JP5221311B2 - Door check device - Google Patents

Description

  The present invention relates to a door check device using a one-way valve.

Patent Document 1 below describes a door check device in which a valve body is held with a large force at a closed position and the force for holding the valve body decreases when the valve body moves in an opening direction.
The door check device includes a case filled with a liquid, a shaft disposed in the case and rotatably supported by the case, and provided on a peripheral surface of the shaft. A flap divided into a second chamber, a first conduit, a second conduit provided in the flap such that one opening faces the first chamber and the other opening faces the second chamber; A valve body provided in the first pipe line, a hole provided in the first pipe line upstream of the valve body and closed when the valve body closes, and the valve body plugs the hole part. A first one-way valve having an outlet provided downstream of the valve body, wherein the biasing means moves the hole as the valve body approaches the hole. Is formed so as to increase the force of closing the part, and A first force that always exerts an urging force in the direction of closing the hole, allows the liquid to flow from the first chamber to the second chamber, and prevents the liquid from flowing from the second chamber to the first chamber. A directional valve, a valve body provided in the second pipe, a hole provided in the second pipe upstream of the valve body and closed when the valve body is closed, and the valve body An urging means for urging the hole in a closing direction, and a second one-way valve having an outlet provided downstream from the valve body, wherein the urging means has the valve body at the hole. As the force approaches, the force for closing the hole is increased, and the urging force is always applied to the valve body in the direction for closing the hole, so that the liquid from the second chamber to the first chamber A second one-way valve that allows the flow of liquid and blocks the flow of liquid from the first chamber to the second chamber; It is.

  In this door check device, when the shaft is rotated, the liquid flows through the first pipe line and the second pipe line. When the liquid flows from the first chamber toward the second chamber, the valve body of the first one-way valve of the first pipe is pushed away from the hole by the pressure of the liquid. At this time, since the force for closing the hole is large, a large force (peak torque) is required to move the door. Further, the valve body of the second one-way valve of the second pipe line is pushed in a direction to close the hole by the pressure of the liquid. When the valve body of the first one-way valve moves away from the hole against the urging force of the urging means, the force for closing the hole of the urging force of the urging means is small, so the The door can be moved with a stable force (steady torque).

When the rotation of the shaft is stopped, the valve body of the first one-way valve quickly closes the hole by the urging force of the urging means.
On the other hand, when the liquid flows from the second chamber toward the first chamber, the valve body of the second one-way valve of the second conduit is pushed in a direction away from the hole due to the pressure of the liquid. Further, the valve body of the first one-way valve of the first pipe line is pushed in the direction of closing the hole by the pressure of the liquid. When the valve body of the second one-way valve moves away from the hole against the urging force of the urging means, the urging force of the urging means becomes small.

When the rotation of the shaft stops, the valve body of the second one-way valve quickly closes the hole by the urging force of the urging means.
JP 2008-008309 A (FIG. 13)

  In the door check device having the above configuration, when the door is opened and closed quickly, the urging force of the urging means rapidly decreases after a while after the door starts to move, so the valve body that has blocked the hole of the one-way valve has a fast speed. Thus, there is a problem in that a large pressure fluctuation occurs in the liquid that moves away from the hole and moves downstream from the hole, resulting in a large operating noise.

Conversely, if the outlet of the one-way valve is reduced in order to reduce the pressure fluctuation, the door operating resistance is increased.
The present invention has been made in view of the above problems, and an object thereof is to provide a door check device in which the door operating resistance is reduced and the operating noise is reduced.

  The invention according to claim 1 is provided with a case filled with liquid, a shaft disposed in the case and rotatably supported by the case, and provided on a peripheral surface of the shaft. A flap divided into a chamber and a second chamber; a first conduit, a second conduit provided so that one opening faces the first chamber and the other opening faces the second chamber; A first one-way valve provided in one conduit, which allows a liquid flow from the first chamber to the second chamber and prevents a liquid flow from the second chamber to the first chamber. A first one-way valve and a second one-way valve provided in the second pipe line, permitting a liquid flow from the second chamber to the first chamber, and from the first chamber to the first chamber A door check device comprising: a second one-way valve for blocking liquid flow to the second chamber; The one-way valve and the second one-way valve are respectively provided in a pipe line through which a liquid flows, a valve body that moves forward and backward in the pipe line, and the pipe line upstream of the valve body. A hole portion that is closed by being blocked by the valve, an urging means that urges the valve body so that a force for closing the hole portion increases as the valve body approaches the hole portion, and a liquid The first flow path includes a first flow path and a second flow path that are guided from the hole portion to the downstream side of the valve, the flow resistance of the first flow path is set to be larger than the flow resistance of the hole portion, When the hole is closed, it is in a closed state, and when the valve body is separated from the hole, it is in a fully open state, and when the valve body is closing the hole, the second flow path is It is in a closed state, the valve body is separated from the hole, and starts to open after the first flow path is fully open. A door check apparatus characterized by being configured to.

