JP2015108313A - Exhaust gas recirculation valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce gas leakage through an abutment joint of a seal ring in a valve element of an EGR valve.SOLUTION: An EGR valve 1 includes: a housing 10 having a flow passage 22; a disk-shaped valve element 15 stored with a minute clearance from an inner wall surface of the flow passage 22 and having a peripheral groove 24 on an outer periphery thereof; and annular seal rings 16A and 16B held in the peripheral groove 24 in a thickness direction, arranged to be movable in a radial direction, and having abutment joints 16a and 16b. When the valve element 15 is fully closed, outer peripheral surfaces of the seal rings 16A and 16B are brought into close contact with the inner wall surface of the flow passage 22 with the usage of elastic deformation force in the radial direction of the seal rings 16A and 16B, and thereby, the inner wall surface of the flow passage 22 and an outer peripheral surface 15a of the valve element 15 are made to be air tight. The two seal rings 16A and 16B are arranged to be overlapped in an axial direction of the valve element 15 in the peripheral groove 24, and are arranged in such a manner of being displaced so that the abutment joints 16a and 16b of the two seal rings 16A and 16B are not overlapped in the direction of an axis L1.

Description

  The present invention relates to an exhaust gas recirculation valve provided in an exhaust gas recirculation passage constituting an exhaust gas recirculation device for an engine.

  Conventionally, as this type of technique, for example, a butterfly valve type exhaust gas recirculation (EGR) valve described in Patent Document 1 below is known. This EGR valve is accommodated through a minute gap between a housing having an EGR gas flow path and an inner wall surface of the flow path, and a substantially disc-shaped valve body having a peripheral groove on the outer periphery, A substantially annular seal ring that is held in the circumferential direction within the circumferential groove and arranged to be movable in the radial direction. When the valve body is fully closed, the EGR valve uses the elastic deformation force in the radial direction of the seal ring to bring the outer peripheral surface of the seal ring into close contact with the inner wall surface of the flow path. It is comprised so that an outer peripheral surface of this may be airtight. Here, the seal ring is provided such that an end surface in the axial direction thereof is in contact with an inner surface in the axial direction of the circumferential groove, and at least one of the end surface of the seal ring or the inner surface of the circumferential groove is different from the planar shape. Formed. As a result, the sticking force between the seal ring and the valve body can be greatly reduced, and the end surface and the peripheral surface of the seal ring are not increased without increasing the contact surface pressure between the outer peripheral surface of the seal ring and the inner wall surface of the flow path. An increase in wear with the inner surface of the groove is prevented.

JP 2005-113872 A

  However, in the EGR valve described in Patent Document 1, the seal ring is not composed of a closed loop, and a part of the ring is opened to form a joint. Therefore, even when the valve body is fully closed, EGR gas may leak from the gap at the joint. Here, it is conceivable to reduce the gap by processing the shape of the joint, but there is a problem that processing is limited and processing cost is high.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an exhaust gas recirculation valve that can reduce gas leakage through a joint of a seal ring.

  In order to achieve the above object, the invention according to claim 1 is housed between a housing having an exhaust recirculation gas flow path and an inner wall surface of the flow path through a minute gap, and has a circumferential groove on the outer periphery. A disc having a substantially disc shape and a seal ring having a substantially annular shape having a joint held in the circumferential groove in the thickness direction and movably arranged in the radial direction. When the cylinder is fully closed, the outer circumferential surface of the seal ring is brought into close contact with the inner wall surface of the flow channel by utilizing the elastic deformation force in the radial direction of the seal ring, so that the inner wall surface of the flow channel and the outer circumferential surface of the valve element are hermetically sealed. The butterfly valve type exhaust gas recirculation valve is configured to include a plurality of seal rings, and the plurality of seal rings are arranged in the circumferential direction so as to overlap each other in the axial direction of the valve body. Do not position the joint so that it does not overlap in the axial direction. And the purpose that it is arranged.

