JP5955763B2 - Valve structure - Google Patents

Description

  The present invention relates to a valve structure.

  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 solenoid valve according to a conventional example using a linear solenoid will be described with reference to FIGS. FIG. 7 is a schematic cross-sectional view showing a state in which the valve in the vicinity of the valve portion is closed in the solenoid valve according to the conventional example. FIG. 8 is a schematic cross-sectional view showing a state in which the valve in the vicinity of the valve portion is opened in the solenoid valve according to the conventional example. FIG. 9 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. 7). 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 seating surface 220, so that the valve hole 210 is opened (see FIG. 8).

  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. 8, 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. 9, a phenomenon occurs in which the fluid flow rate increases momentarily immediately after the start of energization. In FIG. 9, L1 shows a state when the current value increases from a non-energized state, and L2 shows a state until the current value decreases from a high current value until it 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, since the O-ring 300 sticks to the seating surface 200, the behavior at the time of deformation is not stable (not constant). It stabilizes and increases the hysteresis, which causes the flow rate control accuracy to deteriorate. In the above description, the problem about the valve structure in the solenoid valve has been described. However, the drive source is other than the solenoid (pneumatic actuator,
Similar problems can occur even with valve structures in hydraulic actuators, piezoelectric actuators, etc.).

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

  The objective of this invention is providing the valve structure which aimed at the improvement of the precision of flow control.

  The present invention employs the following means in order to solve the above problems.

That is, the valve structure of the present invention is
A valve body provided at the tip of a reciprocating member configured to reciprocate by a reciprocating actuator;
A valve seat that is closed when the valve portion of the valve body is seated on the seat surface, and is opened when the valve portion is separated from the seat surface; and
In a valve structure comprising:
The valve body includes a first valve portion, and a rubber second valve portion that expands in an umbrella shape toward the valve seat from a position farther from the valve seat than the first valve portion,
The valve seat is provided so as to surround the first seat surface facing the second valve portion and a first seat surface on which the first valve portion is seated, and a groove is predetermined from the first seat surface. An annular second seating surface formed at a distance of
In the state in which the reciprocating member is moved to the seat surface side, the first valve portion is seated on the first seat surface, and the second valve portion is bent in the second valve portion. The opposite surface side of the second seating surface is seated on the second seating surface, and in the radial direction, an annular region between the first seating surface and the region where the groove is provided is a seal region,
As the reciprocating member moves in a direction away from the seat surface, the first valve portion is separated from the first seat surface, and the second valve portion is separated from the second seat surface. It is characterized by that.

  According to the present invention, when the valve is closed, the reciprocating member moves in a direction in which the first valve portion and the second valve portion of the valve body are separated from the first seat surface and the second seat surface of the valve seat, respectively. When going, the second valve portion seated on the second seat surface in a bent state is deformed so as to return to the original shape, and away from the second seat surface. Here, the 2nd valve part in this invention employ | adopted the structure which spreads in an umbrella shape toward the valve seat from the position away from the valve seat rather than the 1st valve part. Accordingly, the second valve portion of the valve body according to the present invention is more easily separated from the seat surface than when it is separated from the seat surface from the state compressed from both sides as in the case of the conventional O-ring. In the present invention, a groove is formed in the second seat surface at a predetermined distance from the first seat surface. Accordingly, in the process of returning from the bent state of the second valve portion to the original shape, the fluid flows through the groove from the stage before the second valve portion leaves the second seat surface. From the above, it is possible to stably perform fluid control immediately after the valve starts to open. Further, since the valve portion is easily separated from the seat surface, an error in flow rate control due to hysteresis can be reduced.

The first seating surface is an inner peripheral surface of the valve hole,
The first valve portion may have a seating surface that faces the first seating surface and a tapered surface that tapers from the seating surface toward the tip.

  Thereby, the position shift of the central axis with respect to the valve seat when the valve body reciprocates can be suppressed. Therefore, the accuracy of the position where the second valve portion of the valve body is seated on the second seat surface can be increased. In addition, since the tip side of the seating surface of the first valve portion is a tapered surface, the change in the degree of valve opening after the first valve portion is separated from the first seating surface becomes gentle, and the change in flow rate becomes gentle. Become.

