COMPOSITE SEALING RING

Abstract

Composite sealing ring, comprising: a resin sealing ring (301 to 306) configured to be installed in an outer circumferential groove (25) of a valve (70) which opens and closes a passage (80) by a rotary displacement, and designed to seal between an inner wall (84) of the passage (80) and the valve in a fully closed state of the valve, wherein the resin sealing ring (301 to 306) has an annular groove; and a spring (50) which is metallic and which is arranged within the annular groove and is designed to press the resin sealing ring (301) radially outwards and radially inwards due to a pressure acting on the resin sealing ring or a deformation of the resin sealing ring; wherein in a radial direction there is a first gap between a radially outer circumference of the spring and a radially outer circumference of the annular groove and a second gap between a radially inner circumference of the spring and a radially inner circumference of the annular groove.

Description

AREA OF INVENTION

[0001] The present disclosure relates to a composite sealing ring in which a metal spring is combined with a resin sealing ring. STATE OF THE ART

[0002] In a conventional throttle valve type valve device used to open and close a passage through which gas flows for exhaust gas recirculation (hereinafter referred to as "EGR") or the like, a sealing ring is known which is mounted in an outer circumferential groove of a valve and seals a gap between an outer circumferential wall of the valve and an inner wall of a passage section.

[0003] In a conventional valve device, the ambient temperature of the gas passage section covers a wide range, from low temperatures in a cold environment to high temperatures exposed to the exhaust gas. Furthermore, since the materials of the valve, sealing ring, nozzle forming the gas passage section, and the like differ from one another, a clearance is determined based on the difference in linear expansion of each material.

[0004] For example, in the valve device disclosed in patent specification 1, a resin sealing ring is used instead of a metal sealing ring, which was previously commonly used. When the metal sealing ring is used, an inner circumferential sliding surface of the gas passage section, which is a mating face of the sealing ring, is required to ensure hardness through surface treatment or the like to prevent abrasion. This is not necessary when the resin sealing ring is used. Therefore, it is possible to eliminate the need for surface treatment of the gas passage section and the like. LITERATURE ON THE STATE OF THE TECHNOLOGY

[0005] Patent specification 1: Japanese patent publication JP 2017-89675A

[0006] Further state of the art is disclosed in the following documents.

[0007] DE 28 28 238 A1 discloses a sealing device for butterfly valves or ball valves, in which a soft sealing ring circumferentially surrounding the valve disc edge or the ball plug shell is fastened to the valve disc or the ball plug by screws via a retaining ring provided on the side facing away from the eccentric bearing and rests against a frustoconical metallic housing seat in the closed position of the shut-off valve, characterized in that the sealing ring consists of a plastic, preferably polytetrafluoroethylene, which is particularly resistant to higher temperatures and has plastomeric properties, and has a U-shaped cross-section with a groove open towards the retaining ring, wherein a metallic spring element, which causes an elastic springback of the U-profile, is inserted into the sealing ring, and the inner leg of the sealing ring is firmly fixed between the valve disc or the ball plug.the ball stud and the retaining ring are clamped in place, while the outer sealing ring leg, which has play towards the retaining ring, forms a movable sealing lip that, with the apex of its curved outer surface, rests against the frustoconical housing seat surface in a sealing manner.

[0008] DE 10 2005 048 417 A1 discloses a tolerance ring for a throttle valve. The tolerance ring for the throttle valve consists of a metallic base body with a continuous gap and an outer nickel coating in which homogeneously distributed polytetrafluoroethylene lubricants are incorporated.

[0009] WO 96 / 17 423 A1 discloses an elongated and compressible seal in which, in use, two ends are connected to each other by means of at least one connecting pin which is arranged in at least one opening in each end and extends between them, wherein the connecting pin or pins are hollow and compressible and the seal is therefore compressible at the connection between the two ends.

