JP2015209925A - Unidirectional valve and fluid system with unidirectional valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unidirectional valve of high structural reliability in which a flow passage resistance under forward flow is low and a sealing characteristic under reverse flow is high, and provide a fluid system realizing a high performance under arrangement of the unidirectional valve.SOLUTION: An outer shape line of a valve plate 3NO is set in such a shape as one in which a large diameter part 3NOe having a larger curvature radius than that of a radius of a valve area sectional circle 204c having a valve seat at its bottom part into which the valve plate is fed a small diameter part 3NOd having a smaller curvature radius than a radius of the valve area, a normal line drawn from an optional point on a small diameter part crosses at a right angle with the large diameter part to form a crossing point, a distance between the optional point and the crossing point is always kept constant, the distance is increased higher than a sum of the valve area radius and an inner edge radius of the valve seat surface only by a specified amount of expansion.

Description

  The present invention relates to a one-way valve, and in particular, a valve plate is inserted into an engraved valve region having a valve seat at the bottom of a hole having a circular cross section, and a central axis of the valve region (hereinafter referred to as “valve”). A valve plate shape of a one-way valve of a type (hereinafter referred to as “flapper type”) having a retainer surface that defines a valve plate movement amount in a direction called “shaft” and a fluid including a fluid machine including the same About the system.

  In the flow path of the fluid system including the fluid machine, it is provided in the middle of the flow path of the working fluid, and the flow is allowed in the state where the flow resistance is low with respect to the forward flow (forward flow), but the reverse flow Each part is provided with a one-way valve that performs an operation of preventing (reverse flow) (hereinafter referred to as “rectifying operation”). The flapper type one-way valve has a simple configuration in which the inward movement regulation of the surface perpendicular to the valve axis of the valve body (hereinafter referred to as “valve horizontal plane”) is performed only on the side surface of the cylindrical valve region. One way valve. Examples of this embodiment include a flapper type one-way valve mounted on a fluid machine (scroll compressor) disclosed in Embodiment 10 of Patent Document 1. This is a flapper type one-way valve in which a circular valve plate is introduced into a valve region (cylindrical dug), and is used as a bypass valve that connects a compression chamber and a fixed back chamber that is a discharge chamber. When the pressure in the compression chamber rises above the fixed back chamber pressure (discharge pressure) (overcompression), the flapper type one-way valve opens and the working fluid flows out from the compression chamber to the fixed back chamber. The pressure drops. And the valve opening state continues until the compression chamber pressure falls to the discharge pressure. As a result, overcompression is suppressed, unnecessary work is suppressed, and compressor efficiency is improved.

JP-A-11-132164

  However, the conventional flapper type one-way valve described above has a gap between the outer edge of the valve plate and the side of the valve region through which the forward working fluid passes after passing through the gap between the valve plate and the valve seat (hereinafter referred to as the valve seat gap) ( Hereinafter, there was a problem that the cross-sectional area of the outer edge gap) was small. As a result, the flow path resistance of the outer edge gap increases, the pressure difference before and after the outer edge gap increases, and eventually the pressure in the compression chamber rises above the discharge pressure on the downstream side even if forward flow occurs. . That is, there is a problem that over-compression cannot be suppressed and the performance of the fluid machine equipped with this flapper type one-way valve is deteriorated.

  Therefore, as a first countermeasure for solving the above problem, it is possible to reduce the diameter of the valve plate in order to increase the cross-sectional area of the outer edge gap. Here, even if the diameter of the circle which is the valve plane sectional diagram of the valve region (hereinafter referred to as “valve region sectional circle”) is increased, the cross-sectional area of the outer edge gap can be increased, but the essential difference is Because there is not, explanation is omitted. By this means, the flow resistance of the outer edge clearance is reduced, but even if the valve plate is eccentric to the maximum, the valve plate does not come off the valve seat (more specifically, if the valve seat has an annular shape having a width, There is a restriction in reducing the diameter so that it does not deviate from the inner edge line of the bearing surface. This is because without this restriction, sealing is not performed when the valve should be closed, and the function of preventing backflow is lost. As a result, there has been a problem that the cross-sectional area of the outer edge gap cannot be significantly increased and the flow path resistance during forward flow cannot be significantly reduced. This tendency becomes stronger as the inner edge line of the valve seat surface moves away from the axis.

  As described above, the reduction of the channel resistance by the first countermeasure means has a limited effect. Furthermore, the countermeasure means causes an expansion of the movable range in the valve horizontal plane of the valve plate, which inhibits the rectifying operation, as will be described later. Normally, the valve plate is eccentric in any direction on the valve horizontal plane and is in contact with the side surface of the valve area. The maximum distance between the valve shaft and the centroid of the valve plate when moving in the region increases.

  The valve body that has moved to the vicinity of the retainer surface by the valve opening operation constantly changes the eccentric direction in the valve horizontal plane due to minute fluctuations in the working fluid flowing through the outer edge gap. As described above, since the amount of eccentricity increases, the moving speed of the valve body in the valve horizontal plane accompanying the change in the eccentric direction of the valve body increases. For this reason, the formation state (gap distribution) of the outer edge gap constantly changes violently, and the time variation of the flow of the working fluid increases. As a result, the vorticity inside the flow increases, the energy dissipation inside the flow increases, and a large pressure drop occurs. That is, there arises a problem that the flow path resistance of the outer edge gap is increased.

  Further, due to the increase in the time fluctuation of the flow of the working fluid, the posture deviation of the valve plate from the valve horizontal plane direction is expanded. For this reason, even after the valve plate moves to the valve seat along the valve shaft by the valve closing operation, it is necessary to change the posture so that the valve plate is parallel to the valve seat, and the valve is closed from the time when the valve should be closed. It takes a long time to reach, and the backflow increases. That is, there arises a problem that the sealing performance is deteriorated during reverse flow.