  According to the configuration of the above invention, the plurality of seal rings are arranged in the circumferential groove so as to overlap in the axial direction of the valve body, and the positions of the plurality of seal rings are shifted so as not to overlap in the axial direction. Since they are arranged, the joints of the seal rings do not communicate with each other, and the joints are closed.

  In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, each of the plurality of seal rings is formed in a corrugated shape that continuously undulates in the circumferential direction, and the plurality of seal rings Are superimposed so that the wave shapes engage each other.

  According to the configuration of the invention, in addition to the operation of the invention according to claim 1, since the plurality of seal rings are overlapped so as to engage the corrugated shape, the positions of the seal rings are not shifted from each other. The positions of a plurality of joints that are arranged at different positions are not relatively displaced.

  In order to achieve the above object, the invention described in claim 3 is that, in the invention described in claim 1, the valve body is provided with an engaging portion that engages with a joint of each seal ring. .

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 1, since the engaging portion that engages with the joint of each seal ring is provided in the valve body, each joint engages with the engaging portion. As a result, the seal rings are prevented from rotating and the positions of the seal rings are not shifted from each other, and the positions of the plurality of joints arranged with the positions shifted are relatively not shifted.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the third aspect of the present invention, the engaging portion is a protrusion protruding into the circumferential groove corresponding to the joint of each seal ring. The purpose is that.

  According to the configuration of the above invention, in addition to the operation of the invention according to the third aspect, each seal ring can be prevented from rotating only by providing a protrusion in the circumferential groove.

  To achieve the above object, according to a fifth aspect of the present invention, in the third aspect of the present invention, the engaging portion is a partition that divides the circumferential groove in the circumferential direction corresponding to the joint of each seal ring. The purpose is to be.

  According to the configuration of the above invention, in addition to the operation of the invention according to the third aspect, each seal ring can be prevented from rotating only by providing the partition wall in the circumferential groove.

  In order to achieve the above object, the invention according to claim 6 is accommodated between the housing having the flow path of the exhaust recirculation gas and the inner wall surface of the flow path through a minute gap, and has a circumferential groove on the outer periphery. A disc having a substantially disc shape and a seal ring having a substantially annular shape having a joint held in the circumferential groove in the thickness direction and movably arranged in the radial direction. When the cylinder is fully closed, the outer circumferential surface of the seal ring is brought into close contact with the inner wall surface of the flow channel by utilizing the elastic deformation force in the radial direction of the seal ring, so that the inner wall surface of the flow channel and the outer circumferential surface of the valve element are hermetically sealed. In the butterfly valve type exhaust gas recirculation valve, the seal ring is formed in a spiral shape with a length of not less than one round and less than one and a half of the outer periphery of the valve body, and both end portions of the circumferential groove are vertically moved on the outer periphery of the valve body. The circumferential groove is spirally formed so as to overlap the The seal ring of a spirit that both end portions of the seal ring by being accommodated in a spiral circumferential grooves are disposed so as to overlap vertically.

  According to the configuration of the above invention, since the spiral seal ring is accommodated in the spiral circumferential groove, both end portions of the seal ring are arranged so as to overlap vertically in the circumferential groove. Both end portions are in contact with each other up and down, and the gap between the both end surfaces is closed.

  In order to achieve the above object, the invention according to claim 7 is housed between the housing having the flow path of the exhaust gas recirculation gas and the inner peripheral wall surface of the flow path through a minute gap, and surrounds the outer periphery. A valve body having a substantially disc shape having a groove, and a substantially annular seal ring having a joint held in the circumferential groove in the thickness direction and movably arranged in the radial direction, When the body is fully closed, the outer circumferential surface of the seal ring is brought into close contact with the inner wall surface of the flow channel by utilizing the elastic deformation force in the radial direction of the seal ring, so that the inner wall surface of the flow channel and the outer circumferential surface of the valve body are hermetically sealed. In the butterfly valve type exhaust gas recirculation valve configured to be formed, a liquid sealing material is applied to the joint of the seal ring, and the end surface facing the upstream side of the exhaust gas recirculation gas among the end surfaces in the thickness direction of the seal ring Liquid sealant was applied on top And the spirit the door.

