JP6701436B2 - Butterfly valve and exhaust gas recirculation valve - Google Patents

Description

  The present invention relates to a butterfly valve and an exhaust gas recirculation valve in which a valve contacts a step provided in a fluid passage.

  The engine of a vehicle is equipped with an exhaust gas recirculation device (EGR device) that recirculates exhaust gas to the intake side. The exhaust gas recirculation device recirculates a part of the exhaust gas to an intake passage that circulates air to the engine by a recirculation passage that branches from an exhaust gas passage that circulates the exhaust gas of the engine. The exhaust gas recirculation device is provided with an exhaust gas recirculation valve for adjusting the flow rate of exhaust gas that recirculates to the intake passage. This exhaust gas recirculation valve has a valve seat that is a step provided in the recirculation passage, by rotating the valve that opens and closes the recirculation passage integrally with the valve shaft that is supported by the housing by an actuator such as a motor. The butterfly valve closing the recirculation passage by contacting the valve adjusts the flow rate of the exhaust gas that recirculates.

  Therefore, in the conventional butterfly valve, the gap between the valve body and the inner wall of the passage member is closed by the seal ring. It is configured by including an inner peripheral lip and an outer peripheral lip forming a cavity. (For example, Patent Document 1)

JP, 2012-127207, A

The conventional butterfly valve described above is configured by forming an annular hollow portion having a groove bottom portion on the upstream side of the EGR gas in the seal ring, and including an elastically deformable inner peripheral lip and an outer peripheral lip. Therefore, the outer peripheral lip is deformed to the inside of the annular cavity by the pressure of the EGR gas, and the sealing performance is deteriorated. As a result, there is a problem that leakage of EGR gas occurs in the butterfly valve.

  Further, for example, as shown in FIG. 5, in the conventional valve seal 11 configured by forming the annular cavity portion 8 having an opening on the upstream side of the exhaust gas and including the lip portion 12 made of an elastic body, Since the gas flows into the annular cavity portion 8, the lip portion 12 is deformed to the outside of the annular cavity portion 8 by the pressure of the exhaust gas. Therefore, the contact resistance increases when the lip portion 12 contacts the valve seat 7. As a result, there is a problem in that the lip portion 12 is deformed or curled during the valve closing operation of the valve 5 and the sealing property and durability are deteriorated. Further, since the contact resistance when the lip portion 12 contacts the valve seat 7 increases, the rotational resistance of the valve 5 also increases. Therefore, a motor with a large output is required, and the exhaust gas recirculation valve also becomes large.

  The present invention has been made to solve the above-mentioned problems, and improves the sealing performance and durability, reduces the rotational resistance of the valve, and enables the use of a low-output motor, which leads to a reduction in size. It is intended to obtain a butterfly valve and an exhaust gas recirculation valve capable of

A butterfly valve and an exhaust gas recirculation valve according to the present invention are provided with a housing having a fluid passage, a valve shaft axially supported by the housing and penetrating the fluid passage, and arranged inside the fluid passage and fixed to the valve shaft. Disk-shaped valve that rotates in a vertical direction, an annular valve seat that is arranged on the inner wall of the fluid passage to form a convex step, and a valve seat that is formed on the peripheral edge of the valve and that opens when the fluid passage contacts the valve seat. and a valve seal of the closure to the elastic body, the valve seal, to form a cavity of annular opening at the upstream side of the fluid, has an arc lip portion formed an outer peripheral section of the cavity in a circular arc shape, the valve The center of rotation, the center of the arc of the arc lip portion, and the contact point of the valve seat and the valve seal are arranged on the same line .

  The butterfly valve and the exhaust gas recirculation valve configured as described above are sealed by providing the valve seal with an annular hollow portion that receives fluid pressure and an arc lip portion that abuts the valve seat and closes the fluid passage. Of the butterfly valve and exhaust gas recirculation valve, which can improve the durability and durability, reduce the rotational resistance of the valve, use a low-output motor, and can be downsized.

1 is a perspective one-side sectional view showing the overall configuration of a butterfly valve according to Embodiment 1 of the present invention. It is sectional drawing of the XY plane of FIG. 1 which shows Embodiment 1 of this invention, FIG.2(a) shows the state which the butterfly valve closed, and FIG.2(b) shows the state which the butterfly valve opened. It is a principal part enlarged view of FIG. 2(a) which shows Embodiment 1 of this invention. FIG. 3 is a main-portion cross-sectional view showing a state of the valve seal when the butterfly valve according to Embodiment 1 of the present invention is closed. It is a principal part sectional view which shows the state of the valve seal in the conventional butterfly valve.

  Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.

Embodiment 1.
The butterfly valve according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a perspective one-side sectional view showing the overall configuration of a butterfly valve according to Embodiment 1 of the present invention. 2 is a cross-sectional view of the XY plane of FIG. 1 showing Embodiment 1 of the present invention, FIG. 2(a) shows a state in which the valve is closed, and FIG. 2(b) shows a state in which the butterfly valve is open. Indicates. FIG. 3 is an enlarged view of a main part of FIG. 2A showing the first embodiment of the present invention. FIG. 4 is a sectional view of relevant parts showing a state of the valve seal with the butterfly valve closed according to the first embodiment of the present invention.