  As described above, the first countermeasure means for reducing the diameter of the valve plate has a problem in that it is impossible to simultaneously reduce the flow resistance during forward flow and improve the sealing performance during reverse flow.

  Then, as a 2nd countermeasure means which solves the problem in the said 1st countermeasure means, the flapper type one-way valve disclosed by Example 13 of patent document 1 is mention | raise | lifted, for example. This is to provide a notch cut into the outer edge of the valve plate in order to increase the cross-sectional area of the outer edge gap. Such a shape is defined as a shape in which there is a straight line connecting two points inside the valve plate shape that intersects the outer edge of the valve plate, and is hereinafter referred to as a “concave shape”. If the diameter of the original disc without a notch is close to the diameter of the valve region cross-sectional circle, both the reduction of the flow resistance of the outer edge gap and the reduction of the eccentric amount of the valve plate can be realized by this means. By the way, when the flow changes from the forward flow to the reverse flow, the valve body usually collides with the valve seat and shifts to the valve closed state. At that time, a large impact force is applied to the valve body. For this reason, in the concave valve plate, a large stress concentration occurs at the bottom of the notch. As a result, there is a problem that the risk of crack generation starting from the notch bottom is increased and the reliability of the structural strength is lowered.

  An object of the present invention is to provide a flapper type one-way valve that solves the above three problems at the same time, and to improve the performance of a fluid system including a fluid machine including the one-way valve.

  In order to solve such a problem, the one-way valve according to the present invention is the upstream region side section among the connection flow paths connecting the two fluid regions of the upstream region and the downstream region where the working fluid exists. A valve area in which a section closer to the downstream area than the valve inflow path and the valve inflow path is enlarged in a columnar shape, a valve area bottom surface which is an end portion of the valve area on the valve inflow path side, and the valve in the valve inflow path An annular valve seat surface perpendicular to the valve shaft, which is the central axis of the valve region, around the valve inlet that is the region side end, and disposed in the valve region closer to the downstream region than the valve seat surface A retainer surface, a valve plate having a shape and dimension that can be inherent in a valve region cross-sectional circle that is a cross section perpendicular to the valve axis of the valve region, and between the valve seat surface and the retainer surface in the valve region A one-way valve comprising: a valve plate that is placed in a valve inner region that is the valve region; A valve contour line that is an outer edge line of the plate, a two-dimensional shape surrounded by the valve contour line is a convex shape and rotationally symmetric with respect to the centroid, and the valve contour line is a radius of the valve region cross-sectional circle A large-diameter portion that is a linear portion having a radius of curvature larger than the region radius A, and a small-diameter portion that is a linear portion having a radius of curvature smaller than the valve region radius including a corner portion, and any on the small-diameter portion A normal circle drawn from a point and the normal point is perpendicular to the large-diameter portion to form an intersection point, and the general diameter that is the distance between the arbitrary point and the intersection point is always the same, and the general circle The diameter should be larger by a certain amount of expansion than the sum of the valve region radius, which is the cross-sectional circle radius of the valve region, and the valve seat inner radius, which is the maximum distance between the inner edge line of the valve seat surface and the valve shaft. Features.

  Moreover, the fluid system including the fluid machine according to the present invention includes the one-way valve.

  According to the present invention, there is provided a one-way valve having high rectification operability that has high reliability of structural strength because there is no stress concentration portion, and that reduces flow resistance during forward flow and improves sealing performance during reverse flow. , High performance of a fluid system including a fluid machine including the same can be realized.

1 is a longitudinal sectional view of a one-way valve in Embodiment 1. FIG. The cross-sectional view of the one-way valve of Example 1 (AA cross section of FIG. 1). The geometric explanatory drawing of the valve outline which is a valve-plate outer edge line of the one-way valve of Example 1. FIG. The top view of the valve plate of the one-way valve of Example 1. FIG. The relationship between the rotational frequency of the valve plate of the one-way valve of Example 1 and the area. The relationship between the number of rotational symmetry of the valve plate of the one-way valve of Example 1 and the amount of eccentricity. The top view of the valve plate of the one-way valve of Example 2. FIG. The relationship between the radius r of the small circular arc part of the valve plate of the one-way valve of Example 3, and an area. The relationship between the small circular arc part radius r of the valve plate of the one-way valve of Example 3, and the amount of eccentricity. The top view of the valve plate of the one-way valve of Example 3. FIG. The top view of the valve plate of the one-way valve of Example 4. FIG. The top view of the valve plate of the one-way valve of Example 5. FIG. The top view of the valve plate of the one way valve of Example 6. FIG. The cross-sectional view of the one-way valve of Example 7 (AA cross section of FIG. 1). FIG. 10 is a longitudinal sectional view of a one-way valve according to an eighth embodiment. 10 is a longitudinal sectional view of a scroll compressor including first to eighth one-way valves according to Embodiment 9. FIG. FIG. 17 is a partial enlarged cross-sectional view of the vicinity of a bypass valve and a back pressure valve (near T portion in FIG. 16) of the scroll compressor of Example 9.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

  A flapper type one-way valve V, which is a kind of one-way valve according to the first embodiment, will be described with reference to FIGS. 1 is a longitudinal sectional view of a one-way valve according to a first embodiment. FIG. 2 is a cross-sectional view of the one-way valve (cross section AA in FIG. 1). FIG. 3 is a geometric explanatory diagram of a valve outline that is a valve plate outer edge line of the one-way valve. FIG. 4 is a plan view of the valve plate of the one-way valve. FIG. 5 shows the relationship between the number of rotational symmetry and the area of the valve plate of the one-way valve. FIG. 6 shows the relationship between the number of rotational symmetry of the valve plate of the one-way valve and the amount of eccentricity.