[0010] GB 2 083 575 A discloses seals. An annular rubber seal is formed by inserting one or more layers of fiberglass fabric against a surface in the mold cavity of a suitable annular mold. A tubular, ring-shaped insert of semi-vulcanized silicone rubber, with a garter or coil spring in the bore of the tubular insert, is placed in the mold cavity over the fiberglass fabric. The tubular insert is dimensioned such that the coil spring inside causes the insert to contract and exert a compressive force on the fiberglass fabric. This holds the fabric against the surface in the mold cavity. A ring of unvulcanized silicone rubber is placed in the mold cavity, which is then closed and heated to cure the rubber.The resulting seal consists of fiberglass fabric covering a surface of the seal, with the coil spring inside the seal being held at a distance from the inner surface of the fiberglass fabric.

[0011] US 6,045,135 A discloses a sealing ring washer for a seal on a piston rod with a circular cross-section. The sealing ring washer comprises an annular sealing part with a sector-shaped recess and a closing part with a main part adapted to the recess such that the main part, extending in the circumferential direction of the sealing part, can be inserted into the recess to join the two parts to form a single sealing ring washer.

[0012] US 3,552,407 A discloses a method for adjusting the seal of a throttle valve. A throttle valve is provided comprising a valve seat, a flap, and an annular seal arranged between them. The annular seal consists of an elastomer in which at least one metal wire ring is concentrically embedded. A fibrous material may also be embedded in the annular packing. Either the valve seat or the flap is provided with a radially open circular or elliptical circumferential groove in which the annular packing is slidably mounted. SUMMARY

[0013] Although the resin sealing ring can ensure a seal through elastic deformation, it suffers from insufficient stiffness at high temperatures. Therefore, when the valve is open, the sealing ring experiences internal pressure and deforms elastically in a radial direction, potentially causing it to fall out of the valve's outer circumferential groove. If the ejected sealing ring cuts between the valve and the passage, it can break or the valve can become jammed.

[0014] Furthermore, the high-temperature creep of the resin reduces the tension of the sealing ring, whereby the sealing surface pressure decreases with the passage section and sealing failure can occur.

[0015] The present disclosure was set forth with regard to the above-mentioned problems and its object is to provide a composite sealing ring which prevents falling out of the outer circumferential groove of the valve due to internal pressure and ensures tension after high-temperature creep.

[0016] This problem is solved by the features of claims 1, 13 and 15. Further advantageous embodiments and developments are the subject of the subsequent claims.

[0017] According to one aspect of the present disclosure, a composite sealing ring has a resin sealing ring (301 to 306) and a metal spring (50).

[0018] A resin sealing ring is installed in an outer circumferential groove (75) of a valve (70) which opens and closes a passage (80) by a rotary displacement, and the resin sealing ring seals between an inner wall (84) of the passage (80) and the valve in a fully closed state of the valve.

[0019] The resin sealing ring has a ring-shaped groove.

[0020] A metal spring is arranged inside the annular groove and the metal spring is designed to push the sealing ring radially outwards and radially inwards due to pressure acting on the sealing ring or deformation of the sealing ring.

[0021] In a radial direction, there is a first gap between a radially outer circumference of the spring and a radially outer circumference of the annular groove, and a second gap between a radially inner circumference of the spring and a radially inner circumference of the annular groove.

[0022] For example, the spring is received in a spring groove (35) formed on an end surface (31) in an axial direction of the sealing ring (301-304, 306). Alternatively, at least part of the spring is embedded in the sealing ring (305).

