JP6038661B2 - Solenoid valve - Google Patents

Description

The present invention relates to a solenoid valve .

  Conventionally, solenoid valves have been widely used to control the flow rate and the fluid pressure associated with the flow rate. As the solenoid valve, a solenoid valve using a linear solenoid that makes the amount of current flowing to the coil proportional to the flow rate is known. A conventional solenoid valve using a linear solenoid will be described with reference to FIGS. FIG. 4 is a schematic cross-sectional view showing a state where the valve in the vicinity of the valve portion is closed in the solenoid valve according to the conventional example. FIG. 5 is a schematic cross-sectional view showing a state in which a valve in the vicinity of the valve portion is opened in a solenoid valve according to a conventional example. FIG. 6 is a graph showing the relationship between the energization amount to the coil and the flow rate in the solenoid valve according to the conventional example.

  In the solenoid valve according to this conventional example, a valve body 120 that protrudes further in the distal direction from the center of the distal end surface 110 of the rod 100 that reciprocates according to the energization amount to the coil is provided integrally with the rod 100. Yes. A rubber O-ring 300 is attached to the outer periphery of the valve body 120. The valve seat 200 is provided with a valve hole 210.

  With the above configuration, when the coil is not energized, the valve body 120 of the rod 100 enters the valve hole 210 of the valve seat 200, and the O-ring 300 is connected to the distal end surface 110 of the rod 100 and the valve seat 200. It is the state pinched | interposed between the seating surfaces 220 of this. As a result, the valve hole 210 is closed by the valve body 120 and the O-ring 300 (see FIG. 4). When the coil is energized, the rod 100 moves in a direction in which the tip surface 110 of the rod 100 is separated from the seating surface 220. As a result, the valve body portion 120 is removed from the valve hole 210 and the O-ring 300 is separated from the seat surface 220, so that the valve hole 210 is opened (see FIG. 5).

  Here, the rubber O-ring 300 has adhesiveness. In the conventional example, the O-ring 300 is sandwiched between the tip surface 110 of the rod 100 and the seat surface 220 of the valve seat 200. Therefore, immediately after the rod 100 starts to move from the state in which the valve is closed, the O-ring 300 extends slightly in the axial direction due to adhesion with the seating surface 220 and then moves away from the seating surface 220 to the original shape. To return to. In FIG. 5, an O-ring 300 a indicated by a dotted line shows a state in which the O-ring 300 a extends in the axial direction due to adhesion with the seating surface 220. Therefore, as shown in the X part of the graph in FIG. 6, a phenomenon occurs in which the fluid flow rate increases momentarily immediately after the start of energization. In FIG. 6, L1 shows a state when the current value increases from a non-energized state, and L2 shows a state from when the current value is high until the current value decreases and becomes non-energized. ing. As can be seen from this graph, the flow rate is different between L1 and L2 even at the same current value. This difference in flow rate is called hysteresis, and it can be seen that the greater this hysteresis, the greater the error in flow rate for a given energization amount. As one of the causes of this hysteresis, it is considered that there is a problem of sticking of the O-ring 300 described above.

As described above, the O-ring 300 sticking to the seating surface 220 makes the flow control unstable immediately after the start of energization (immediately after the valve starts to open), and increases the hysteresis. This is a cause of reducing the accuracy of control. In the above description, the problem regarding the valve structure in the solenoid valve has been described. However, the same applies to the valve structure in which the drive source is other than the solenoid (pneumatic actuator, hydraulic actuator, piezoelectric actuator, etc.). Problems can arise.

JP 2006-226352 A Japanese Utility Model Publication 3-29645

An object of the present invention is to provide a solenoid valve that improves the accuracy of flow rate control.