When the shaft rotates, the liquid flows through the first pipe line and the second pipe line.
When the liquid flows from the first chamber toward the second chamber, the valve body of the first one-way valve of the first pipe is pushed away from the hole by the pressure of the liquid. Further, the valve body of the second one-way valve of the second pipe line is pushed in a direction to close the hole by the pressure of the liquid. Then, the valve body of the first one-way valve moves in a direction away from the hole against the urging force of the urging means. When the rotation of the door stops, the valve element of the first one-way valve closes the hole quickly by the component force in the direction closing the hole of the urging force of the urging means.

  On the other hand, when the liquid flows from the second chamber toward the first chamber, the valve body of the second one-way valve of the second conduit is pushed in a direction away from the hole due to the pressure of the liquid. Further, the valve body of the first one-way valve of the first pipe line is pushed in the direction of closing the hole by the pressure of the liquid. When the valve body of the second one-way valve moves away from the hole against the urging force of the urging means, the component force in the direction of closing the hole of the urging force of the urging means is reduced. When the rotation of the door stops, the valve body of the second one-way valve quickly closes the hole by the component force in the direction to close the hole of the biasing force of the biasing means.

  According to a second aspect of the present invention, the second flow path is a flow path that has an opening in the wall surface of the pipeline downstream of the hole and is provided outside the pipeline, and the biasing force The means is provided on one side of the pipe line side and the valve body side, and provided on the other side of the pipe line side and the valve body side, and the spring is provided on the valve body side. A surface that is always pressed from a direction that intersects the moving direction and that constantly exerts an urging force in a direction that closes the hole with respect to the valve body, the surface being continuous with the first surface and the first surface And the second surface is set so that the urging force exerted on the valve body is smaller than that of the first surface, and the opening of the second flow path is formed by the spring acting on the first surface. In the pressed state, it is in a closed state and starts to open when the spring moves from the first surface to the second surface. A door check device according to claim 1,.

  The invention according to claim 3 is provided with a stopper portion that prohibits the downstream movement of the valve body, and when the valve body is prohibited from further downstream movement by the stopper portion, the second flow The door check device according to claim 1 or 2, wherein the opening of the road is fully open.

  According to the first to third aspects of the present invention, the first one-way valve and the second one-way valve have a first flow path and a second flow for guiding liquid from the hole to the downstream side of the valve. And the first flow path is closed when the flow resistance is set to be greater than the flow resistance of the hole, and the valve body closes the hole, and the valve body is When the valve body is separated from the hole, the second flow path is fully opened, and when the valve body closes the hole, the second flow path is closed, the valve body is separated from the hole, and the first flow It was configured to start opening after the road was fully open.

  Therefore, when the valve body is separated from the hole portion from the state where the valve body closes the hole portion, first, only the first flow path whose flow resistance is set larger than the flow resistance of the hole portion is opened. The speed at which the body separates from the hole is slowed down, no large pressure fluctuations occur in the liquid moving downstream from the hole, and no large operating noise is generated.

  And since the said 2nd flow path begins to open after the said valve body leaves | separates from the said hole part and the said 1st flow path becomes fully open, the flow resistance of a liquid becomes small, door opening / closing operation force becomes small, and a door Operability when opening and closing is improved. At this time, since the moving speed of the valve body does not increase, a large pressure fluctuation does not occur in the liquid moving to the downstream side from the hole, and no large operating noise is generated.