[0023] In the composite sealing ring of the present disclosure, stiffness against internal pressure and stress at high temperature can be ensured by determining the free diameter and the stress of the metal spring combined with the resin sealing ring. Therefore, it is possible to preferably solve the problems of the prior art resin sealing ring, namely "falling out of the outer circumferential valve groove due to internal pressure" and "decreasing stress after high-temperature creep" at high temperatures, where resin stiffness is reduced. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a diagram showing a schematic view of an EGR valve device in a first embodiment; Fig. 2 is a diagram showing an enlarged cross-sectional view of Part II in Fig. 1 represents; Fig. Figure 3A is a diagram showing a front view of a composite sealing ring in the first embodiment; Fig. 3B is a diagram showing an enlarged cross-sectional view along line IIIb-IIIb in Fig. 3A is taken from, represents; Fig. Figure 4 is a diagram showing a schematic cross-sectional view to explain an effect of the composite sealing ring when a valve is completely closed; Fig. Figure 5 is a diagram showing a schematic cross-sectional view to explain an effect of the composite sealing ring when a valve is open; Fig. Figure 6A is a front view showing a state in which the fitting openings of the composite sealing ring are arranged in the same position in a second embodiment; Fig. Figure 6B is a front view showing a state in which the fitting openings of the composite sealing ring are arranged at different positions in the second embodiment; Fig. Figure 7 is a diagram showing a front view of a composite sealing ring in a third embodiment; Fig. Figure 8 is a diagram showing a front view of a composite sealing ring in a fourth embodiment; Fig. 9A is a diagram showing a front view of a composite sealing ring in a fifth embodiment; Fig. 9B is a diagram showing an enlarged cross-sectional view along line IXb-IXb in Fig. 9A is taken from, represents; Fig. 10A is a diagram showing an extended view of a composite sealing ring in one direction from arrow Xa in Fig. 10B in a sixth embodiment; Fig. 10B is a diagram showing a front view of the composite sealing ring in Fig. 10A represents; Fig. Figure 11A is a diagram showing a front view of a resin sealing ring in a comparative example; Fig. 11B is a diagram showing an enlarged cross-sectional view along line XIb-XIb in Fig. 11A is taken from, represents; Fig. Figure 12A is a diagram showing a front view to explain a deformation effect of the resin sealing ring due to insufficient stiffness; Fig. 12B is a diagram showing an enlarged cross-sectional view along line XIIb-XIIb in Fig. 12A is taken from, represents; Fig. Figure 13A is a diagram showing a front view to explain a deformation effect of a deformed resin sealing ring from an outer circumferential groove of the valve and Fig. 13B is a diagram showing an enlarged cross-sectional view along line XIIIb-XIIIb in Fig. 13A is taken from this. DETAILED DESCRIPTION

[0024] Several embodiments of the connecting sealing ring are described below with reference to the drawings. In the various embodiments and the comparative example, essentially the same design is indicated by the same reference numeral, and its description is omitted. Furthermore, the following first to sixth embodiments are generally referred to as the "present embodiment".

[0025] In this patent description, the "composite sealing ring" refers to a sealing ring formed by combining a resin sealing ring with a metal spring. The composite sealing ring of the present embodiment is applied to a valve device that opens and closes the passage of the EGR gas and sets a degree of opening in the EGR system, which recirculates a portion of the exhaust gas into an intake passage. [Design of the valve device]

[0026] Fig. 1 and Fig. Figure 2 represents a schematic embodiment of a valve device. Since the representation of the valve device is similar to that described in patent specification 1 (Japanese patent publication no. 2016-211678), a detailed description is omitted, and it is briefly described below. Fig. 1 and Fig. Figure 2 shows the composite sealing ring as a representative of the composite sealing ring 101 of the first embodiment.

[0027] The valve device 90 has a housing 91 with a passage 80 for the EGR gas, a valve 70 which is integrally rotatable with the shaft 95 inside the housing 91 and which is a throttle valve for opening and closing the passage by a rotary displacement, and a sensor housing 96, etc.

[0028] Among the sections that form the passage 80 in the housing 91, a section in which the valve 70 rotates is designated as passage section 81. As in Fig. 1 and Fig. As shown in Figure 2, passage section 81 consists of the nozzle which is inserted into the hole of the housing 91, and the inner wall of this nozzle corresponds to "the inner wall of passage section 81".

[0029] For example, the housing 91 is made of die-cast aluminum alloy, and the nozzle is made of stainless steel or the like, which is excellent in terms of heat resistance and corrosion resistance.

[0030] The shaft 95 is rotatably supported by bearings 92 and 94, which are provided in the housing 91. A sealing element 93 is provided between bearing 92 and bearing 94. The shaft 95 rotates while the rotation of the motor (not shown) is slowed down and transmitted.

