JP5321035B2 - Check valve - Google Patents

Description

  The present invention provides a valve plate in a gap between a valve seat and a valve seat, allows fluid flowing from the valve seat side to pass through a fluid passage hole formed in the valve plate, and flows in from the valve seat side. The present invention relates to a check valve that shields the valve by a valve plate.

Conventionally, a valve plate has been provided in the gap between the valve seat and the valve seat, and the fluid flowing in from the valve seat side is passed through the fluid passage hole formed in the valve plate, and the fluid flowing in from the valve seat side A check valve that is blocked by a valve plate is known (for example, see Patent Document 1).
Such a check valve is provided, for example, at a suction port and a discharge port of a reciprocating compressor, and is used as a suction valve or a discharge valve of the reciprocating compressor.

In the check valve of Patent Document 1, the fluid passage hole formed in the valve seat and the fluid passage hole formed in the valve seat are formed so as not to overlap each other when viewed from the fluid flow direction, and are formed on the valve plate. The fluid passage hole is overlapped with the fluid passage hole formed in the valve seat when viewed from the fluid flow direction, and the valve plate is biased toward the valve seat side in the gap formed between the valve seat and the valve seat. Has been placed.
In such a check valve, when fluid flows in from the valve seat side, the valve plate is pushed into the valve receiving side by the fluid, and the fluid can pass through the fluid passage hole formed in the valve plate. . On the other hand, when fluid flows in from the valve receiving side, the valve plate remains biased to the valve seat side, so the fluid through hole formed in the valve seat is closed by the valve plate, thereby shielding the fluid. Is done.
JP 2002-81380 A

By the way, in the check valve as described above, the fluid through hole formed in the valve seat and the fluid through hole formed in the valve plate are formed so as not to overlap with the fluid flow direction. When the fluid is allowed to pass, the flow direction of the fluid locally changes.
In other words, when the fluid is allowed to pass, the valve plate is pushed into the valve receiving side, and the fluid through hole formed in the valve seat once again hits the valve plate and changes its flow direction again. The flow direction is changed and flows into the fluid through hole of the valve plate.

  In such a check valve, when the fluid that has once hit the valve plate and whose flow direction has changed flows into the fluid through hole of the valve plate, the fluid peels off from the inner wall surface of the fluid through hole of the valve plate. The pressure loss becomes high.

  The fluid separation on the inner wall surface of the fluid through hole of the valve plate is formed so that the fluid through hole formed in the valve seat and the fluid through hole formed in the valve plate do not overlap with the fluid flow direction. This is not a problem limited to the check valve, but is a problem common to check valves including a valve plate that is exposed to a fluid flow field and has a fluid through hole.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce pressure loss by suppressing fluid separation from an inner wall surface of a fluid through hole of a valve plate in a check valve.

  The present invention adopts the following configuration as means for solving the above-described problems.

  According to a first aspect of the present invention, a valve plate is provided in a gap between the valve seat and the valve seat, and the fluid flowing in from the valve seat side is passed through a fluid passage hole formed in the valve plate, A check valve that shields the fluid flowing in from the side by the valve plate, and the cross-sectional shape of the inner wall surface of the fluid passage hole is a chord shape in which at least the valve seat side swells toward the center of the fluid passage hole The structure of having is adopted.

  A second invention adopts a configuration in which the cross-sectional shape of the inner wall surface of the fluid passage hole is the entire chord shape in the first invention.

According to a third aspect of the present invention, in the first or second aspect of the invention, the chord shape is a separation distance from the front edge when x is a distance from the leading edge to the trailing edge of the chord shape being 1. , Y _t is the distance from the center line to the chord when the distance from the leading edge to the trailing edge of the chord shape is 1, and t is the distance from the leading edge to the trailing edge of the chord shape is 1. In this case, a configuration is adopted in which the shape is defined by the following expression (1), which is twice the maximum separation distance from the center line to the chord.

  A fourth invention adopts a configuration in which the t is 0.1 or more and 0.2 or less in the third invention.