  First, the configuration of the flapper type one-way valve V will be described with reference to FIGS. 1 and 2. A connection flow path formed by a valve inflow path 203 and a valve area 204 that connects the two areas is provided in the blocking area 200 that partitions the upstream area 201 and the downstream area 202. Here, the valve region 204 is installed closer to the downstream region 202 than the valve inflow passage 203 and has a shape in which the diameter of the valve inflow passage 203 is expanded in a columnar shape. An annular valve seat surface 205 is provided around the valve inlet 203a which is the valve region side end of the valve inflow passage 203 at the valve region bottom surface which is the valve inflow passage side end of the valve region 204. The valve seat surface 205 is perpendicular to the valve shaft 204 a that is the central axis of the valve region 204. Then, an N-shaped circular valve plate 3N0, which is a valve plate having a shape and dimension that can be mounted on the valve seat surface 205, is inserted. More specifically, the shape dimension that can be mounted on the valve seat surface 205 means that it is included in a valve region sectional circle 204c that is a circle in a section perpendicular to the valve shaft 204a of the valve inner region 204b. The N-shaped circular valve plate 3N0 will be described in detail later. After inserting the N-shaped circular valve plate 3N0, a retainer 206 is provided on the downstream region 202 side of the N-shaped circular valve plate 3N0 so as to define the maximum distance from the valve seat surface 205 in the direction of the valve shaft 204a of the N-shaped circular valve plate 3N0. Arrange. Thereby, an in-valve region 204b in which the N-shaped circular valve plate 3N0 is movable by a finite distance in the direction of the valve shaft 204a is formed. Normally, the retainer 206 is fixedly arranged with respect to the valve seat surface 205 by being fixedly arranged in the blocking region 200. However, in some cases, the retainer 206 is substantially movable only in the direction of the valve shaft. The installation method may be such that the range is limited. Here, in the retainer 206, a surface defining the maximum distance from the valve seat surface 205 of the N-shaped circular valve plate 3N0 is referred to as a retainer surface 206a. In the case of the present embodiment, the tip of the protrusion at the center of the lower surface of the retainer 206 corresponds to the retainer surface 206a. The retainer 206 is provided with a plurality of retainer holes 206b penetrating therethrough. Since these are installed around the central discharge part with the retainer surface 206a, even when the N-shaped circular valve plate 3N0 is in the open state where it floats most from the valve seat surface 205, it is downstream of the valve inner region 204b. Since the region 202 can maintain the communication, the flow of the working fluid is not hindered.

  Next, referring to FIG. 3, the N-shaped circular valve plate 3N0 to be introduced into the flapper type one-way valve V will be described. The geometrical description of the N-square circle 3N0a, which is a two-dimensional shape having the valve outline of the N-square circle valve plate 3N0 as an outline, will be mainly described. The outline of the N-square circle 3N0a is a closed curve formed by alternately connecting arcs of two radii N times (however, odd numbers of 3 or more). Here, out of two arcs of radius, an arc with a small radius r (including a case of r = 0 as a special case) is a small arc part 3N0d which is a small diameter part, and an arc with a large radius R is a large diameter part. It is called a certain large arc portion 3N0e. The N-cornered circle 3N0 is a figure that is N-fold symmetric about the N-corner centroid 3N0b. Furthermore, all the connection points of the small arc portion 3N0d and the large arc portion 3N0e are smoothly connected (however, when r = 0, there is no small arc portion 3N0d, so the condition of smooth connection is omitted). . Here, the smooth connection means that the derivative is continuous. In this case, since the two curves to be connected are both arcs, the center of both arcs is on the normal of the connection point.

  A drawing method of the N-square circle 3N0a, which is a two-dimensional figure that satisfies the above conditions, will be described with reference to FIG. It is a regular N-gon in the N-square circle 3N0a, and the length L of one side is

Consider an N-square inner polygon 3N0c. Since the N-cornered polygon 3N0c is a regular polygon, the base angle φ of the isosceles triangle formed by one vertex, a vertex adjacent to the vertex, and the centroid of the N-cornered polygon 3N0c is

It becomes. Using these relationships, adjacent vertices can be obtained one after another from one vertex, and an N-square circle-containing polygon 3N0c is finally drawn. Next, a small circular arc portion 3N0d and a large circular arc portion 3N0e are drawn with the vertex being such that a straight line passing through each vertex of the N-square circle 3N0c and the centroid is a symmetric line. And the range of those angles is that the vertical angle θ of the sector formed by these arcs is

Draw as follows. Here, the small arc portion 3N0d is drawn on the countercentric side when viewed from the apex, and the large arc portion 3N0e is drawn on the centroid side when viewed from the apex. By similarly performing this drawing at each of the N vertices, all the small arc portions 3N0d and the large arc portion 3N0e are smoothly connected, and the outline of the N-cornered circle 3N0a, which is a closed curve, is drawn. The N-corner centroid 3N0b of the N-corner circle 3N0a drawn in this way clearly coincides with the centroid of the polygon N3c in the N-corner circle. Further, the N-angle circle 3N0a is clearly N-fold symmetric about the N-angle circle centroid 3N0b. Furthermore, it becomes clearly a convex shape. Here, the convex shape is a shape that is not the concave shape, and when originally defined, is a shape in which all straight lines connecting the two internal points do not intersect the valve outline.