[0031] The valve 70 is attached to a distal end section of the shaft 95 in order to be inclined with respect to the axis of the shaft 95, and adjusts the degree of opening of the passage 80 by rotating in one piece with the shaft 95.

[0032] The sensor housing 96 accommodates a rotary angle sensor 97 for detecting the opening degree of the valve 70 by detecting the rotation angle of the shaft 95. The return spring 98 pushes the valve 70 in the valve closing direction.

[0033] The valve 70 is formed as a disc shape, and an outer circumferential groove 75 with a rectangular cross-section is formed over the entire circumference of the outer circumferential edge. A composite sealing ring 101, formed by combining a resin sealing ring 301 with a metal spring, is received in the outer circumferential groove 75.

[0034] The sealing ring 301 is a flat ring made of a resin material such as PPS, PTFE, PEEK, or the like. The sealing ring 301 is elastically deformable and seals between the valve 70 and the inner wall 84 of the passage section 81 when the valve 70 is fully closed.

[0035] The spring 50 is formed from a metal wire material with a spring property and is arranged in a ring shape within a region of the radial width of the sealing ring 301.

[0036] However, the detailed configuration in which the spring 50 is arranged within the radial width of the sealing ring differs according to each embodiment. The detailed configuration, operation, and effect of the composite sealing ring are described below for each embodiment. The reference numerals for the composite sealing ring and the resin sealing ring in each embodiment are assigned to the third digit after "10" and "30," respectively. (First embodiment)

[0037] With reference to Fig. 3A and Fig. Section 3B describes the design of the composite sealing ring 101 of the first embodiment. In the composite sealing ring 101 of the first embodiment, a spring 50 is received in a spring groove 35, which is formed in an axial end surface 31 of the sealing ring 301.

[0038] The cross-section in an axial direction of the sealing ring 301 is essentially rectangular, enclosed in the axial direction by one end face 31, the other end face 32, the inner circumferential surface 33, and the outer circumferential surface 34, and the spring groove 35 is formed on one end face 31. The spring groove 35 has a groove bottom wall 352, a radially inner groove inner wall 353, and a radially outer groove inner wall 354 and is formed to accommodate the spring 50. The spring 50 is accommodated in the spring groove 35 to be positioned within the radial width of the sealing ring 301.

[0039] Furthermore, the sealing ring 301 has a fitting opening 39 for increasing and decreasing the diameter at one point in the circumferential direction. Fig. Figure 3A shows the fitting opening 39 in a form in which the ring is simply divided. In practice, however, the fitting opening 39 can be formed in a form in which both circumferential end sections overlap in the radial and axial directions, as in the form of Fig. 2 of patent specification 1 or the sixth embodiment described later.

[0040] When the sealing ring 301 is installed in the outer circumferential groove 75 of the valve, the operator increases its diameter by separating the pass-through opening 39 through elastic deformation and inserts it into the outer circumferential groove 75. After insertion, the diameter of the sealing ring 301 decreases. Furthermore, when the sealing ring 301 is used in the valve assembly 90, its diameter expands due to the pressure of the gas, and the pass-through opening 39 widens further. However, when the valve is fully closed, the pass-through opening 39 is formed to close the gap.

[0041] In the sealing ring 301 in the first embodiment, the circumferential end wall 36, which seals the spring groove 35, is formed on both circumferential end sections that face the fitting opening 39.

[0042] The spring 50 has a fitting opening 59 at a position in the circumferential direction, and the position of the circumferential end section 56, which faces the fitting opening 59, is regulated by the circumferential end wall 36 in a state in which it is received in the spring groove 35. Therefore, the fitting opening 39 of the sealing ring 301 and the fitting opening 59 of the spring 50 are arranged at the same position in the circumferential direction.

[0043] With this design, the rotational movement, i.e., the relative movement of the spring 50 with respect to the sealing ring 301, is suppressed in the composite sealing ring 101 of the first embodiment. Therefore, the abrasion of the sealing ring 301 due to sliding of the spring 50 is suppressed.

