JP2012072788A - Passage switching valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a passage switching valve that can reduce wear resulting from friction between a valve body and a sheet, and can improve vibration resistance.SOLUTION: The passage switching valve 10 includes: a movable sheet 16 having a sheet face 48 on which the valve body 14 is seated; an annular sealing member 52 arranged at the external periphery of the movable sheet 16; an elastomer 54 which biases the movable sheet 16 toward the side of the valve body 14; and a stopper 56 which regulates an advance position of the movable sheet 16 to the side of the valve body 14. The valve body 14 is arranged so as to turn around an axial line A1 which is eccentric from the center. The passage switching valve 10 is brought into a valve-closed state by an effect that a spherical part 30 of the valve body 14 abuts on the sheet face 48 and closes the movable sheet 16, and brought into a valve-opened state by an effect that the displacement of the movable sheet 16 is regulated by the stopper 56, and the valve body 14 is separated from the movable sheet 16.

Description

  The present invention relates to a flow path opening / closing valve that switches a flow state of a fluid by opening and closing a flow path through which the fluid flows.

  2. Description of the Related Art Conventionally, for example, a channel opening / closing valve that is connected to a fluid flow channel and controls the fluid flow state by switching the communication state of the flow channel is known. In such a channel opening / closing valve, a ball valve is provided inside the valve body, and a shaft connected to an upper portion of the ball valve rotates to form a through hole of the ball valve in the valve body. A pair of passages (a gas inlet and a gas outlet) communicate with each other. Further, a fixed seat and a movable seat are provided on the gas inlet side and the gas outlet side of the ball valve so as to sandwich the ball valve, and the movable seat is urged toward the ball valve side by a spring member. The ball valve is held. With this configuration, since the ball valve is always in contact with the fixed seat and the movable seat, a sealing property is ensured (see, for example, Patent Document 1).

JP-A-57-114068

  In the above-described prior art, since the ball valve is always in contact with and sliding with the movable seat and the fixed seat, friction is always generated between these components, and there is a problem of wear and durability of each component. is there. Further, since the ball valve is pressed by the spring member, the pressing load directly affects the vibration resistance.

  The present invention has been made in view of such circumstances, and provides a flow path opening / closing valve capable of reducing wear caused by friction between a valve body and a seat and improving vibration resistance. The purpose is to do.

  In order to achieve the above object, a flow path opening / closing valve according to the present invention includes a valve body rotatably provided via a shaft, a body main body having a valve chamber that houses the valve body, and the valve body. A movable seat having a seat surface on which the seat is seated, an annular seal member disposed on an outer peripheral portion of the movable seat and in contact with an inner peripheral surface of the valve chamber, and an elastic force for biasing the movable seat toward the valve body A body and a position of the movable seat on the opposite side of the elastic body in the body main body, toward the inner side of the valve chamber and closer to the center of the movable seat than the outer periphery of the movable seat. A stopper that protrudes to a position, and the valve body has, as at least a part thereof, a spherically shaped portion formed on a spherical surface, and the shaft has an axis deviated from the center of curvature of the spherically shaped portion. The valve body in position The movable seat has a communication hole having an axis in a direction substantially orthogonal to the axis of the shaft, and the spherical shape portion of the valve body abuts on the seat surface to close the communication hole. Thus, the valve is closed, and the displacement of the movable sheet is restricted by the stopper, and the valve body is separated from the movable sheet to open the communication hole, thereby opening the valve.

  According to the above configuration, the valve body rotates (swings) about the eccentric rotation axis, and the valve body is seated on the movable seat, thereby closing the valve, and the valve body is separated from the movable seat. The valve is opened. In such a configuration, the conventional fixed seat is unnecessary, and the valve body is in contact with the movable seat only when the valve seated on the movable seat is in the closed state. Since there is no constant contact, it is possible to reduce wear of the valve body and the movable seat and to prevent an increase in rotational torque.

  Further, when the valve body in the valve closed state swings away from the movable seat, the followability of the movable seat to the valve body is forcibly cut by the stopper, so that the valve body and the movable seat are Wear can be reduced. Furthermore, since the vibration from the movable sheet is not transmitted to the valve body while the valve body is separated from the movable sheet, the influence on the vibration resistance can be reduced.