  The N-angle circle having the closed curve as the outer shape as described above is the normal line drawn from an arbitrary point on a small arc portion 3N0d to the inner side of the N-circle circle, and the N-square circle is the center of the small arc portion 3N0d. It is clear from the above drawing method that the polygon 3N0c passes through one vertex of the polygon 3N0c and is orthogonal to the large arc portion 3N0e on the opposite side. It is also clear that the distance between the arbitrary point on the small arc portion 3N0d and the intersection of the large arc portion 3N0e is r + R. This relationship is established at an arbitrary point on the small arc portion 3N0d. That is, when an N-angle circle is sandwiched between calipers, the measured value of r + R is always shown. Henceforth, the value of r + R is called "general diameter". Since the “general diameter” of the N-angle circle is a constant value no matter where it is measured, the figure set to which the N-angle circle belongs is called “general circle”. And this time, this general diameter is set to the valve seat inner radius ZI which is the maximum distance from the valve shaft 204a among the valve region sectional radius A, the inner edge line 205a of the valve seat surface and the inner edge line 205a (a circle having a radius of ZI). A + ZI + OV, which is larger than the sum of the “valve seat circle” 205a ′) by a certain expansion amount OV. That is,

R and R are determined so that the following relationship holds. FIG. 4 is an enlarged view when the unit is mm and r = 0.5, R = 6, N = 5, A = 3.75, ZI = 1.9, and OV = 0.85. This flapper type one-way valve V uses a pentagonal valve plate 350. Since the pentagonal valve plate 350 moves freely in the valve horizontal plane, the pentagonal valve plate 350 is normally in contact with the side surface of the valve region at two locations as shown in FIG. 4 (∵ R> A). Further, since R> A, the large arc portion 350e does not contact the circular region cross-sectional circle 204c, and all the contacts are the small arc portions 350d. Since the normal of the contact always passes through the valve shaft 204a, which is the center of the circular region cross-sectional circle 204c, the pentagonal valve plate 350 is a circle having a radius of ZI + OV from the valve shaft 204a (hereinafter, “ It can be seen that the reference circle “208” is necessarily covered. That is, it can be seen that even when the seal width is the smallest, sealing is possible during backflow with a margin of the expansion amount OV. This is the same as the conventional flapper type one-way valve V ′ using a circular valve plate having a diameter of r + R.

  Next, a flapper type one-way valve V using an N-shaped circular valve plate is replaced with a conventional flapper type one-way valve V ′ using a circular valve plate having a circle having a diameter equal to the general diameter as a valve outline. The following two points are compared. The first point is the outer edge clearance area representing the degree of forward flow path resistance reduction. The second point is the amount of eccentricity representing the degree of flow resistance reduction during forward flow and the degree of sealability during reverse flow. Since the outer edge clearance area at the first point can be obtained by subtracting the area of the N-cornered circle from the area of the circular region cross-sectional circle, the area S of the N-square circle was derived. An equation for the eccentricity G was also derived. Here, the amount of eccentricity G differs between R> A and R ≦ A because the contact state with the maximum amount of eccentricity differs.

  FIG. 5 shows an area S (formula (5)) and an outer edge clearance area when N (hereinafter referred to as “number of corners”) among the parameters of the pentagonal circle shown in FIG. 4 is changed. FIG. 6 shows the amount of eccentricity G when R is changed (since R> A, equation (6)). From this, it can be seen that as N increases, S increases and G also increases. And it turns out that it approaches the conventional flapper type one-way valve V 'using a circular valve plate suddenly. Thus, the flapper type one-way valve V using a generally circular valve element has a larger outer edge clearance area and a smaller amount of eccentricity than the conventional flapper type one-way valve V ′. Therefore, as described above, it can be seen that the structure strength reliability can be improved due to the convex shape as well as the performance of the rectifying operation by reducing the flow resistance at the forward flow and the sealing performance at the back flow.

  At the same time, FIGS. 5 and 6 show that the outer edge clearance area is the largest and the amount of eccentricity is smaller when N = 3 than when N = 5 in the present embodiment.

  A flapper type one-way valve V, which is a kind of one-way valve according to the second embodiment, will be described with reference to FIG. 7 which is a plan view of a valve plate of the one-way valve.

  Since it is the same as that of Example 1 except using the triangular valve plate 330 as N = 3 shown at the end of above-mentioned Example 1, description other than N = 3 is abbreviate | omitted. It can be seen from FIGS. 5 and 6 that when N is changed from 5 to 3, S decreases rapidly and G also decreases abruptly. Therefore, the flapper type one-way valve V using the three-way circular valve plate 330 has a larger outer edge clearance area and is more eccentric than the conventional flapper type one-way valve V ″ using the circular valve plate. The amount is even smaller. Therefore, as described above, there is an effect that the flow path resistance at the time of forward flow can be further reduced, the sealing performance at the time of reverse flow can be further improved, and the performance of the rectifying operation can be further improved.

  A flapper type one-way valve V, which is a kind of one-way valve according to the third embodiment, will be described with reference to FIGS. FIG. 8 shows the relationship between the radius r of the small arc portion of the valve plate of the one-way valve of Example 3 and the area, and FIG. 9 (the solid line portion is drawn by equation (6) and the broken line portion is drawn by equation (7)). Is the relationship between the radius r of the small arc portion of the valve plate of the one-way valve and the amount of eccentricity, and FIG. 10 is a plan view of the valve plate of the one-way valve. Since it is the same as that of the second embodiment except that a sharp triangular valve plate 331 in which r is reduced to the limit 0 and R is increased to the maximum is used, description other than the operational effect by r = 0 is omitted. To do.

  From FIG. 8 and FIG. 9, it can be seen that as r is decreased, S decreases rapidly and G also decreases abruptly. Therefore, the flapper type one-way valve V using the sharp triangular valve plate 331 has a larger outer edge clearance area than the conventional flapper type one-way valve V ′ using the circular valve plate. The amount of eccentricity becomes even smaller, and in the case of the present embodiment, it becomes almost zero. Therefore, as described above, there is an effect that the flow path resistance at the time of forward flow can be further reduced, the sealing performance at the time of reverse flow can be further improved, and the performance of the rectifying operation can be further improved. Furthermore, since the sharp triangular valve plate 331 has a shape close to an equilateral triangle, it is possible to reduce the end material when removing the valve plate from the seat, and there is also an effect of cost reduction.

