JP2005344803A - Ball valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance sealability between a valve body and a seat ring of a ball valve. <P>SOLUTION: Since the seat ring 51 of the ball valve is floatingly supported by a valve housing 41, when rotating the valve body 42 around a rotary shaft 44 by an actuator, wrench can be prevented from being generated between an annular first seal surface 46a of the valve body 42 and an annular second seal surface 51a of the seat ring 51. When opening the ball valve indicated in (C), a part of the first seal surface 46a of the valve body 42 contacts with a part of the second seal surface 51a of the seat ring 51, and even if the seat ring 51 tries to incline by an unbalanced load applied to its contact part, a regulating member 41c arranged in the valve housing 41 regulates the movement of the seat ring 51 to the valve body 42 side, and generation of the wrench and reduction in the sealability can be further effectively prevented by checking an inclination of the seat ring 51. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ball valve in which an annular first seal surface formed on a valve body and an annular second seal surface formed on a seat ring are in spherical contact with each other so as to be slidable and seatable.

A ball in which a spherical valve body 40 having a through hole between a pair of seat rings 60 and 70 disposed in a fluid passage is rotatably supported, and the seat rings 60 and 70 and the valve body 40 are slidably brought into spherical contact. A valve is known from US Pat. This ball valve is opened when the through hole of the valve body 40 connects the upstream and downstream fluid passages, and the valve body 40 rotated 90 ° from that state is connected to the upstream and downstream fluid passages. Closes when communication is cut off.
JP-A-9-242893

  By the way, in the conventional ball valve described above, the valve body 40 is in contact with the entire circumference of the annular seat rings 60 and 70 regardless of whether the spherical valve body 40 is in the valve opening position or the valve closing position. The uneven load does not act on the seat rings 60 and 70 from the body 40, and therefore there is no possibility that the seat rings 60 and 70 are inclined due to the uneven load. As described above, the valve body 40 is in contact with the entire circumference of the annular seat rings 60 and 70 because the valve body 40 has a substantially perfect spherical shape, and the surface area that can contact the seat rings 60 and 70 is large. Because.

  However, when the valve body is rotated back and forth at high speed with an actuator, the moment of inertia of the valve body needs to be as small as possible. For this reason, the spherical surface of the valve body is limited to a narrow annular range, and only when the valve is closed. It is conceivable to seat the spherical surface of the body all around the seat ring. In such a case, since the valve body contacts only a part of the seat ring when the ball valve is opened, there is a possibility that the seat ring receives an offset load from the valve body and tilts.

  In particular, when the seat ring is floatingly supported on the valve housing in order to prevent galling between the valve body and the seat ring, the seat ring is largely inclined due to the uneven load, and the seal between the valve body and the valve body is prevented. May be impaired.

  The present invention has been made in view of the above circumstances, and an object thereof is to improve the sealing performance between the valve body and the seat ring of the ball valve.

  In order to achieve the above object, according to the first aspect of the present invention, an annular first seal surface formed of a part of a spherical surface is provided and is rotatably supported by a valve housing by a rotary shaft. A valve body, an annular second seal surface on which the first seal surface of the valve body is slidable and seatable, and a seat ring floatingly supported on the valve housing with an opening penetrating the center of the second seal surface A ball valve in which the valve housing 41 closes the opening of the seat ring when the first seal surface is seated on the second seal surface. A ball valve is proposed in which a restricting member for restricting movement to the valve body side is provided in the valve housing.

  Further, according to the invention described in claim 2, in addition to the configuration of claim 1, a ball valve characterized by including a biasing member that biases the seat ring toward the valve body is proposed. .

  According to the invention described in claim 3, in addition to the structure of claim 2, a retaining ring having a lower friction coefficient than that of the seat ring is disposed on the outer peripheral surface of the seat ring facing the valve housing. A ball valve is proposed.

  According to the invention described in claim 4, in addition to the structure of claim 1, when the valve body opens the opening of the seat ring, the first seal surface of the valve body and the second seal surface of the seat ring are A ball valve characterized by abutting at one point is proposed.