[0044] Next, the effect of the composite sealing ring 101 of the first embodiment is described, while it is compared with the resin sealing ring of the comparative example.

[0045] As in Fig. 11A and Fig. As shown in Figure 11B, the resin sealing ring 309 is not provided with the spring groove 35 in comparison to the sealing ring 301 of the first embodiment, and the resin sealing ring 309 has a simple, essentially rectangular shape in cross-section.

[0046] Fig. 12A, Fig. 12B, Fig. 13A and Fig. Section 13B describes the problems that arise when the resin sealing ring 309 is used for the valve device 90.

[0047] In Fig. 12B and Fig. 13B The EGR gas flows in the flow direction from the upstream end face 71 towards the downstream end face 72 of the valve 70. The outer circumferential groove 75 of the valve has an inner groove wall 751 on the upstream side, an inner groove wall 752 on the downstream side and a bottom groove wall 753.

[0048] In a state in which the sealing ring 309 is received in the outer circumferential groove 75, as in Fig. As shown in Figure 12B, the outer circumferential surface 34 of the sealing ring 309 is positioned radially outside the outer circumferential surface 73 of the valve 70, and the inner circumferential surface 33 of the sealing ring 309 is fitted inside the outer circumferential groove 75.

[0049] The pressure P of the gas flowing in the "flow direction" acts on one end surface 31 of the sealing ring 309, and the other end surface 32 is pressed against the inner wall 752 of the groove on the downstream side of the outer circumferential groove 75. The pressure P of the gas flowing between the inner circumferential surface 33 of the sealing ring 309 and the bottom wall 753 of the outer circumferential groove 75 causes the inner circumferential surface 33 to expand outwards in the radial direction. The pressure P acting radially outwards from one side of the bottom wall 753 of the outer circumferential groove 75 onto the circumferential surface 33 is therefore referred to as the "internal pressure".

[0050] In Fig. 12A and Fig. 12B, if the stiffness of the sealing ring 309 is insufficient, the sealing ring 309, which has absorbed the internal pressure P to enlarge the pass opening 39, deforms and expands its diameter.

[0051] As in Fig. 13A and Fig. As shown in Figure 13B, when the valve is open such that the outer circumferential surface 34 of the sealing ring 309 is exposed, the fitting opening 39 widens. This is because the sealing ring 309 moves radially outwards and can fall out of the outer circumferential groove. If the dislodged sealing ring 309 cuts into the space between the valve 70 and the passage section 81, the sealing ring 309 can break, or the valve 70 can become jammed.

[0052] The effect of the composite sealing ring 101 according to the first embodiment in comparison to the comparative example is described with reference to Fig. 4 and Fig. 5 described. The internal pressure P of the gas flowing in the “flow direction” acts on one end surface 31 of the sealing ring 301, and the other end surface 32 is pressed against the inner wall of the groove 752 on the downstream side of the outer circumferential groove 75.

[0053] In the fully closed state of the valve, as in Fig. As shown in Figure 4, the outer circumferential surface 34 of the sealing ring 301 comes into contact with the inner wall 84 of the passage section 81, and radial expansion in the outward direction is suppressed. Furthermore, the pressure on one side of the inner circumferential surface 33 of the sealing ring 301 increases, and the pressure decreases on one side of the outer circumferential surface 34, generating the internal pressure P due to the differential pressure. At this point, the outer circumferential surface of the spring 50 rests against the inner wall 354 of the groove on the radially outer side of the spring groove 35, and the spring force Fsp acts in the outward direction. Consequently, the sealing ring 301 is pressed against the inner wall 84 of the passage section 81. Therefore, even if the tension of the sealing ring 301 is reduced due to high-temperature creep, the sealing property is ensured when the valve is fully closed.