  Furthermore, when the valve body is seated on the movable seat, the movable seat is constantly urged to the valve body side by the elastic body, so the adhesion between the valve body and the movable seat is high, and the movable seat Since the sealing performance between the movable seat and the valve chamber is ensured by the sealing member provided on the outer periphery, the sealing performance in the valve closed state can be reliably ensured.

  In the flow path opening / closing valve, the movable sheet may be disposed so as to be displaceable in a direction orthogonal to the axial direction within a range of elastic deformation of the seal member.

  According to the above configuration, when the valve body is seated on the movable seat, the position of the movable seat is automatically adjusted even if a deviation caused by a manufacturing error or an assembly error is between the valve body and the movable seat. The For this reason, in a valve closed state, a valve body and a movable sheet contact | adhere reliably, and it can ensure favorable sealing performance.

  In the flow path opening / closing valve, an angle formed between the axial direction of the movable seat and the seat surface is defined as a seat angle on a cross section in a plane perpendicular to the axis of the shaft and including the center of curvature of the valve body. When the valve body is in a closed state with respect to the straight line in a region on the opposite side of the movable seat with respect to a straight line passing through the center of curvature of the spherical shape portion of the valve body and perpendicular to the axis of the movable seat The rotation axis of the valve body may be set in a region that is angled by the seat angle around the center of curvature.

  When the position of the pivot axis of the valve body is set as described above, the rotation trajectory of the valve body does not pass through the inside of the movable sheet, so that the valve body is not pushed into the movable sheet, and between the valve body and the movable sheet “Kojiri” can be prevented. Therefore, wear caused by friction between the valve body and the movable seat can be more effectively reduced.

  In the flow path opening / closing valve, the formation range of the spherical shape portion in the valve body is within the rotation range of the valve body, regardless of the rotation state of the valve body, through the communication hole of the movable seat. It is good to set so that only the said spherical-shaped part can always be seen when seeing a valve body from an upstream.

  According to the above configuration, since the spherical shape portion of the valve body faces the opening of the movable seat regardless of the rotation state of the valve body, the gas that has passed through the communication hole of the movable seat is always the spherical shape portion of the valve body. And flows into the valve chamber. Thereby, the gas flow rate is substantially proportional to the rotation angle of the valve body, and the linear characteristic of the gas flow rate can be ensured.

  According to the flow path opening / closing valve according to the present invention, wear due to friction between the valve body and the seat can be reduced, and vibration resistance can be improved.

It is a partial cross section perspective view of the channel on-off valve concerning one embodiment of the present invention. 2A is a cross-sectional view taken along the line IIA-IIA in FIG. 1, and FIG. 2B is a cross-sectional view showing the ball valve and its peripheral portion in the valve open state. It is explanatory drawing about the area | region with a "squeeze" and a "no-squeeze" area | region prescribed | regulated based on the seat angle in the fully closed position relationship between a seat and a valve. FIG. 4A is a schematic explanatory view showing that the pivot axis of the valve body is located in a region where “squeezing” is present, and FIG. FIG. 4C is a schematic explanatory view showing that the pivot axis of the valve body is located at the boundary between the “squeeze” presence region and the “squeeze” non-region, and FIG. It is a schematic explanatory drawing which shows that it is located in.

  Hereinafter, preferred embodiments of a flow path opening / closing valve according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a partial cross-sectional perspective view of a flow path opening / closing valve 10 according to the first embodiment of the present invention. The flow path opening / closing valve 10 includes a body main body 12, a valve body 14 that is rotatably provided inside the body main body 12, a movable sheet 16 that contacts the valve body 14, and an elastic body that biases the movable sheet 16. 54 and a driving force transmission mechanism 18 that is provided on the upper portion of the body main body 12 and applies a rotational driving force to the valve body 14.

  The flow path opening / closing valve 10 according to the present embodiment is configured as an exhaust gas circulation valve (EGR valve) 10A, and a gas inlet through which exhaust gas containing vaporized fuel is supplied to the lower portion of the body main body 12. 22 is provided, and on the opposite side of the gas inlet 22 with the valve body 14 therebetween, a gas outlet 24 for leading exhaust gas and circulating it to an internal combustion engine (not shown) is provided.