According to the present invention, the cross-sectional shape of the inner wall surface of the fluid passage hole formed in the valve plate has a chord shape that swells toward the center of the fluid passage hole. When the chord shape is arranged in the flow field, fluid separation is suppressed as compared with the linear shape.
For this reason, it becomes possible to suppress fluid separation by making the cross-sectional shape of the inner wall surface of the fluid passage hole formed in the valve plate a chordal shape.
Therefore, according to the present invention, in the check valve, it is possible to reduce pressure loss by suppressing fluid separation from the inner wall surface of the fluid through hole of the valve plate.

  Hereinafter, an embodiment of a check valve according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

FIG. 1 is a perspective view of the check valve 1 of the present embodiment, and FIG. 2 is a partial cross-sectional view of the check valve 1 shown in FIG. The check valve 1 of the present embodiment is provided, for example, at a suction port and a discharge port of a reciprocating compressor that compresses BOG (Boil Off Gas) generated by heat input to LNG (Liquefied Natural Gas). It is used as a valve and a discharge valve.
As shown in FIGS. 1 and 2, the check valve 1 includes a seat 2 (valve seat) disposed on the upstream side of the fluid F, and a guide 3 (valve seat) disposed on the downstream side of the fluid F. I have. The sheet 2 and the guide 3 are formed in a substantially cylindrical shape having substantially the same diameter, and are arranged so as to overlap with the inflow direction of the fluid F (the arrow direction in the figure).

  As shown in FIG. 2, the outer peripheral portion 2 a of the surface of the sheet 2 on the guide 3 side is in close contact with the outer peripheral portion 3 a of the surface of the guide 3 on the sheet 2 side. A recess 3 b is formed on the surface of the guide 3 on the sheet 2 side, and a gap S is formed between the sheet 2 and the guide 3. A disc-shaped plate 4 (valve plate) is accommodated in the recess 3 b, and the plate 4 is disposed in the gap S between the seat 2 and the guide 3.

  As shown in FIGS. 1 and 2, a plurality of fluid introduction holes 2 b that penetrate the sheet 2 in the normal H direction of the plate 4 are formed in the sheet 2. The fluid introduction holes 2b have a circular arrangement in which a plurality of fluid introduction holes 2b are arranged on the same circumference when viewed from the normal H direction of the plate 4, and a plurality of circular arrangements having different diameters are concentric. Is arranged. Further, the fluid introduction hole 2b has a long hole shape extending in the circumferential direction of each circular arrangement.

  As shown in FIG. 2, a plurality of fluid outlet holes 3 c are formed in the guide 3. The fluid outlet hole 3 c is provided so as to penetrate the guide 3 in the normal H direction of the plate 4. The fluid lead-out holes 3c of the guide 3 and the fluid introduction holes 2b of the sheet 2 are alternately formed in the surface direction of the plate 4 and are arranged at positions shifted without overlapping when viewed from the normal line H direction of the plate 4. . That is, the fluid outlet hole 3 c of the guide 3 and the fluid inlet hole 2 b of the sheet 2 do not overlap each other when viewed from the normal line H direction of the plate 4.

  The fluid outlet hole 3c of the guide 3 is a circle in which a plurality of fluid outlet holes 3c are arranged on the same circumference as seen from the normal line H direction of the plate 4 in the same manner as the fluid inlet hole 2b of the sheet 2 shown in FIG. A plurality of circular arrays having different diameters are arranged concentrically. Further, the fluid outlet hole 3c of the guide 3 has a long hole-like shape extending in the circumferential direction of each circular arrangement, like the fluid introduction hole 2b of the sheet 2 shown in FIG.