  A flapper type one-way valve V, which is a kind of one-way valve of Embodiment 4, will be described with reference to FIG. FIG. 11 is a plan view of the valve plate of the one-way valve of the fourth embodiment, except that a round triangular valve plate 332 in which R is increased while R is smaller than A is used. Therefore, the description other than the effect of increasing r is omitted.

  Since the small arc portion is a portion in contact with the valve region side surface, if r is small, there is a risk that the frictional force with the valve region side surface becomes large. In this embodiment, since r is increased, the risk is reduced, the vertical movement of the valve body is smoothed, and the operation delay of the valve opening / closing operation is reduced. Therefore, there is an effect that the performance of the rectifying operation can be improved.

  A flapper type one-way valve V, which is a kind of one-way valve of Embodiment 5, will be described with reference to FIG. FIG. 12 is a plan view of the valve plate of the one-way valve of the fifth embodiment. While r is slightly increased, R is slightly decreased and a valve hole 333f is provided at a position (shaded portion) that does not cover the reference circle 208. Since the third embodiment is the same as the second embodiment except that the holed triangular valve plate 333 is used, the description other than the effect obtained by slightly increasing r and providing the hole is omitted.

  In Example 2, since r was smaller, the frictional force with the side surface of the valve region was increased. In order to avoid the risk of this frictional force increase, r is slightly increased, and reduction of the outer edge clearance area (see FIG. 8), which is a harmful effect caused by the increase of r, is suppressed by the valve hole 333f. is there. As a result, the vertical movement of the valve body is smooth, and the operation delay of the valve opening / closing operation is reduced. Furthermore, there is an effect that the performance of the rectifying operation can be improved by expanding the outer edge flow path area.

Example 6 A flapper type one-way valve V which is a kind of one-way valve will be described with reference to FIG. FIG. 13 is a plan view of the valve plate of the one-way valve of the sixth embodiment. The cut 3 is set with a cut portion 334g indicated by cross-hatching in which a portion that does not contact the side surface of the valve region is offset by the maximum amount OV. Since it is the same as that of Example 5 which closed the hole except using the square valve plate 334, description of the effect other than having provided the cut part is abbreviate | omitted. As a result, the outer edge clearance area can be greatly increased without changing the eccentricity while securing the seal. As a result, the flow path resistance during forward flow can be greatly reduced, and the performance of the rectifying operation can be improved. Here, when the cut portion 334g has an inner convex shape (defined by the offset line 334a), the outer edge clearance area can be increased to the maximum, and the flow path resistance during forward flow can be reduced to the maximum. On the other hand, when the linear offset 334a ′ is used so that the cut portion 334g is only a rough cross-hatched portion, the cut triangular disc 334 has a convex shape, and therefore there is no stress concentration portion, and reliability in structural strength. There is an effect that can be secured.

  A flapper type one-way valve V, which is a kind of one-way valve in Embodiment 7, will be described with reference to FIG. FIG. 14 is a cross-sectional view of the one-way valve of the seventh embodiment. The inner edge line of the valve seat is a non-circular non-circular valve seat inner edge line 215a, and the shape of the valve seat inner circle is different from the inner edge line of the valve seat. This is the case of the valve seat inner circle 215 ′. Since it is the same as that of Example 1 thru | or Example 6 except setting it as such a non-uniform | annular annular shape non-uniform | annular annular valve seat 215, it demonstrates except the change of the action operation by non-uniform | heterogenous valve seat shape. Is omitted.

  Since the area of the valve seat can be increased, there is an effect that the sealing performance at the time of backflow can be improved.

  A flapper type one-way valve V, which is a kind of one-way valve in Embodiment 8, will be described with reference to FIG. FIG. 15 is a longitudinal sectional view of a one-way valve according to an eighth embodiment, in which a helical valve body spring 207 is provided between the retainer 206 and the N-shaped circular valve plate 3N0. When there is such a valve body spring, it is a one-way valve that also sets the conditions for opening the valve. When the spring is compressed and inserted, the pressure difference between the upstream region 201 and the downstream region 202 is set. In such a case, it is necessary to prevent the valve spring 207 from coming off the N-shaped circular valve plate 3N0 in addition to the previous embodiments. For this reason, when the spring outer radius B which is the outer radius of the valve spring is larger than the valve seat inner radius ZI, the valve seat inner radius ZI is replaced with the spring outer radius B, and the spring outer radius B is If it is larger than the outer radius ZO, the valve seat outer radius ZO may be replaced with the spring outer radius B. Thereby, since the valve body spring 207 can be prevented from being detached from the N-shaped circular valve plate 3N0, there is an effect that the pressure setting which the valve body spring 207 bears can be ensured.

<Scroll compressor as an example of fluid system>
Next, a ninth embodiment in which the one-way valve of the first to eighth embodiments is mounted on a scroll compressor of a fluid system will be described with reference to FIGS. 16 and 17. FIG. 16 is a longitudinal sectional view of the scroll compressor 1 according to the ninth embodiment. FIG. 17 is a partial enlarged cross-sectional view of the vicinity of the bypass valve and the back pressure valve (near S part in FIG. 16) of the scroll compressor 1. A flapper type one-way valve of the type having a valve spring in the above-described embodiment is mounted on these bypass valve and back pressure valve. Here, since the valve spring used for the bypass valve is hardly compressed, it is substantially close to no spring. Incidentally, the diameter of the scroll compressor 1 of Example 9 is, for example, about 10 mm to 1000 mm.

  As shown in FIGS. 16 and 17, the scroll compressor 1 according to the ninth embodiment includes main components of a fixed scroll 2, an orbiting scroll 3, a frame 4, an Oldham ring 5 (see FIG. 17), a crankshaft 6, and a motor 10. Is sealed with a casing 8.