As shown in FIG. 1, a butterfly valve 1 includes a housing 2 installed in a recirculation passage (not shown) that recirculates exhaust gas of an engine, and a motor (supported by a rotatably supported housing 2). A valve shaft 3 connected to an actuator (not shown) or the like, and a valve 5 fastened to the valve shaft 3 with a screw (not shown) or the like to rotate integrally with the valve shaft 3 to open or close the fluid passage 4. , And a valve seal 6 which is arranged on the periphery of the valve 5 to seal the fluid passage 4. Here, the axis of the valve shaft 3 is the Z axis, the center of the valve 5 is the X axis, and the radial direction of the valve 5 is the Y axis.

  As shown in FIG. 2( a ), the housing 2 has a tubular shape and is provided with a fluid passage 4 through which exhaust gas flows, and a valve seat 7 having an annular convex step on the inner wall of the fluid passage 4. ing.

The valve shaft 3 is rotatably rotatably supported by a bearing (not shown) arranged in the housing 2 with a seal member (not shown) interposed so as to prevent exhaust gas from leaking and a fluid passage. Penetrates 4 An actuator such as a motor (not shown) is connected to the valve shaft 3. The center of rotation of the valve shaft 3 is on the origin perpendicular to the X and Y axes.

The valve 5 has a disc shape and is fastened to the outer periphery of the valve shaft 3 with a screw (not shown) or the like, and rotates integrally with the valve shaft. The center of the valve 5 is on the X axis and closes the fluid passage 4 at a position parallel to the Y axis. A valve seal 6 is provided on the periphery of the valve 5 so as to contact the valve seat 7 and seal the exhaust gas so that the exhaust gas does not leak.

  As shown in FIG. 3, the valve seal 6 has an annular shape and has a groove formed on the inner peripheral side, and the peripheral edge of the valve 5 is fitted into the groove and attached to the valve 5. The valve seal 6 is formed of rubber, a thin metal plate, or an elastic body such as resin. Further, the valve seal 6 is provided with an arc lip portion 9 having a C-shaped cross section in which an annular cavity portion 8 having an opening on the upstream side of exhaust gas is formed. Although the valve seal 6 has an annular shape having a groove on the inner peripheral side, it may be configured to cover the outer surface of the valve 5 or to cover only one of the downstream side and the upstream side of the exhaust gas.

  The valve seat 7 has an annular shape, and an end portion on the downstream side of the exhaust gas has a taper shape in which an inner diameter spreads on the downstream side, and is provided as an annular convex step on the inner wall of the fluid passage 4 of the housing 2. ing. The circular arc lip portion 9 of the valve seal 6 contacts the valve seat 7, and contacts the contact point S1 when the valve 5 is closed. The taper shape of the valve seat 7 is formed along the circumference of a radius R1 from the center O1 which is the rotation center of the valve shaft 3 to the contact point S1.

The annular cavity portion 8 is an annular cavity provided in the valve seal 6 and has an opening on the upstream side of the exhaust gas. The inner wall of the annular cavity portion 8 is formed in an arc shape in cross section. The diameter of the inner wall of the cross section of the annular cavity portion 8 is larger than the width of the opening. Although the cross section of the inner wall of the annular cavity 8 is arcuate, it is not limited to an arcuate shape, and the cross section of the annular cavity 8 may be formed into an elliptical shape or a rectangular shape.

  The arc lip portion 9 is provided on the outer periphery of the valve seal 6 and forms the inner wall of the annular cavity portion 8. The outer circumference of the circular arc lip portion 9 has a circular arc shape in cross section. The outer periphery of the arc lip portion 9 contacts the valve seat 7, and contacts the contact point S1 when the valve 5 is closed. The circular arc shape of the outer circumference of the circular arc lip portion 9 is formed with a radius R2 with the center O2 as the center point. The center O2 forming the arc lip portion 9 is arranged on a line connecting the center O1 which is the rotation center of the valve shaft 3 and the contact point S1 between the arc lip portion 9 of the valve seal 6 and the valve seat 7. Further, the radius R2 of the cross section of the outer circumference of the arc lip portion 9 is larger than the radius R1 from the center O1 which is the rotation center of the valve shaft 3 to the contact point S1 between the arc lip portion 9 of the valve seal 6 and the valve seat 7. small.

  FIG. 4 shows a state in which the valve 5 is closed to close the fluid passage 4 and the valve seal 6 is in contact with the valve seat 7 so as to prevent exhaust gas from leaking in the configuration of FIG.