The present invention employs the following means in order to solve the above problems.
That is, the solenoid valve of the present invention is
In a solenoid valve comprising a solenoid part as a reciprocating actuator, a valve part as a valve structure, and a housing part that houses these solenoid parts and various members constituting the valve part,
The solenoid part has a center post and a first spring;
The valve portion is
A plunger as a reciprocating member that reciprocates by magnetic attraction of the center post and biasing of the first spring in a direction away from the center post ;
A first valve body provided on the distal end side of the plunger and having a rubber-like elastic body;
A second spring as an elastic member provided on the distal end side of the plunger further than the first valve body, one end of which is fixed to the first valve body;
A second valve body, which is provided further on the distal end side of the plunger than the second spring , and is formed of a rigid body to which the other end of the second spring is fixed;
A first valve seat surface on which a rubber-made elastic body portion of the first valve body is seated and a second valve seat surface on which the second valve body is seated are provided, and the rubber-elastic body portion is formed by closed by seating the first valve seat surface, it is closed by the first valve hole to be opened by spaced, and that the second valve body is seated on the second valve seat, opened by separating A cylindrical valve seat member in which a second valve hole is formed ;
With
In a state where the plunger is moved to the distal end side of the plunger , the first valve hole and the second valve hole are closed while the second spring is compressed, and the solenoid unit is activated. brought by the plunger is moved toward the rear end direction of the plunger, by the second valve hole to open after the first valve hole is opened, the flow through the first valve hole through the second valve hole A path is formed .

  According to the present invention, in a state where the reciprocating member is moving toward the distal end side of the reciprocating member, the elastic member having one end fixed to the first valve body and the other end fixed to the second valve body is compressed. In such a state, the first valve hole and the second valve hole are configured to be closed. That is, the second valve body closes the second valve hole by being seated on the second valve seat surface while being urged by the elastic force of the compressed elastic member. In addition, the 1st valve body has closed the 1st valve hole by seating the site | part made from the rubber-like elastic body which the 1st valve body has on the 1st valve seat surface. Then, as the actuator operates, the reciprocating member moves toward the rear end of the reciprocating member. That is, the first valve body provided on the distal end side of the reciprocating member moves in a direction away from the first valve seat surface immediately after the reciprocating member starts moving. Here, since the end of the elastic member fixed to the first valve body also moves in the same direction by the movement of the first valve body, the elastic member extends from the compressed state. When the elastic member itself is extended in this manner, the other end of the elastic member starts to move behind the movement of one end of the elastic member. That is, the second valve body fixed to the other end of the elastic member starts moving later than the first valve body fixed to one end of the elastic member. The direction in which the second valve element starts moving is the direction opposite to the direction in which the second valve element is urged, that is, the direction away from the second valve seat surface. Therefore, according to the present invention, it is possible to move the second valve body in a direction away from the second valve seat surface after moving the first valve body in a direction away from the first valve seat surface. Thereby, the second valve hole can be opened after the first valve hole is opened. As a result, since the fluid is suppressed from flowing immediately after the first valve hole is opened, the rubber-made elastic body part that was seated on the first valve seat surface is separated from the first valve seat surface. Even if it is deformed immediately thereafter, a phenomenon that the flow rate of the fluid flowing out from the valve structure becomes unstable is avoided.

  According to the present invention, when the actuator further operates and the reciprocating member further moves in the rear end direction, the second valve body moves in a direction away from the second valve seat surface. Here, in the present invention, since the second valve body is made of a rigid body, the second valve body is restrained from being deformed when the second valve body moves and separates from the second valve seat surface. That is, the change in the fluid flow rate due to the deformation of the second valve body is suppressed. As a result, even if the fluid flows immediately after the second valve hole is opened, a phenomenon that the flow rate of the fluid flowing out from the valve structure becomes unstable is avoided.

  From the above, according to the present invention, it is possible to stably perform fluid control immediately after the start of movement of the reciprocating member. Further, since the second valve body is not substantially deformed and is easily separated from the seat surface, an error in flow rate control due to hysteresis can be reduced.

  As described above, according to the present invention, the accuracy of flow rate control can be improved.

