JP7354961B2 - composite seal ring - Google Patents

Description

The present invention relates to a composite seal ring.

Conventionally, in a butterfly valve type valve device used to open and close a passage through which exhaust gas recirculation (hereinafter referred to as "EGR") gas or the like flows, a seal ring that seals a gap between a valve and a gas passage is known. For example, Patent Document 1 discloses a composite seal ring in which a metal spring is inserted into an insertion groove formed in a resin seal ring.

This composite seal ring is attached to an outer circumferential groove of a valve that opens and closes a gas passage, and when the valve is fully closed, the seal ring comes into close contact with the inner wall of a nozzle that forms part of the gas passage. The spring resists the pressure of the EGR gas, keeps the seal ring in close contact, and prevents the seal ring from falling off the valve.

JP2019-39441A

Normally, a seal ring is formed into a perfect circle with an outer diameter that corresponds to the inner diameter of the inner wall of the passage, and an abutment is formed in a part of the circumference, and the abutment opens and closes as the gas pressure fluctuates. Expands and contracts in the direction and radially inward direction. However, if there are variations within the tolerance range in the outer diameter of the seal ring or the inner diameter of the fluid passage, the seal ring deforms into an oval shape when the valve is fully closed, and the gap between the seal ring and the inner wall of the passage Fluid may leak.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a composite seal ring that can suppress fluid leakage regardless of variations in the outer diameter of the seal ring or the inner diameter of the fluid passage. It's about doing.

The composite seal ring of the present invention is a composite seal ring (20) that is attached to an outer circumferential groove (141) of a valve (14) that opens and closes a fluid passage (12), and is attached to an inner wall (131, 111) of the fluid passage. It includes a seal ring (21) made of resin that slides into contact, and a C-shaped spring (22) made of a metal material inserted into an insertion groove (211) formed on one end surface in the axial direction of the seal ring. . The seal ring has an abutment part (213) that can be opened and closed in a part of the circumferential direction, and is elastically deformable in the radial direction about a fulcrum (P) on the opposite side of the abutment part across the center of the seal ring. be. A pair of protrusions (214) are provided at circumferentially intermediate positions between the fulcrum and the abutment so as to be able to abut the spring from the radial direction, and the seal ring and spring are inserted into the insertion groove in the angle range excluding the protrusions. It has a cavity (215) that allows relative movement in the radial direction.

According to the composite seal ring of the present invention, it is made up of a combination of a resin seal ring and a metal spring, and when fluid pressure acts on the seal ring when the valve is fully closed, the elastic repulsive force of the spring is applied to the seal through the protrusion. transmitted to the ring. Since the protrusion is provided at an intermediate position between the abutment of the seal ring and the fulcrum, which is the center of deformation, the elastic repulsive force of the spring is transmitted over a wide angular range around the protrusion. In the angular range excluding the projection, the gap allows relative movement between the seal ring and the spring, so the seal ring deforms to follow the shape of the inner wall of the passage. Therefore, even if there are variations in the outer diameter of the seal ring or the inner diameter of the fluid passage, the gap can be minimized, and fluid leakage when the valve is fully closed can be suppressed.

1 is a schematic cross-sectional view of an EGR valve device to which an embodiment of the present invention is applied. 2 is an enlarged view of part II in FIG. 1. FIG. FIG. 1 is a front view showing a composite seal ring according to an embodiment of the present invention. 4 is a sectional view taken along the line IV-IV in FIG. 3. FIG. FIG. 3 is a front view showing the composite seal ring with the abutment portion open. FIG. 7 is a reference diagram pointing out problems of a comparative example in which no protrusion is provided. FIG. 3 is a cross-sectional view of the composite seal ring of the present embodiment, showing the effect of the protrusions. FIG. 2 is a partial cross-sectional view of a composite seal ring showing Example 1 of a protrusion. FIG. 7 is a partial cross-sectional view of a composite seal ring showing Example 2 of a protrusion. FIG. 7 is a partial cross-sectional view of a composite seal ring showing Example 3 of a protrusion. FIG. 7 is a partial cross-sectional view of a composite seal ring showing Example 4 of a protrusion. FIG. 7 is a partial cross-sectional view of a composite seal ring showing Example 5 of a protrusion. It is a schematic sectional view of the EGR valve device of other embodiments.

(One embodiment)
Hereinafter, one embodiment of the present invention will be described based on the drawings. The composite seal ring of this embodiment is applied to a valve device that opens and closes an EGR gas passage in an EGR system that recirculates a portion of exhaust gas from a vehicle engine to an intake passage.

