JP5734738B2 - Valve structure - Google Patents

Description

  The present invention relates to a valve structure that is opened and closed by engaging and disengaging a valve member with a seat member, and more particularly to a valve structure suitable for a poppet valve or the like that employs a tapered surface for the valve member or the seat member.

  In a valve structure such as a poppet type often used for a flow control valve, the engagement surface of the valve member with the seat member in order to ensure the sealing performance when the valve is closed or the required flow rate when the valve is opened. In many cases, the inner peripheral surface of the sheet member is a tapered surface.

  Such a valve structure can be suitably used for, for example, an EGR valve used in an exhaust gas recirculation system of an internal combustion engine. In this case, moisture contained in the exhaust gas recirculated to the intake system is condensed and condensed. In addition to being liable to generate liquid, sulfur compounds and the like in the exhaust gas are easily dissolved in the condensed water. Therefore, it is required to have a valve structure that can prevent the parts of the EGR valve from being corroded or the durability of the EGR valve from being deteriorated by strong acidic condensed water.

  As this type of conventional valve structure, for example, a structure in which the axis of the fluid passage on the upstream side of the engaging portion between the valve member and the seat member is inclined rather than horizontal or the mounting surface of the valve device is inclined is known. (For example, refer to Patent Document 1).

  Further, in a butterfly type valve structure, there is known a structure in which the inner wall surface of the passage in the vicinity of the valve member is used as a top portion and the inner wall surface of the front and rear passages is inclined (see, for example, Patent Document 2).

JP 09-151811 A Japanese Patent Laying-Open No. 2007-231826 (particularly FIG. 9)

  However, in the conventional valve structure as described above, when the valve member is in the valve closing position, an annular recess is formed between the seat member and the valve member so as to open upward. The seal part at the time of valve closing (henceforth a cyclic | annular seal line) was formed in the inner back side.

  Therefore, if the axis of the fluid passage is inclined so that the condensed water can easily flow from the vicinity of the valve member, a relatively large amount of acidic condensed water is present in the annular recess and on the lower side in the vertical direction (corrosion). Therefore, it is very difficult to prevent corrosion of the seat member and valve member forming the annular recess.

  Therefore, the present invention provides a compact valve structure that can prevent the condensed water from accumulating inside the annular recess and reliably prevent corrosion of the seat member and the valve member. is there.

  In order to solve the above problems, the valve structure according to the present invention is (1) an annular seat member that forms a valve hole, and a closed member that engages with an inner peripheral portion of the annular seat member to close the valve hole. A valve member disengaged from a valve position and an inner peripheral portion of the annular seat member to open the valve hole and displaceable to a valve opening position, and when the valve member is in the valve closing position, A valve structure in which an annular recess that is opened upward by the valve member and the valve member is formed, and the annular seat member and the valve member in the valve-closed position are located inside the annular recess. The valve hole is closed on the side, and the central axis of the annular seat member is inclined with respect to the vertical direction, and the lowermost side in the vertical direction among the upper surfaces of the annular seat member forming the annular recess In Part of the upper surface of the circumferential direction of location is characterized in that the opening angle is increased with respect to the center axis of the annular seat member compared to the top surface of the peripheral direction of the balance.

  With this configuration, in the present invention, since the upper surface of a part of the circumferential direction located on the lowermost side in the vertical direction has a larger opening angle than the upper surface of the remaining portion in the circumferential direction, the liquid is contained in the annular recess. When the liquid flows into the vicinity of the lowest point of the annular seal line on the inner side, the liquid annularly passes through the upper surface of a part of the annular sheet member in the circumferential direction from the flow starting point located in the vicinity. It becomes easy to be discharged to the outside of the recess. In addition, since the opening angle of the upper surface of the remaining portion in the circumferential direction can be small, it is not necessary to increase the diameter of the annular sheet member.

  In the valve structure of the present invention, it is preferable that (2) the top surface of a part of the annular seat member in the circumferential direction be the highest in the vertical direction in the vicinity of the radially inner end of the annular seat member. It has a point and has a vertical height equal to or less than the flow start point over the entire region outside the flow sheet start point in the radial direction of the annular sheet member. With this configuration, it is possible to prevent the condensed water from accumulating inside the annular recess while ensuring the processing and durability of the valve seal portion.

  In the valve structure according to the present invention, (3) a part of the upper surface in the circumferential direction of the annular seat member has a lower vertical height outside the radial direction with respect to the flow start point. preferable. Thereby, it can prevent reliably that condensed water accumulates in the inner back side of a cyclic | annular recessed part.