  According to the configuration of the first aspect, since the seat ring is floatingly supported on the valve housing, the first seal surface of the valve body and the second seal surface of the seat ring are rotated when the valve body is rotated around the rotation axis by the actuator. Can be prevented from occurring between the two. Further, when the ball valve is opened, a part of the annular first seal surface of the valve body comes into contact with a part of the annular second seal surface of the seat ring, and the seat ring tends to tilt due to an offset load applied to the contact portion. In addition, by restricting the seat ring from moving toward the valve body with a restricting member provided in the valve housing, the tilt of the seat ring is prevented, and the occurrence of the scouring and the deterioration of the sealing performance are more effectively prevented. be able to.

  According to the configuration of the second aspect, since the seat ring is urged toward the valve body by the urging member, the first and second second seal surfaces of the seat ring are brought into close contact with the first seal surface of the valve body. The sealing performance between the sealing surfaces can be enhanced.

  According to the third aspect of the present invention, since the low friction coefficient holding ring disposed on the outer peripheral surface of the seat ring is brought into contact with the valve housing, the first and first seat rings are smoothly biased by the biasing member. The sealing performance between the two sealing surfaces can be further enhanced.

  According to the configuration of claim 4, when the valve body opens the opening of the seat ring and the first and second sealing surfaces come into contact with each other at one point, the seat ring is most easily inclined by receiving a large offset load from the valve body. However, it is possible to reliably prevent the seat ring from tilting due to the uneven load by the action of the regulating member.

  Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a sectional view of a cylinder head portion and a ball valve of an engine, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. FIG. 4 is a perspective view of the valve body, and FIG. 5 is an explanatory view of the operation of the ball valve.

  As shown in FIG. 1, a piston 13 is slidably fitted to a cylinder sleeve 12 provided in a cylinder block 11 of the engine E, and a cylinder head 14 coupled to a deck surface of the cylinder block 11 and a piston 13 are connected to each other. A combustion chamber 15 is defined between the top surface and the top surface. An intake port 16 and an exhaust port 17 connected to the combustion chamber 15 are formed in the cylinder head 14. An intake valve hole that opens the intake port 16 to the combustion chamber 15 is opened and closed by an intake valve 18, and the exhaust port 16 is opened to the combustion chamber. The exhaust valve hole opened to 15 is opened and closed by the exhaust valve 19. The intake valve 18 and the exhaust valve 19 are urged in the valve closing direction by valve springs 20 and 21, respectively.

  An intake camshaft 23 and an intake rocker arm shaft 24 are provided inside a head cover 22 coupled to the upper surface of the cylinder head 14, and are pivotally supported on the intake rocker arm shaft 24 by an intake cam 25 provided on the intake camshaft 23. The intake valve 18 is driven to open and close through the intake rocker arm 26. Further, an exhaust camshaft 27 and an exhaust rocker arm shaft 28 are provided inside the head cover 22, and an exhaust cam 29 provided on the exhaust camshaft 27 via an exhaust rocker arm 30 pivotally supported on the exhaust rocker arm shaft 28. The exhaust valve 19 is driven to open and close.

  An intake passage member 31 connected to the intake port 16, an intake control valve 32 formed of a ball valve, and an intake pipe 33 are connected to the cylinder head 14. A surge tank and a throttle valve (not shown) are connected upstream of the intake pipe 33. Is placed. The intake passage member 31 is provided with a fuel injection valve 34 that injects fuel into the intake port 16.

  Next, the structure of the intake control valve 32 will be described with reference to FIGS.

  The intake control valve 32 includes a valve housing 41 sandwiched between an intake passage member 31 and an intake pipe 33, and a first intake passage 33 a formed in the intake pipe 33 and a second intake passage formed in the valve housing 41. 41a and a third intake passage 31a formed in the intake passage member 31 are connected in series in the direction of the axis L1.

  The valve body 42 housed inside the valve housing 41 is provided integrally with the cylindrical portion 43, a short cylindrical cylindrical portion 43, a pair of rotating shafts 44 and 45 extending in a direction away from the cylindrical portion 43, and the cylindrical portion 43. And a thin disk-shaped disk portion 46 formed. An opening 43 a having a circular cross section passes through the cylindrical portion 43, and an annular first seal surface 46 a constituting a part of a spherical surface is formed on the outer periphery of the disc portion 46.

  The pair of rotating shafts 44 and 45 are disposed on an axis L2 orthogonal to the axis L1 of the first to third intake passages 33a, 41a and 31a. One rotating shaft 44 is connected to the valve housing 41 via a ball bearing 47. The other rotary shaft 45 is rotatably supported by the valve housing 41 via a ball bearing 48 and a seal member 49 and is connected to an actuator 50 fixed to the valve housing 41.