  As shown in FIG. 2, the plate 4 has a plurality of positions that do not overlap with the fluid introduction hole 2 b of the sheet 2 but overlap with the fluid outlet hole 3 c of the guide 3 when viewed from the normal H direction of the plate 4. A through hole 4a (fluid passage hole) is formed. The through hole 4 a is provided so as to penetrate the plate 4 in the normal H direction of the plate 4. In addition, a round bar-shaped spindle 5 is provided so as to pass through the central portion of the sheet 2, the guide 3, and the plate 4 in the normal line H direction of the plate 4, and the plate 4 is fixed to the spindle 5.

  A male screw portion 5 a is formed at the proximal end portion of the spindle 5 on the guide 3 side. A male screw part 5 a at the base end of the spindle 5 is screwed into a female screw part 3 d provided at the center of the guide 3 and fixed to the guide 3. The spindle 5 is provided such that a tip portion opposite to the base end portion where the male screw portion 5a is formed protrudes to the upstream side of the fluid F.

  A male screw portion 5 b is formed on the upstream side of the fluid F with respect to the sheet 2 at the center of the spindle 5. A nut 6 is screwed into the male screw portion 5 b at the center of the spindle 5, and a washer 7 is inserted between the nut 6 and the seat 2. Thereby, the sheet 2 and the guide 3 are integrally fixed, and a pressing force is applied between the outer peripheral portion 2a of the surface of the sheet 2 on the guide 3 side and the outer peripheral portion 3a of the surface of the guide 3 on the sheet 2 side. Has been.

FIG. 3 is a side view showing the plate 4 and the spindle 5. FIG. 4 is a plan view of a plate material constituting the plate 4, where (a) shows the valve plate 41 and (b) shows the backing plate 42.
As shown in FIG. 3, the plate 4 is composed of two plate members, a valve plate 41 and a backing plate 42, and is fixed to a spindle 5 that passes through a through hole 4 b provided in the center. The valve plate 41 and the backing plate 42 are disposed so as to overlap in the axial direction of the spindle 5, the valve plate 41 is disposed on the seat 2 side, and the backing plate 42 is disposed on the guide 3 side.

  As shown in FIGS. 4A and 4B, spring portions 4 d are provided on both the valve plate 41 and the backing plate 42 around the central portion 4 c of the plate 4 fixed to the spindle 5. Yes. The spring part 4d is formed in an arcuate band shape by forming arcuate cutouts on the outside and inside of the spring part 4d. Thereby, the spring part 4d connects a part of the center part 4c and a part of the outer peripheral part 4e on the opposite side to 180 °. The spring portion 4d is elastically deformed when a predetermined force is applied in the normal H direction of the plate 4, and the plate 4 is moved to the guide 3 side so that the plate 4 in which the through hole 4a is formed moves to the guide 3 side. It is energizing to the 2 side.

  Similar to the fluid introduction hole 2b of the sheet 2 shown in FIG. 1, the through-hole 4a of the plate 4 is a circular shape in which a plurality of through-holes 4a are arranged on the same circumference when viewed from the normal line H direction of the plate 4. A plurality of circular arrays having different diameters are arranged concentrically. Further, the through holes 4 a of the plate 4 have a long hole shape extending in the circumferential direction of a circular arrangement, like the fluid introduction holes 2 b of the sheet 2 and the fluid outlet holes 3 c of the guide 3.

5 is an enlarged cross-sectional view of a main part of the check valve 1 shown in FIGS. 1 and 2, and FIG. 6 is a cross-sectional view of the main part of FIG. 5 further enlarged.
As shown in these drawings, the cross-sectional shape of the inner wall surface 4a1 of the through hole 4a of the plate 4 is a chord shape that swells toward the center of the through hole 4a over the entire region in the flow direction.

In the check valve 1 of this embodiment, the chord shape is a shape defined by the following expression (1).
Note that in the following equation (1), the distance from the leading edge when the x is set to 1 the distance from the leading edge to the trailing edge of the wing chord shape, a trailing edge from the leading edge of y _t is chord shape The distance from the center line to the chord when the distance to the chord is 1, and t is the maximum distance from the center line to the chord when the distance from the leading edge to the trailing edge of the chord is 1 Double distance.