  In the valve structure of the present invention, (4) the upper surface of a part of the annular seat member in the circumferential direction is inclined over substantially the entire radial direction so that the height in the vertical direction becomes lower toward the outer side in the radial direction. It is preferable. As a result, even if liquid enters the annular recess, it is discharged by flowing down, and it is possible to reliably prevent the condensed water from accumulating inside the annular recess.

  In the valve structure of the present invention, (5) a notch groove extending in the radial direction of the annular seat member is formed in a part of the annular seat member in the circumferential direction, and an inner bottom surface of the notch groove is the annular seat member. It may be a part of the upper surface in the circumferential direction of the sheet member. In this case, by forming a notch groove in a part in the circumferential direction, it is possible to reliably prevent liquid from accumulating in the annular recess while suppressing the diameter of the annular sheet member.

  In the valve structure of the present invention, (6) the upper surface of the annular seat member extends radially outward from the inner periphery of the valve hole within a range excluding a part of the annular seat member in the circumferential direction. It is desirable that an annular inclined surface inclined with respect to the central axis of the valve hole is formed. In this case, the liquid entering the annular recess can be reliably collected in a part in the circumferential direction and discharged from the upper surface of a part in the circumferential direction to the outside of the annular recess.

  In the valve structure having the configuration of (6) above, (7) the central axis of the valve hole of the annular seat member is biased so as to deviate from the central axis of the outer peripheral surface of the annular seat member, An opening angle of the annular inclined surface with respect to the central axis of the valve hole may be increased on a part of the annular seat member in the circumferential direction. In this case, the diameter of the annular seat member can be suppressed while increasing the opening angle of the annular inclined surface with respect to the central axis of the valve hole in a part of the circumferential direction of the annular seat member.

  In the valve structure of the present invention, (8) a valve housing that further forms an upstream passage and a downstream passage before and after the valve hole and holds the annular seat member is provided, and the valve housing starts the flow down It is preferable to have an adjacent inner wall surface adjacent to a part of the upper surface in the circumferential direction of the annular sheet member at a vertical height below the point. In this case, the liquid entering the annular recess can be reliably discharged radially outward from the upper surface of the annular sheet member.

  According to the present invention, with respect to the central axis of the annular sheet member, the opening angle of a part of the upper surface in the circumferential direction located on the lowermost side in the vertical direction among the upper surfaces of the annular sheet member is set to the remaining portion in the circumferential direction. Since the opening angle of the upper surface is larger, when liquid enters the annular recess and flows near the lowest point of the annular seal line, the circumference of the annular sheet member starts from the flow starting point located in the vicinity thereof. The liquid easily passes through the top surface in the direction and is discharged to the outside of the annular recess, and the annular seat member does not need to have a large diameter. It is possible to provide a compact valve structure that can surely prevent the liquid that is easily invited from accumulating.

It is a schematic sectional drawing of the valve structure which concerns on 1st Embodiment of this invention. FIG. 2 (a) is an enlarged cross-sectional view showing the main part of the valve structure according to the first embodiment of the present invention, and FIG. 2 (b) shows the inner shape of the valve seat in FIG. 2 (a). It is the elements on larger scale seen toward the right side. It is operation | movement explanatory drawing of 1st Embodiment of this invention. FIG. 4 (a) is an enlarged cross-sectional view showing a main part of the valve structure according to the second embodiment of the present invention, and FIG. 4 (b) shows the inner surface shape of the valve seat in FIG. 4 (a). It is the elements on larger scale seen toward the right side. FIG. 5 (a) is an enlarged cross-sectional view showing a main part of a valve structure according to a third embodiment of the present invention, and FIG. 5 (b) shows the inner surface shape of the valve seat in FIG. 5 (a). It is the elements on larger scale seen toward the right side. FIG. 6 (a) is an enlarged half sectional view of the main part of the valve structure according to the fourth embodiment of the present invention, and FIG. 6 (b) is an enlarged main part of the valve structure according to the fifth embodiment of the present invention. It is sectional drawing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an application of the valve structure according to the first embodiment of the present invention to an EGR valve (exhaust gas recirculation valve) equipped in an EGR system (exhaust gas recirculation system) of an internal combustion engine for an automobile (vehicle). is there. Although the EGR system itself is not described in detail, the EGR valve is disposed in the middle of an EGR passage (exhaust recirculation passage) that recirculates a part of the exhaust gas from the exhaust passage side of the internal combustion engine to the intake passage. The valve can be switched between an open state in which the passage is connected to the intake passage and a closed state in which the connection is restricted, for example, blocked.

  First, the configuration of the present embodiment will be described.

  As shown in FIG. 1, an EGR valve 10 of this embodiment includes a valve housing 11, an annular seat member 12 and a poppet-like valve member 13 housed in the valve housing 11, and the valve member 13 as a seat member. And a valve drive mechanism 14 for relative displacement with respect to 12.