  In the body main body 12, the gas inlet 22 and the gas outlet 24 are provided on a substantially straight line. In the body main body 12, a valve chamber 26 is formed between the gas inlet 22 and the gas outlet 24, and the spherical valve body 14 is rotatably disposed in the valve chamber 26. The valve body 14 is formed with a through hole 28 that passes through the central portion of the valve body 14 and penetrates from one side to the other side. In the valve body 14, the outer peripheral surface of the portion excluding the through hole 28 and the upper and lower portions is configured as a spherical shape portion 30, and the valve body 14 abuts on the movable sheet 16 on the surface of the spherical shape portion 30.

  The upper end portion of the first shaft 32 is connected and fixed to the lower portion of the valve body 14, and the lower end portion of the second shaft 34 is connected and fixed to the upper portion of the valve body 14. The first shaft 32 is supported by a bearing 36 attached and fixed to the lower portion of the body body 12 so as to be rotatable about the axis A1. The second shaft 34 is supported by a bearing 38 attached and fixed to the upper part of the body main body 12 so as to be rotatable about the axis A1. That is, the first shaft 32 and the second shaft 34 rotate around the same axis A1. The axis A1 is parallel to a straight line orthogonal to the axis C of the movable sheet 16.

  Here, in FIG. 1, the axis C of the movable sheet 16 is a straight line that passes through the center of the gas inlet 22 and the center of the gas outlet 24. The arrow X direction is a direction along the axis C, and the arrow Z direction is a direction perpendicular to the X direction and along the axis A1 of the first shaft 32 and the second shaft 34 (the vertical direction in FIG. 1). The arrow Y direction is a direction orthogonal to the X direction and the Z direction.

  The position of the axis A1 of the first shaft 32 and the second shaft 34 is set to a position that is eccentric from the axis A2 that is parallel to the axis A1 and passes through the center of the valve body 14. That is, the axis A1 is set apart from the axis A2 of the valve body 14 by a predetermined distance. Therefore, the valve body 14 is installed in the valve chamber 26 so as to rotate (swing) about the axis A1 set at a position eccentric from the axis A2.

  The driving force transmission mechanism 18 is connected to the above-described second shaft 34, the rotary yoke 40 connected to the upper end portion of the second shaft 34, and the upper portion of the body main body 12, and the second shaft 34 via the rotary yoke 40. And a drive source 42 for rotationally driving the motor.

  The upper end portion of the second shaft 34 is inserted through the substantially central portion of the rotary yoke 40 and is fixed by tightening the nut 44. The drive source 42 is composed of, for example, a stepping motor or a rotary actuator that is rotationally driven under an energization action, and the rotational driving force is transmitted to the second shaft 34 via the rotary yoke 40, whereby The connected valve body 14 rotates around the axis A1. In this case, the first shaft 32 connected to the lower portion of the valve body 14 rotates integrally with the valve body 14 under the support action of the bearing 36.

  2A is a cross-sectional view taken along line IIA-IIA in FIG. As shown in FIGS. 1 and 2A, the movable seat 16 is a ring-shaped member disposed between the valve body 14 and the gas inlet 22, and a circle of the seat mounting portion 46 formed in the valve chamber 26. The annular inner peripheral surface is disposed so as to be slidable in the X direction (direction along the axis C).

  A communication hole 17 penetrating in the direction of the axis C is formed at the center of the movable sheet 16. A seat surface 48 on which the valve body 14 is seated is formed on the X1 direction side of the communication hole 17 in the movable seat 16. The seat surface 48 is an annular surface extending about the axis C of the movable sheet 16 and is inclined with respect to the axis C by a predetermined angle. That is, the seat surface 48 is formed so that the inner diameter linearly increases as it goes toward the X1 direction.