[0054] On the other hand, if the valve is in Fig. When the outer circumferential surface 34 of the sealing ring 301 is in a free state, the internal pressure P acting on the inner circumferential surface 33 pushes the sealing ring 301 radially outward. At this point, the inner circumferential surface of the spring 50 rests against the inner wall of the groove 353 on the radially inner side of the spring groove 35, and the spring force Fsp acts in the radially inward direction. Consequently, the deformation of the sealing ring 301 in the radially outward direction is suppressed by the internal pressure P, and it is possible to prevent the sealing ring 301 from falling out of the outer circumferential groove 75. Therefore, it is possible to adequately avoid problems such as the sealing ring 301 breaking and the valve 70 locking.

[0055] As previously described, the metal spring 50, combined with the resin sealing ring 301, can push the sealing ring 301 radially outward and radially inward due to the pressure P acting on the sealing ring 301 or due to deformation of the sealing ring 301. Therefore, according to the composite sealing ring 101 of the present embodiment, the stiffness against the internal pressure P can be ensured by determining the free diameter and the tension of the metal spring 50, and the tension at high temperatures can be guaranteed. Consequently, the problems that arise with the resin sealing ring 309 in the comparative example, namely "falling out of the outer circumferential groove 75 of the valve due to the internal pressure P" and "reducing the tension after high-temperature creep" at high temperatures, where the resin stiffness is particularly low, can be solved.

[0056] Next, the composite sealing rings of the second to sixth embodiments will be described with reference to Fig. Sections 6A to 9B describe the front view in each embodiment. Fig. 3A in the first embodiment.

[0057] Similar to the first embodiment, in each embodiment the composite sealing ring ensures stiffness against the internal pressure through the metal spring 50, which is combined with the resin sealing rings 302 to 306, and can prevent it from falling out of the outer circumferential groove 75 of the valve. In addition, the tension after high-temperature creep can be ensured. (Second embodiment)

[0058] The second embodiment is described with reference to Fig. 6A and Fig. 6B explained.

[0059] In the composite sealing ring 102 of the second embodiment, the circumferential end walls 36 are not formed at both circumferential end sections of the sealing ring 302 in relation to the first embodiment. Therefore, the spring 50 is freely movable in the circumferential direction. Fig. 6A represents a state in which the fitting opening 59 of the spring 50 and the fitting opening 39 of the sealing ring 302 are arranged at the same fitting opening, and Fig. 6B represents a condition in which the fit 59 of the spring 50 and the fitting opening 39 of the sealing ring 302 are arranged in different positions.

[0060] In the second embodiment, the load caused by the collision between the spring 50 and the sealing ring 302 is reduced, since the spring 50 can move freely. (Third embodiment)

[0061] The third embodiment is described with reference to Fig. 7 explained.

[0062] In the composite sealing ring 103 of the third embodiment, a partition 37 is formed in the circumferential direction on the side opposite the fitting opening 39 of the sealing ring 303. The spring 50 is received in the spring groove 35 such that the partition 37 is positioned between the fitting opening 59 and the spring 50. Therefore, the fitting opening 39 of the sealing ring 303 faces the section of the spring 50 that is opposite the fitting opening 59.

[0063] In the third embodiment, the abrasion of the sealing ring 303 is suppressed because, as in the first embodiment, the relative movement of the spring 50 with respect to the sealing ring 303 is suppressed due to the sliding of the spring 50. Furthermore, since the fitting opening 39 of the sealing ring 303 and the fitting opening 59 of the spring 50 are arranged at different positions in the circumferential direction, the deformation of the composite sealing ring 103 as a whole is suppressed, and falling out of the outer circumferential valve groove 75 is prevented. In addition, the surface pressure in the circumferential direction can be made to be almost uniform. (Fourth embodiment)

[0064] The fourth embodiment is described with reference to Fig. 8 explained.

[0065] In the composite sealing ring 104 of the fourth embodiment, several contact sections 38 are formed, projecting radially from the inner walls 353, 354 of the groove 35 of the sealing ring 304, relative to the composite sealing ring 101 of the first embodiment. The contact section 38 projecting radially outward from the inner wall 353 of the groove contacts the inner circumferential surface of the spring 50, and the contact section 38 projecting radially inward from the outer inner wall 354 of the groove is in contact with the spring 50. Consequently, the positions where the contact sections 38 are provided are specified as the surface pressure generating section produced by the spring 50.