  According to the configuration of the above invention, the liquid sealing material is applied to the joint of the seal ring, and the liquid sealing material is applied on the end surface in the thickness direction of the seal ring that faces the upstream side of the exhaust gas recirculation gas. Therefore, the gap of the exhaust gas recirculation gas at the joint and the circumferential groove is closed.

  According to the first aspect of the present invention, it is possible to reduce gas leakage through the joint of the seal ring at the valve body of the exhaust gas recirculation valve.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the seal rings are relatively rotated while the exhaust gas recirculation valve is used, and a plurality of joints are prevented from overlapping. be able to.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1, the seal rings are relatively rotated while the exhaust gas recirculation valve is used, and a plurality of joints are prevented from overlapping. be able to.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 3, the exhaust gas recirculation gas leakage can be reduced with a relatively simple and inexpensive configuration.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 3, it is possible to reduce the exhaust gas recirculation gas leakage with a relatively simple and inexpensive configuration.

  According to the sixth aspect of the present invention, it is possible to reduce gas leakage through the joint of the seal ring at the valve body of the exhaust gas recirculation valve.

  According to the seventh aspect of the present invention, it is possible to reduce gas leakage through the joint of the seal ring and the peripheral groove in the valve body of the exhaust gas recirculation valve.

Sectional drawing (partially external view) which concerns on 1st Embodiment and shows the whole structure of an EGR valve. The AA sectional view taken on the line of FIG. 1 which shows an EGR valve according to the first embodiment. Sectional drawing which concerns on 1st Embodiment and expands and shows the part enclosed with the chain-line ellipse B of FIG. The perspective view which concerns on 1st Embodiment and exaggeratedly shows the characteristic of a butterfly valve. The perspective view which concerns on 1st Embodiment and isolate | separates and shows two seal rings. The perspective view which concerns on 2nd Embodiment and exaggeratedly shows the characteristic of a butterfly valve. The perspective view which concerns on 2nd Embodiment and isolate | separates and shows two seal rings. Sectional drawing which concerns on 2nd Embodiment and shows a sleeve and a butterfly valve. Sectional drawing which concerns on 3rd Embodiment and shows a butterfly valve. The CC sectional view taken on the line of FIG. 9 which concerns on 3rd Embodiment and shows a butterfly valve. The DD sectional view taken on the line of FIG. 9 which concerns on 3rd Embodiment and shows a butterfly valve. The front view which concerns on 4th Embodiment and shows a butterfly valve. The perspective view which concerns on 4th Embodiment and shows a valve body. The perspective view which concerns on 4th Embodiment and shows a seal ring. Sectional drawing which concerns on 5th Embodiment and shows a sleeve and a butterfly valve. The perspective view which concerns on 5th Embodiment and shows a seal ring. FIG. 16 is an enlarged cross-sectional view showing a portion surrounded by a chain line circle E in FIG. 15 according to the fifth embodiment.

<First Embodiment>
Hereinafter, a first embodiment of an exhaust gas recirculation valve (EGR valve) according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view (partially an external view) showing the overall configuration of the EGR valve 1. FIG. 2 shows the EGR valve 1 by a cross-sectional view taken along line AA of FIG. FIG. 3 is an enlarged cross-sectional view of a portion surrounded by a chain line ellipse B in FIG.

  As shown in FIGS. 1 and 2, the EGR valve 1 includes a housing 10, a sleeve 12, a butterfly valve 14, a seal ring 16, a shaft 18, an electric actuator 20, and the like, and is configured as a butterfly valve type.

  As shown in FIG. 2, the housing 10 has a flow path 22 through which EGR gas flows. In FIG. 2, the flow path 22 has an upstream side portion 22 a on the right side and a downstream side portion 22 b on the left side with the butterfly valve 14 as a boundary. The inlet of the upstream side portion 22a is connected to an exhaust passage (both not shown) via an EGR passage so that EGR gas is introduced. The outlet of the downstream side portion 22b is connected to an intake passage (both not shown) via an EGR passage so that EGR gas is led out.