  For example, when the check valve 1 of the present embodiment configured as described above is used as a discharge valve by being attached to a discharge port pipe of a reciprocating compressor (not shown), the check valve shown in FIGS. 1 and 2 is used. It arrange | positions so that the sheet | seat 2 side of the valve 1 may become a discharge outlet side (upstream side of the fluid F). Further, when used as a suction valve by being attached to a pipe of the suction port, the check valve 1 is arranged so that the guide 3 side is on the suction port side (downstream side of the fluid F).

  When the reciprocating compressor sucks the fluid F from the suction port, the check valve 1 provided at the suction port of the reciprocating compressor has a guide 3 side connected to the suction port via a pipe. The fluid F has a lower pressure than the fluid F on the seat 2 side. Due to the pressure difference of the fluid F, a force in the direction of the guide 3 in the normal H direction of the plate 4 acts on the plate 4 of the check valve 1. By this force, the spring portion 4d of the plate 4 shown in FIG. 4 is elastically deformed and the outer peripheral portion 4e moves to the guide 3 side, so that the plate 4 moves to the guide 3 side as shown in FIG. Then, as shown in FIG. 6, the fluid F that has flowed into the fluid introduction hole 2 b of the sheet 2 flows into the fluid outlet hole 3 c of the guide 3 through the flow path formed between the sheet 2 and the plate 4. . The fluid F flowing into the fluid outlet hole 3c of the guide 3 is discharged from the guide 3 side to the outside of the check valve 1 and flows into the suction port of the reciprocating compressor.

On the other hand, in the check valve 1 provided at the discharge port of the reciprocating compressor, the fluid F on the seat 2 side connected to the discharge port via a pipe has a lower pressure than the fluid F on the guide 3 side. Due to the pressure difference of the fluid F, a force in the direction of the seat 2 in the normal H direction of the plate 4 acts on the plate 4 of the check valve 1. By this force, the spring portion 4d of the plate 4 shown in FIG. 4 is elastically deformed and the outer peripheral portion 4e moves to the seat 2 side. As a result, the plate 4 moves to the sheet 2 side as shown in FIG. Then, the valve plate 41 disposed on the seat 2 side of the plate 4 contacts the seat 2. As a result, the fluid introduction hole 2b of the sheet 2 is closed, and the flow of the fluid F from the fluid outlet hole 3c of the guide 3 to the fluid introduction hole 2b of the sheet 2 is blocked.
In this way, by using the check valve 1 of the present embodiment for the suction port and the discharge port of the reciprocating compressor, when the fluid F is sucked by the reciprocating compressor, the fluid F flows into the discharge port. The fluid F can be sucked from the suction port by blocking.

Further, when the fluid F compressed by the reciprocating compressor is discharged from the discharge port, the check valve 1 provided at the discharge port of the reciprocating compressor has a seat 2 connected to the discharge port via a pipe. The fluid F on the side becomes a higher pressure than the fluid F on the guide 3 side. Due to the pressure difference of the fluid F, a force in the direction of the guide 3 in the normal H direction of the plate 4 acts on the plate 4 of the check valve 1. By this force, the spring portion 4d of the plate 4 shown in FIG. 4 is elastically deformed, and the outer peripheral portion 4e moves to the guide 3 side.
As a result, the plate 4 moves toward the guide 3 as shown in FIG. Then, the fluid F that has flowed into the fluid introduction hole 2b of the sheet 2 flows into the fluid outlet hole 3c of the guide 3 through a flow path formed between the sheet 2 and the plate 4, as shown in FIG. . The fluid F that has flowed into the fluid outlet hole 3 c of the guide 3 is discharged from the guide 3 side to the outside of the check valve 1.