[0066] In the fourth embodiment, the contact sections 38 are specified independently of dimensional deviations and form accuracy of the spring groove 35 and the spring 50, and the contact pressure can be stabilized. Furthermore, since the spring 50 is stationary, wear of the sealing ring 304 due to sliding of the spring 50 is reliably suppressed.

[0067] In the example of Fig. 8, according to the first embodiment, the design of the contact sections 38, although the fitting opening 39 of the sealing ring 304 and the fitting opening 59 of the spring 50 are arranged in the same position in the circumferential direction, can, however, be applied to the third embodiment in which the fitting openings 39, 59 are arranged in different positions in the circumferential direction.

[0068] Furthermore, in the modification of the fourth embodiment, the contact sections 38 can be formed only on the inner wall of the groove 353 on the radially inner side of the spring groove 35 or only on the inner wall of the groove 354 on the radially outer side. (Fifth embodiment)

[0069] The fifth embodiment is described with reference to Fig. 9A and Fig. 9B explained.

[0070] In the composite sealing ring 105 of the fifth embodiment, at least a portion of the spring 50 is embedded in the sealing ring 305. Typically, the spring 50 is cast in to be formed within the sealing ring 305. The spring 50 is arranged annularly within the radial width of the sealing ring 305 by being embedded within it.

[0071] In the fifth embodiment, the abrasion of the sealing ring 354 is suppressed because the spring 50 is embedded and fixed, due to the sliding of the spring 50, and in addition, it is prevented that the installation of the spring 50 is forgotten in the parts management phase, and it is prevented that the spring 50 falls out of the spring groove 35.

[0072] Furthermore, the circumferential end section 56, which faces the fitting opening 59 of the spring 50, is exposed by the fitting opening 39 of the sealing ring 305. Since the circumferential end section 56 of the spring 50 is exposed, the thermal stress can be reduced. (Sixth embodiment)

[0073] The sixth embodiment is described with reference to Fig. 10A and Fig. 10B explained.

[0074] The sealing ring 306 in the composite sealing ring 106 of the sixth embodiment is formed such that both circumferential end sections overlap in the radial direction and the axial direction at the fitting opening 39 of the sealing ring 301 of the first embodiment.

[0075] The fitting opening 40 of the sealing ring 306 consists of engaging sections 41, 42 extending from one end section and the other end section of the radially outer side, and engaging sections 43, 44 corresponding to the respective engaging sections 41, 42 on the radially inner side. The engaging section 41 and the engaging section 43, and the engaging section 42 and the engaging section 44, overlap in the radial direction, and the engaging section 41 and the engaging section 42 overlap in the axial direction. Therefore, when the valve is completely closed, the gap of the fitting opening 40 can be brought into close contact, and the sealing performance can be improved.

[0076] Furthermore, as disclosed in Japanese patent publication no. 2017-89675, an overlapping connection can be provided in a wide area in the axial direction, in the sense of a modification of the sixth embodiment.

[0077] The design of the columns in the sixth embodiment and the modifications can be applied to the second to fifth embodiments. (Other embodiments)

[0078] The composite sealing ring of the present disclosure is not limited to the EGR valve device, but can also be applied to throttle valve devices through which intake gas flows, various on / off valves that use throttle valves, flow-regulating valves, pressure-regulating valves and the like.

[0079] As previously described, the present disclosure is by no means limited to the aforementioned embodiment and can be implemented in various modes without departing from the scope of the disclosure.

