JP2022035261A - Composite seal ring - Google Patents

Abstract

To provide a composite seal ring capable of suppressing leakage of a fluid.SOLUTION: A composite seal ring 20 comprises a resin seal ring 21 in slide-contact with an inner wall of a passage in which an EGR gas is circulated, and a C-shaped spring 22 consisting of a metal material inserted into an insertion groove 211 of the seal ring 21. The seal ring 21 includes an abutment part 213 which can be opened/closed, in a portion in a circumferential direction, and is radially deformable around a support point P at an opposite side of the abutment part 213. The seal ring 21 includes a pair of projections 214 which can be abutted to the spring 22 in a radially outer direction, at a substantially intermediate position between the support point P and the abutment part 213. In an angle range excluding the projections 214, a cavity part 215 is formed in the insertion groove 211 of the seal ring 21, and relative movements of the seal ring 21 and the spring 22 in the radial direction are allowed by the cavity part 215. Thus, leakage of a fluid can be suppressed regardless of variations in an outer diameter dimension of the seal ring or an inner diameter dimension of the fluid passage.SELECTED DRAWING: Figure 3

Description

The present invention relates to a composite seal ring.

Conventionally, in a butterfly valve type valve device used for opening and closing a passage through which an exhaust gas recirculation (hereinafter referred to as "EGR") gas or the like flows, a seal ring for sealing a gap between the valve and the 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 mounted in the outer peripheral groove of the valve that opens and closes the gas passage, and when the valve is fully closed, the seal ring comes into close contact with the inner wall of the 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 out of the valve.

Japanese Unexamined Patent Publication No. 2019-39441

Normally, the seal ring is formed into a perfect circle with an outer diameter corresponding to the inner diameter of the inner wall of the passage, and a joint portion is formed in a part in the circumferential direction. Scales in the direction and inward. However, if the outer diameter of the seal ring and the inner diameter of the fluid passage vary within the tolerance range, the seal ring deforms into an elliptical shape when the valve is fully closed, and the gap created between the seal ring and the inner wall of the passage Fluid may leak.

The present invention has been made by paying attention to the above problems, and an object of the present invention is to provide a composite seal ring capable of suppressing fluid leakage regardless of variations in the outer diameter dimension of the seal ring and the inner diameter dimension of the fluid passage. To do.

The composite seal ring of the present invention is a composite seal ring (20) mounted on the outer peripheral groove (141) of the valve (14) that opens and closes the fluid passage (12), and is attached to the inner wall (131, 111) of the fluid passage. It includes a resin seal ring (21) that is in sliding contact, and a C-shaped spring (22) made of a metal material inserted into an insertion groove (211) formed on one end surface of the seal ring in the axial direction. .. The seal ring has a joint opening (213) that can be opened and closed in a part in the circumferential direction, and can be elastically deformed in the radial direction around a fulcrum (P) on the opposite side of the joint with the center of the seal ring. be. A pair of protrusions (214) are provided in the middle position in the circumferential direction between the fulcrum and the abutment so that they can abut on the spring from the outside diameter, and the seal ring and spring are placed in the insertion groove in the angle range excluding the protrusions. It has a gap portion (215) that allows relative movement in the radial direction.

According to the composite seal ring of the present invention, it is composed of a combination of a resin seal ring and a metal spring, and when a fluid pressure acts on the seal ring when the valve is fully closed, the elastic repulsive force of the spring seals through the protrusion. It is transmitted to the ring. Since the protrusion is provided at an intermediate position between the joint of the seal ring and the fulcrum which is the center of deformation, the elastic rebound force of the spring is transmitted to a wide angle range around the protrusion. In the angle range excluding the protrusions, the gap allows relative movement of the seal ring and the spring, so that the seal ring deforms according to the shape of the inner wall of the passage. Therefore, even if the outer diameter of the seal ring or the inner diameter of the fluid passage varies, the gap can be minimized and fluid leakage can be suppressed when the valve is fully closed.