  As shown in FIG. 2, the sleeve 12 has a cylindrical shape and is fixed by being press-fitted into the inner wall surface 10 a of the flow path 22. In this fixed state, the inner wall surface 12 a of the sleeve 12 forms a part of the flow path 22. The sleeve 12 is formed of a material excellent in heat resistance and corrosion resistance (for example, stainless steel).

  As shown in FIG. 2, the butterfly valve 14 is disposed inside the sleeve 12. As shown in FIG. 3, the butterfly valve 14 includes a valve body 15 and two seal rings 16A and 16B. The valve body 15 is accommodated between the inner wall surface 12a of the sleeve 12 through a minute gap. The valve body 15 is formed in a substantially disc shape from a material excellent in heat resistance and corrosion resistance (for example, stainless steel), and has a circumferential groove 24 on the outer periphery. The butterfly valve 14 is fixed to the tip of the shaft 18 by welding or the like, and is cantilevered by the shaft 18. As shown in FIGS. 2 and 3, the two seal rings 16 </ b> A and 16 </ b> B are fitted into the circumferential groove 24 of the valve body 15. The two seal rings 16A, 16B are arranged in the circumferential groove 24 so as to be held in the thickness direction and movable in the radial direction. Each of the seal rings 16A and 16B has a substantially annular shape, and has one joint 16a and 16b (see FIGS. 4 and 5). The seal rings 16A and 16B are formed in a substantially C shape and a rectangular cross section by a metal material such as stainless steel.

  As shown in FIGS. 1 and 2, the shaft 18 rotatably supports the butterfly valve 14 in the housing 10. The shaft 18 is rotationally driven by the electric actuator 20. The shaft 18 is provided in the housing 10 so as to penetrate the inside of the electric actuator 20 and the inside of the sleeve 12, and is supported rotatably via a needle bearing 26 and a ball bearing 28. The shaft 18 is made of a material excellent in heat resistance and corrosion resistance (for example, stainless steel or the like), and is formed in a substantially cylindrical shape whose outer diameters are large and small in the axial direction. A seal member 30 for preventing EGR gas from leaking from the flow path 22 into the electric actuator 20 is provided between the housing 10 and the shaft 18.

  As shown in FIG. 1, the electric actuator 20 includes an electric motor 32, a reduction gear 34, a return spring 36, and the like. The electric motor 32 is composed of, for example, a DC motor, and rotates the shaft 18 via a speed reducer 34. The reduction gear 34 is composed of a plurality of gears combined with each other. The reduction gear 34 amplifies the rotational torque of the electric motor 32 and transmits it to the shaft 18. The return spring 36 biases the butterfly valve 14 in the fully closed direction.

  The EGR valve 1 configured as described above is configured to rotationally drive the butterfly valve 14 by rotating the shaft 18 by the electric actuator 20. As a result, the EGR valve 1 is configured such that the butterfly valve 14 is in a fully closed state in which the entire outer peripheral surfaces of the seal rings 16A and 16B are in close contact with the inner wall surface 12a of the sleeve 12, and the outer peripheral surfaces of the seal rings 16A and 16B The opening is variable between the fully open state and the 12 inner wall surfaces 12a. When the butterfly valve 14 is fully closed, as shown in FIG. 3, the outer peripheral surface of each seal ring 16A, 16B is used as the inner wall surface of the sleeve 12 by utilizing the elastic deformation force in the radial direction of the two seal rings 16A, 16B. The inner wall surface 12a of the sleeve 12 and the outer peripheral surface 15a of the valve body 15 are configured to be airtight by being brought into close contact with 12a.