  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 an enlarged view of the vicinity of the valve in FIG. FIG. 3 is a view showing a state where the valve in the vicinity of the valve portion is closed in the solenoid valve according to the embodiment of the present invention. FIG. 4 is a view showing a state in which the second valve portion and the second seat surface in the vicinity of the valve portion are opened in the solenoid valve according to the embodiment of the present invention. FIG. 5 is a view showing a state where the valve in the vicinity of the valve portion is completely opened in the solenoid valve according to the embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing the cross-sectional shape of the groove of the second seat surface in the solenoid valve according to the embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a state in which the valve in the vicinity of the valve portion is closed in the solenoid valve according to the conventional example. FIG. 8 is a schematic cross-sectional view showing a state in which the valve in the vicinity of the valve portion is opened in the solenoid valve according to the conventional example. FIG. 9 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.

<Overall 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. The solenoid valve SV is composed of a solenoid part S that is an actuator for reciprocating movement, a valve part V as a valve structure, and a housing part H that accommodates the solenoid part S and various members constituting the valve part V.

The solenoid part S is magnetically attracted to the center post 14 by forming a magnetic circuit by the bobbin 11, the coil 12 wound around the bobbin 11 and generating a magnetic field by energization, and the magnetic field generated by the coil 12. And a plunger 13 as a reciprocating member. The solenoid part S also includes a pair of plates 15a and 15b and a case 15c, both of which are made of a magnetic member, so as to form the above magnetic circuit. The solenoid part S includes a spring 16a that urges the plunger 13 away from the center post 14, a spring receiver 16b that receives the spring 16a, and an adjustment screw 16c that adjusts the position of the spring receiver 16b. . The solenoid unit S also includes a terminal 17 that is electrically connected to the coil 12. Furthermore, the solenoid part S is provided with a stopper 50 for defining the end position of the stroke of the plunger 13 when the valve is closed in the reciprocating movement of the plunger 13.

  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 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 valve body 30 provided at the tip of the plunger 13 and a valve seat 40 that opens and closes when the valve body 30 is seated or separated. Further, the valve portion V includes a seal ring 60 that seals a gap between the outer peripheral surface of the valve seat 40 and the inner peripheral surface of the housing body 21, and a support member 70 that supports the valve seat 40.

  The adjustment screw 16c controls the spring receiving so that a desired flow rate (or fluid pressure associated with the flow rate) is controlled by the balance between the biasing force by the spring 16a and the magnetic force by the amount of current applied to the coil 12. The position of 16b is adjusted.

<Valve part (valve structure)>
<< Valve configuration >>
In particular, the configuration of the valve portion V will be described in more detail with reference to FIGS. As described above, the valve portion V includes the valve body 30 and the valve seat 40.

  The valve body 30 includes a shaft portion 30a, a first valve portion 31, and a second valve portion 32. The valve body 30 is fixed to the distal end of the plunger 13 by screwing a shaft portion 30 a having a male thread portion into a female thread portion of a concave portion of a support member 13 a attached to the distal end of the plunger 13. Thereby, when the plunger 13 reciprocates, the valve body 30 also reciprocates together with the plunger 13. The first valve portion 31 includes a seating surface 31a that is a circumferential surface parallel to the axis, and a tapered surface 31b whose diameter changes so as to taper toward the tip on the tip side from the seating surface 31a. Yes. The second valve portion 32 has a cylindrical portion 32a fixed to the outer periphery of the shaft portion 30a. From the cylindrical portion 32a, that is, from the position farther from the valve seat 40 than the first valve portion 31, the valve seat 40 is moved to the valve seat 40. It is configured to expand in an umbrella shape. A surface of the second valve portion 32 that faces the valve seat 40 is a seating surface 32b. The second valve portion 32 is a rubber member, and may be provided by integral molding with respect to the shaft portion 30a, or may be assembled after molding. The valve body 30 is configured such that the central axes of the shaft portion 30a, the first valve portion 31, and the second valve portion 32 coincide with each other.

  The valve seat 40 is an annular member, and a valve hole 40a that is a through hole is provided at the center thereof. The central axis of the valve hole 40 a is provided so as to coincide with the central axis of the plunger 13 and the valve body 30. In the valve seat 40, the inner peripheral surface of the valve hole 40a is a first seat surface 41 on which the seating surface 31a of the first valve portion 31 is seated, and the region facing the valve body 30 on the annular end surface around the valve hole 40a. However, the seating surface 32b of the second valve portion 32 becomes the second seating surface 42 on which the seating is performed. The second seat surface 42 is provided with a plurality of grooves 43 at a predetermined distance from the valve hole 40a (first seat surface 41) and spaced from each other in the circumferential direction. The groove 43 is provided so as to extend radially around the valve hole 40a. The distance between the groove 43 and the valve hole 40a is appropriately set according to specifications such as the opening timing of the first valve portion 31 and the second valve portion 32.

