body衝止impact Is further reduced. The urging force of the compression coil spring 12 is not less than the weight of the valve 2 due to the free mounting posture of the pilot solenoid valve, and less than the force of the differential pressure of the valve 2 at the minimum operating differential pressure.

Further, FIG. 3 shows that the communication hole 1b which is larger than the effective cross-sectional area of the pilot hole 3b is drilled on the inner peripheral side 6c of the attachment surface of the cover body 6 so that it is closed by the diaphragm 4d of the valve body 4 with a slight opening. It is installed. Valve opening process, the rapid decrease of the communication chamber 1 pressure, because the diaphragm 4d is to close the communication hole 1b deflection in the valve chamber 3 side, the valve body speed is slower than a conventional early. In the valve closing process, as the valve body 4 approaches the valve seat 5, the pressure at the inlet 5 a increases and the pressure difference from the valve chamber 3 pressure increases, and the diaphragm 4 d bends toward the valve chamber 3 , and the communication hole 1 b starts immediately before closing the valve. Is closed by the diaphragm 4d . Except under small quantity Kana opening, to open the communication hole 1b, clogging of the orifice 1a is further reduced. By reducing this reduced amount and further narrowing the orifice 1a , water hammer and valve element impact impact are further reduced without causing any disadvantage in terms of clogging. In addition, the number of parts is small and inexpensive.

Furthermore, FIG. 1, the squeeze orifice 1a in place of the communication hole 1b eliminates the communication hole 1b, as at the orifice 1a restrictive orifice 1a is less than the bleed hole 3a effective area, the circumference of the valve 2 closed surface 2a A groove 2b is provided in the direction (FIG. 5). For this reason, the accumulated debris in the groove 2b when the orifice 1a is throttled is removed immediately after the chain is opened, and clogging is reduced. Reducing this reduction and further reducing the cross-sectional area of the groove 2b does not make the clogging more disadvantageous, and further reduces water hammer and valve body impact impact due to valve opening and closing or valve closing. In the closing surface 2a or the seat seat surface 8, as long as the orifice 1a is smaller than the effective sectional area of the bleed hole 3a when the orifice 1a is squeezed, it is not limited to the groove 2, but may be unevenness or surface roughness.

Example Vertical cross-sectional view of pilot solenoid valve when closed Example Vertical cross-sectional view of pilot solenoid valve when closed Example Vertical cross-sectional view of pilot solenoid valve when closed Example Vertical cross-sectional view of pilot solenoid valve when closed A three-dimensional view enlarging the vicinity of the groove 2b of the valve 2 of FIG. The three-dimensional view which expanded the groove | channel 6b vicinity of the groove | channel 4b of FIG. Longitudinal sectional view of a conventional pilot solenoid valve when closed Longitudinal sectional view of a conventional pilot solenoid valve when closed

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication chamber 4 Valve body 6 Cover body 1a Orifice 4a Valve body sliding part 6a Guide hole 1b Communication hole 4b Groove 6b Groove 2 Valve 4c Diaphragm receiver 6c Mounting surface inner peripheral side 2a Closed surface 4d Diaphragm 8 Seat seat surface 2b Groove 4g Bulkhead 9 Pilot valve 3 Valve chamber 5 Valve box 10 Plunger 3a Bleed hole 5a Inlet 11 Return spring 3b Pilot hole 5b Valve port 12 Compression coil spring 3c Through hole 5c Outlet 13 Valve body compression spring 3d Through hole 5d Valve seat 14 Valve Body tension spring

Claims (7)

  A valve port communicating with the inflow port and the outflow port, a valve body facing the valve port and opening and closing the valve port, a valve chamber formed on the opposite side of the valve port across the valve body, In a pilot solenoid valve having a bleed hole that communicates with an inflow port, a pilot hole that communicates with the outflow port, and a pilot valve that opens and closes the pilot hole by reciprocating movement of a plunger, the communication that connects the bleed hole and the pilot hole A pilot solenoid valve provided with a chamber, an orifice having an effective cross-sectional area less than the bleed hole, which communicates the communication chamber and the valve chamber.   The guide hole provided in the communication chamber of the lid body and the valve body sliding portion provided in the valve body that slides in the communication hole are cylindrical, and the valve body slides when the valve body is opened. The pilot solenoid valve according to claim 1, wherein the portion restricts only the bleed hole outlet to be less than the effective area of the bleed hole.   The orifice, which is an annular gap between the guide hole and the valve body sliding portion, has a diaphragm with a peripheral edge sandwiched and fixed above the slight opening of the valve body, and the groove provided in the guide hole and the valve body slide The pilot solenoid valve according to claim 2, wherein the pilot solenoid valve is fitted with a groove provided in the moving portion and increases beyond the effective area of the pilot hole.   A communication hole that communicates the communication chamber and the valve chamber, a valve that opens and closes the communication hole, and a compression coil spring that suppresses opening of the valve due to total pressure, and a slight opening degree of the valve body The pilot solenoid valve according to claim 1 or 2, wherein when the valve is opened by being reciprocated by the valve body, the communication hole is larger than the effective area of the pilot hole.   5. The pilot solenoid valve according to claim 4, wherein the valve is on the side of the communication chamber, and the compression coil spring is less than the total pressure of the valve instead of preventing the valve from being opened due to the total pressure.   The said communicating hole more than the said pilot hole effective cross-sectional area is drilled in the attachment surface inner peripheral side of the said cover body so that it may be closed by the said diaphragm of the said valve body from immediately before valve closing. Pilot solenoid valve.   The communication hole is eliminated, the orifice is opened and closed instead of the communication hole, and a groove is recessed in the closed surface or seat seat surface of the orifice so that the orifice is less than the effective area of the bleed hole when the orifice is closed. The pilot solenoid valve according to claim 4, 5 or 6.

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