  FIG. 4 is a perspective view exaggerating the characteristics of the butterfly valve 14. FIG. 5 is a perspective view showing two seal rings 16A and 16B separated. As shown in FIGS. 4 and 5, the two seal rings 16A and 16B are arranged in the circumferential groove 24 so as to overlap in the direction of the axis L1 of the valve body 15, and the two seal rings 16A and 16B. The abutments 16a and 16b are arranged with their positions shifted so that they do not overlap vertically in the direction of the axis L1. In this embodiment, the joints 16a and 16b of the two seal rings 16A and 16B are arranged with a phase shift of 180 ° about the axis L1 of the valve body 15 (in FIG. 4, for convenience, the upper and lower joints 16a and 16b 16b is visible).

  As shown in FIGS. 4 and 5, the two seal rings 16A and 16B are each formed in a wave shape that continuously undulates in the circumferential direction. Further, the two seal rings 16A and 16B are overlapped so that the wave shapes are engaged with each other. That is, the two seal rings 16A and 16B are aligned so that the corrugated concave and convex portions overlap and the convex and convex portions overlap.

  According to the EGR valve 1 of this embodiment described above, the two seal rings 16A and 16B are arranged in the circumferential groove 24 so as to overlap in the direction of the axis L1 of the valve body 15, and the two seal rings 16A. , 16B are located at different positions so that the joints 16a, 16b do not overlap in the direction of the axis L1. Accordingly, the joints 16a and 16b of the seal rings 16A and 16B do not communicate with each other, and the joints 16a and 16b are closed. For this reason, in the valve body 15 of the EGR valve 1, EGR gas leakage through the joints 16a, 16b of the two seal rings 16A, 16B can be reduced.

  Further, in this embodiment, the two seal rings 16A and 16B are overlapped so that the wave shapes are engaged with each other. Therefore, the positions of the seal rings 16A and 16B are not shifted from each other, and the positions of the two abutments 16a and 16b that are arranged at different positions are relatively not shifted. For this reason, it can be prevented that the seal rings 16A and 16B rotate relatively while the EGR valve 1 is used and the two joints 16a and 16b overlap each other.

Second Embodiment
Next, a second embodiment in which the exhaust gas recirculation valve (EGR valve) of the present invention is embodied will be described in detail with reference to the drawings.

  In each embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described.

This embodiment differs from the first embodiment in the configuration of the butterfly valve 14. FIG. 6 is a perspective view exaggerating the characteristics of the butterfly valve 14. FIG. 7 is a perspective view showing two seal rings 17A and 17B separately. FIG. 8 is a sectional view showing the sleeve 12 and the butterfly valve 14. As shown in FIGS. 6 and 7, in this embodiment, two normal flat seal rings 17A and 17B that do not form a wave shape are used. The two seal rings 17A and 17B are arranged in the circumferential groove 24 so as to overlap in the direction of the axis L1 of the valve body 15, and the joints 17a and 17b of the two seal rings 17A and 17B are arranged in the direction of the axis L1. The positions are shifted so as not to overlap each other. In this embodiment, the joints 17a and 17b of the two seal rings 17A and 17B are arranged with a phase shift of 180 ° around the axis L1 of the valve body 15. Further, in this working liquid, the joint 17 of each seal ring 17A, 17B.
Two protrusions 25a and 25b are provided as engaging portions that engage with a and 17b. Each protrusion 25a, 25b is formed so as to protrude into the circumferential groove 24 corresponding to the joint 17a, 17b of each seal ring 17A, 17B. These two protrusions 25 a and 25 b are formed by partially caulking the outer peripheral surface of the valve body 15.

  According to the EGR valve 1 of this embodiment described above, the two seal rings 17A and 17B are arranged in the circumferential groove 24 so as to overlap in the direction of the axis L1 of the valve body 15, and the two seal rings 17A. , 17B and the joints 17a, 17b are arranged so as to be shifted so as not to overlap in the direction of the axis L1. Accordingly, the joints 17a and 17b of the seal rings 17A and 17B do not communicate with each other, and the joints 17a and 17b are closed. For this reason, in the valve body 15 of the EGR valve B1, EGR gas leakage through the joints 17a, 17b of the two seal rings 17A, 17B can be reduced.