Claims

[1] Composite sealing ring comprising: a resin sealing ring (301 to 306) configured to be installed in an outer circumferential groove (25) of a valve (70) which opens and closes a passage (80) by a rotary displacement, and designed to seal between an inner wall (84) of the passage (80) and the valve in a fully closed state of the valve, wherein the resin sealing ring (301 to 306) has an annular groove; and a spring (50) which is metallic and which is arranged within the annular groove and is designed to press the resin sealing ring (301) radially outwards and radially inwards due to a pressure acting on the resin sealing ring or a deformation of the resin sealing ring; wherein in a radial direction there is a first gap between a radially outer circumference of the spring and a radially outer circumference of the annular groove and a second gap between a radially inner circumference of the spring and a radially inner circumference of the annular groove. [2] Composite sealing ring according to claim 1, wherein the annular groove is formed on an end surface (31) in an axial direction of the resin sealing ring (301 to 304, 306). [3] Composite sealing ring according to claim 2, wherein Each of the resin sealing ring and the spring has a fitting opening (39, 59) at a point in a circumferential direction and The fitting opening of the resin sealing ring and the fitting opening of the spring are arranged in the same position in the circumferential direction. [4] Composite sealing ring according to claim 2, wherein Each of the resin sealing ring and the spring has a fitting opening (39, 59) at a point in a circumferential direction and The fitting opening of the resin sealing ring and the fitting opening of the spring are arranged at different positions in the circumferential direction. [5] Composite sealing ring according to one of claims 2 to 4, wherein a contact section (38) extends radially from an inner groove wall (353, 354) of the annular groove to contact at least one of an inner surface and an outer surface of the spring. [6] Composite sealing ring according to claim 3, wherein at least a part of the spring is embedded in the resin sealing ring (305). [7] Composite sealing ring according to claim 6, wherein a circumferential end section (56) of the spring, which faces the fitting opening, is exposed by the resin sealing ring. [8] Composite sealing ring according to one of claims 2 to 7, wherein In the fully closed state of the valve, an outer circumferential surface of the resin sealing ring comes into contact with the inner wall, and an outer circumferential surface of the spring rests against an inner wall on a radial outer side of the annular groove. In an open state of the valve, an inner circumferential surface of the spring rests against an inner wall on an inner side in the radial direction of the annular groove. [9] Composite sealing ring according to claim 1, wherein the annular groove is C-shaped in such a way that circumferential end walls are formed at both circumferential ends of the annular groove; the metal spring is C-shaped such that there is a first gap between one end of the spring and a circumferential end wall, and a second gap between the other end of the spring and the other circumferential end wall; and the movement of the spring is limited by the surrounding end walls. [10] Composite sealing ring according to claim 1, wherein the resin sealing ring is divided to include an opening, an engaging piece (41, 42) and an engaging piece (43, 44); the engaging piece (41, 42) and the engaging piece (43, 44) overlap in a radial direction. [11] Composite sealing ring according to claim 1, wherein an outer circumferential surface of the sealing ring comes into contact with the inner wall in the fully closed state of the valve, wherein radial expansion in a radial direction outwards is suppressed. [12] Composite sealing ring according to claim 1, wherein the metal spring is configured to provide an inward radial force by abutting a surface of the annular groove when an outer peripheral surface of the sealing ring is in a free state and the sealing ring is pushed radially outward by a pressure. [13] Composite sealing ring for use in a throttle valve comprising a body with a passage containing an inner wall, a valve inside the body which opens and closes the passage by a rotary displacement, and an outer circumferential groove, wherein the composite sealing ring has a resin sealing ring configured to be positioned in the outer circumferential groove and configured to seal between the inner wall and the valve in a fully closed state of the valve, wherein the resin sealing ring has an annular groove; and a solid metal spring, which is arranged within the annular groove and is configured to push the resin sealing ring radially outwards and radially inwards as a result of pressure acting on the resin sealing ring or deformation of the resin sealing ring. [14] Composite sealing ring according to claim 13, wherein the resin sealing ring has a first gap in a circumferential direction of the resin sealing ring, the solid metal spring has a second gap in a circumferential direction of the solid metal spring, and The first slit and the second slit have different circumferential distances. [15] Valve assembly comprising the composite sealing ring according to claim 13 and the throttle valve, wherein the composite sealing ring is arranged in the outer circumferential groove. [16] Composite sealing ring according to claim 14, wherein two ends of the solid metal spring, which are adjacent to the second gap, extend into the first gap. [17] Composite sealing ring according to claim 14, wherein two ends of the solid metal spring which are adjacent to the second gap do not extend into the first gap.

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