The stopper 50 is an annular member, is attached to the valve portion V side of the inner peripheral surface of the case 15c of the solenoid portion S, and moves the plunger 13 by contacting the tip surface 13b of the plunger 13 on the valve portion V side. A regulating surface 50a for regulating The position of the restriction surface 50a defines the end position of the stroke when the plunger 13 is closed.

<< Valve mechanism >>
In particular, the mechanism of the valve portion V will be described with reference to FIGS. FIG. 3A is an enlarged schematic cross-sectional view showing the vicinity of the valve in a state where the valve is closed, and FIG. 3B is a cross-sectional view taken along AA in FIG. FIG. 4A is a schematic cross-sectional view showing, in an enlarged manner, the vicinity of the valve in a state where the valve body 30 has moved and the second valve portion 32 and the second seating surface 42 have been opened, and FIG. These are BB sectional drawings of Drawing 4 (a). FIG. 5A is a schematic cross-sectional view showing an enlarged vicinity of the valve in a state where the valve body 30 is further moved and the valve is completely opened. FIG. 5B is a schematic cross-sectional view of FIG. It is CC sectional drawing.

  As shown in FIG. 3A, no magnetic force is generated when the coil 12 of the solenoid unit S is not energized, and the plunger 13 is separated from the center post 14 by the urging force of the spring 16a. It moves in the direction and stops at a position regulated by the stopper 50. Thereby, as shown in FIG. 3A, the first valve portion 31 and the second valve portion 32 of the valve body 30 are seated on the first seat surface 41 and the second seat surface 42 of the valve seat 40, respectively. . At this time, the umbrella-shaped second valve portion 32 is bent and the surface of the second valve portion 32 facing the second seat surface 42 is seated on the second seat surface 42. As a result, the valve is closed.

  FIG. 3B shows the positional relationship between the second seat surface 42 and the second valve portion 32 in a state where the valve is closed. In a state where the second valve portion 32 is seated on the second seat surface 42, the surface of the second valve portion 32 facing the second seat surface 42 has a plurality of grooves provided on the second seat surface 42. A portion inside the region facing 43 is in close contact with the second seat surface 42. Thereby, in the state where the second valve portion 32 is seated on the second seat surface 42, in the radial direction, between the region where the first seat surface 41 is provided and the region where the plurality of grooves 43 are provided. The annular region (the peripheral region of the seal line R in FIG. 3B) becomes the seal region. Thereby, the flow path from the input port portion 21a to the output port portion 21b is blocked by the seal region.

  As shown in FIG. 4A, the magnetic attractive force increases as the energization amount of the solenoid portion S to the coil 12 is increased. Therefore, the plunger 13 moves toward the center post 14 against the urging force of the spring 16a. Moving. Along with this, the valve body 30 provided at the tip of the plunger 13 also moves toward the center post 14, so that the second valve portion 32 of the valve body 30 is an area on the center side (side closer to the valve hole 40a). Gradually begins to move away from the second seating surface 42 of the valve seat 40. And as shown in FIG.4 (b), the seal line R (FIG.3 (b)) located inside the groove | channel 43 of the 2nd seat surface 42 is gradually expanded in diameter (it moves outside), When reaching a position overlapping the groove 43, a gap is formed between the second valve portion 32 and the second seat surface 42 via the groove 43. At this time, the seating surface 31 a of the first valve portion 31 is not completely separated from the first seating surface 41.

As shown in FIG. 5A, when the energization amount for the coil 12 is further increased, the plunger 13 further moves toward the center post 14, and the valve body 30 further moves away from the valve seat 40. Accordingly, the second valve portion 32 is separated from the second seat surface 42, the seal line R disappears (FIG. 5 (b)), and the seating surface 31a of the first valve portion 31 is also separated from the first seat surface 41. Leave. Thereby, the flow path which goes out from the valve hole 40a to the outer peripheral surface side of the valve body 30 is formed (refer arrow A in FIG. 5A). Therefore, the fluid flowing in from the input port portion 21a is discharged from the output port portion 21b. Here, the position of the valve body 30 provided at the tip of the plunger 13 is determined according to the amount of current supplied to the coil 12, the gap between the first valve portion 31 and the first seat surface 41, the second valve portion 32, The size of the gap with the second seating surface 42 is 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.