FIG. 1 is a schematic cross-sectional view of a solenoid valve according to an embodiment of the present invention. FIG. 2 is a view for explaining a valve seat according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing an open / close state of the first valve hole and the second valve hole in the solenoid valve according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a state where the valve in the vicinity of the valve portion is closed in the solenoid valve according to the conventional example. FIG. 5 is a schematic cross-sectional view showing a state in which a valve in the vicinity of the valve portion is opened in a solenoid valve according to a conventional example. FIG. 6 is a graph showing the relationship between the energization amount to the coil and the flow rate in the solenoid valve according to the conventional example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. . In the following description, a solenoid valve will be described as an example of an apparatus to which the valve structure is applied.

(Example)
A solenoid valve according to an embodiment of the present invention will be described with reference to FIGS.
<Configuration of solenoid valve>
With reference to FIG. 1, the whole structure of the solenoid valve based on the Example of this invention is demonstrated. FIG. 1 is a schematic cross-sectional view of a solenoid valve according to an embodiment of the present invention, showing a state before energization is started.

As shown in FIG. 1, the solenoid valve SV includes a solenoid portion S as a reciprocating actuator, a valve portion V as a valve structure, and a housing portion that houses various members constituting the solenoid portion S and the valve portion V. H. The solenoid unit S includes a bobbin 11 and a coil 12 that is wound around the bobbin 11 and generates a magnetic field when energized. Note that a magnetic circuit is formed by the magnetic field generated by the coil 12, whereby a plunger 13 as a reciprocating member, which will be described later in detail, is magnetically attracted to the center post 14. The solenoid part S also includes a pair of plates 15a and 15b and a case 15c each made of a magnetic member so as to form the above magnetic circuit. The solenoid portion S includes a first spring 16a that urges the plunger 13 in a direction away from the center post 14, a spring receiver 16b that receives the first spring 16a, and an adjustment screw 16c that adjusts the position of the spring receiver 16b. It has. Further, the solenoid unit S includes a terminal 17 that is electrically connected to the coil 12.

  The housing portion H includes a housing main body 21 that houses various members constituting the solenoid portion S and the valve portion V, a cover 22 that is fixed to the housing main body 21, and a reinforcing member 23 that reinforces the housing main body 21. . The housing body 21 is provided with an input port portion 21a for allowing fluid to flow from the input side (source pressure side) and an output port portion 21b for discharging fluid to the output side (control pressure side). The housing body 21 is also provided with a connector portion 21c for making an electrical connection in order to obtain an electric supply from an external power source.

  The valve portion V includes a plunger 13 as a reciprocating member that reciprocates by the solenoid portion S. The plunger 13 has a cylindrical shape provided with an insertion hole through which the rod 30 is inserted. The valve portion V includes a valve body portion 31 as a first valve body formed at the distal end of the rod 30 inserted and fixed by the plunger 13, and a rubber-like member attached to the outer periphery of the distal end of the valve body portion 31. And a rubber O-ring 32 which is a portion made of an elastic body. Further, the valve portion V includes a second spring 33 as an elastic member having one end (end portion on the plunger 13 side) fixed to the valve body portion 31. The valve portion V includes a ball 34 as a second valve body fixed to the other end of the second spring 33. Further, the first valve seat surface 35a on which the O-ring 32 is seated and the ball 34 are seated. A valve seat 35 provided with a second valve seat surface 35b is provided. The sphere 34 is manufactured from a rigid body having high rigidity such as stainless steel. Further, the valve portion V includes a seal ring 36 that seals a gap between the outer peripheral surface of the valve seat 35 and the inner peripheral surface of the housing body 21, and a support member 37 that supports the valve seat 35.

  The valve body portion 31 has a cylindrical shape that is open on the input side of the solenoid valve SV, and is fixed so that the second spring 33 is accommodated therein. In the present embodiment, the valve body 31 is formed at the tip of the plunger 13 by being integrally formed at the tip of the rod 30, but the valve body 31 is a separate component. And may be fixed to the tip of the rod 30. That is, the valve body portion 31 can be configured in various forms as long as it is provided on the distal end side of the plunger 13 as a reciprocating member.