Next, the operation of the butterfly valve thus configured will be described with reference to FIGS. As shown in FIG. 2A, the exhaust gas flows from the valve 5 side to the valve shaft 3 side in the X-axis direction of the fluid passage 4 provided in the housing 2 of the butterfly valve 1.
As shown in FIG. 2B, the valve 5 of the butterfly valve 1 opens the fluid passage 4 at a position parallel to the X axis. When an actuator such as a motor (not shown) connected to the valve shaft 3 for controlling the flow rate of exhaust gas is driven, the valve shaft 3 rotates. Then, as shown in FIG. 2A, the valve 5 attached to the valve shaft 3 is rotated to a position parallel to the Y axis to close the fluid passage 4. As a result, as shown in FIG. 3, the arc-shaped lip portion 9 of the valve seal 6 attached to the peripheral edge of the valve 5 abuts the tapered end portion of the valve seat 7 and rotates to the position of the abutment point S1. It is actuated to block the fluid passages and seal the exhaust gases from leaks. Therefore, the arc lip portion 9 contacts the end portion of the valve seat 7 and is rotated, so that the arc lip portion 9 is deformed or curled. The deformation or curling of the circular arc lip portion 9 is suppressed because the outer peripheral cross section of the circular arc lip portion 9 has an arc shape.

  Next, when the arc lip portion 9 is brought into contact with the valve seat 7 at the contact point S1, the exhaust gas flowing through the fluid passage 4 flows into the annular cavity portion 8. Then, due to the pressure of the exhaust gas flowing into the annular cavity portion 8, the arc lip portion 9 swells and elastically deforms outward. As a result, the sealing force 10 of the circular arc lip portion 9 that abuts on the valve seat 7 increases, so that the valve seal 6 is reliably sealed.

As described above, in the butterfly valve shown in the first embodiment, the valve seal is provided with the annular cavity portion and the arc lip portion that abuts the valve seat and closes the fluid passage. Since the arcuate shape of the cross-section of the outer circumference of the arc lip portion prevents entrainment due to contact when the valve is rotated, the valve seal 6 is larger than the case where the conventional valve seal 11 having the lip portion 12 is used. Deformation and curling are suppressed. Further, due to the arc shape of the cross section of the outer circumference of the arc lip portion, the valve seat comes into line contact with the arc lip, so that the contact resistance is reduced. As a result, it is possible to obtain a butterfly valve and an exhaust gas recirculation valve that can improve the sealing property and durability, reduce the valve rotation resistance and use a low output motor, and can be downsized. Produce an effect.

  Further, by forming the annular hollow portion, the arc lip portion bulges by the pressure of the exhaust gas flowing into the annular hollow portion and elastically deforms outward. As a result, the sealing force of the circular arc lip portion that contacts the valve seat increases. As a result, the valve seal can be reliably sealed.

Further, in the butterfly valve described in the first embodiment, the valve seat is formed with a taper shape in which the inner diameter is widened on the downstream side at the end of the valve seat on the downstream side of the exhaust gas, whereby the valve seal is deformed or rolled up. Is suppressed and the contact resistance is reduced. As a result, it is possible to obtain a butterfly valve and an exhaust gas recirculation valve that can improve the sealing property and durability, reduce the valve rotation resistance and use a low output motor, and can be downsized. Produce an effect.

  By the way, the butterfly valve shown in the above-described embodiment has been described as an exhaust gas recirculation valve for adjusting the flow rate of exhaust gas in the exhaust gas recirculation device mounted on the engine of the vehicle. It is needless to say that the flow rate of the fluid different from the exhaust gas may be adjusted.

Further, in the present invention, within the scope of the invention, it is possible to freely combine the respective embodiments, modify any constituent element of each embodiment, or omit any constituent element in each embodiment. .

  The butterfly valve and the exhaust gas recirculation valve of the present invention can be used for controlling the opening degree of the exhaust gas recirculation device mounted on the engine.

  1 butterfly valve, 2 housing, 3 valve shaft, 4 fluid passage, 5 valve, 6 valve seal, 7 valve seat, 8 annular cavity part, 9 arc lip part, 10 sealing force, 11 conventional valve seal, 12 lip part, S1 contact point, R1 radius, R2 radius, O1 center, O2 center, X X axis, Y Y axis, Z Z axis

Claims (6)

A housing provided with a fluid passage,
A valve shaft axially supported by the housing and penetrating the fluid passage,
A disk-shaped valve that is disposed inside the fluid passage and that is fixed to the valve shaft and rotates.
An annular valve seat disposed on the inner wall of the fluid passage to form a convex step,
An elastic valve seal formed on a peripheral portion of the valve to close the fluid passage when abutting against the valve seat,
The valve seal is formed with an annular hollow portion that is open to the upstream side of the fluid, and has an arc lip portion in which the outer peripheral cross section of the hollow portion is formed in an arc shape .
The center of rotation of the valve, the center of the arc of the arc lip portion, and the contact point of the valve seat and the valve seal are arranged on the same line.
Butterfly valve characterized by. The butterfly valve according to claim 1, wherein the valve seal is formed of an elastic body of rubber, thin metal, or resin. The butterfly valve according to claim 1 or 2, wherein the valve seal is formed in an annular shape. The butterfly according to any one of claims 1 to 3 , wherein a radius of the circular arc of the circular arc lip portion of the valve seal is smaller than a distance from a rotation center of the valve to the contact point. valve. The butterfly valve according to any one of claims 1 to 4 , wherein the valve seat is formed in a tapered shape in which an inner diameter thereof widens on the downstream side of the fluid. An exhaust gas recirculation valve provided with the butterfly valve according to any one of claims 1 to 5 .

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