  The actuator 50 is composed of, for example, a rotary solenoid or a step motor, and reciprocates the valve body 42 at a rotation angle of 90 °. When the valve body 42 is at one rotation end, the axis L3 of the disc portion 46 coincides with the axis L1 of the first to third intake passages 33a, 41a, 31a, and the axis L4 of the cylindrical portion 43 is orthogonal. (See FIG. 5A). When the valve body 42 is at the other rotation end, the axis L3 of the disc portion 46 is orthogonal to the axis L1 of the first to third intake passages 33a, 41a, 31a, and the axis L4 of the cylindrical portion 43 is coincident. (See FIG. 5C).

  An annular seat ring 51 is attached to a step portion 41 b formed at the downstream end of the valve housing 41 coupled to the upstream end of the intake passage member 31. The seat ring 51 includes a partially spherical and annular second seal surface 51a on which the first seal surface 46a of the valve body 42 can slide and seat, and an opening having a circular cross section that penetrates the inner periphery of the second seal surface 51a. 51b. The valve housing 41 is integrally formed with an annular regulating member 41c that can abut on the upstream end surface of the seat ring 51.

  As apparent from FIG. 3, the distance D between the upstream end of the intake passage member 31 and the restricting member 41c is slightly larger than the thickness T of the seat ring 51, and therefore the seat ring 51 moves in the direction of the axis L1. Floating support is possible. At this time, an urging member 52 made of NBR or fluororubber O-ring is mounted in a compressed state in an annular groove 31b formed so as to surround the third intake passage 31a at the upstream end of the intake passage member 31. The seat ring 51 is biased toward the valve body 42 by the biasing force of the biasing member 52.

  The diameter R1 of the stepped portion 41b of the valve housing 41 is slightly larger than the diameter R2 of the seat ring 51. Therefore, the seat ring 51 is floatingly supported so as to be movable in the radial direction around the axis L1. At this time, a holding ring 53 made of PTFE (fluororesin) is mounted in an annular groove 51 c formed on the outer periphery of the seat ring 51, and the seat ring 51 slides on the step 41 b of the valve housing 41 via the holding ring 53. Abuts freely. The PTFE holding ring 53 has a smaller coefficient of friction than the seat ring 51.

  Next, the operation of the embodiment having the above configuration will be described.

  During idling of the engine E in which the throttle valve (not shown) provided upstream of the intake pipe 33 is in a closed state, the intake control valve 32 is periodically opened and closed by the actuator 50, thereby improving the stability of the idling operation. The so-called blow-back phenomenon, in which exhaust gas blows back from the exhaust port 17 side to the intake port 16 side, is suppressed.

  That is, when the engine E is idling, the intake control valve 32 is opened after a valve overlap period in which the end of the valve opening period of the exhaust valve 19 and the initial period of the intake valve 18 overlap, and then the predetermined period is reached. The intake control valve 32 is closed after the intake valve 18 is closed after a lapse of time. As a result, intake air is sucked into the combustion chamber 15 only at the end of the valve opening period of the intake valve 18, and the idling operation at a predetermined rotational speed can be performed by limiting the intake amount of the intake air.

  Further, since the intake control valve 32 is opened for a while after the intake valve 18 is closed, the pressure in the intake passage can be returned to substantially atmospheric pressure during that time, and the intake air is taken in during the valve overlap period of the next cycle. Even if both the valve 18 and the exhaust valve 19 are opened, it is possible to prevent the exhaust from blowing back from the exhaust port 17 side to the intake port 16 side.

  Since the valve body 42 of the intake control valve 32 is reciprocally rotated at an extremely high speed by the actuator 50, the first seal surface 46a of the valve body 42 formed of a part of a spherical surface is suppressed to a necessary minimum area. As a result, the valve body 42 can be driven back and forth with high responsiveness by the small and low-power actuator 50 by removing the luxury of the valve body 42 and minimizing the moment of inertia around the rotary shafts 44 and 45.