  According to the invention of claim 2, the opening of the second flow path is in a closed state when the spring presses the first surface, and the spring is from the first surface to the second surface. When you move to, it begins to open. That is, after the spring moves from the first surface to the second surface, the force for closing the hole of the valve element becomes small, and the door can be moved with a small and stable force. Since it starts to open, the flow resistance of the liquid becomes small, so the operability when opening and closing the door is good. At this time, since the moving speed of the valve body does not increase, a large pressure fluctuation does not occur in the liquid moving to the downstream side from the hole, and no large operating noise is generated.

  According to the invention of claim 3, after the valve body is separated from the hole and the first flow path is fully opened, the second flow path starts to open, and the valve body is further moved by the stopper portion. In the state where the downstream movement is prohibited, the opening of the second flow path is fully open, so that the flow resistance of the liquid is reduced, the door opening / closing operation force is reduced, and the operability at the time of door opening / closing is reduced. Will improve. At this time, since the moving speed of the valve body does not increase, a large pressure fluctuation does not occur in the liquid moving to the downstream side from the hole, and no large operating noise is generated.

  First, the structure for attaching the door check device of this embodiment to a vehicle will be described with reference to FIGS. As shown in FIG. 5, the door 300 is rotatably attached to the body 305 using an upper hinge 301 and a lower hinge 303. A door check device 351 is provided on the upper hinge 301 side.

  As shown in FIG. 6, the upper hinge 301 includes a hinge female 311 whose base end is attached to the body 305, a hinge mail 313 whose base end is attached to the door 300, and a distal end side of the hinge female 311. Is fitted into and fixed to a hinge pin hole 311 a provided in the hinge, and is loosely fitted into a hinge pin hole 313 a provided on the distal end side of the hinge mail 313 so as to be integrated with the hinge female 311 relative to the hinge mail 313. And a hinge pin 315 that rotates. A door check device 351 is attached to the lower side of the hinge mail 313 on the door 300 side, and the shaft 5 of the door check device 351 is coupled to the hinge pin 315 so that the hinge pin 315 and the shaft 5 rotate integrally. Yes.

  Next, a schematic configuration of the door check device 351 will be described with reference to FIGS. 7 is an exploded perspective view of the door check device 351, and FIG. 8 is a cross-sectional view taken along line AA when the door check device shown in FIG. 7 is assembled.

As shown in these drawings, the door check device 351 includes a case 3, a base 51, and a shaft 5.
The case 3 is a molded product of fiber reinforced plastic, and includes a bottomed cylindrical case main body 1 having an open surface 1 a and a lid 11 that covers the open surface 1 a of the case main body 1. In this embodiment, a seal ring (not shown) is disposed between the case body 1 and the lid 11 so that the case body 1 and the lid 11 are sealed.

  On the inner bottom surface of the case main body 1, one end side of the shaft 5 is fitted, and a concave portion that rotatably supports the shaft 5 is formed. The case body 1 is filled with a viscous fluid (for example, oil). A flap 9 is attached to the peripheral surface of the shaft 5 in the case body 1. The inside of the case body 1 is divided into a first chamber 2 and a second chamber 3 by the flap 9.

  A lid 11 is provided so as to cover the open surface 1a of the case body 1. The lid 11 is also a molded product of fiber reinforced plastic, and a convex portion 11a is formed at a substantially central portion. The other end side of the shaft 5 is inserted into the convex portion 11a, and the shaft 5 is rotatably supported. A hole 13 is provided. The other end side of the shaft 5 projects to the outside of the case 3 through the hole 13 of the lid 11 and is coupled to the hinge pin 315 described above.

The base 51 is a metal deep-drawn product having a recessed portion 51a into which the case 3 is inserted and an overhanging portion 51b formed around the recessed portion 51a and capable of contacting the vehicle body.
If the direction in which the shaft 5 protrudes is defined as the top, a hole 59 through which a bolt can be inserted is formed in the upper and lower portions of the overhanging portion 51b of the base 51, and the mounting portion 61 is in contact with the vehicle body side. .

Next, the flap 9 will be described with reference to FIG. FIG. 9 is an exploded perspective view of the flap 9.
The flap 9 has one opening 4a (see FIG. 1) in the first chamber 2, the other opening 4b in the second chamber 3, and one opening 5a in the second chamber 3. A second duct 5 is provided such that the other opening (not shown) faces the first chamber 2. In this embodiment, in the first pipeline 4 and the second pipeline 5, the opening area of one opening 4a, 5a is set to be narrower than the opening area of the other opening 4b.

