JP6644085B2 - Exhaust gas recirculation valve device - Google Patents

Description

The present invention relates to an exhaust gas circulation valve device having a seal for suppressing fluid leakage.

  In a conventional valve device, a valve shaft in a housing is slid while being supported on a bearing by an actuator or the like, and a valve attached to the valve shaft opens and closes a fluid passage in the housing, so that the flow rate of the fluid is reduced. regulate.

  However, the conventional valve apparatus, the fluid had leaked into unnecessary portions from between the valve shaft and the bearing.

  As a remedy, the conventional exhaust gas circulation valve device is provided with a seal portion composed of an elastic body and a seal provided so as to cover the outer surface of the elastic body, between the housing and the valve shaft. Seal portion, the plug is pressed in close contact with the housing, the elastic member with pressing the seal to the valve shaft by the elastic member is spread radially presses the seal plug. Since the conventional exhaust gas circulation valve device is configured as described above, exhaust gas, foreign matter, moisture, and the like are not affected by the exhaust pressure, and a gap between the valve shaft and the bearing allows the exhaust gas, foreign matter, moisture, and the like to slide on the valve shaft and the valve. Leakage to the actuator for driving the shaft is suppressed, and the sealing performance between the valve shaft and the bearing is improved. (For example, refer to Patent Document 1.)

International Publication No. 2010/018650

  However, it is necessary to improve the sealing performance more than the above-mentioned conventional exhaust gas circulation valve device without changing the magnitude of the force of the elastic body, while making it easier to transmit the pressing force of the elastic body to the seal and maintaining durability. Is required.

  The present invention was made to solve the above problems, easily convey the pressing of the elastic body to seal, while providing durability, without changing the magnitude of the force of the elastic body , and to provide a valve device to further improve the sealing property.

An exhaust gas circulation valve device according to the present invention includes a housing having a fluid passage through which a fluid passes, a valve shaft slidably provided in the housing, and a valve for opening and closing the fluid passage by sliding, a housing and a valve shaft. A seal provided radially around the valve shaft, having a concave portion in the axial direction of the valve shaft and deformable by pressure, and an elastic member provided in the concave portion of the seal and pressing the seal in the radial direction of the valve shaft. Ru and a sealing portion having a and. Seal portion, half of the second thickness group portion first thickness group root side on the valve stem side of the seal of the recesses is in contact with the valve shaft side on the valve shaft side of the recess of the seal And the base is set to a quarter of the length from the bottom of the seal recess to the end of the seal opening and the side of the seal recess on the valve stem side. shape of the portion in contact with the valve shaft is curved.

  ADVANTAGE OF THE INVENTION According to the valve apparatus which concerns on this invention, since a seal becomes easy to deform | transform, it becomes easy to transmit the press of an elastic body to a seal | sticker, and, while maintaining durability, without changing the magnitude of the force of an elastic body, a valve shaft. The followability of the seal to the seal can be improved, and the sealability can be improved.

FIG. 1 is an axial sectional view of an exhaust gas circulation valve device including a valve device according to Embodiment 1 of the present invention. FIG. 3 is an enlarged axial sectional view of a filter of the exhaust gas circulation valve device including the valve device according to Embodiment 1 of the present invention. FIG. 2 is an enlarged axial sectional view of a seal portion of the exhaust gas circulation valve device including the valve device according to Embodiment 1 of the present invention.

  Hereinafter, the exhaust gas circulation valve apparatus comprising a valve device according to the present invention as an example will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is an axial sectional view of an exhaust gas circulation valve device 1 including a valve device according to Embodiment 1 of the present invention. Exhaust gas recirculation valve device 1 according to the first embodiment of the present invention is to regulate the flow rate of the exhaust gas. Exhaust gas recirculation valve device 1 comprises a housing 2 having a passage through which fluid, a valve shaft 3 within the housing 2, a bearing 4 for supporting the valve shaft 3, an actuator 5 for sliding the valve shaft 3, the valve Valves 6 and 7 attached to the shaft 3 to open and close the passage of the housing 2, valve seats 8 and 9 that contact the valves 6 and 7, and a spring receiving seat 10 that contacts an end of the valve shaft 3 on the actuator 5 side. An urging body 11 for urging the spring receiving seat 10, a filter 12 for removing deposits on the surface of the valve shaft 3, a seal portion 13 for sealing between the housing 2 and the valve shaft 3, and a bearing 4. A fixing portion 14 for fixing the filter 12 and the seal portion 13 to the housing 2, a shaft end support 15 for supporting an end of the valve shaft 3 on the side opposite to the actuator 5 side, and a lid 16 for covering the shaft end support 15. It is equipped with a.