  As shown in FIG. 5A, when the intake control valve 32 is closed, that is, the axes L1 and L3 are in a straight line and the entire circumference of the first seal surface 46a of the disc portion 46 is the second of the seat ring 51. In a state in which the opening 51b of the seat ring 51 is closed in close contact with the seal surface 51a, the seat ring 51 floating supported by the step portion 41b of the valve housing 41 is applied to the valve body 42 by the elastic force of the urging member 52. Since it is urged | biased toward, it can prevent that swarf generate | occur | produces between the 1st, 2nd sealing surfaces 46a and 51a, and can improve a sealing performance.

  At this time, the retaining ring 53 having a low coefficient of friction mounted on the outer peripheral surface of the seat ring 51 is in sliding contact with the step portion 41b of the valve housing 41, so that the seat ring slides smoothly in the direction of the axis L1 with respect to the valve housing 41. In addition, the sealing function of the retaining ring 53 can prevent intake air leakage.

  As shown in FIG. 5B, at the intermediate position where the valve body 42 rotates toward the valve opening position, the valve body 42 is in sliding contact with the second seal surface 51a of the seat ring 51 at two locations on the first seal surface 46a. Since the two positions are displaced from both ends in the diameter direction of the second seal surface 51 a of the seat ring 51, the seat ring 51 biased by the biasing member 42 receives an unbalanced load that tilts counterclockwise.

  As shown in FIG. 5C, when the intake control valve 32 opened by 90 ° of the valve body 42, that is, the axes L1 and L4 are in a straight line and the opening 43a of the cylindrical portion 43 is the opening of the seat ring 51. When fully communicating with 51b, the first seal surface 46a of the disc portion 46 contacts the second seal surface 51a of the seat ring 51 at one point, and therefore the seat ring 51 receives the maximum offset load. However, even if the seat ring 51 tends to tilt counterclockwise due to the unbalanced load, the regulating member 41c provided on the valve housing 41 abuts against the seat ring 51 and regulates the tilt, so the first and second sealing surfaces 46a. , 51a can be prevented from being damaged, and the sealing performance can be prevented from being impaired.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, an O-ring is employed as the biasing member 52, but any other biasing member such as a disc spring can be employed.

  In the embodiment, PTFE is used as the material of the retaining ring 53, but any material having a smaller friction coefficient than the seat ring 51 can be used.

  The ball valve of the present invention can be applied to any use other than the intake control valve 32 of the engine E.

  In the embodiment, the restricting member 41c is formed integrally with the valve housing 41. However, the restricting member 41c may be formed as a separate member and fixed to the valve housing 41, and the restricting member 41c does not have to be annular, It suffices if it is provided at a plurality of locations above.

Cross section of engine cylinder head and ball valve 1 is an enlarged view of the main part of FIG. Part 3 enlarged view of FIG. Perspective view of valve body Action diagram of ball valve

Explanation of symbols

41 Valve housing 41c Restricting member 42 Valve body 44 Rotating shaft 45 Rotating shaft 46a First seal surface 50 Actuator 51 Seat ring 51a Second seal surface 51b Opening 52 Energizing member 53 Holding ring

Claims (4)

A valve body (42) having an annular first seal surface (46a) formed of a part of a spherical surface and rotatably supported on the valve housing (41) by a rotation shaft (44, 45);
The first seal surface (46a) of the valve body (42) has an annular second seal surface (51a) capable of sliding and seating and an opening (51b) penetrating the center of the second seal surface (51a). A seat ring (51) floatingly supported by the valve housing (41),
An actuator (50) for reciprocatingly rotating the valve body (42) about the rotation axis (44, 45);
The valve housing (41) closes the opening (51b) of the seat ring (51) when the first seal surface (46a) is seated on the second seal surface (51a),
A ball valve characterized in that a regulating member (41c) for regulating movement of the seat ring (51) toward the valve body (42) is provided in the valve housing (41).   The ball valve according to claim 1, further comprising a biasing member (52) for biasing the seat ring (51) toward the valve body (42).   The ball according to claim 2, wherein a retaining ring (53) having a lower coefficient of friction than the seat ring (51) is arranged on the outer peripheral surface of the seat ring (51) facing the valve housing (41). valve. When the valve body (42) opens the opening (51b) of the seat ring (51), the first seal surface (46a) of the valve body (42) and the second seal surface (51a) of the seat ring (51) are 1. The ball valve according to claim 1, wherein the ball valve abuts at a point.

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