  The first conduit 4 includes a first one-way valve 7 that allows a liquid flow from the first chamber 2 to the second chamber 3 and prevents a liquid flow from the second chamber 3 to the first chamber 2. Is provided. Further, the second one-way valve that allows the liquid flow from the second chamber 3 to the first chamber 2 and prevents the liquid flow from the first chamber 2 to the second chamber 3 in the second pipe 5. (Not shown) is provided.

  Next, the one-way valve will be described with reference to FIG. 1, FIG. 9, and FIG. Since the first one-way valve 7 and the second one-way valve in the present embodiment have the same configuration, only the first one-way valve will be described, and the description of the second one-way valve will be omitted. FIG. 1 is a configuration diagram for explaining the first one-way valve 7, and FIG. 10 is a diagram for explaining a protrusion formed on the lid.

  The first pipe line 4 is provided with a rectangular tube-like pipe line 71 through which liquid flows. A groove 71 a is formed in one set of side portions of the two sets of side portions facing each other of the pipe line 71. Furthermore, a hole 71b that connects the groove 71a and the inside of the pipe 71 is formed on the side of the opening 4a of the first pipe 4 of the pipe 71 on the side where the groove 71a of the pipe 71 is formed. .

  A valve body 72 that moves forward and backward in the pipeline 71 is provided inside the pipeline 71. The valve body 72 has a bottomed cylindrical shape in which one side facing the opening 4a is a bottom 72b and the other side is an open surface, and a protrusion 72a that can enter the opening 4a is formed on the bottom 72b. ing. In addition, a hole 72c facing the peripheral edge of the opening 4a is formed in the bottom 72b of the valve body 72.

On the upstream side of the valve body 72, a hole portion that is closed when the valve body 72 is closed is provided. In this embodiment, the opening 4a is a hole.
An annular seal ring 76 is provided at the base of the protrusion 72 a of the valve body 72. When the protrusion 72a of the valve body 72 enters the opening 4a and the valve body 72 blocks the opening 4a, the seal ring 76 contacts the edge of the opening 4a and improves the sealing performance of the valve body 72. Is.

  A lid 73 is provided downstream of the valve body 72 so as to close the open surface of the pipe 71. The lid 73 is formed with a hole 73 f that connects the outside of the lid 73 and the inside of the pipe 71. In this embodiment, the cross-sectional area of the hole 73f is set smaller than the cross-sectional area of the opening 4a.

  With this configuration, in the present embodiment, two flow paths that guide the liquid on the opening 4 a side to the downstream of the first one-way valve 7 are configured. The first flow path FR is a flow path that passes through the inside of the pipe 71 through the hole 72 c of the valve body 72 and reaches the downstream of the first one-way valve 7 through the hole 73 f of the lid 73. The second flow path SR is a flow path that reaches the downstream of the first one-way valve 7 through the groove 71 a provided outside the pipe line 71 through the hole 71 b of the pipe line 71.

  Further, the first one-way valve 7 has an urging means for urging the valve body 72 so that the force to close the opening (hole) 4a increases as the valve body 72 approaches the opening (hole) 4a. Provided. The biasing means of the present embodiment is formed continuously on a plate spring 75 provided between the valve body 72 and the lid 73 and a surface of the lid 73 facing the valve body 72, and has different inclination angles. The projection 73b has a first surface 73c and a second surface 73d. The leaf spring 75 has an inverted U-shape, and one end side abuts on the surface of the bottom 72b of the valve body 72 opposite to the surface provided with the protrusion 72a, and the other end side protrudes. One of the first surface 73c and the second surface 73d is always pressed across the 73b, and the urging force is always exerted on the valve body 72 in the direction of closing the opening (hole) 4a. In addition, the inclination of the protrusion 73b with respect to the direction perpendicular to the direction in which the liquid flows on the first surface 73c is formed more gently than the inclination of the second surface 73d. Therefore, the urging force exerted on the valve body 72 via the leaf spring 75 is smaller on the second surface 73d than on the first surface 73c. That is, as the valve body 72 approaches the opening (hole) 4a, the force for closing the opening (hole) 4a increases.

In this embodiment, the protrusion 73 b having the first surface 73 c and the second surface 73 d is formed on the lid 73. However, the protrusion is formed on the valve body 72, and the leaf spring 75 is connected to the protrusion 73 and the lid 73. You may arrange | position between.
Further, as shown in FIG. 1, the lid 73 is formed with a stopper portion 73 e that abuts the valve body 72 and prohibits the valve body 72 from moving downstream.