The housing 2 is provided with an inlet 17 through which exhaust gas flows from a pipe (not shown) communicating with the housing 2, and outlets 18 and 19 through which exhaust gas flows out into a pipe (not shown) communicating with the housing 2. the inlet 17 and the outlet 18, 19 are communicated with each passage in the housing 2.
The housing 2, the projection 27 for fixing the bearing 4 and the filter 12 and the seal portion 13 by the fixing portion 14 is provided.

The valve shaft 3 has a cylindrical shape, and is provided in the housing 2 so as to be slidable in the axial direction.
In addition, the valve shaft 3 is not limited to this as long as it is not a columnar shape but a rod-like shape that can slide in the axial direction.

The bearing 4 has a cylindrical shape having a larger diameter than the valve shaft 3. Bearing 4 is disposed in the housing 2, through hole in the axial direction through the valve stem 3 is provided, slidably supports the valve shaft 3 in the axial direction. That is, the radial cross section of the bearing 4 is annular.
Incidentally, the bearing 4 is set to have a cylindrical shape, provided with a through hole through which the valve shaft 3, as long as it can support the valve shaft 3 is not limited thereto. Further, the radial cross-section of the bearing 4 is set to have an annular shape, as long as it can support the valve shaft 3 is not limited thereto.

The actuator 5 is attached to the end face of the housing 2. The actuator 5 has an actuator shaft 20 to press the valve shaft 3 in the axial direction, sliding the valve shaft 3 by pressing the valve shaft 3 via the spring seat 10 in the actuator shaft 20.
The actuator 5 is, for example, a motor or the like.

Each of the valves 6 and 7 has a disk shape having a larger diameter than the valve shaft 3, and is provided with a through hole through which the valve shaft 3 passes. The valves 6 and 7 have a circular cross section in the radial direction, and a trapezoidal shape in which the right and left corners are cut so that the valves 6 and 7 can easily contact the valve seats 8 and 9 in the axial direction. I have.
The valve 6, 7 through the valve shaft 3 in the through-hole, is attached to the valve shaft 3, with the sliding of the valve shaft 3, moves within the housing 2. In this way, the valve 6 and 7, an outlet 18, 19 is attached to the valve shaft 3 so as to be open and close the passage communicating respectively with the inlet 17 of the housing 2.
The valves 6 and 7 have an annular cross section in the radial direction, and a trapezoidal shape in which the right and left corners are cut so that the valves 6 and 7 can easily contact the valve seats 8 and 9 in the axial direction. and has a was but it is provided with a through hole through which the valve shaft 3, capable of opening and closing a passage between the inlet 17 of the housing 2 by bringing into contact with the valve seat 8, 9 and outlet 18 and 19 respectively communicating However, the shape is not limited to this.

The valve seats 8 and 9 are provided with through holes, the outer diameters of the valve seats 8 and 9 are larger than the outer diameters of the valves 6 and 7, and the inner diameters of the valve seats 8 and 9 are larger than the outer diameters of the valves 6 and 7. It has a small annular. The valve seat 8 and 9, when closing the passage valves 6 and 7 the inlet 17 of the housing 2 and the outlet port 18 and 19 are communicated with each the housing 2 so as to seal in contact with the valve 6, 7 It is attached. The valve seat 8 and 9, for example made of resin sealing. When the valve seats 8 and 9 are made of resin-made seals, the sealing performance is improved when the valves 6 and 7 close the passages where the inflow ports 17 and the outflow ports 18 and 19 of the housing 2 communicate with each other.
Incidentally, the valve seat 8 and 9 is set to have an annular, when closing the passage valves 6 and 7 the inlet 17 of the housing 2 and the outlet 18, 19 respectively communicating, the valve 6, if contact with shaped to seal 7 it is not limited thereto.

The spring receiving seat 10 has a shape in which a protruding portion is provided on an edge that extends in a radial direction and on a side opposite to the actuator 5 side. The spring receiving seat 10 is attached to the valve shaft 3 such that a convex portion of the spring receiving seat 10 contacts an end of the valve shaft 3 on the actuator 5 side.
The spring receiving seat 10 has a shape in which a radially extending edge and a convex portion are provided on the side opposite to the actuator 5 side. If there is an abutting part, it is not limited to this.