  A seal mounting groove 50 extending in an annular shape around the axis is formed on the outer peripheral portion of the movable sheet 16, and an annular seal member 52 is mounted in the seal mounting groove 50. The seal member 52 is a member that can be elastically deformed, and can be formed of, for example, a rubber elastic body such as an O-ring. The seal member 52 mounted in the seal mounting groove 50 is in contact with and in close contact with the inner peripheral surface of the sheet mounting portion 46 over the entire outer periphery. As a result, a seal is formed between the outer peripheral portion of the movable seat 16 and the inner peripheral surface of the valve chamber 26 (specifically, the seat mounting portion 46), and the movable seat 16 extends along the inner peripheral surface of the valve chamber 26. And is slidable. Further, the movable sheet 16 can be displaced in a direction orthogonal to the direction of the axis C within the range of elastic deformation of the seal member 52, that is, in the YZ plane.

  An elastic body 54 that elastically biases the movable sheet 16 toward the valve body 14 (X1 direction side) is disposed on the movable sheet 16 in the X2 direction side. The elastic body 54 according to the configuration example illustrated in FIG. 1 and the like is configured as a wave washer. This wave washer is a ring-shaped component formed so that the phase in the axial direction differs depending on the position in the circumferential direction, and functions as a spring. The elastic body 54 is not limited to a wave washer, and may be another spring material such as a coil spring, or may be a rubber elastic body having a function of urging the movable seat 16 toward the valve body 14.

  On the X1 direction side (the side opposite to the elastic body) of the movable sheet 16, a stopper 56 is provided that regulates the position where the movable sheet 16 advances to the valve body 14 side. The stopper 56 is provided in the body main body 12 at a position opposite to the elastic body 54 of the movable seat 16, and toward the center of the movable seat 16 from the outer peripheral portion of the movable seat 16 toward the inside of the valve chamber 26. It protrudes to the position.

  The stopper 56 in the illustrated example is a ring-shaped member that is fixedly mounted on a stopper mounting portion 58 formed on the X1 direction side of the sheet mounting portion 46, and comes into contact with the movable sheet 16 on the surface on the X2 side. The movable sheet 16 is prevented from moving further in the X1 direction side. The stopper 56 is not limited to the ring shape, and may be constituted by a plurality of stopper pieces arranged at intervals in the circumferential direction of the stopper mounting portion 58. The stopper 56 may be formed integrally with the body body 12 instead of being configured as a member different from the body body 12.

  The flow path opening / closing valve 10 according to the present embodiment is basically configured as described above. Next, the operation and effects thereof will be described. Here, as shown in FIG. 1 and FIG. 2A, the valve closed state in which the flow path between the gas inlet 22 and the gas outlet 24 is blocked by the valve body 14 will be described as an initial position.

  As shown in FIG. 2A, in the initial position, the through hole 28 of the valve body 14 is oriented in a direction perpendicular to the gas inlet 22 and the gas outlet 24, and the spherical shape portion 30 provided on the side surface of the valve body 14 is provided. The sheet is in contact with a sheet surface 48 provided on the movable sheet 16. That is, the valve body 14 is seated on the movable seat 16 and the communication hole 17 of the movable seat 16 is closed. In this case, since the movable sheet 16 is elastically urged toward the valve body 14 by the elastic body 54, the sealing performance between the seat surface 48 of the movable sheet 16 and the spherical surface portion 30 of the valve body 14 is maintained. Is done. Further, the sealing performance between the movable sheet 16 and the inner peripheral surface of the valve chamber 26 is maintained by the seal member 52 provided on the outer peripheral portion of the movable sheet 16. As a result, the flow path between the gas inlet 22 and the gas outlet 24 is blocked. Therefore, although a gas (not shown) is supplied to the gas inlet 22, the gas does not flow downstream from the movable sheet 16.

  When the drive source 42 shown in FIG. 1 is driven from such a valve closed state, the rotational driving force of the drive source 42 is transmitted to the second shaft 34 via the rotary yoke 40 and is connected to the second shaft 34. The valve body 14 rotates about the axis A1 set at a position eccentric from the axis A2, and the state shown in FIG. 2B is obtained. Thus, when the valve body 14 rotates around the eccentric axis A1, the valve body 14 is displaced in the direction of retreating with respect to the movable seat 16 (X1 direction).