  Further, in this embodiment, the projections 25a and 25b that engage with the joints 17a and 17b of the seal rings 17A and 17B are provided on the valve body 15, so that the joints 17a and 17b engage with the projections 25a and 25b. Thus, the seal rings 17A and 17B are prevented from rotating and are not displaced from each other, and the positions of the two abutments 17a and 17b arranged at different positions are relatively not displaced. For this reason, it can be prevented that the seal rings 17A and 17B rotate relatively while the EGR valve 1 is used and the two joints 17a and 17b overlap each other.

  Further, in this embodiment, the seal ring 17A, 17B can be prevented from rotating only by partially caulking the outer periphery of the valve body 15 and providing the projections 25a, 25b in the circumferential groove 24. For this reason, EGR gas leakage can be reduced with a relatively simple and inexpensive configuration.

<Third Embodiment>
Next, a third embodiment in which the exhaust gas recirculation valve (EGR valve) of the present invention is embodied will be described in detail with reference to the drawings.

  This embodiment differs from the above embodiments in the configuration of the butterfly valve 14. FIG. 9 is a sectional view of the butterfly valve 14. FIG. 10 shows the butterfly valve 14 by a cross-sectional view taken along the line CC of FIG. FIG. 11 shows the butterfly valve 14 by a cross-sectional view taken along the line DD of FIG. As shown in FIGS. 9 to 11, in this embodiment, two flat seal rings 19 </ b> A and 19 </ b> B that do not form a wave shape are used. The two seal rings 19A and 19B are each formed to be short to a circumference of about 2/3 of the circumference of each of the seal rings 17A and 17B of the second embodiment. , 19b are formed large. The two seal rings 19A and 19B are arranged in the circumferential groove 24 so as to overlap each other in the direction of the axis L1 of the valve body 15, and the joints 19a and 19b of the two seal rings 19A and 19B are in the axis L1. The positions are shifted so that they do not overlap vertically. In this embodiment, the joints 19a and 19b of the two seal rings 19A and 19B are arranged with a phase shift of 180 ° around the axis L1 of the valve body 15. Further, in this embodiment liquid, the circumferential groove 24 is partitioned in the circumferential direction corresponding to the joints 19a and 19b of the seal rings 19A and 19B as engaging portions that engage with the joints 19a and 19b of the seal rings 19A and 19B. Partition walls 27a and 27b are provided. These two partition walls 27a and 27b are formed by partially omitting a part of the circumferential groove 24 corresponding to the joints 19a and 19b.

  According to the EGR valve 1 of this embodiment described above, the two seal rings 19A and 19B are arranged in the circumferential groove 24 so as to overlap each other in the direction of the axis L1 of the valve body 15, and the two seal rings 19A. 19B, the joints 19a, 19b of the seal rings 19A, 19B are not in communication with each other so that the joints 19a, 19b of the seal rings 19A, 19B are not in communication with each other. 19b is blocked. For this reason, in the valve body 15 of the EGR valve 1, EGR gas leakage through the joints 19a and 19b of the two seal rings 19A and 19B can be reduced.

  Moreover, in this embodiment, since the partition 27a, 27b engaged with the joints 19a, 19b of the seal rings 19A, 19B is provided in the valve body 15, each joint 19a, 19b is engaged with the partitions 27a, 27b. Thus, the seal rings 19A and 19B are prevented from rotating, so that the positions of the seal rings 19A and 19B are not shifted from each other, and the positions of the two abutments 19a and 19b arranged to be shifted from each other are relatively not shifted. For this reason, it can be prevented that the seal rings 19A and 19B rotate relatively while the EGR valve 1 is used, and the two joints 19a and 19b overlap each other.

  Further, in this embodiment, the seal rings 19A and 19B can be prevented from rotating only by partially omitting the circumferential groove 24 of the valve body 15 and providing the partition walls 27a and 27b. For this reason, EGR gas leakage can be reduced with a relatively simple and inexpensive configuration.