It is the schematic sectional drawing of the EGR valve apparatus to which one Embodiment of this invention was applied. FIG. 1 is an enlarged view of part II of FIG. It is a front view which shows the composite seal ring of one Embodiment of this invention. FIG. 3 is a sectional view taken along line IV-IV of FIG. It is a front view which shows the composite seal ring with the abutment part open. It is a reference figure which points out the problem of the comparative example which a protrusion is not provided. It is sectional drawing of the composite seal ring of this embodiment which shows the action of a protrusion. It is a partial cross-sectional view of the composite seal ring which shows Example 1 of the protrusion. It is a partial cross-sectional view of the composite seal ring which shows Example 2 of the protrusion. It is a partial cross-sectional view of the composite seal ring which shows Example 3 of the protrusion. It is a partial cross-sectional view of the composite seal ring which shows Example 4 of the protrusion. It is a partial cross-sectional view of the composite seal ring which shows Example 5 of the protrusion. It is the schematic sectional drawing of the EGR valve apparatus of another embodiment.

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

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

A valve 14 made of a disk-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 to the outer peripheral groove 141 by fitting, and is rotated by the shaft 15 together with the valve 14 in a state of being in contact with the inner wall 131.

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

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

An insertion groove 211 is formed in a C shape on one end surface of the seal ring 21 in the axial direction, and a spring 22 is inserted into the insertion groove 211 through a predetermined gap. Then, with the composite seal ring 20 mounted on 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.

A pair of step cut portions 212 that engage with each other provides an abutment portion 213 in a part of the seal ring 21 in the circumferential direction, and the seal ring 21 can be opened and closed in the circumferential direction by gas pressure or an external force at the time of assembly. ing. The spring 22 is formed in a C shape in which the portion corresponding to the abutment portion 213 is open.

The seal ring 21 can be elastically deformed in the inward and outward directions around the fulcrum P shown in FIG. 3 with the opening and closing of the abutment portion 213. The fulcrum P is located on the opposite side of the abutment portion 213 across the center of the seal ring 21, so that the pair of protrusions 214 face the seal ring 21 in the radial direction at an intermediate position between the fulcrum P and the abutment portion 213. Is formed in.

The protrusion 214 is projected from the inner wall surface on the outer peripheral side of the insertion groove 211 at a height of, for example, about 0.1 mm, and can come into contact with the spring 22 from the outside diameter direction. Further, in the angle range excluding the two protrusions 214, the gap portion 215 is formed in the insertion groove 211 so as to extend in the circumferential direction, and here, the relative movement of the seal ring 21 and the spring 22 in the radial direction is allowed. There is.

Next, the operation of the composite seal ring 20 will be described. When assembling the composite seal ring 20 to the valve device 10, as shown in FIG. 5, the seal ring 21 is expanded in the outer diameter direction around the fulcrum P against the elasticity of the spring 22, and the abutment portion 213 is opened. Will be done.

At this time, the abutment portion 213 is opened by a displacement amount according to the distance from the fulcrum P, and the seal ring 21 which was a perfect circle in the natural state is deformed into an elliptical shape. That is, the seal ring 21 has an elliptical shape in which the semi-major axis of the abutment portion 213 most distal to the fulcrum P is R1 and the minor axis radius of the intermediate portion between the fulcrum P and the abutment portion 213 is R2 (R1> R2). Transforms into.

During the operation of the valve device 10, as shown in FIG. 6, the seal ring 21 rotates integrally with the valve 14 and slides along the inner wall 131 of the nozzle 13. When the pressure of EGR gas 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 a comparative example in which the protrusion 214 is not provided, when the seal ring 21 is deformed into an elliptical shape due to variations in the outer diameter dimension of the seal ring 21 and the inner diameter dimension of the inner wall of the passage, the seal is sealed. A gap G that maximizes the intermediate portion between the fulcrum P and the abutment portion 213 (the portion surrounded by the broken line in the figure) is generated between the ring 21 and the inner wall 131 of the nozzle 13, and the EGR gas is generated from this gap G. May leak.