  In this case, the movable sheet 16 is urged toward the valve body 14 by the elastic body 54, but since the advance position is restricted by the stopper 56, displacement from the restricted position toward the valve body 14 is prevented. Is done. As a result, the followability of the movable sheet 16 to the valve body 14 is forcibly cut off, and the valve body 14 moves away from the movable sheet 16 in accordance with the displacement in the X1 direction side, and the movable sheet 16 and the valve body 14 A gap is formed between the two. 2B shows a state in which the valve body 14 is rotated 90 ° counterclockwise around the axis A1 from the state shown in FIG. 2A, and the through hole 28 is aligned with the gas inlet 22 and the gas outlet 24. It has become.

  In such a valve open state, the gas supplied to the gas inlet 22 flows through the gap formed between the movable seat 16 and the valve body 14 and the through hole 28 of the valve body 14 and flows out from the gas outlet. Thus, it is introduced into an internal combustion engine (not shown).

  As described above, according to the flow path opening / closing valve 10 (EGR valve 10A) according to the present embodiment, the valve element 14 rotates (swings) about the rotation axis (axis A1) that is eccentric, and the valve The valve 14 is closed when the body 14 is seated on the movable seat 16, and the valve is opened when the valve body 14 is separated from the movable seat 16. In such a configuration, the conventional fixed seat is unnecessary, and the valve body 14 is in contact with the movable seat 16 only when the valve seated on the movable seat 16 is in the closed state. Since there is no constant contact between the movable body 16 and the movable seat 16, wear of the valve body 14 and the movable seat 16 can be reduced, and an increase in rotational torque can be prevented.

  Further, when the valve body 14 in the valve closed state swings away from the movable seat 16, the followability of the movable seat 16 to the valve body 14 is forcibly cut by the stopper 56. The wear between the movable sheet 14 and the movable sheet 16 can be reduced.

  Furthermore, since the vibration from the movable sheet 16 is not transmitted to the valve body 14 while the valve body 14 is separated from the movable sheet 16, the influence on the vibration resistance can be reduced. Furthermore, when the valve body 14 is seated on the movable seat 16, the movable seat 16 is always urged toward the valve body 14 by the elastic body 54, so that the adhesion between the valve body 14 and the movable seat 16 is maintained. In addition, since the sealing performance between the movable seat 16 and the valve chamber 26 is ensured by the sealing member 52 provided on the outer periphery of the movable seat 16, the sealing performance in the valve closed state can be reliably ensured. .

  Further, since the movable seat 16 can be displaced in a direction orthogonal to the axial direction within the range of elastic deformation of the seal member 52, when the valve body 14 is seated on the movable seat 16, production errors and Even if the displacement due to the assembly error is between the valve element 14 and the movable sheet 16, the position of the movable sheet 16 is automatically adjusted. That is, the error can be allowed by the alignment function of the movable sheet 16. For this reason, in the valve closed state, the valve body 14 and the movable sheet | seat 16 contact | adhere reliably, and it can ensure favorable sealing performance.

  By the way, in the configuration described above, a so-called “twist” may occur between the valve body 14 and the movable seat 16 depending on the rotational axis of the valve body 14, that is, the position of the axis A <b> 1. Such “squeezing” promotes the wear of the valve body 14 and the movable seat 16 and affects the durability. Therefore, it is desirable to prevent or reduce this. Hereinafter, a configuration for preventing or reducing such “twisting” will be described.

  First, with reference to FIG. 3, the “Kojiri” area K2 and the “Kojiri” no area K1 determined by the sheet angle will be described. As shown in FIG. 3, the axial direction of the movable seat 16 and the seat surface 48 are formed on a cross section in a plane orthogonal to the axes of the first shaft 32 and the second shaft 34 and including the center of curvature of the valve body 14. The angle is defined as the sheet angle θ. The center of the sphere S when the spherically shaped portion 30 of the valve body 14 in the valve closed state is a part of the sphere (virtual sphere) S is denoted by P1, and the seat of the valve body 14 and the movable seat 16 The contact position with the surface 48 is indicated by P2. In addition, when the valve body 14 is substantially spherical as in the present embodiment, the center of the sphere S coincides with the center of the valve body 14.

  Under such conditions, the sphere with respect to the straight line B in the region on the opposite side of the movable seat 16 with respect to the straight line B passing through the center of the sphere S when the valve is closed and perpendicular to the axis of the movable seat 16 A region around the center of S by an angle corresponding to the sheet angle θ is a “koji” non-region K1, and a region exceeding the sheet angle θ is a “saw” region K2. The boundary line L that is inclined by the seat angle θ with respect to the straight line B is included in the “koji” no region K1.