  Further, the second spring 33 is in a compressed state when the energization amount to the coil 12 is zero as shown in FIG. It is comprised so that it may become. Here, when the energization amount is zero, the magnetic attraction force does not act on the plunger 13, so the second spring 33 is biased by the elastic force (biasing force) of the first spring 16a that is also in a compressed state. Yes. Note that the biasing force at this time can be adjusted by adjusting the position of the spring receiver 16b with the adjusting screw 16c described above. Here, the characteristics (spring constant, natural length, etc.) of the second spring 33 as an elastic member are set so that the compressed state is maintained until the O-ring 32 is separated from the first valve seat surface 35a. ing.

  Next, in particular, the configuration of the valve seat 35 will be described in more detail with reference to FIG. 2 is a diagram for explaining the configuration of the valve seat 35. FIG. 2A is a front view of the valve seat 35 as viewed from the first valve seat surface 35a side (downstream side). b) is a cross-sectional perspective view of the valve seat 35. For the sake of explanation, the sphere 34 is also shown in FIG.

  As shown in FIG. 2, the valve seat 35 is a substantially cylindrical member in which a flow path through which a fluid flows is formed, and is made of a material that is somewhat hard, such as PPS (polyphenylene sulfide) resin. The valve seat 35 is provided with an opening end of a first valve seat surface 35a and a first valve hole 35c on an end surface that is on the downstream side in the fluid flow direction when mounted in the solenoid valve SV. The first valve hole 35c is a valve hole that is closed when the O-ring 32 attached to the valve body 31 is seated on the first valve seat surface 35a. The first valve hole 35 c includes an inner peripheral surface having an inner diameter larger than the diameter of the sphere 34. A second valve seat surface 35b is formed on the upstream side of the first valve hole 35c. The second valve seat surface 35b is formed of a tapered surface that further decreases in diameter toward the upstream side. That is, as shown in FIG. 1, when the valve seat 35 is attached to the solenoid valve SV, the second valve seat surface 35 b becomes a tapered surface that increases in diameter toward the second spring 33 side. A second valve hole 35d is formed on the upstream side of the second valve seat surface 35b. The second valve hole 35d is a valve hole that is closed when the ball 34 is seated on the second valve seat surface 35b. That is, when the ball 34 is seated on the second valve seat surface 35b, an annular seal line R as shown in FIG. 2A is formed, thereby closing the second valve hole 35d. As indicated by the seal line R, the sphere 34 and the second valve seat surface 35b are in line contact with each other. The formation position of the seal line R is determined by the taper angle of the second valve seat surface 35 b and the diameter of the sphere 34. Here, the taper angle of the second valve seat surface 35b and the diameter of the sphere 34 may be appropriately determined as long as the seal line R is formed. The larger the taper angle of the second valve seat surface 35b and the smaller the diameter of the sphere 34, the larger the increase in the fluid flow rate with respect to the movement amount of the sphere 34 after the second valve hole 35d is opened. . In particular, if the taper angle is increased, the maximum flow rate when the second valve hole 35d is opened can be increased.

  A plurality of (eight in the present embodiment) groove portions 35e are formed on the second valve seat surface 35b on the downstream side of the seal line R with a circumferential interval. By forming such a groove 35e, the cross-sectional area of the annular fluid passage formed by the gap between the sphere 34 and the second valve seat surface 35b (the cross-sectional area by the cross section perpendicular to the fluid flow direction) is reduced. Can be made larger. Thereby, the increase amount of the fluid flow rate with respect to the moving amount of the sphere 34 can be increased, and the maximum flow rate can be increased. It should be noted that the amount of increase in the fluid flow rate relative to the amount of movement of the sphere 34 can be adjusted by appropriately adjusting the number, depth, width, etc. of the groove 35e.