First, the configuration of the valve device will be explained based on FIGS. 1 and 2. A housing 11 of the valve device 10 is formed with a passage 12 (fluid passage) through which EGR gas flows. A cylindrical nozzle 13 is provided in a part of the passage 12, and an inner wall 131 of the nozzle 13 forms a part of the inner wall of the passage 12.

A valve 14 made of a disc-shaped butterfly valve is arranged inside the nozzle 13, and an outer peripheral groove 141 (see FIG. 2) having a rectangular cross section is formed on the outer periphery of the valve 14. The composite seal ring 20 is fitted into the outer circumferential groove 141 and rotated together with the valve 14 by the shaft 15 while in contact with the inner wall 131 .

The shaft 15 is rotatably supported by the housing 11 with bearings 16 and 17, and is rotated by a motor (not shown). A valve 14 is obliquely fixed to the shaft 15, and the passage 12 is opened/closed or the degree of opening is adjusted by the rotational displacement of the valve 14 via the composite seal ring 20.

Next, the configuration of the composite seal ring 20 will be explained based on FIGS. 3 and 4. The composite seal ring 20 includes a seal ring 21 and a spring 22. The seal ring 21 is made of a resin material such as PPS, PTFE, or PEEK and is formed into a substantially annular shape. The spring 22 is made of a metal material such as stainless steel. Although the spring illustrated in FIG. 4 has a circular cross-sectional shape, a spring having a rectangular cross-sectional shape may also be used.

A C-shaped insertion groove 211 is formed in one axial end surface of the seal ring 21, and a spring 22 is inserted into this insertion groove 211 through a predetermined gap. Then, with the composite seal ring 20 attached to the valve 14, the spring 22 brings the seal ring 21 into close contact with the inner wall 131 of the nozzle 13 against the pressure of the EGR gas.

An abutment part 213 is provided in a part of the circumferential direction of the seal ring 21 by a pair of step cut parts 212 that engage with each other, and the seal ring 21 can be opened and closed in the circumferential direction by gas pressure or external force during assembly. ing. Note that the spring 22 is formed in a C-shape with an open portion corresponding to the abutment portion 213.

The seal ring 21 is elastically deformable in the radially inward and radially outward directions about the fulcrum P shown in FIG. 3 as the abutment portion 213 opens and closes. The fulcrum P is located on the opposite side of the abutment part 213 across the center of the seal ring 21, and at an intermediate position between the fulcrum P and the abutment part 213, a pair of protrusions 214 are arranged so as to face the seal ring 21 from the radial direction. is formed.

The protrusion 214 is provided to protrude from the inner wall surface of the outer peripheral side of the insertion groove 211 at a height of, for example, about 0.1 mm, and can abut against the spring 22 from the radially outer direction. Further, in the angular range excluding the two protrusions 214, a gap 215 is formed in the insertion groove 211 so as to extend in the circumferential direction, and here, relative movement in the radial direction between the seal ring 21 and the spring 22 is allowed. There is.

Next, the function of the composite seal ring 20 will be explained. When assembling the composite seal ring 20 to the valve device 10, as shown in FIG. be done.

At this time, the abutment portion 213 opens by a displacement amount corresponding to the distance from the fulcrum P, and the seal ring 21, which is perfectly circular in its natural state, is deformed into an elliptical shape. In other words, the seal ring 21 has an elliptical shape in which the major axis radius of the abutment part 213 distal from the fulcrum P is R1, and the short axis radius of the intermediate part between the fulcrum P and the abutment part 213 is R2 (R1>R2). transforms into

During operation of the valve device 10, the seal ring 21 rotates together with the valve 14 and slides along the inner wall 131 of the nozzle 13, as shown in FIG. When the EGR gas pressure acts on the seal ring 21 when the valve is fully closed, the elastic repulsive force of the spring 22 is transmitted to the seal ring 21 via the protrusion 214.

Here, as shown in FIG. 6, according to the comparative example in which the protrusion 214 is not provided, if the seal ring 21 is deformed into an oval shape due to variations in the outer diameter of the seal ring 21 or the inner diameter of the inner wall of the passage, the seal A gap G is generated between the ring 21 and the inner wall 131 of the nozzle 13, and the gap G is maximized at the intermediate area between the fulcrum P and the abutment part 213 (the area surrounded by a broken line in the figure), and the EGR gas is discharged from this gap G. may leak.

On the other hand, according to the present embodiment, as shown in FIG. The generated force presses a portion corresponding to the protrusion 214 against the inner wall 131 of the nozzle 13, and the pressing force propagates over a wide range in the circumferential direction around the protrusion 214.

Since relative movement between the seal ring 21 and the spring 22 is allowed by the cavity 215 in an angular range excluding the protrusion 214, the seal ring 21 deforms over a wide range following the inner wall 131, and its entire circumference is the inner wall. Maintain close contact with 131. Therefore, in the valve device 10 through which EGR gas flows, gas leakage when the valve is fully closed can be suppressed.