  Of these, the orbiting scroll 3 has an orbiting lap 3b standing on the upper surface of the orbiting end plate 3a, and a pin portion 6a that is an eccentric portion of the crankshaft 6 is inserted into the orbiting bearing 23 on the rear surface. The orbiting scroll 3 is adapted to orbit as the crankshaft 6 that is rotatably supported by the main bearing 24 rotates.

  On the other hand, the fixed scroll 2 has a fixed wrap 2b erected on the lower surface side of the fixed end plate 2a, and a fixed base plate 2q is disposed around the fixed wrap 2b. The fixed wrap 2b and the swirl wrap 3b are engaged with each other, and a compression chamber 100 is formed between them.

  Further, the fixed scroll 2 is provided with a suction port 2s, into which a suction pipe 50 for introducing working fluid from the outside of the scroll compressor 1 into the fixed scroll 2 is press-fitted, and the check valve 21 is connected to the suction pipe 50. It is provided at the bottom. This is to prevent the backflow of the working fluid immediately after the scroll compressor 1 is stopped. A discharge hole 2 d is formed near the center of the fixed scroll 2.

  Further, a bypass hole 2e that penetrates the fixed end plate 2a is formed around the discharge hole 2d in the fixed scroll 2 so as to connect the compression chamber 100 and the fixed back chamber 120 (see FIG. 17). The bypass hole 2e is provided with a one-way valve bypass valve which will be described in detail later. Further, a U-shaped back pressure hole 2g that connects the peripheral groove 2p provided on the lower surface of the fixed base plate 2q and the compression chamber 100 is formed. This is a passage connecting the back pressure chamber 110 (described later) and the compression chamber 100 formed on the lower surface side of the fixed base plate 2q (see FIG. 17). The back pressure hole 2g is provided with a back pressure valve of a one-way valve which will be described in detail later.

  In the fixed scroll 2 having the above-described configuration, the Oldham ring 5 (see FIG. 17) and the crankshaft 6 are attached to the frame 4, and the outer side portion of the fixed base plate 2q is fixed to the frame 4 with screws. Thus, a back pressure chamber 110 is formed on the back surface of the orbiting scroll 3 (between the orbiting scroll 3 and the frame 4). The Oldham ring 5 is disposed between the frame 4 and the orbiting scroll 3 in order to prevent the orbiting scroll 3 from rotating.

  The crankshaft 6 is formed with an oil supply hole 6b penetrating vertically, and an oil supply pipe 6x is press-fitted into the lower end. In addition, a shaft balance 80 and a counterbalance 82 are fixedly arranged below the frame 4 of the crankshaft 6 for rotational balance.

  The auxiliary bearing 25 is composed of a ball 25a and a ball holder 25b fixedly disposed on the lower frame 35, and is configured such that no contact occurs even if the crankshaft 6 is bent.

  The motor 10 includes a rotor 10 a fixed to the crankshaft 6 and a stator 10 b that is shrink-fitted, press-fitted, or welded to the cylindrical casing 8 a, and a hermetic terminal 220 that is a motor wire that supplies power to the motor 10. It is connected.

  The casing 8 includes a cylindrical casing 8a, an upper casing 8b welded to the upper part of the cylindrical casing 8a, and a bottom casing 8c welded to the lower part of the cylindrical casing 8a. The frame 4, the crankshaft 6, the motor 10 and the like are surrounded.

  In the cylindrical casing 8a, the frame 4 is welded and fixedly arranged inside, the discharge pipe 55 is fixedly arranged on the side surface, and the lower frame 35 that supports the auxiliary bearing 25 is fixedly arranged on the lower part. A groove extending in the vertical direction is formed in the outer peripheral portion when the fixed scroll 2 is screwed to the frame 4, and the fixed back chamber 120 and the other internal space of the casing 8 communicate with each other through this groove. . Further, a suction pipe 50 press-fitted into the hermetic terminal 220 and the fixed scroll 2 is fixedly arranged in the upper casing 8b. Further, oil is sealed in the casing 8 at an appropriate stage of assembly. Thereby, the oil storage part 125 is formed at the bottom of the casing 8.

  Next, the operation of compressing the working fluid in the scroll compressor 1 will be described. The orbiting scroll 3 orbits by the crankshaft 6 rotated by the motor 10, and a compression chamber 100 is formed between the orbiting scroll 3 and the fixed scroll 2. Along with this, the working fluid flows from the suction pipe 50 into the compression chamber 100, and the volume is reduced to be compressed and become high pressure. Thereafter, the working fluid flows out from the discharge hole 2d and the bypass hole 2e to the fixed back chamber 120. As described above, the fixed back chamber 120 is connected to the other internal space of the casing 8, so that the entire internal area of the casing 8 serves as the discharge pressure. Finally, the working fluid is discharged to the outside from the discharge pipe 55 connected to the upper space of the motor 10.