  As described above, the first valve seat surface 35 a and the second valve seat surface 35 b are formed in a single valve seat 35. With such a configuration, the number of components can be reduced, so that the manufacturing cost can be reduced.

<Solenoid valve operation mechanism>
Next, the operation mechanism of the solenoid valve SV will be described with reference to the drawings.
As shown in FIG. 1, in a state where the plunger 13 is moving toward the tip end of the plunger 13 (a state where the coil 12 of the solenoid part S is not energized), the first spring 16a and the second spring 33 are both It is in a compressed state. As described above, since no magnetic force is generated in the coil 12, the second spring 33 is compressed via the plunger 13 by the elastic force (biasing force) of the first spring 16a. The plunger 13 is urged by the first spring 16 a and moves in a direction away from the center post 14. As a result, the O-ring 32 of the valve body 31 provided on the distal end side of the plunger 13 is seated on the first valve seat surface 35a of the valve seat 35, and thus the first valve hole 35c is closed. At this time, since the O-ring 32 is sandwiched between the valve body portion 31 and the first seat surface 35a, good sealing performance is exhibited.

On the other hand, as shown in FIG. 3A, the second valve hole 35d is closed by the ball 34 biased by the second spring 33 seated on the second valve seat surface 35b. FIG. 3A is a schematic cross-sectional view showing a state where both the first valve hole 35c and the second valve hole 35d are closed. As described above, since the second valve seat surface 35b is configured by a tapered surface whose diameter is increased toward the second spring 33 side, when the biased ball 34 is seated on the second valve seat surface 35b, An annular seal line R is formed. Thus, by closing both the first valve hole 35c and the second valve hole 35d, the flow path from the input port portion 21a to the output port portion 21b is blocked. Since the ball 34 is a rigid body, the sealing performance of the seal wire R is smaller than that of the O-ring 32, but the sealing performance of the solenoid valve SV as a whole is exhibited by the O-ring 32.

  Next, with reference to FIG. 3 in particular, the case where the solenoid valve SV is opened will be described. 3B is a schematic cross-sectional view showing a state in which only the first valve hole 35c is opened, and FIG. 3C is a diagram in which both the first valve hole 35c and the second valve hole 35d are opened. It is typical sectional drawing which shows a state.

  As the solenoid portion S is operated, that is, as the energization amount of the solenoid portion S to the coil 12 is increased, the magnetic attractive force is increased. Move towards. That is, the plunger 13 moves toward the rear end thereof. Along with this, the valve body 31 provided at the tip of the rod 30 fixed to the plunger 13 also moves toward the center post 14, so that the O-ring 32 attached to the valve body 31 also has the first valve seat. It moves away from the surface 35a. At this time, the second spring 33 whose one end is fixed to the valve body portion 31 is extended from a state compressed by the movement of the valve body portion 31. That is, the other end of the second spring 33 to which the sphere 34 is fixed does not move simultaneously with the one end of the second spring 33 and starts to move with a delay. The direction is a direction away from the second valve seat surface 35b. Thereby, the second valve hole 35d can be opened after the first valve hole 35c is opened. In the following, the movement of the sphere 34 in the present embodiment will be described in more detail.

  When the second spring 33 is extended from the compressed state due to the movement of the valve body 31, the elastic force of the second spring 33 decreases. The spring constant and the natural length are set so that the compressed state is maintained until the O-ring 32 moves away from the first valve seat surface 35a. In other words, at least the compressed state is maintained until the amount of movement of the valve body 31 when the O-ring 32 moves away from the first valve seat surface 35a becomes equal to the amount of extension of the second spring 33. The spring constant and natural length are set in. Therefore, since the second spring 33 has an elastic force (biasing force) until the extension amount reaches the movement amount, as shown in FIG. 3B, the ball 34 is not opened until the first valve hole 35c is opened. Thus, the ball 34 can be kept seated on the second valve seat surface 35b against the fluid pressure acting from the upstream side (input side). As a result, the second valve hole 35d can be opened later than the first valve hole 35c, so that the first valve hole 35c is opened immediately after (or almost simultaneously with) the first valve hole 35c. It is possible to avoid a situation where the fluid circulates. As a result, even if a phenomenon occurs in which the O-ring 32 is deformed immediately after the energization is started and the valve body portion 31 starts moving due to adhesion between the O-ring 32 and the first valve seat surface 35a, A phenomenon in which the flow rate of the fluid discharged from the output port portion 21b of the solenoid valve SV increases momentarily is avoided in design.