  The valve housing 11 is detachably supported by a part of an internal combustion engine (not shown), for example, an intake manifold, a cylinder head, or a cylinder block. When the valve housing 11 is supported by a part of the internal combustion engine, an annular seat member is provided. 12 and the central axis C of the valve member 13 are inclined by a predetermined inclination angle ψ with respect to the vertical direction which is the extending direction of the one-dot chain line V in FIG.

  Further, inside the valve housing 11, an inlet passage 11 a (upstream side passage) connected to communicate with the exhaust passage of the internal combustion engine on the outer end side which is the mounting surface side of the valve housing 11, and the attachment of the valve housing 11 An outlet passage 11b (downstream passage) connected to communicate with the intake passage of the internal combustion engine on the outer end side that is the surface side, and a valve hole 11c that connects the inner ends of the inlet passage 11a and the outlet passage 11b with each other. , Each is formed.

  Here, the inlet passage 11a and the outlet passage 11b extend substantially parallel to each other on the inner end side, and the circular valve hole 11c between the inner end portions of the inlet passage 11a and the outlet passage 11b is It is formed inside the annular seat member 12 held by the valve housing 11.

  As shown in FIG. 2, the annular sheet member 12 is thick on the outer peripheral side and thin on the inner peripheral side. Further, an upper surface 12f adjacent to the inner peripheral portion 12e of the annular seat member 12 is a line segment (straight line, curved line or bent line) inclined radially outward with respect to the central axis C of the valve hole 11c of the annular seat member 12. Or any one of these combinations) is a peripheral wall surface rotated around the central axis of the stem portion 13b.

  The valve member 13 has a head portion 13a that can be engaged with the inner peripheral portion 12e of the annular seat member 12, a head portion 13a that is fixed to one end side, and is axially movable to the valve drive mechanism 14 on the other end side. And a stem portion 13b supported. The valve member 13 is driven in the axial direction by the valve drive mechanism 14 and engages with the inner peripheral portion 12e of the annular seat member 12 to close the valve hole 11c (valve indicated by a solid line in FIG. 1). The position of the member 13) and the valve opening position (the position of the valve member 13 indicated by the phantom line in FIG. 1) where the valve hole 11c is released by releasing from the inner peripheral portion 12e of the annular seat member 12 can be displaced. It has become.

  Further, the head portion 13a of the valve member 13 has a substantially conical shape or a truncated cone shape with a portion supported by the stem portion 13b as a top portion, and a tapered surface 13f of the head portion 13a is formed on the stem portion 13b. It is a peripheral wall surface obtained by rotating a line segment (either a straight line, a curved line, a bent line, or a combination thereof) inclined inward in the radial direction with respect to the central axis C around the central axis of the stem portion 13b.

  The valve drive mechanism 14 includes, for example, an electromagnetic drive unit that generates an electromagnetic force that urges the valve member 13 toward the valve opening side, and a known compression coil spring (return spring) that constantly urges the valve member 13 toward the valve closing side. It is a publicly known thing having. The valve drive mechanism 14 can control the opening degree by changing the length (duty ratio) of the supply time of the valve opening instruction signal per predetermined time supplied to the electromagnetic drive unit. ing. The valve drive mechanism 14 may be a mechanism that generates an urging force using fluid pressure, or a mechanism that generates an urging force using a screw, a cam, a motor, or the like. Further, the valve drive mechanism 14 is engaged with the inner peripheral portion 12e of the annular seat member 12 by rotating a valve body such as the head portion 13a of the valve member 13 around an axis perpendicular to the stem portion 13b. Such a mechanism may be used. That is, the EGR valve 10 does not need to move the valve member 13 directly.

  As shown in FIGS. 1 and 2, an annular recess 15 is formed between the annular seat member 12 and the valve member 13 so as to be opened obliquely upward toward the valve drive mechanism 14 side. When the valve member 13 is in the valve closing position, the upper surface 12 f of the annular seat member 12 that forms the annular recess 15 and the tapered surface 13 f of the head portion 13 a of the valve member 13 are inward of the annular recess 15. An annular seal line 16 for closing the valve hole 11c in a liquid-tight manner is formed on the side. The annular seat member 12 and the valve member 13 in the closed position are configured to close the valve hole 11c on the inner side of the annular recess 15 when the valve member 13 is in the closed position.

  Further, since the central axis C of the annular sheet member 12 is inclined with respect to the vertical direction, a part of the upper surface 12fa in the circumferential direction of the upper surface 12f of the annular sheet member 12 forms an annular recess 15. The upper surface 12f of the annular sheet member 12 is positioned on the lowermost side in the vertical direction. Furthermore, an opening angle of the partial upper surface 12fa in the circumferential direction with respect to the central axis C of the annular sheet member 12 is larger than that of the remaining upper surface 12fb in the circumferential direction of the annular sheet member 12.