Next, the shape of the protrusion 214 will be described with reference to several examples.
(Example 1)
As shown in FIG. 8, the protrusion 214 of Example 1 has a concave curved surface 2141 having the same curvature as the outer peripheral surface of the spring 22, that is, the convex curved surface. The concave curved surface 2141 increases the contact area between the seal ring 21 and the spring 22, thereby reducing the surface pressure of the contact portion and suppressing wear due to rubbing.

(Example 2)
The protrusion 214 of the second embodiment has a flat surface 2142 that can come into contact with the curved surface of the spring 22, as shown in FIG. According to the plane 2142, the area in which the seal ring 21 and the spring 22 can come into contact is reduced, so that the elastic force of the spring 22 can be applied locally and the seal ring 21 can be greatly deformed.

(Example 3)
As shown in FIG. 10, the protrusion 214 of Example 3 has at least one tip 2143 that can come into contact with the curved surface of the spring 22. The pointed end 2143 causes the elastic force of the spring 22 to act intensively on the seal ring 21, thereby making it possible to greatly deform the seal ring 21.

(Example 4)
As shown in FIG. 11, the protrusion 214 of the fourth embodiment includes a plurality of protrusions 2144 that are long in the axial direction and are provided in the circumferential direction so as to be able to come into contact with the curved surface of the spring 22. By providing a plurality of protrusions 2144, the seal ring 21 can be smoothly deformed within a required angular range.

(Example 5)
As shown in FIG. 12, the protrusion 214 of the fifth embodiment has a plurality of protrusions 2144 that make line contact with the outer peripheral surface of the spring 22 at wider intervals in the circumferential direction than in the fourth embodiment. . In this way, the seal ring 21 can be deformed more smoothly.

(Other embodiments)
In the above embodiment, the abutment portion 213 of the seal ring 21 is formed by the step cut portion 212, but in other embodiments, the abutment portion may be formed by a gently sloped surface. Alternatively, as shown in FIG. 13, the valve device 10 may not be provided with a nozzle, and the composite seal ring 21 may be in sliding contact with the inner wall 111 of the fluid passage formed by the housing 11.

In the above embodiment, the composite seal ring 20 according to the present invention is applied to the EGR valve device 10, but in other embodiments, the composite seal ring 20 according to the present invention is applied to a throttle valve device through which intake gas flows, or other butterfly valves. It can be applied to various on-off valves, flow rate adjustment valves, pressure adjustment valves, etc. The composite seal ring of the present invention is not limited to passages through which gas flows, but can also be applied to passages through which liquids such as water and oil flow. Further, regarding the protrusion of the present invention, the height is not limited to the numerical value of the above-described embodiment, and the shape is not limited to the shape of the above-described embodiment.

In addition, the present invention is not limited to the embodiments described above, and the shapes and configurations of each part can be changed as appropriate without departing from the spirit of the invention.

10... Valve device, 12... Fluid passage,
131... Inner wall of a nozzle forming part of a fluid passage, 14... Valve,
141... Outer circumferential groove, 20... Composite seal ring, 21... Seal ring,
211... Insertion groove, 213... Abutment part, 214... Projection part,
215...Gap portion, 22...Spring, P...Fully point.

Claims (5)

A composite seal ring (20) installed in an outer peripheral groove (141) of a valve (14) that opens and closes a fluid passageway (12),
a resin seal ring (21) slidingly in contact with the inner wall (131, 111) of the fluid passage;
a C-shaped spring (22) made of a metal material inserted into an insertion groove (211) formed on one end surface in the axial direction of the seal ring;
The seal ring is
It has an abutment part (213) that can be opened and closed in a part of the circumferential direction,
It is elastically deformable in the radial direction about a fulcrum (P) on the opposite side of the abutment part across the center of the seal ring,
a pair of protrusions (214) that can abut the spring from a radial direction at a circumferentially intermediate position between the fulcrum and the abutment;
A composite seal ring having a cavity (215) in the insertion groove in an angular range excluding the protrusion, which allows relative movement of the seal ring and the spring in the radial direction. The composite seal ring according to claim 1, wherein the protrusion includes a curved surface (2141) having the same curvature as the curved surface of the spring. The composite seal ring of claim 1, wherein the protrusion includes a flat surface (2142) capable of abutting a curved surface of the spring. The composite seal ring of claim 1, wherein the protrusion includes at least one tip (2143) capable of abutting a curved surface of the spring. The composite seal ring according to claim 1, wherein the protrusion includes a plurality of protrusions (2144) in the circumferential direction that can abut against the curved surface of the spring.

Images