Then, after the O-ring 32 is separated from the first valve seat surface 35a and the valve hole 35c is opened, the solenoid portion S is further activated (the energization amount is increased) and the movement amount of the plunger 13 is increased. The two springs 33 extend further. Thereby, since the elastic force by the 2nd spring 33 falls, the elastic force which urges the ball | bowl 34 with respect to the 2nd valve seat surface 35b reduces. Eventually, when the fluid pressure acting on the ball 34 from the input side of the solenoid valve SV, that is, the upstream side of the valve seat 35 exceeds the elastic force of the second spring 33, the ball 34 moves away from the second valve seat surface 35b. To do. When the second valve hole 35d is thus opened, as shown in FIG. 3C, a gap is formed between the second valve seat surface 35b and the ball 34, and the second valve hole 35d is already opened from the second valve hole 35d. A flow path leading to the first valve hole 35c is formed (see arrow A in FIG. 3). Therefore, the fluid flowing in from the input port portion 21a is discharged from the output port portion 21b. In this case, as described above, the flow rate of the fluid flowing through the annular fluid passage formed by the gap between the ball 34 and the second valve seat surface 35b is the taper angle of the second valve seat surface 35b or the groove 35e. It is determined according to the shape etc.

  Here, in the present embodiment, since the sphere 34 is manufactured from a rigid body, the sphere 34 does not stick to the second valve seat surface 35b. Therefore, since the sphere 34 is avoided from being deformed when the sphere 34 is separated from the second valve seat surface 35b, a change in the fluid flow rate immediately after the second valve hole 35d is opened can be suppressed.

  Further, in the state where the second valve hole 35d is opened, the force in the central axis direction of the valve seat 35 acting on the ball 34 is substantially balanced. That is, when the pressure of the fluid acting on the sphere 34 from the input side is substantially constant, the sphere 34 is moved to the second valve when the urging force of the second spring 33 falls below the fluid pressure due to the movement of the plunger 13. Separated from the seating surface 35b. At substantially the same time as the separation, the second spring 33 is compressed by the fluid pressure, so that the fluid pressure acting on the sphere 34 and the elastic force are substantially balanced. When the energization amount further increases in this state, the valve body 31 moves together with the plunger 13 in the rear end direction according to the energization amount. However, the length of the second spring 33 is substantially constant due to the balance of the force in the sphere 34. To be kept. Thereby, since the position of the sphere 34 is substantially determined according to the energization amount, the size of the gap between the sphere 34 and the second valve seat surface 35b can be determined. Therefore, by controlling the energization amount to the coil 12, the flow rate and fluid pressure of the fluid discharged from the output port portion 21b can be controlled.

  On the other hand, when the fluid pressure fluctuates in the state where the second valve hole 35d is opened, the second spring 33 expands and contracts, and the fluid pressure acting on the sphere 34 and the elastic force are substantially balanced. For example, when the energization amount is a predetermined amount and the position of the plunger 13 is constant, the position of the valve body 31 is also constant. When the fluid pressure fluctuates in such a case, the second spring 33 expands and contracts so that the elastic force balances the fluid pressure via the sphere 34. As a result, it is possible to perform control to increase or decrease the flow rate in accordance with increase or decrease of the fluid pressure.