On the other hand, in the check valve 1 provided at the suction port of the reciprocating compressor, the fluid F on the guide 3 side connected to the suction port via a pipe has a higher pressure than the fluid F on the seat 2 side. Due to the pressure difference of the fluid F, a force in the direction of the seat 2 in the normal H direction of the plate 4 acts on the plate 4 of the check valve 1. By this force, the spring portion 4d of the plate 4 shown in FIG. 4 is elastically deformed and the outer peripheral portion 4e moves to the seat 2 side. As a result, the plate 4 moves to the sheet 2 side as shown in FIG. Then, the valve plate 41 disposed on the seat 2 side of the plate 4 contacts the seat 2. As a result, the fluid introduction hole 2b of the sheet 2 is closed, and the flow of the fluid F from the fluid outlet hole 3c of the guide 3 to the fluid introduction hole 2b of the sheet 2 is blocked.
Thus, by using the check valve 1 of the present embodiment for the suction port and the discharge port of the reciprocating compressor, when the fluid F is discharged by the reciprocating compressor, the fluid F flows out from the suction port. The fluid F can be discharged from the discharge port by blocking.

In the check valve 1 according to the present embodiment, the cross-sectional shape of the inner wall surface 4a1 of the through hole 4a included in the plate 4 swells toward the center of the through hole 4a over the entire area in the flow direction of the fluid F. It has a string shape.
In such a check valve 1 of this embodiment, when the fluid F that has flowed in from the seat 2 side and collided with the plate 4 flows into the through hole 4a of the plate 4, it peels from the inner wall surface 4a1 of the through hole 4a. This can be suppressed.
Therefore, according to the check valve 1 of the present embodiment, fluid loss from the inner wall surface 4a1 of the through hole 4a of the plate 4 can be suppressed and pressure loss can be reduced.

7 to 10 show the state of fluid separation on the inner wall surface 4a1 of the through hole 4a formed in the plate of the check valve 1 of the present embodiment and the cross-sectional shape formed in the plate of the conventional check valve. FIG. 6 is a pressure distribution diagram for illustrating a state of fluid separation on an inner wall surface of a through hole having a linear shape.
FIG. 7 shows the pressure distribution in the vicinity of the inner wall surface of the through hole formed in the plate of the conventional check valve. FIG. 8 shows a pressure distribution in the vicinity of the inner wall surface 4a1 having a cross-sectional shape defined by t in the above equation (1) being 0.154. FIG. 9 shows the pressure distribution in the vicinity of the inner wall surface 4a1 having a cross-sectional shape defined by t in the above equation (1) being 0.2. FIG. 10 shows the pressure distribution in the vicinity of the inner wall surface 4a1 having a cross-sectional shape defined by t in the above equation (1) being 0.1.
In FIGS. 7 to 10, the pressure distribution is indicated by the density of printing, the dark area indicates a relatively low pressure, and the light area indicates a relatively high pressure. .

  As shown in FIGS. 7 to 10, in the vicinity of the inner wall surface 4 a 1 whose cross-sectional shape is a chord shape like the check valve 1 of the present embodiment, the cross-sectional shape is the same as that of the conventional check valve. It was found that the pressure drop region was reduced compared with the vicinity of the inner wall surface that was made linear, and the fluid separation was suppressed.

Compared with the conventional check valve, the check valve 1 of this embodiment shown in FIG. 8 is 6.56%, the check valve 1 of this embodiment shown in FIG. 9 is 7.24%, and FIG. It has been confirmed that the check valve 1 of the present embodiment shown can reduce pressure loss by 4.71%.
That is, when t in the above formula (1) is 0.1 or more and 0.2 or less, it is possible to reliably reduce the pressure loss.

As described above, according to the check valve 1 of the present embodiment, the cross-sectional shape of the inner wall surface 4a1 of the through hole 4a formed in the plate 4 has a chord shape that swells toward the center of the through hole 4a. Yes. The chord shape suppresses fluid separation when compared with the linear shape when arranged in the flow field.
For this reason, it becomes possible to suppress separation of the fluid by making the cross-sectional shape of the inner wall surface 4a1 of the through hole 4a formed in the plate 4 into a chordal shape.
Therefore, according to the check valve 1 of the present embodiment, fluid loss from the inner wall surface 4a1 of the through hole 4a of the plate 4 can be suppressed and pressure loss can be reduced.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above-described embodiment, the configuration in which the check valve of the present invention is used as the suction valve and the discharge valve provided at the suction port and the discharge port of the reciprocating compressor has been described.
However, the present invention is not limited to this, and the use of the check valve of the present invention is arbitrary.