<Excellent point of solenoid valve according to this embodiment>
According to the solenoid valve SV according to the present embodiment, energization is started from a state in which the coil 12 is not energized, and the first valve portion 31 and the second valve portion 32 of the valve body 30 increase as the energization amount increases. The plunger 13 moves in a direction away from the first seat surface 41 and the second seat surface 42 of the valve seat 40. At this time, the second valve portion 32 seated on the second seating surface 42 in a bent state moves away from the second seating surface 42 while deforming so as to return to the original shape.

  Here, the second valve portion 32 according to the present embodiment employs a configuration that expands in an umbrella shape toward the second seat surface 42 of the valve seat 40 from a position farther from the valve seat 40 than the first valve portion 31. ing. Accordingly, the second valve portion 32 of the valve body 30 according to the present embodiment is more likely to be located on the second seat surface 42 than when the seat member is separated from the seat surface from a state compressed from both sides as in the case of the conventional O-ring. Easy to leave. In the present embodiment, a plurality of grooves 43 are formed in the second seat surface 42 of the valve seat 40 at a predetermined distance from the first seat surface and spaced apart from each other in the circumferential direction. Therefore, the fluid flows through the plurality of grooves 43 from the stage before the second valve portion 32 leaves the second seat surface 42 in the process of returning from the bent state of the second valve portion 32 to the original shape. . Then, after the flow between the second valve portion 32 and the second seat surface 42 becomes possible, the first valve portion 31 is separated from the first seat surface 41. From the above, fluid control can be stably performed immediately after the start of energization (immediately after the valve starts to open). Further, since the second valve portion 32 is easily separated from the second seat surface 42, an error in flow rate control due to hysteresis can be reduced. In the case of the O-ring of the conventional example, the adhesion state changes every time the plunger reciprocates, and the flow characteristics vary. In the case of the solenoid valve SV according to the present embodiment, Such a problem is solved and the flow rate characteristic can be stabilized.

  In the solenoid valve SV according to the present embodiment, the first valve portion 31 of the valve body 30 is inserted into the valve hole 40a of the valve seat 40 as the plunger 13 moves, and the seat is a peripheral surface parallel to the axis. The surface 31a is configured to be seated on the first seat surface 41 which is the inner peripheral surface of the valve hole 40a. Thereby, the position shift of the central axis with respect to the valve seat 40 when the valve body 30 reciprocates can be suppressed. Therefore, the accuracy of the position where the second valve portion 32 of the valve body 30 is seated on the second seat surface 42 can be increased. Moreover, the front end side of the seating surface 31a of the 1st valve part 31 is the taper surface 31b which becomes tapered. Accordingly, since the flow passage area between the first valve portion 31 and the valve hole 40a gradually changes during the reciprocating movement of the valve body 30, the insertion operation of the first valve portion 31 into the valve hole 40a is performed smoothly. .

  The first valve portion 31 may not be configured to completely close the valve hole 40a, that is, the seating surface 31a is in close contact with the first seating surface 41. That is, the state in which the valve is closed may be substantially formed by the second valve portion 32 being in close contact with the second seat surface 42. The first valve portion 31 gradually throttles the flow rate by the tapered surface 31b during the valve closing operation, and minimizes the flow rate in a state where the seating surface 31a faces the first seating surface 41. In the second valve portion 32, the seal line R moves inward from the groove 43 after the flow rate flowing between the first valve portion 31 and the first seat surface 41 is minimized. It will be in the state which contacts the seating surface 42 completely. By doing so, the behavior of the second valve portion 32 when the valve is closed can be stabilized. Further, during the valve opening operation, the first valve portion 31 minimizes the flow rate while the seating surface 31a faces the first seating surface 41 while the seal line R is positioned inside the groove 43. The flow rate is gradually increased by the tapered surface 31b after the groove 43 is able to flow between the second valve portion 32 and the second seat surface 42. That is, the change in the valve opening degree after the first valve portion 31 is separated from the first seat surface 41 becomes gentle, and the change in the flow rate becomes gentle. By doing so, it is possible to suppress the fluid pressure from the input port portion 21 from being excessively applied to the second valve portion 32 when the valve is opened, and to stabilize the valve opening operation.