<Excellent point of solenoid valve according to this embodiment>
According to the solenoid valve SV according to the present embodiment, when the plunger 13 is moving toward the tip end of the solenoid valve SV (when the energization amount of the solenoid portion S to the coil 12 is zero), one end is connected to the valve body portion 31. The first valve hole 35c and the second valve hole 35d are configured to be closed while the second spring 33, which is fixed and the other end is fixed to the sphere 34, is compressed. That is, the ball 34 closes the second valve hole 35d by being seated on the second valve seat surface 35b while being urged by the elastic force of the compressed second spring 33. The valve body portion 31 closes the first valve hole 35c by seating the rubber-like elastic O-ring 32 of the valve body portion 31 on the first valve seat surface 35a. When energization of the coil 12 is started and the solenoid part S starts to operate, the plunger 13 moves toward the rear end as it operates. That is, the valve body 31 provided on the distal end side of the plunger 13 moves in a direction away from the first valve seat surface 35a immediately after the plunger 13 starts moving. Here, as the valve body 31 moves, one end of the second spring 33 fixed to the valve body 31 also moves in the same direction, so that the second spring 33 extends from the compressed state. As the second spring 33 itself is extended in this manner, the other end of the second spring 33 starts to move after the movement of one end of the second spring 33. That is, the ball 34 fixed to the other end of the second spring 33 starts to move later than the valve body 31 fixed to one end of the second spring 33. The direction in which the sphere 34 starts moving is the direction opposite to the direction in which the sphere 34 is urged, that is, the direction away from the second valve seat surface 35b.
Therefore, according to the present embodiment, it is possible to move the ball 34 in the direction away from the second valve seat surface 35b after moving the valve body portion 31 in the direction away from the first valve seat surface 35a. Thereby, the second valve hole 35d can be opened after the first valve hole 35c is opened. As a result, since the fluid is suppressed from flowing immediately after the first valve hole 35c is opened, immediately after the O-ring 32 seated on the first valve seat surface 35a is separated from the first valve seat surface 35a. Even when deformed, the phenomenon that the flow rate of the fluid flowing out from the solenoid valve SV becomes unstable is avoided.

  According to the present embodiment, when the solenoid portion S is further operated (the amount of energization is increased) and the plunger 13 is further moved in the rear end direction, the ball 34 is moved in a direction away from the second valve seat surface 35b. . Here, in the present invention, since the sphere 34 is formed of a rigid body, the sphere 34 is prevented from being deformed when the sphere 34 moves and separates from the second valve seat surface 35b. That is, the change in the fluid flow rate due to the deformation of the sphere 34 is suppressed. As a result, even if the fluid flows immediately after the second valve hole 35d is opened, a phenomenon that the flow rate of the fluid flowing out from the solenoid valve SV becomes unstable is avoided.

  From the above, according to the present invention, it is possible to stably perform fluid control immediately after the start of movement of the plunger 13. Further, since the sphere 34 is not substantially deformed and is easily separated from the seating surface, an error in flow rate control due to hysteresis can be reduced.

  Further, according to the present embodiment, the second spring 33 is a spring so that the compressed state is maintained until the valve body portion 31 moves and the O-ring 32 is separated from the first valve seat surface 35a. A constant or natural length is set. Therefore, until the first valve hole 35c is opened, the ball 34 can continue to be seated on the second valve seat surface 35b against the fluid pressure acting on the second spring 33 by the elastic force (biasing force). . Accordingly, since the second valve hole 35d can be opened later than the first valve hole 35c, the first valve hole 35c is opened immediately after (or almost at the same time as) the first valve hole 35c. It is possible to avoid a situation where a fluid flows. As a result, a phenomenon in which the flow rate of the fluid discharged from the output port portion 21b of the solenoid valve SV increases momentarily due to the deformation of the O-ring 32 is avoided in design.

  Moreover, according to the present Example, the 1st valve seat surface 35a and the 2nd valve seat surface 35b are formed in the single valve seat. Thereby, since the number of parts can be reduced, the manufacturing cost of the solenoid valve SV can be reduced.