  As shown in FIGS. 3 (a) and 3 (b), the opening angle referred to here is a circumferential circumference in the upper surface 12f of the annular sheet member 12 forming the main portion 15a of the annular recess 15 in the radial direction. An imaginary straight line h that is in contact with the inner end of a part of the upper surface 12fa in the direction and the upper end of the portion that is radially outward from the inner end and located at the highest position in the vertical direction is an annular sheet member 12 This is an angle (an included angle) formed with respect to the central axis C. In the present embodiment, since a part of the upper surface 12fa in the circumferential direction is an annular inclined surface having a straight line as a generating line, the inner end e1 and the radially outer side of the inner end e1 are the highest in the vertical direction. The straight line in contact with the portion located at the position passes through the outer end e2 of the partial upper surface 12fa in the circumferential direction, and the straight line connecting the inner end e1 and the outer end e2 of the partial upper surface 12fa in the circumferential direction is an annular sheet. An angle formed with respect to the central axis C of the member 12 is an opening angle. The main portion 15a of the annular recess 15 is a slight annular gap portion 15b between the annular seat member 12 and the valve member 13 at the valve closing position in the annular recess 15 (see FIG. 3B). This annular gap portion 15b is required in the vicinity of the annular seal line 16 in terms of parts processing and durability.

  Specifically, a part of the upper surface 12fa in the circumferential direction of the annular sheet member 12 has an inner end serving as a flow start point located at the highest position in the vertical direction in the vicinity of the inner end in the radial direction of the annular sheet member 12. e1 (hereinafter referred to as a flow start point e1), and has a vertical height equal to or lower than the flow start point e1 over the entire area outside the flow start point e1 in the radial direction of the annular sheet member 12. The upper surface 12fa in the circumferential direction of the annular sheet member 12 is preferably slightly lower in the vertical direction on the outer side in the radial direction with respect to the flow start point e1, more preferably the flow down. It is inclined downward over substantially the entire radial direction so that the height in the vertical direction gradually decreases toward the outside in the radial direction from the start point e1.

  That is, a part of the upper surface 12fa in the circumferential direction of the annular sheet member 12 has an upper end at a flow start point e1 located in the vicinity of the lowest point 16a located on the lowermost side in the vertical direction of the annular seal line 16. It has a lower vertical height. Even if liquid such as condensed water enters the annular recess 15, the liquid is discharged to the outside of the annular recess 15 by flowing down.

  More specifically, a part of the annular sheet member 12 in the circumferential direction is formed with a notch groove 12g extending in the radial direction on the inner peripheral side upper surface thereof, and the inner wall surface of the notch groove 12g is A part of the upper surface 12fa in the circumferential direction of the annular sheet member 12 is formed. Then, a part of the upper surface 12fa in the circumferential direction is the inner bottom part of the notch groove 12g (the center part in the width direction of the notch groove 12g in FIG. 2B; a part in the circumferential direction of the annular sheet member 12). Thus, it is located at the vertical height below the flow starting point e1 over the entire radial direction (range of the radial width a in FIG. 2A).

  Further, a part of the upper surface 12fa in the circumferential direction is such that the vertical height of the flow starting point e1 and the vertical height of the radial outer end e2 are the same at the inner bottom of the notch groove 12g or the radial outer end. The vertical height of e2 is slightly lower. A part of the upper surface 12fa in the circumferential direction has a lower vertical height outside the radial direction of the annular sheet member 12 at the inner bottom portion of the notch groove 12g, and the upper surface 12fa extends from above the upper surface 12f of the annular sheet member 12. It is desirable to incline in the same direction over the entire radial direction so that condensed water can be drained.

  The height and inclination referred to here are based on the attitude when the internal combustion engine to which the EGR valve 10 of this embodiment is attached is stopped or the attitude that the internal combustion engine takes for the longest time. Further, it is assumed that the vehicle does not tilt when the internal combustion engine takes the reference posture.

  As described above, the upper surface 12f of the annular sheet member 12 has a vertical direction equal to or lower than the flow start point e1 at the inner bottom portion of the notch groove 12g formed in a part of the circumferential direction of the annular sheet member 12. It has a height and is inclined by an opening angle θa with respect to the central axis C of the valve hole 11c. Further, the upper surface 12fb of the remaining portion in the circumferential direction of the annular sheet member 12 extends in the entire radial direction so as to spread outward from the annular seal line 16 within the range of the remaining portion in the circumferential direction excluding the notch groove 12g. And an annular inclined surface inclined by an opening angle θb smaller than the opening angle θa with respect to the central axis C of the valve member 13 and the annular seat member 12.