  Next, the flow of oil will be described. The oil in the oil storage part 125 is supplied from the oil storage part 125 to the oil supply pipe 6x and the crankshaft 6 by the differential pressure between the discharge pressure (pressure inside the casing 8) and the back pressure (pressure inside the back pressure chamber 110). After the slewing bearing 23 and the main bearing 24 are lubricated through the hole 6b, they flow into the back pressure chamber 110. Here, since the pressure in the orbiting bearing chamber 115 above the pin portion 6a becomes the discharge pressure, it plays a role of pressing the orbiting scroll 3 against the fixed scroll 2. Further, the auxiliary bearing 25 is supplied with oil from the oil supply hole 6b by centrifugal force. Since the pressure of the oil before flowing into the back pressure chamber 110 is the discharge pressure, the pressure of the back pressure chamber 110 is increased by the inflow of the oil. In addition, since the working fluid is always dissolved in the oil (in most cases, the mass concentration is 10% or more), the working fluid is rapidly gasified (foamed) from the oil by the pressure reduction caused by the flow into the back pressure chamber 110. ) When the working fluid is gasified, the volume increases by one digit or more. For this reason, in most cases, the oil in the back pressure chamber 110 becomes a mist state in which fine oil droplets float in the gasified working fluid and is dispersed throughout the back pressure chamber 110. There is an oil supply path to the back pressure chamber 110 as described above. This is a back pressure chamber fluid introduction path. Thereby, the Oldham ring 5 shown in FIG. 2 is lubricated. Thereafter, the oil flows into the compression chamber 100 through the back pressure hole 2g provided with the back pressure valve 7 on the way. As a result, the sealing performance of the compression chamber 100 is improved, leakage during compression is suppressed, and the compressor efficiency is improved. Then, it discharges to the fixed back chamber 120 with a working fluid, mixing with the working fluid in the compression chamber 100 in a mist state. The oil adheres to the inner wall of the casing 8 and the elements in the casing and is separated from the working fluid, and then returns to the oil storage part 125 at the bottom of the scroll compressor 1 through the attached inner wall and elements of the casing.

  Next, the bypass valve 9 provided in the bypass excavation 2f that is the valve region will be described in detail with reference to FIG. In the bypass excavation 2f, a bypass valve plate 9a, which is an N-square circle plate (in particular, a triangle circle), is disposed. A bypass valve seat 9b that abuts the bypass valve plate 9a is provided at the bottom of the bypass digging 2f. The bypass valve plate 9a is pressed against the bypass valve seat 9b with a very small load by the bypass valve spring 9c. The upper end of the bypass valve spring 9c is inserted into the protrusion of the spring retainer 9d. Then, the upper surface of the spring retainer 9d is pressed by the presser plate 9f. Thereby, the spring retainer 9d is positioned. The spring retainer 9d and the retainer plate 9f are provided with holes that penetrate vertically. As described above, the bypass valve 9 of the flapper type one-way valve using the N-shaped circular valve plate as the valve plate is configured. As is clear from the configuration described above, the bypass valve 9 opens when the pressure in the compression chamber 100 that is the upstream region becomes equal to or higher than the discharge pressure (pressure in the fixed back chamber 120 that is the downstream region).

  Accordingly, the bypass valve 9 performs an opening / closing operation so that the pressure in the compression chamber 100 facing the bypass hole 2e does not exceed the discharge pressure. Thus, over-compression is suppressed under over-compression conditions, and the effect of improving the efficiency of the scroll compressor 1 is achieved. In addition, there is an effect that liquid compression that occurs depending on the operating condition is avoided, damage to the fixed wrap 2b and the turning wrap 3b is prevented, and reliability of the scroll compressor 1 is improved. This time, since the bypass valve plate 9a is an N-shaped circle (especially a triangular circle), the performance of the rectification operation is improved, and over-compression can be further suppressed, and liquid compression can be further avoided, so that The reliability can be improved.

  Further, as shown on the right side of FIG. 17, the fixed scroll 2 is provided with a back pressure valve flow path. The back pressure valve channel serves to discharge the oil that has flowed into the back pressure chamber 110 to the compression chamber 100. At the same time, the pressure (back pressure) in the back pressure chamber 110 is controlled by the back pressure valve 7 in the middle. This back pressure valve flow path passes through the back pressure chamber hole 2g facing the back pressure chamber 110 through the peripheral groove 2p, the back pressure digging 2h opened from the upper surface side of the fixed scroll 2, and the back pressure communication passage 2i. Finally, it merges into the outermost bypass hole 2e1 and is connected to the compression chamber 100. That is, the back pressure valve flow path allows the back pressure chamber 110 and the compression chamber 100 to communicate with each other.

  Next, the configuration of the back pressure valve 7 will be described. The back pressure valve 7 is a flapper type one-way valve. First, a back pressure valve seat 7b which is an N-square (particularly triangular) valve plate is provided at the bottom of the back pressure dig 2h which is a valve region. The back pressure valve plate 7a is placed on the back pressure valve seat 7b. The back pressure valve plate 7a is pressed against the back pressure valve seat 7b by a back pressure valve spring 7c. This pressing load is set to a predetermined value. A value obtained by dividing this value by the inner area of the seal portion of the back pressure valve seat 7b is a differential pressure set by the back pressure valve. The optimum value of the differential pressure is set to a value, because if a bypass valve flow path that suppresses overcompression is installed, it is derived from force balance calculation that it becomes a constant value even during a wide range of operation. The set differential pressure is determined by the compression amount of the back pressure valve spring 7c. In this embodiment, the value is determined by the amount of insertion of the back pressure valve cap 7d serving as a retainer for inserting the upper end of the back pressure valve spring into the back pressure digging 2h. The back pressure valve 7 is configured as described above.

  As a result, the back pressure valve flow path has a back pressure (back pressure in the upstream area) that is higher than the average pressure in the compression chamber 100, which is the downstream area where the back pressure valve flow path, by the differential pressure set by the back pressure valve 7. The pressure in the chamber 110). By such an operation of the back pressure valve 7, the back pressure is higher than the suction pressure that is the pressure in the suction port 2 s and the suction region 95, and maintains an intermediate pressure that is lower than the discharge pressure that is the pressure of the discharge hole 2 d. It has become. As a result, the back pressure chamber 110 is one of the pressing force generating means for pressing the orbiting scroll 3 against the fixed scroll 2 together with the orbiting bearing chamber 115 having a discharge pressure described later.