  3 is based on the premise that the rotation direction of the valve element 14 when the valve element 14 is opened is the counterclockwise direction in FIG. 3, the region where the seat angle θ is taken with respect to the straight line B is the axis C. When the valve body 14 is rotated in the clockwise direction in FIG. 3 when the valve body 14 is opened, the region taking the seat angle θ with respect to the straight line B is above the axis C. Become.

  By setting the rotational axis of the valve body 14, that is, the position of the center position (axis line A 1) of the first shaft 32 and the second shaft 34 within the “koji” no region K 1, the rotational trajectory of the valve body 14 can be changed. Since it does not pass through the movable sheet 16, the valve body 14 is not pushed into the movable sheet 16, and “squeezing” between the valve body 14 and the movable sheet 16 can be prevented.

  With reference to FIGS. 4A to 4C, the relationship between the position of the rotational axis of the valve body 14 and the occurrence of “twisting” will be described by taking a case where the seat angle θ is 45 ° as an example. 4A to 4C, the rotation axis of the valve body 14 is indicated by the reference symbol P3.

  In FIG. 4A, the rotation axis P3 is at a position where the amount of eccentricity x is larger than the amount of eccentricity y (the amount of eccentricity x> the amount of eccentricity y). For this reason, the rotation axis P3 is set in the “Kojiri” area K2. In this case, since the rotation trajectory T1 of the valve body 14 enters the movable seat 16, the valve body 14 is movable with the valve body 14 when the valve body 14 is seated on the movable seat 16 or when the valve body 14 is detached from the movable seat 16. A “squeeze” occurs between the sheet surface 48 of the sheet 16.

  In FIG. 4B, the position of the rotational axis P3 is at a position where the amount of eccentricity x and the amount of eccentricity y are the same (the amount of eccentricity x = the amount of eccentricity y). For this reason, the position of the rotational axis P3 is set to a “no-koji” region K1 on the boundary line inclined by 45 ° with respect to the straight line B. In this case, since the rotation trajectory T1 of the valve body 14 does not enter the movable seat 16, when the valve body 14 is seated on the movable seat 16 or when the valve body 14 is detached from the movable seat 16, No “squeezing” occurs between the movable sheet 16 and the sheet surface 48.

  In FIG. 4C, the position of the rotational axis P3 is at a position where the amount of eccentricity x is smaller than the amount of eccentricity y (the amount of eccentricity x <the amount of eccentricity y). For this reason, the position of the rotational axis P3 is set in the “no-koji” no-region K1. In this case, since the rotation trajectory T1 of the valve body 14 does not enter the movable seat 16, when the valve body 14 is seated on the movable seat 16 or when the valve body 14 is detached from the movable seat 16, No “squeezing” occurs between the movable sheet 16 and the sheet surface 48.

  When the position of the pivot axis is set as shown in FIG. 4B, the trajectory T2 at the center of the valve body 14 (center of the sphere S) is minimized, and the valve body 14 is accommodated compared to the case of FIG. 4C. Since the required space of the valve chamber 26 to be reduced can be reduced, the body body 12 can be reduced in size.

  The valve body 14 described above may be formed in a shape in which the through hole 28 is eliminated (substantially the entire valve body 14 is spherical). Even when the valve body 14 does not have the through hole 28, when the valve body 14 is separated from the movable sheet 16, the gas can flow downstream through the gap formed between the valve body 14 and the movable sheet 16. is there. When the through hole 28 is not provided in the valve body 14 as described above, the valve body 14 is viewed from the upstream side through the communication hole 17 regardless of the rotation state of the valve body 14 within the rotation range of the valve body 14. Therefore, only the spherical surface portion 30 is always visible. That is, when the valve element 14 is viewed through the movable seat 16, the valve element 14 is in the valve closed state, in the valve open state, or in the middle of the valve open state from the valve open state. However, only the spherical surface portion 30 is always visible.