  On the other hand, the valve housing 11 is adjacent to the adjacent inner wall surface 11fa adjacent to a part of the upper surface 12fa in the circumferential direction of the annular seat member 12 at a vertical height equal to or less than the flow starting point e1, and the upper surface 12fb of the remaining part in the circumferential direction. And an adjacent inner wall surface 11fb.

  Next, the operation will be described.

  In the EGR valve 10 of the present embodiment configured as described above, moisture in the exhaust gas of the internal combustion engine condenses in the exhaust passage, or the sulfur compound in the exhaust gas dissolves in the condensed water and is an acidic liquid. It becomes.

  When such acidic condensed water flows into the annular recess 15 and the condensed water accumulates in a certain amount or more in the annular recess 15, for example, moisture of the condensed water evaporates during operation of the internal combustion engine. There is a possibility that the valve closing state continues for a long time in a state where the concentration of the condensed water is high. Furthermore, if a certain amount or more of condensed water accumulates in the annular recess 15, even if the moisture in the condensed water evaporates, the sulfur compounds and the like dissolved therein are deposited on the surfaces of the annular seat member 12 and the valve member 13. Factors that increase the concentration of condensed water that remains attached and remains in the annular recess 15 will increase. Therefore, if the valve seat shape as in the prior art is maintained, the annular seat member 12 and the upper surfaces 12f and 13f of the valve member 13 are easily corroded in the vicinity of the lowest point 16a of the annular seal line 16.

  However, in this embodiment, when the condensed water flows into the annular recess 15 and flows down to the vicinity of the annular seal line 16, the circumferential direction of the annular sheet member 12 from the vicinity of the lowest point 16a. Is discharged to the outside of the annular recess 15 through a part of the upper surface 12fa. Therefore, a relatively large amount of condensed water exceeding a certain amount is prevented from accumulating inside the annular recess 15.

  That is, when the opening angle of the upper surface on the inner peripheral side of the valve seat is constant as in the prior art, the liquid level can be as indicated by the imaginary line 15c1 in FIG. A relatively large amount of condensed water can accumulate. On the other hand, in this embodiment, the liquid level height of the condensed water which accumulates in the annular recess 15 is limited to the liquid level height when it starts to flow over the flow start point e1. Therefore, a relatively large amount of condensed water exceeding a certain amount is prevented from accumulating inside the annular recess 15.

  Further, in the present embodiment, a part of the upper surface 12fa in the circumferential direction of the annular sheet member 12 is equal to or lower than the lowest point 16a over the entire radial direction in a part of the annular sheet member 12 in the circumferential direction. Since it has a low vertical height, it is slightly inclined over the entire radial direction so that the vertical height is lower outside in the radial direction. Can be reliably prevented from accumulating.

  In the present embodiment, a notch groove 12g extending in the radial direction of the annular sheet member 12 is formed in a part of the annular sheet member 12 in the circumferential direction, and the inner bottom surface of the notch groove 12g is an annular sheet. Since the upper surface 12fa is a partial upper surface 12fa in the circumferential direction of the member 12, it is possible to reliably prevent the liquid from accumulating in the annular recess 15 while suppressing the diameter of the annular sheet member 12.

  In addition, the upper surface within a range excluding a part in the circumferential direction of the annular sheet member 12, that is, the upper surface 12 fb of the remaining portion in the circumferential direction is radial from the inner peripheral edge of the annular sheet member 12 forming the annular seal line 16. Since the annular inclined surface that is inclined with respect to the central axis C of the valve hole 11c is formed so as to spread outward, the condensed water entering the annular recess 15 is reliably collected in a part of the circumferential direction, A part of the upper surface 12fa can be discharged to the outside of the annular recess 15.

  In the present embodiment, an inlet passage 11a and an outlet passage 11b are formed before and after the valve hole 11c, and a valve housing 11 that holds the annular seat member 12 is provided. The valve housing 11 is below the flow start point e1. Since the adjacent inner wall surface 11fa is adjacent to a part of the upper surface 12fa in the circumferential direction of the annular sheet member 12 at the height in the vertical direction, the liquid entering the annular recess 15 is allowed to flow into the annular sheet member 12. It can be reliably discharged radially outward from the upper surface 12f.