  Further, the back pressure valve 7 controls the back pressure to an intermediate pressure by the above-described operation, and presses the orbiting scroll 3 against the fixed scroll 2 with an appropriate force. Thereby, there is an effect that the thrust loss of the end plate portion is reduced and the compressor efficiency is improved. This time, because the back pressure valve body uses an N-shaped circle (especially a triangular circle), the performance of the rectifying operation is improved, and the back pressure is set to an ideal value such as the pressure in the compression chamber 100 in the downstream region + a constant value. The shape can be close to. Thereby, there is an effect that the thrust loss can be reduced under all operating conditions, and the performance of the scroll compressor can be improved over the entire area.

  The scroll compressor 1 which concerns on a present Example can be used as a compressor of the refrigerating-cycle apparatus which is a fluid system provided with the refrigerating cycle (heat pump cycle) provided with a compressor, a condenser, an expansion valve, and an evaporator. Note that examples of the refrigeration cycle apparatus include a heat pump water heater, a refrigerator, and an air conditioner. By using the scroll compressor 1 according to the present embodiment, the efficiency of the refrigeration cycle apparatus is improved.

V Flapper type one-way valve 1 Scroll compressor 2 Fixed scroll 2a Fixed end plate 2b Fixed lap 2e Bypass hole 2f Bypass digging 2g Back pressure hole 2h Back pressure digging 3 Rotating scroll 3a Rotating end plate 3b Rotating wrap 4 Frame 6 Crankshaft 7 Back Pressure valve 7a Back pressure valve plate 7b Back pressure valve seat 7c Back pressure valve spring 7d Back pressure valve cap 9 Bypass valve 9a Bypass valve plate 9b Bypass valve seat 9c Bypass valve spring 9d Spring presser 100 Compression chamber 110 Back pressure chamber 125 Oil storage portion 200 Shielding region 201 Upstream Region 202 Downstream region 203 Valve inflow passage 204 Valve region 204a Valve shaft 204b Valve inner region 204c Circular region cross-sectional circle 205 Valve seat surface 205a Valve seat inner edge line 205a 'Valve seat inner circle 205b Valve seat outer edge line 205b' Valve seat outer circle 206 Retainer 206a Retainer surface 207 Valve spring 208 Reference circle 3N0 N 3N0a N-angle circle 3N0b N-angle circle centroid 3N0c N-angle inner polygon 3N0d N-angle circle small diameter portion 3N0e N-angle circle large diameter portion 350 5-corner circle valve plate 330 Triangle circle valve plate 331 Pointed triangle circle Valve plate 332 Round triangle valve plate 333 Hole triangle valve plate 334 Cut triangle valve plate

Claims (9)

Of the connection flow paths connecting the two fluid regions, the upstream region and the downstream region where the working fluid exists, the upstream side region of the valve inflow passage and the portion closer to the downstream region than the valve inflow passage are cylindrical. An expanded valve area,
A valve region bottom surface which is an end portion of the valve region on the valve inflow path side;
An annular valve seat surface perpendicular to the valve shaft that is the central axis of the valve region around the valve inlet that is the end of the valve region on the valve region side;
A retainer surface disposed closer to the downstream region than the valve seat surface in the valve region;
A valve plate having a shape and dimension that can be inherent in a valve region cross-sectional circle that is a cross section perpendicular to the valve axis of the valve region;
A valve plate disposed in the valve region, which is the valve region between the valve seat surface and the retainer surface in the valve region;
In a one-way valve consisting of
A two-dimensional valve outline figure having an outer shape of the valve outline that is the outer edge of the valve plate is convex and rotationally symmetric with respect to the centroid, and the valve outline is the radius of the valve region cross-sectional circle. A small-diameter portion that is a linear portion having a radius of curvature smaller than the valve region cross-sectional radius A, a large-diameter portion having a radius of curvature larger than the radius of curvature of the small-diameter portion, and an arbitrary point on the small-diameter portion and the arbitrary point The normal drawn from is perpendicular to the large diameter portion to form an intersection, and the general diameter that is the distance between the arbitrary point and the intersection is always the same, and the general diameter is the valve. A one-way valve characterized in that it is made larger by a constant expansion amount OV than a sum of a region cross-sectional radius A, a valve seat inner radius ZI which is a maximum distance between an inner edge line of the valve seat surface and the valve shaft.   2. The one-way valve according to claim 1, wherein a radius of curvature of the large diameter portion is larger than a radius A of the valve region cross section.   3. The expansion amount OV is set to be equal to or less than a difference between a valve seat outer radius ZO that is a maximum distance between an outer edge line of the valve seat surface and the valve shaft, and the valve seat inner radius ZI. One-way valve as described.   In the general circle, all of the small diameter portions are small arc portions having the same value r including a curvature radius of 0, all of the large diameter portions are large arc portions having the same radius of curvature R, and The number of rotational symmetry N is an odd number of 3 or more, and a regular N-angle centroid with a side length of Rr and a straight line passing through each vertex are used as a line symmetry axis. Disposing the small arc portion having an apex angle of π / N radians on the opposite centroid side, and disposing the large arc portion having an apex angle of π / N radians from each apex to the centroid side of the N-angle; The one-way valve according to claim 2 or 3, wherein   The one-way valve according to claim 4, wherein the rotational symmetry number N is set to 3. 5.   An offset line in which the general circular inner side offset amount is equal to or less than the expansion amount at a line portion that does not contact the valve region side surface that is a circumferential surface of the valve inner region among the outer edge lines of the general circle. The one-way valve according to claim 5, wherein   The one-way valve according to claim 6, wherein the general circle has a convex shape.   A helical compression spring is provided between the retainer surface and the valve plate to urge the valve plate toward the valve seat surface, and an outer radius B of the helical compression spring is greater than an inner radius of the valve seat. Is larger than the valve seat outside radius B, and when the spring outside radius B is larger than the valve seat outside radius, the valve seat outside radius ZO is also outside the spring outside. The one-way valve according to claim 5, wherein the one-way valve is replaced with a radius B.   A fluid system comprising the one-way valve according to claim 1.