  Here, the operation of the door check device configured as described above will be described. When the shaft 5 is rotated, the liquid flows through the first conduit 4 and the second conduit 5. When the liquid flows from the first chamber 2 toward the second chamber 3, the valve body 72 of the first one-way valve 7 of the first conduit 4 is pushed away from the opening (hole) 4a by the pressure of the liquid. It is. At this time, since the force for closing the opening (hole) 4a is large, a large force (peak torque) is required to move the door. Further, the valve body of the second one-way valve of the second pipe line 5 is pushed in a direction to close the hole by the pressure of the liquid. When the valve element 72 of the first one-way valve 7 moves away from the opening (hole) 4a against the urging force of the urging means, the leaf spring 75 is moved from the first surface 73c to the second surface 73d. Since the force for closing the opening (hole) 4a of the urging force of the urging means is reduced, the door can be moved with a small and stable force (steady torque).

When the rotation of the shaft 5 is stopped, the valve body 72 of the first one-way valve 7 quickly closes the hole by the urging force of the urging means.
On the other hand, when the liquid flows from the second chamber 3 toward the first chamber 2, the valve body of the second one-way valve 8 of the second conduit 5 is pushed away from the hole by the pressure of the liquid. Further, the valve body 72 of the first one-way valve 7 in the first pipe line 4 is pushed in a direction to close the hole by the pressure of the liquid. When the valve body of the second one-way valve 8 moves away from the hole against the urging force of the urging means, the leaf spring moves from the first surface to the second surface, and the urging means The biasing force is reduced.

Then, when the rotation of the shaft 5 stops, the valve body of the second one-way valve 8 quickly closes the hole by the urging force of the urging means.
Here, the operation of the one-way valve (first one-way valve 7) will be described with reference to FIGS.

(1) As shown in FIG. 1, when the valve body 72 closes the opening (hole) 4a, the first flow path FR and the second flow path SR are in a closed state.
(2) As shown in FIG. 2, when the valve body 72 is pushed away from the opening (hole) 4a by the pressure of the liquid, the valve body 72 is slightly separated from the opening (hole) 4a. At this time, the leaf spring 75 still presses the first surface 73c of the protrusion 73b.

In such a state, the first flow path FR is fully opened, but the second flow path SR is closed because the valve body 72 blocks the hole 71b of the pipe line 71.
(3) As shown in FIG. 3, when the valve body 72 is further pushed by the pressure of the liquid and the leaf spring 75 moves to the second surface 73d of the protrusion 73b, the pipe line 71 that has been blocked by the valve body 72. Hole 71b begins to open, and second flow path SR begins to open.

 (4) As shown in FIG. 4, when the valve body 72 comes into contact with the stopper portion 73e of the lid 73 and the further downstream movement of the valve body 72 is prohibited, the hole 71b of the pipe line 71 is fully opened. The second flow path SR is also fully opened.

According to the one-way valve having such a configuration, the following effects can be obtained.
(1) The flow resistance of the first flow path FR is larger than the flow resistance of the opening (hole) 4a because the cross-sectional area of the hole 73f is set smaller than the cross-sectional area of the hole (opening) 4a. Yes.

  As shown in FIG. 1, when the valve element 72 is separated from the opening (hole part) 4a from the state where the valve element 72 closes the opening (hole part) 4a, the second flow path SR is not opened and the flow resistance is first opened. Since only the first flow path FR set larger than the flow resistance of the (hole) 4a is opened, the speed at which the valve body 72 is separated from the opening (hole) 4a is slow, and the downstream side from the opening (hole) 4a. There is no sudden large pressure fluctuation in the moving liquid, and no large operating noise is generated.

  And since the valve body 72 leaves | separates from the opening (hole part) 4a and the 1st flow path FR becomes fully open, the 2nd flow path SR begins to open, Therefore The flow resistance of a liquid becomes small and door opening / closing operation force is It becomes smaller and the operability when opening and closing the door is improved.