  Thus, when the valve body 14 does not have the through hole 28, the spherical shape portion 30 of the valve body 14 faces the communication hole 17 of the movable sheet 16 regardless of the rotational state of the valve body 14. The gas that has passed through 17 always flows along the spherical shape portion 30 of the valve body 14 and flows into the valve chamber 26 on the downstream side. Thereby, the gas flow rate is substantially proportional to the rotation angle of the valve body 14, and the linear characteristic of the gas flow rate can be ensured.

  In order to ensure the linear characteristic of the gas flow rate, it is not necessary for the entire valve body 14 to have a spherical shape, and the formation range of the spherical portion 30 in the valve body 14 is within the rotation range of the valve body 14. Therefore, it is sufficient that the spherical body 30 is always visible only when the valve body 14 is viewed from the upstream side through the communication hole 17 of the movable seat 16 regardless of the rotation state of the valve body 14. Therefore, for example, the valve body 14 may be formed in a shape obtained by cutting a portion on the opposite side to the movable sheet 16 into a flat shape.

  When the valve body 14 is formed in this way, the spherical shape portion 30 is always seen from the upstream side through the movable seat 16 in the valve closed state, and is always seen from the upstream side through the movable seat 16 in the valve open state. The spherical shape portion 30 is visible, and the spherical shape portion 30 is also visible in the middle of the valve closed state and the valve open state. Therefore, the gas flow rate is substantially proportional to the rotation angle of the valve body 14b, and the linear characteristic of the gas flow rate can be ensured.

  The application range of the present invention is not limited to the EGR valve, and can be used as a valve for opening and closing various fluid flow paths.

  In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

DESCRIPTION OF SYMBOLS 10 ... Flow-path on-off valve 10A ... EGR valve 12 ... Body main body 14 ... Valve body 16 ... Movable sheet 17 ... Seat surface 22 ... Gas inflow port 24 ... Gas outflow port 26 ... Valve chamber 30 ... Spherical shape part 52 ... Sealing member 54 ... elastic body 56 ... stopper

Claims (4)

A valve body rotatably provided via a shaft;
A body body having a valve chamber for accommodating the valve body;
A movable seat having a seat surface on which the valve body is seated;
An annular seal member disposed on an outer peripheral portion of the movable seat and contacting an inner peripheral surface of the valve chamber;
An elastic body for urging the movable seat toward the valve body;
In the body main body, the movable seat is provided at a position opposite to the elastic body, and protrudes inward of the valve chamber from the outer peripheral portion of the movable seat to a position closer to the center of the movable seat. And a stopper,
The valve body has, as at least a part thereof, a spherical shape portion formed on a spherical surface,
The shaft is attached to the valve body at a position where the axis thereof deviates from the center of curvature of the spherical shape portion,
The movable sheet has a communication hole having an axis in a direction substantially orthogonal to the axis of the shaft,
The spherical shape portion of the valve body comes into contact with the seat surface and closes the communication hole, thereby closing the valve.
Displacement of the movable sheet is regulated by the stopper, and the valve body is separated from the movable sheet to open the communication hole, thereby opening the valve.
A flow path opening / closing valve characterized by that. The flow path opening / closing valve according to claim 1,
The movable sheet is disposed so as to be displaceable in a direction orthogonal to the axial direction within a range of elastic deformation of the seal member.
A flow path opening / closing valve characterized by that. In the flow path on-off valve according to claim 1 or 2,
On a cross section in a plane perpendicular to the axis of the shaft and including the center of curvature of the valve body,
When the angle formed between the axial direction of the movable sheet and the sheet surface is defined as a sheet angle,
The curvature with respect to the straight line in a region on the opposite side of the movable seat with respect to a straight line passing through the center of curvature of the spherical shape portion of the valve body in the valve closed state and orthogonal to the axis of the movable seat. The rotation axis of the valve body is set in a region that is angled by the seat angle around the center,
A flow path opening / closing valve characterized by that. In the flow path on-off valve according to any one of claims 1 to 3,
The formation range of the spherical shape portion in the valve body is within the rotation range of the valve body, regardless of the rotation state of the valve body, and the valve body is viewed from the upstream side through the communication hole of the movable seat. Is set so that only the spherical shape portion is always visible when
A flow path opening / closing valve characterized by that.

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