<Fourth embodiment>
Next, a fourth embodiment in which the exhaust gas recirculation valve (EGR valve) of the present invention is embodied will be described in detail with reference to the drawings.

  This embodiment differs from the above embodiments in the configuration of the butterfly valve 14. FIG. 12 is a front view of the butterfly valve 14. FIG. 13 is a perspective view of the valve body 15. FIG. 14 is a perspective view of the seal ring 21. As shown in FIGS. 12 and 14, in this embodiment, one spiral seal ring 21 is used. The seal ring 21 is formed in a spiral shape with a length of not less than one circle and less than one and a half of the outer periphery of the valve body 15. As shown in FIGS. 12 and 13, the circumferential groove 29 is formed in a spiral shape so that both end portions of the circumferential groove 29 overlap vertically on the outer periphery of the valve body 15, and the spiral seal ring 21 is formed in a spiral shape. By being accommodated in the circumferential groove 29, both end portions 21 a, 21 b of the seal ring 21 are arranged so as to overlap vertically.

  According to the EGR valve 1 of this embodiment described above, the seal ring 21 having a spiral shape is accommodated in the circumferential groove 29 formed in a spiral shape, so that both end portions 21a and 21b of the seal ring 21 are surrounded. It arrange | positions so that it may overlap in the groove | channel 24 up and down. Accordingly, both end portions 21a and 21b of the seal ring 21 are in contact with each other in the vertical direction, and the gap between the both end surfaces 21c and 21d is closed. For this reason, EGR gas leakage via the joint of the seal ring 21 can be reduced.

<Fifth Embodiment>
Next, a fifth embodiment in which the exhaust gas recirculation valve (EGR valve) of the present invention is embodied will be described in detail with reference to the drawings.

  This embodiment differs from the above embodiments in the configuration of the butterfly valve 14. FIG. 15 is a sectional view showing the sleeve 12 and the butterfly valve 14. FIG. 16 is a perspective view showing the seal ring 37. FIG. 17 is an enlarged sectional view showing a portion surrounded by a chain line circle E in FIG. As shown in FIG. 16, in this embodiment, a single flat seal ring 37 is used. As shown in FIGS. 15 and 17, in this embodiment, a liquid sealing material 38 is applied to the joint 37 a of the seal ring 37, and the end face in the thickness direction of the seal ring 37 is directed to the upstream side of the EGR gas. A liquid sealing material 38 is applied on the end face 37b.

  Therefore, according to the EGR valve 1 of this embodiment, the gap of the EGR gas in the circumferential groove 24 is closed. For this reason, it is possible to reduce EGR gas leakage through the joint 37 a and the circumferential groove 24 of the seal ring 37.

  Note that the present invention is not limited to the above-described embodiments, and a part of the configuration can be changed as appropriate without departing from the spirit of the invention.

  (1) In the first and second embodiments, two seal rings 16A, 16B, 17A, and 17B are used as a plurality of seal rings. However, an appropriate number of three or more seal rings may be used. it can.

  (2) In the third embodiment, the circumferential length of each of the seal rings 19A, 19B is about 2/3 of the circumferential length of each of the seal rings 17A, 17B of the second embodiment, and the seal rings 19A, 19B Although the partition walls 27a and 27b corresponding to the sizes of the joints 19a and 19b are provided in the circumferential groove 24, the circumferential length of each seal ring and the sizes of the joints and the partition walls are not limited to the above sizes.

  The present invention can be used for an EGR device applied to a gasoline engine or a diesel engine.