  As described above, in the valve structure of the present embodiment, a part of the circumferential direction located on the lowermost side in the vertical direction of the upper surface 12f of the annular seat member 12 with respect to the central axis C of the annular seat member 12. Since the opening angle θa of the upper surface 12fa is larger than the opening angle θb of the remaining upper surface 12fb in the circumferential direction, liquid enters the annular recess 15 and flows down to the vicinity of the lowest point 16a of the annular seal line 16 When this occurs, the liquid can easily be discharged from the flow starting point e1 located in the vicinity thereof onto the circumferential upper surface 12fa of the annular sheet member 12 to the outside of the annular recess 15, and the annular sheet member Therefore, it is possible to provide a compact valve structure that can surely prevent liquid that easily corrodes the main parts of the valve from being accumulated in the inner side of the annular recess 15. The

(Second Embodiment)
FIG. 4 (a) is an enlarged cross-sectional view showing a main part of the valve structure according to the second embodiment of the present invention, and FIG. 4 (b) shows the inner surface shape of the valve seat in FIG. 4 (a). It is the elements on larger scale seen toward the right side.

  Each embodiment described below has an overall configuration similar to that of the above-described first embodiment shown in FIGS. 1 to 3, and therefore the same or similar configuration is illustrated in FIGS. 1 to 3. The same reference numerals as the corresponding components in the drawings are used, and detailed description thereof is omitted. In particular, a configuration different from the first embodiment will be described.

  In the present embodiment, a circular valve hole 21 c between the inlet passage 11 a and the outlet passage 11 b of the valve housing 11 is formed inside the annular seat member 22 held by the valve housing 11.

  A part of the annular sheet member 12 in the circumferential direction is formed with a notch groove 22g extending in the radial direction on the inner peripheral upper surface, and the inner wall surface of the notch groove 22g is an annular sheet member 22. This is a partial upper surface 22fa in the circumferential direction. Then, a part of the upper surface 22fa in the circumferential direction is an inner bottom part of the notch groove 22g (a central part in the width direction of the notch groove 22g in FIG. 4B; a part in the circumferential direction of the annular sheet member 22). Therefore, it is located at the vertical height below the flow start point e1 over the entire radial direction (range of the radial width a in FIG. 4A).

  In addition, the upper surface 22fa of a part in the circumferential direction has substantially the same vertical height at the flow start point e1 and vertical height at the radial outer end e2 at the inner bottom portion of the notch groove 22g or The height in the vertical direction of the direction outer end e2 is slightly lower than that of the flow starting point e1. In addition, on a part of the upper surface 22fa in the circumferential direction, the height in the vertical direction is the lowest between the flow start point e1 and the radial outer end e2.

  In this case, since a part of the upper surface 22fa in the circumferential direction of the annular sheet member 22 is not inclined in the same direction at the inner bottom of the notch groove 22g, the amount of condensed water entering the annular recess 15 should be small. For example, the condensed water can be collected in the recessed portion at the center of the notch groove 22g. However, when the accumulated amount reaches a certain amount and the liquid level approaches the vicinity of the lowest point 16a of the annular seal line 16, the condensate is further increased. Condensed water is discharged from the radially outer end e2.

  Therefore, also in the present embodiment, similarly to the first embodiment, it is possible to prevent the condensed water from accumulating inside the annular recess 15, and the corrosion of the annular seat member 22 and the valve member 13 is ensured. It is possible to provide a compact valve structure that can be prevented.

(Third embodiment)
FIG. 5 (a) is an enlarged cross-sectional view showing a main part of a valve structure according to a third embodiment of the present invention, and FIG. 5 (b) shows the inner surface shape of the valve seat in FIG. 5 (a). It is the elements on larger scale seen toward the right side.

  In the present embodiment, a circular valve hole 31 c between the inlet passage 11 a and the outlet passage 11 b of the valve housing 11 is formed inside the annular seat member 32 held by the valve housing 11.

  The central axis C1 of the valve hole 31c of the annular seat member 32 is biased so as to deviate from the central axis C2 of the outer peripheral surface 32p of the annular seat member 32, and the annular seat member 32 with respect to the central axis C1 of the valve hole 31c. The opening angle θa of a part of the upper surface 32fa (annular inclined surface) in the circumferential direction is larger than the opening angle θb of the remaining upper surface 32fb in the circumferential direction of the annular sheet member 32. Further, the opening angle θa of a part of the upper surface 32fa in the circumferential direction of the annular sheet member 32 is the largest among the respective portions in the circumferential direction of the annular sheet member 32.

  Then, the central axes C1 and C2 of the annular sheet member 32 are inclined by the inclination angle ψ with respect to the vertical direction, so that a part of the upper surface 32fa in the circumferential direction of the upper surface 32f of the annular sheet member 32 is Of the upper surface 32 f of the annular sheet member 32 that forms the annular recess 15, it is positioned on the lowermost side in the vertical direction.