  Further, in the solenoid valve SV according to the present embodiment, as described above, before the second valve portion 32 moves away from the second seat surface 42 in the process of returning from the bent state of the second valve portion 32 to the original shape. From this stage, the fluid flows through the plurality of grooves 43. That is, in the process of returning from the bent state of the second valve portion 32 to the original shape, the area of the flow path through which the fluid flows gradually increases from the inner side of the groove 43 (side closer to the valve hole 40a). Go. In this embodiment, as shown in FIGS. 3 to 5, the shape of the groove 43 is a V-shape that tapers toward the valve hole 40 a when viewed in the central axis direction. Further, the depth of the groove 34 is configured to become shallower as it approaches the valve hole 40a. As a result, the area of the flow path through which the fluid flows is prevented from suddenly expanding in the process of returning from the bent state of the second valve portion 32 to the original shape. Note that the change in the flow rate relative to the amount of current supplied to the coil 12 can be made linear and the maximum flow rate can be adjusted by setting the size and number of the groove 43 such as the angle and length. Various configurations can be adopted for the groove 43. As the cross-sectional shape of the groove 43, for example, as shown in FIG. 6, a substantially rectangular shape (FIG. 6A) in which the groove width does not change in the depth direction, the groove width gradually increases in the depth direction. Examples include a substantially triangular shape (FIG. 6B) that becomes narrower, a substantially semicircular shape (FIG. 6C), and the like. Further, the opening shape of the groove 43 is not limited to a substantially triangular shape as shown in FIGS. 3 to 5, for example, a substantially rectangular shape in which the groove width does not change in the axial direction, a trapezoidal shape with a gentle change in groove width, or the like. Can be mentioned. Further, the number and arrangement of the grooves 43 are not limited to the configuration in which twelve are equally arranged as shown in FIGS.

  Further, in the solenoid valve SV according to the present embodiment, the flow rate with respect to a certain current value depends on the setting of the thickness and shape of the second valve portion 32 in the valve body 30 and the shape, size and number of the grooves 43. It can be made not to change so much depending on the size of. The original pressure is the pressure of fluid flowing from the input port portion 21a. Thereby, even if it is a case where a source pressure changes, control pressure (pressure of the fluid discharged | emitted from the output port part 21b) can be stabilized.

  In the above-described embodiment, the configuration in which the valve body 30 is provided at the tip of the plunger 13 via the support member 13a is shown. However, the present invention also applies to the case where the valve body is provided directly at the tip of the plunger. Applicable. 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.

11 Bobbin 12 Coil 13 Plunger 13a Support member 14 Center post 15a, 15b Plate 15c Case 16a Spring 16c Adjust screw 17 Terminal 21 Housing body 21a Input port part 21b Output port part 21c Connector part 22 Cover 23 Reinforcing member 30 Valve body 30a Shaft part 31 1st valve part 31a Seating surface 31b Tapered surface 32 2nd valve part 32a Cylindrical part 32b Seating surface 40 Valve seat 40a Valve hole 41 1st seat surface 42 2nd seat surface 43 Groove 50 Stopper 60 Seal ring 70 Support member SV Solenoid Valve H Housing part S Solenoid part V Valve part

Claims (1)

A valve body provided at the tip of a reciprocating member configured to reciprocate by a reciprocating actuator;
A valve seat that is closed when the valve portion of the valve body is seated on the seat surface, and is opened when the valve portion is separated from the seat surface; and
In a valve structure comprising:
The valve body includes a first valve portion, and a rubber second valve portion that expands in an umbrella shape toward the valve seat from a position farther from the valve seat than the first valve portion,
The valve seat is provided so as to surround the first seat surface facing the second valve portion and a first seat surface on which the first valve portion is seated, and a groove is predetermined from the first seat surface. An annular second seating surface formed at a distance of
In the state in which the reciprocating member is moved to the seat surface side, the first valve portion is seated on the first seat surface, and the second valve portion is bent in the second valve portion. The opposite surface side of the second seating surface is seated on the second seating surface, and in the radial direction, an annular region between the first seating surface and the region where the groove is provided is a seal region,
As the reciprocating member moves in a direction away from the seat surface, the first valve portion is separated from the first seat surface, and the second valve portion is separated from the second seat surface. A valve structure characterized by that.

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