Moreover, in the said embodiment, the non-return valve 1 which selects the passage and shielding of the fluid by the movement to the flow direction of the plate 4 was demonstrated.
However, the check valve of the present invention can be applied to all check valves in which a valve plate (corresponding to the plate 4 of the present embodiment) is exposed to a fluid flow.
For example, the present invention can be applied to an on-off valve whose opening and closing is selected by rotating the valve plate in the circumferential direction.

Moreover, in the said embodiment, the fluid introduction hole 2b of the sheet | seat 2, the through-hole 4a of the plate 4, and the fluid outlet hole 3c of the guide 3 demonstrated the structure which is a long hole shape.
However, the present invention is not limited to this, and the fluid introduction hole 2b of the sheet 2, the through hole 4a of the plate 4, and the fluid outlet hole 3c of the guide 3 have a circular shape, an elliptical shape, or a polygonal shape. There may be.

Moreover, in the said embodiment, the structure where the cross-sectional shape of the whole area of the flow direction of the through-hole 4a formed in the plate 4 was a chord shape was demonstrated.
However, the present invention is not limited to this, and a partial cross-sectional shape on the sheet side in the flow direction of the through hole 4a may be a chordal shape.

It is a perspective view of a check valve in one embodiment of the present invention. It is a fragmentary sectional view of the check valve shown in FIG. It is a side view which shows the plate and spindle of a non-return valve shown in FIG. It is a top view of the board | plate material which comprises the plate of the non-return valve shown in FIG. 1, (a) is a top view of a valve plate, (b) is a top view of a backing plate. It is an expanded sectional view of the principal part of the non-return valve shown in FIG. It is an expanded sectional view which shows the flow of the fluid in the principal part of the non-return valve shown in FIG. It is an expanded sectional view which shows the pressure distribution in the principal part of the conventional check valve. It is an expanded sectional view showing pressure distribution in the important section of a check valve in one embodiment of the present invention. It is an expanded sectional view showing pressure distribution in the important section of a check valve in one embodiment of the present invention. It is an expanded sectional view showing pressure distribution in the important section of a check valve in one embodiment of the present invention.

Explanation of symbols

  1. Check valve, 2 ... Seat (valve seat), 2b ... Fluid introduction hole, 3 Guide (valve receiver), 4 ... Plate (valve plate), 4a ... Through-hole (fluid passage hole), 4a1 …… Inner wall surface

Claims (4)

The fluid which is provided with a valve plate in the gap between the valve seat and the valve seat, allows the fluid flowing in from the valve seat side to pass through the fluid passage hole formed in the valve plate, and flows in from the valve receiving side A check valve that is shielded by the valve plate,
The valve body is formed by overlapping the valve plate on the valve seat side and the backing plate on the valve body side, and the fluid passage hole is provided through the valve plate and the backing plate,
The check valve according to claim 1, wherein a cross-sectional shape of an inner wall surface of the fluid passage hole has a chord shape in which at least the valve seat side swells toward a center of the fluid passage hole.   The check valve according to claim 1, wherein a cross-sectional shape of an inner wall surface of the fluid passage hole is the chord shape throughout. The chord shape, the distance the distance from the leading edge when the x is set to 1 the distance from the leading edge to the trailing edge of the wing chord shape, y _t is from the leading edge to the trailing edge of chord shape The distance from the center line to the chord when t is 1, and the distance t is twice the maximum distance from the center line to the chord when the distance from the leading edge to the trailing edge of the chord is 1 The check valve according to claim 1, wherein the check valve has a shape defined by the following expression (1):

  The check valve according to claim 3, wherein the t is 0.1 or more and 0.2 or less.

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