  Also in the present embodiment, the valve housing 11 has an adjacent inner wall surface 11fa adjacent to a partial upper surface 32fa in the circumferential direction of the annular seat member 32 at a height in the vertical direction equal to or less than the flow start point e1, and a remaining portion in the circumferential direction. An adjacent inner wall surface 11fb adjacent to the upper surface 32fb, and at least the adjacent inner wall surface 11fa of the circumferential upper surface 32fa and the adjacent inner wall surface 11fa is further downward in the vertical direction as the distance from the flow start point e1 increases. Inclined loosely and continuously so as to be located at

  Therefore, also in the present embodiment, similarly to the first embodiment, it is possible to prevent the condensed water from accumulating on the inner back side of the annular recess 15, and the corrosion of the annular seat member 32 and the valve member 13 is ensured. It is possible to provide a compact valve structure that can be prevented.

  In addition, in the present embodiment, while the opening angle θa of the partial upper surface 32fa in the circumferential direction with respect to the central axis C2 of the valve hole 31c is increased, the opening angle θb of the remaining upper surface 32fb in the circumferential direction is decreased. Therefore, the diameter of the annular seat member 32 can be suppressed, and a more compact valve structure can be achieved.

(Fourth embodiment)
FIG. 6A is an enlarged half sectional view of the main part of the valve structure according to the fourth embodiment of the present invention.

  The valve structure of this embodiment uses the valve housing 11 and the annular seat member 12 in the first embodiment shown in FIGS. 1 to 3, but instead of the valve member 13, the inner peripheral portion of the annular seat member 12. A head 43a having a taper surface 43f that can be engaged with the head 43a, and a stem 43b that is fixed to one end and supported by the valve drive mechanism 14 so as to be axially movable at the other end. ing. Here, the taper surface 43f of the head portion 43a is a taper surface in the opposite direction to the taper surface 13f of the head portion 13a of the first embodiment.

  The valve member 43 is driven in the axial direction by the valve drive mechanism 14 and engages with the inner peripheral portion 12e of the annular seat member 12 to close the valve hole 11c, and the inner periphery of the annular seat member 12 The valve can be displaced to the valve opening position where the valve hole 11c is released by separating from the portion 12e.

  Also in this embodiment, similarly to the first embodiment, it is possible to prevent the condensed water from accumulating inside the annular recess 15 and to reliably prevent corrosion of the annular seat member 12 and the valve member 43. A compact valve structure that can be provided can be provided.

(Fifth embodiment)
FIG. 6B is an enlarged cross-sectional view of the main part of the valve structure according to the fifth embodiment of the present invention.

  The valve structure of the present embodiment has a valve member 53 similar to the valve member 43 of the fourth embodiment shown in FIG. 6A and a first inner peripheral side engaged with the tapered surface 53f of the valve member 53. An annular sheet member 52 in which a circular stepped recess 52c is formed so as to have an edge portion 52e1 and a second edge portion 52e2 positioned on the outer side in the light direction and on one side (upper side) in the axial direction from the first edge portion 52e1; It is equipped with. In this case, the inner wall surface of the circular stepped recess 52 c of the inclined annular sheet member 52 becomes the upper surface 52 f of the annular sheet member 52.

  A part of the annular sheet member 52 in the circumferential direction is formed with a notch groove 52g extending in the radial direction on the inner peripheral side upper surface portion thereof, and the inner wall surface of the notch groove 52g is formed on the annular sheet member 52. The upper surface 52fa is a part of the circumferential direction. Then, a part of the upper surface 52fa in the circumferential direction is the entire area in the radial direction at the inner bottom part of the notch groove 52g (the center part in the width direction of the notch groove 52g; the part in the circumferential direction of the annular sheet member 52). Over the range of the radial width a in FIG. 6 (b), it is located at a vertical height equal to or lower than the flow starting point e1 which is the lowest point of the first edge portion 52e1 serving as the flow starting point. ing.

  The valve member 53 is driven in the axial direction by the valve driving mechanism 14 and engages with the inner peripheral portion 52e of the annular seat member 52 to close the valve hole 51c, and the inner periphery of the annular seat member 52 The valve can be displaced to the valve opening position where the valve hole 51c is released from the portion 52e.

  Also in the present embodiment, similarly to the first embodiment, it is possible to prevent the condensed water from accumulating inside the annular recess 15 and to reliably prevent the corrosion of the annular seat member 52 and the valve member 53. A compact valve structure that can be provided can be provided.

  In each of the above-described embodiments, the present invention is applied to the EGR valve 10. However, the present invention includes an annular recess that is opened upward between the valve body and the valve seat. In addition, the present invention can be applied to valve structures other than the EGR valve in which liquid that causes problems such as corrosion tends to accumulate.