On the other hand, according to the present embodiment, as shown in FIG. 7, since the pair of protrusions 214 are provided at the intermediate positions between the abutment portion 213 and the fulcrum P, the seal ring 21 is a bullet of the spring 22. The portion corresponding to the protrusion 214 is pressed against the inner wall 131 of the nozzle 13 by the force, and the pressing force propagates over a wide range in the circumferential direction centering on the protrusion 214.

Since the relative movement between the seal ring 21 and the spring 22 is allowed by the gap portion 215 in the angle range excluding the protrusion 214, the seal ring 21 is deformed in a wide range following the inner wall 131, and the entire circumference thereof 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 some examples.
(Example 1)
As shown in FIG. 8, the protrusion 214 of the first embodiment 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. Since the concave curved surface 2141 increases the contactable area between the seal ring 21 and the spring 22, the surface pressure of the contact portion can be reduced and wear due to rubbing can be suppressed.

(Example 2)
As shown in FIG. 9, the protrusion 214 of the second embodiment has a flat surface 2142 that can abut on the curved surface of the spring 22. According to the flat surface 2142, the contactable area between the seal ring 21 and the spring 22 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 the third embodiment has at least one tip 2143 that can abut on the curved surface of the spring 22. The tip 2143 concentrates the elastic force of the spring 22 on the seal ring 21, and can greatly deform the seal ring 21.

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

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

(Other embodiments)
In the above embodiment, the joint portion 213 of the seal ring 21 is formed by the step cut portion 212, but in other embodiments, the joint portion can be formed on a gently sloping inclined surface. Further, as shown in FIG. 13, the valve device 10 is not provided with a nozzle, and the composite seal ring 21 may be in sliding contact with the inner wall 111 of the fluid passage configured 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 another embodiment, the composite seal ring of the present invention is used as a throttle valve device through which intake gas flows, or other butterfly valves. It can be applied to various on-off valves, flow rate control valves, pressure control valves, etc. used. The composite seal ring of the present invention is not limited to the passage through which gas flows, and can be applied to the passage through which liquids such as water and oil flow. Further, the height of the protrusion of the present invention is not limited to the numerical value of the above-described embodiment, and the shape is not limited to the shape of the above-mentioned embodiment.

In addition, the present invention is not limited to the above embodiment, and the shape and configuration of each part can be appropriately changed and implemented without departing from the spirit of the invention.

10 ... valve device, 12 ... fluid passage,
131 ... Inner wall of nozzle forming part of fluid passage, 14 ... Valve,
141 ... Outer groove, 20 ... Composite seal ring, 21 ... Seal ring,
211 ... Insertion groove, 213 ... Abutment, 214 ... Protrusion,
215 ... gap, 22 ... spring, P ... fulcrum.

Claims (5)

A composite seal ring (20) mounted in the outer peripheral groove (141) of a valve (14) that opens and closes a fluid passage (12).
A resin seal ring (21) that is in sliding contact with the inner wall (131, 111) of the fluid passage, and
A C-shaped spring (22) made of a metal material inserted into an insertion groove (211) formed on one end surface of the seal ring in the axial direction is provided.
The seal ring is
It has a joint (213) that can be opened and closed in a part of the circumferential direction.
It can be elastically deformed in the radial direction around the fulcrum (P) on the opposite side of the abutment portion across the center of the seal ring.
A pair of protrusions (214) capable of contacting the spring from the outside diameter direction are provided at an intermediate position in the circumferential direction between the fulcrum and the abutment portion.
A composite seal ring having a gap portion (215) that allows relative movement of the seal ring and the spring in the radial direction in the insertion groove in an angle range excluding the protrusion. 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 according to claim 1, wherein the protrusion includes a flat surface (2142) capable of contacting a curved surface of the spring. The composite seal ring according to claim 1, wherein the protrusion comprises at least one tip (2143) capable of contacting the 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 capable of contacting the curved surface of the spring.

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