  Further, the second valve seat surface 35b of the solenoid valve SV is a tapered surface that increases in diameter toward the second spring 33 side. Thereby, when the ball | bowl 34 moves to the direction away from the 2nd valve seat surface 35b, the increase amount of the fluid flow rate with respect to the movement amount can be enlarged more, and the maximum flow rate can be enlarged. Further, a groove 35e is formed on the second valve seat surface 35b on the downstream side of the seal line R. Thereby, the increase amount of the fluid flow rate with respect to the moving amount of the sphere 34 can be further increased, and the maximum flow rate can be increased. The maximum flow rate can be adjusted by appropriately changing the taper angle of the second valve seat surface 35b and the number, width, and depth of the grooves 35e.

  In addition, in order to reduce the adhesion between the O-ring 32 and the first valve seat surface 35a, one or both of them may be subjected to a treatment such as fluorine coating. Moreover, in the present Example, although the 1st valve seat surface 35a and the 2nd valve seat surface 35b are formed in the valve seat 35 which is a single member, you may form in a separate member. In the present embodiment, the sphere 34 is employed as the second valve body in the present invention, but a rigid body having another shape may be used. For example, the hemisphere which formed the side fixed to the 2nd spring 33 with a plane may be sufficient.

  Moreover, in the said Example, the case where the valve structure was applied to a solenoid valve was demonstrated as an example. However, the valve structure of the present invention can also be applied to valve structures other than solenoid valves. In other words, the reciprocating actuator for reciprocating the reciprocating member is not limited to a solenoid, and a pneumatic actuator, a hydraulic actuator, a piezoelectric actuator, and the like are also applicable. The present invention is also applicable to a valve structure in which a valve body is provided on a reciprocating member configured to reciprocate by these various reciprocating actuators.

12 Coil 13 Plunger 30 Rod 31 Valve body portion 32 O-ring 33 Second spring 34 Ball 35 Valve seat 35a First valve seat surface 35b Second valve seat surface 35c First valve hole 35d Second valve hole 35e Groove portion SV solenoid valve H Housing part S Solenoid part V Valve part R Seal wire

Claims (2)

In a solenoid valve comprising a solenoid part as a reciprocating actuator, a valve part as a valve structure, and a housing part that houses these solenoid parts and various members constituting the valve part,
The solenoid part has a center post and a first spring;
The valve portion is
A plunger as a reciprocating member that reciprocates by magnetic attraction of the center post and biasing of the first spring in a direction away from the center post ;
A first valve body provided on the distal end side of the plunger and having a rubber-like elastic body;
A second spring as an elastic member provided on the distal end side of the plunger further than the first valve body, one end of which is fixed to the first valve body;
A second valve body, which is provided further on the distal end side of the plunger than the second spring , and is formed of a rigid body to which the other end of the second spring is fixed;
A first valve seat surface on which a rubber-made elastic body portion of the first valve body is seated and a second valve seat surface on which the second valve body is seated are provided, and the rubber-elastic body portion is formed by closed by seating the first valve seat surface, it is closed by the first valve hole to be opened by spaced, and that the second valve body is seated on the second valve seat, opened by separating A cylindrical valve seat member in which a second valve hole is formed ;
With
In a state where the plunger is moved to the distal end side of the plunger , the first valve hole and the second valve hole are closed while the second spring is compressed, and the solenoid unit is activated. brought by the plunger is moved toward the rear end direction of the plunger, by the second valve hole to open after the first valve hole is opened, the flow through the first valve hole through the second valve hole A solenoid valve characterized in that a passage is formed . The rubber-made elastic body portion of the first valve body is an O-ring, the second valve body is a sphere, and the second valve seat surface of the valve seat member faces the second spring side. The solenoid valve according to claim 1, wherein the solenoid valve is formed on a tapered surface that expands in diameter.

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