 (2) The opening of the second flow path SR (the hole 71b of the conduit 71) is in a closed state where the leaf spring 75 is pressing the first surface 73c, and the leaf spring 75 is separated from the first surface 73c. When shifting to the second surface 73d, the valve body 72 starts to open, and when the valve body 72 is further prevented from moving downstream by the stopper portion 73e, the valve body 72 is fully opened. That is, the leaf spring 75 shifts from the first surface 73c to the second surface 73d, and the force for closing the opening (hole) 4a of the valve body 72 is reduced, and the door can be moved with a small and stable force. Since the opening of the second flow path SR (the hole 71b of the pipe 71) starts to open and the flow resistance of the liquid becomes small, the operability at the time of opening and closing the door is good.

  In addition, this invention is not limited to the said example of a form. In the above embodiment, the valve body 72 is in contact with the lid 73 and the stopper portion 73e is formed to prohibit the downstream movement of the valve body 72, but the leaf spring 75 is in contact with the inner wall surface of the lid 73. You may make it prohibit the movement to the downstream of the valve body 72. FIG.

  Further, in the above-described embodiment, when the valve body 72 comes into contact with the stopper portion 73e, the hole 71b of the pipe line 71 is fully opened and the second flow path SR is also fully opened. 71b may be in an intermediate open state, and the second flow path SR may also be in an intermediate open state.

It is a block diagram explaining a 1st one way valve | bulb. It is a figure explaining the action | operation of the 1st one way valve | bulb of FIG. It is a figure explaining the action | operation of the 1st one way valve | bulb of FIG. It is a figure explaining the action | operation of the 1st one way valve | bulb of FIG. It is a disassembled perspective view around the door in which the door check apparatus was provided. FIG. 6 is an enlarged view of an upper hinge portion in FIG. 5. It is a disassembled perspective view of a door check apparatus. It is sectional drawing in cutting line AA when the door check apparatus shown in FIG. 7 is assembled. It is a disassembled perspective view of the flap of FIG. It is a figure explaining the protrusion formed in the lid | cover.

Explanation of symbols

4a Opening (hole)
7 One-way valve 72 Valve body FR First flow path SR Second flow path

Claims (3)

A case filled with liquid;
A shaft disposed in the case and rotatably supported by the case;
A flap that is provided on a peripheral surface of the shaft and divides the inside of the case into a first chamber and a second chamber;
A first conduit and a second conduit provided so that one opening faces the first chamber and the other opening faces the second chamber;
A first one-way valve provided in the first conduit, allowing a liquid flow from the first chamber to the second chamber, and flowing a liquid from the second chamber to the first chamber. A first one-way valve for preventing
A second one-way valve provided in the second conduit, allowing liquid flow from the second chamber to the first chamber, and flowing liquid from the first chamber to the second chamber; A second one-way valve to prevent
In the door check device consisting of
Each of the first one-way valve and the second one-way valve includes a conduit through which a liquid flows,
A valve body that moves forward and backward in the pipeline;
A hole that is provided in the pipe line upstream from the valve body and is closed when the valve body is closed;
A biasing means for biasing the valve body such that a force for closing the hole portion increases as the valve body approaches the hole portion;
A first flow path for guiding liquid from the hole to the downstream of the valve, a second flow path,
The first flow path is
The flow resistance is set larger than the flow resistance of the hole,
When the valve body closes the hole, it is in a closed state,
When the valve body is separated from the hole, it is in a fully open state,
The second flow path is
When the valve body closes the hole, it is in a closed state,
A door check device configured to start opening after the valve body is separated from the hole and the first flow path is fully opened. The second flow path is
An opening in the wall surface of the pipeline downstream from the hole, and a flow path provided outside the pipeline;
The biasing means is
A spring provided on either one of the pipe line side and the valve body side;
A direction that is provided on the other side of the pipe line side and the valve body side, and the spring always presses from the direction intersecting the moving direction of the valve body, and closes the hole with respect to the valve body. The first surface is continuously formed with the first surface, and the surface is set so that the urging force exerted on the valve body is smaller than that of the first surface. The second surface, and the opening of the second flow path is
In a state where the spring presses the first surface, it is in a closed state,
The door check device according to claim 1, wherein the spring starts to open when the spring moves from the first surface to the second surface. Provide a stopper portion that prohibits the downstream movement of the valve body,
3. The door check according to claim 1, wherein the opening of the second flow path is in a fully open state in a state where the valve body is further prevented from moving downstream by the stopper portion. apparatus.

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