DESCRIPTION OF SYMBOLS 1 EGR valve 10 Housing 10a Inner wall surface 12 Sleeve 12a Inner wall surface 14 Butterfly valve 15 Valve body 15a Outer peripheral surface 16 Seal ring 16A Seal ring 16B Seal ring 16a Joint port 16b Joint port 17A Seal ring 17B Seal ring 17a Joint port 17b Joint port 19A Seal ring 19A Seal Ring 19a Abutment 19b Abutment 21 Seal ring 21a End part 21b End part 21c End face 21d End face 22 Flow path 22a Upstream part 22b Downstream part 24 Circumferential groove 25a Projection (engaging part)
25b Protrusion (engagement part)
27a Bulkhead (engagement part)
27b Bulkhead (engagement part)
29 circumferential groove 37 seal ring 37a abutment 37b upstream end face 38 liquid sealing material L1 axis

Claims (7)

A housing having a flow path for exhaust recirculation gas;
A valve body which is accommodated through a minute gap between the inner wall surface of the flow path and has a substantially disk shape having a circumferential groove on the outer periphery;
A sealing ring having a substantially annular shape having a joint held in the circumferential groove in the thickness direction and movable in the radial direction, and when the valve body is fully closed, By utilizing the elastic deformation force in the radial direction, the outer peripheral surface of the seal ring is brought into close contact with the inner wall surface of the flow channel, so that the inner wall surface of the flow channel and the outer peripheral surface of the valve body are hermetically sealed. In the butterfly valve type exhaust gas recirculation valve configured as follows:
A plurality of the seal rings are provided, the plurality of seal rings are arranged in the circumferential groove so as to overlap in the axial direction of the valve body, and the joints of the plurality of seal rings are not overlapped in the axial direction. An exhaust gas recirculation valve characterized in that the exhaust gas recirculation valve is arranged at a different position.   2. Each of the plurality of seal rings is formed in a wave shape that continuously undulates in the circumferential direction, and the plurality of seal rings are overlapped so as to engage the wave shapes with each other. Exhaust recirculation valve.   2. The exhaust gas recirculation valve according to claim 1, wherein an engagement portion that engages with the joint of each of the seal rings is provided in the valve body.   The exhaust gas recirculation valve according to claim 3, wherein the engaging portion is a protrusion protruding into the circumferential groove corresponding to the joint of each seal ring.   4. The exhaust gas recirculation valve according to claim 3, wherein the engaging portion is a partition wall that divides the circumferential groove in a circumferential direction corresponding to the joint of each seal ring. A housing having a flow path for exhaust recirculation gas;
A valve body which is accommodated through a minute gap between the inner wall surface of the flow path and has a substantially disk shape having a circumferential groove on the outer periphery;
A sealing ring having a substantially annular shape having a joint held in the circumferential groove in the thickness direction and movable in the radial direction, and when the valve body is fully closed, By utilizing the elastic deformation force in the radial direction, the outer peripheral surface of the seal ring is brought into close contact with the inner wall surface of the flow channel, so that the inner wall surface of the flow channel and the outer peripheral surface of the valve body are hermetically sealed. In the butterfly valve type exhaust gas recirculation valve configured as follows:
The seal ring is formed in a spiral shape with a length of one or more circumferences and less than one and a half cycles of the outer periphery of the valve body, and the circumferential grooves are spirally formed so that both end portions of the circumferential groove overlap vertically on the outer periphery of the valve body. An exhaust gas recirculation valve formed and disposed so that both end portions of the seal ring overlap each other by being accommodated in the spiral circumferential groove. A housing having a flow path for exhaust recirculation gas;
A valve body that is accommodated through a minute gap between the inner circumferential wall surface of the flow path and has a substantially disk shape having a circumferential groove on the outer circumference;
A sealing ring having a substantially annular shape having a joint held in the circumferential groove in the thickness direction and movable in the radial direction, and when the valve body is fully closed, By utilizing the elastic deformation force in the radial direction, the outer peripheral surface of the seal ring is brought into close contact with the inner wall surface of the flow channel, so that the inner wall surface of the flow channel and the outer peripheral surface of the valve body are hermetically sealed. In the butterfly valve type exhaust gas recirculation valve configured as follows:
A liquid sealing material is applied to the joint of the seal ring, and the liquid sealing material is applied to the end face of the end face in the thickness direction of the seal ring that faces the upstream side of the exhaust gas recirculation gas. An exhaust gas recirculation valve characterized by that.

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