  As described above, the valve structure according to the present invention has the upper surface of a part of the circumferential direction located on the lowest side in the vertical direction among the upper surfaces of the annular seat member with respect to the central axis of the annular seat member. Since the opening angle is larger than the opening angle of the upper surface of the remaining portion in the circumferential direction, when liquid enters the annular recess and flows down near the lowest point of the annular seal line, the flow starts near that point. From the point, the liquid can easily be discharged to the outside of the annular recess through the upper surface of a part of the annular sheet member in the circumferential direction, and the inner diameter of the annular recess can be reduced without increasing the diameter of the annular sheet member. It is possible to provide a compact valve structure that can reliably prevent liquid that tends to cause corrosion of valve main parts on the side, and engage and disengage the valve member with the seat member. Opened and closed Relates valve structure, it is useful in the preferred valve structure in general, especially poppet valves or the like which employs a tapered surface on the valve member and the seat member.

10 EGR valve (valve structure)
11 Valve housing 11a Inlet passage (upstream passage)
11b Exit passage (downstream passage)
11c, 21c, 31c, 51c Valve hole 11fa Adjacent inner wall surface 11fb Adjacent inner wall surface 12, 22, 32, 52 Annular seat member 12e Inner peripheral portion 12f, 22f, 32f Upper surface 12fa, 22fa, 32fa, 52fa Part of the circumferential direction Upper surface 12fb, 22fb, 32fb Upper surface 12g, 22g, 52g of circumferential portion Notch groove 13, 43, 53 Valve member 13a, 43a, 53a Head portion 13b, 43b, 53b Stem portion 13f, 43f, 53f Tapered surface 14 Valve drive mechanism 15 Annular recess 15a Main portion 15b Annular gap portion 16 Annular seal line 16a Bottom point 32p Outer peripheral surface 52c Stepped recess 52e1 First edge 52e2 Second edge C, C1, C2 Center axis e1 Start of flow down Point (inner end)
θa Opening angle of a part of the upper surface in the circumferential direction θb Opening angle of the upper surface of the remaining part in the circumferential direction ψ Inclination angle of the annular seal member

Claims (8)

An annular seat member that forms a valve hole, a valve closing position that engages with an inner peripheral portion of the annular seat member and closes the valve hole, and a valve that disengages from the inner peripheral portion of the annular seat member A valve member that is displaceable at a valve opening position that opens the hole, and when the valve member is in the valve closing position, an annular recess that is opened upward by the annular seat member and the valve member is formed. Valve structure,
The annular seat member and the valve member at the valve closing position close the valve hole on the inner side of the annular recess,
The central axis of the annular sheet member is inclined with respect to the vertical direction,
Of the upper surface of the annular sheet member that forms the annular recess, the upper surface of a part of the circumferential direction located on the lowermost side in the vertical direction is higher than the upper surface of the remaining portion in the circumferential direction. A valve structure characterized in that the opening angle with respect to the central axis is large.   The upper surface of a part of the annular sheet member in the circumferential direction has the highest flow start point in the vertical direction in the vicinity of the inner end in the radial direction of the annular sheet member, and the annular sheet extends from the flow start point. 2. The valve structure according to claim 1, wherein the valve structure has a height in a vertical direction that is equal to or less than the flow start point over the entire region outside the radial direction of the member. 3. The valve structure according to claim 2 , wherein the upper surface of a part of the annular seat member in the circumferential direction has a lower vertical height outside the radial direction with respect to the flow start point. .   The upper surface of a part of the circumferential direction of the annular sheet member is inclined over substantially the entire radial direction so that the height in the vertical direction becomes lower toward the outer side in the radial direction. The valve structure according to any one of claims 3 to 4.   A notch groove extending in the radial direction of the annular sheet member is formed in a part of the annular sheet member in the circumferential direction, and an inner bottom surface of the notched groove is a part of the circumferential direction of the annular sheet member. The valve structure according to any one of claims 1 to 4, wherein the valve structure is an upper surface.   The upper surface of the annular seat member is inclined with respect to the central axis of the valve hole so as to spread radially outward from the inner peripheral edge of the valve hole within a range excluding a part of the annular seat member in the circumferential direction. The valve structure according to any one of claims 1 to 5, wherein an annular inclined surface is formed. The central axis of the valve hole of the annular seat member is biased to deviate from the central axis of the outer peripheral surface of the annular seat member;
7. The valve structure according to claim 6, wherein an opening angle of the annular inclined surface with respect to a central axis of the valve hole is large on a part of a circumferential side of the annular seat member. A valve housing for forming an upstream passage and a downstream passage before and after the valve hole and holding the annular seat member;
Wherein said valve housing, to claims 2, characterized in that it has adjacent inner wall surface adjacent to the part of the upper surface of the circumferential direction of the annular seat member in the vertical direction height of less than or equal to the falling start point The valve structure according to any one of claims 7 to 10.

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