The biasing body 11 is provided in a compressed state between the housing 2 and a radially extending edge of the spring receiving seat 10. Since the urging body 11 is provided in a compressed state between the housing 2 and the spring receiving seat 10, the spring receiving seat 10 is urged toward the actuator 5 by the urging force of the urging body 11. valve shaft 3 the spring receiving seat 10 is mounted to slide actuator 5 side, the valve 6, 7 is attached to the valve shaft 3 is biased in a direction in contact with the valve seat 8 and 9.
The urging body 11 is, for example, a coil spring or the like. The spring is not limited to a coil spring as long as the spring receiving seat 10 can be urged. In addition, the biasing body 11 is provided in a compressed state between the housing 2 and the radially extending edge of the spring receiving seat 10. It is not necessary. The urging body 11 may be provided anywhere as long as the spring receiving seat 10 can be urged.

FIG. 2 is an enlarged axial sectional view of the filter 12 of the exhaust gas circulation valve device 1 including the valve device according to Embodiment 1 of the present invention. The filter 12 is provided with a through hole through which the valve shaft 3 passes, and has a shape in which a radially extending edge reaching the housing 2 and a convex portion are provided on the side opposite to the actuator 5 side. The filter 12 is provided on the side of the passage where the inflow port 17 and the outflow ports 18 and 19 of the housing 2 communicate with each other.
Filter 12 may be scraped off the deposits such as soot in the exhaust gas adheres to the valve shaft 3. By scraping off the deposits such as soot of the exhaust gas, it is possible to prevent the deposits from adhering to the valve shaft 3 and increase the radial direction of the valve shaft 3, thereby preventing sliding.
The filter 12 includes a holder 21, a net 22, and a holding plate 23.

  The holder 21 has a radially extending edge reaching the housing 2 at the end on the bearing 4 side, and a projection having a bottom at the end opposite to the bearing 4. The bottom is provided with a through hole through which the valve shaft 3 passes. Note that the bottom is not limited to a flat shape, but may be a closed shape such as a pointed shape.

The net 22 has a rod shape and is provided in the holder 21. The net 22 is initially longer than the depth from the edge of the holder 21 to the bottom of the projection. The net 22 has a through hole through which the valve shaft 3 passes.
The net 22 is, for example, a wire net. It should be noted, is not limited to the wire mesh.

The holding plate 23 is provided with a through hole through which the valve shaft 3 passes, and has an annular shape. Holding plate 23, in providing a net 22 in the holder 21, by abutting the presser plate 23 on the edge of the holder 21 to press the web 22 to the holder 21. Thus, the network 22 is deformed so as to reduce the through-holes, to accurately contact to the valve shaft 3 surface. In addition, the holding plate 23 prevents the net 22 from damaging the seal portion 13.
The holding plate 23 has an annular shape, but is not limited to this as long as the mesh 22 can be pressed against the holder 21.
Furthermore, for example, the seal portion 13 from the actuator side, bearing 4, when present in the order shown in the filter 12, holding plate 23 may not be used.

Figure 3 shows an enlarged axial cross-sectional view of an exhaust gas circulation valve device 1 of the seal portion 13 including the valve device according to a first embodiment of the present invention. The seal portion 13 is in contact with the valve shaft 3 and has a shape surrounding the valve shaft 3. The seal portion 13 is provided between the bearing 4 and the filter 12 in the axial direction of the valve shaft 3, and is provided between the housing 2 and the valve shaft 3 in the radial direction. The seal part 13 seals a gap between the housing 2 and the valve shaft 3.
The seal portion 13 includes a seal 24, an elastic body 25, and a plug 26.
Incidentally, the sealing portion 13 is set to the axial direction of the valve shaft 3 is provided between the bearing 4 and the filter 12 is not limited thereto. For example, the seal portion 13 may be present on the actuator side of the bearing 4.

  The seal 24 is provided inside the plug 26. The seal 24 is provided with a through hole for passing the valve shaft 3 so as to pass through the valve shaft 3 and surround the valve shaft 3. Further, the seal 24 has a concave portion provided with the elastic body 25 in the axial direction of the valve shaft 3 so as to surround the valve shaft 3, and is deformed by the pressure of the elastic body 25. The thickness values of the portion 29 where the range of thickness values of the side surface of the base 28 in the valve shaft 3 side of the recess of the seal 24 is in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 is thinner than the range. Here, after it will be referred to as "thickness" group a "range of thickness values". Further, the pressure of the exhaust gas pushes and spreads the seal 24, so that the sealing performance can be further improved.

  The base 28 is, for example, h / 4 from the bottom of the concave portion of the seal 24 to the end of the opening of the seal 24 from the bottom of the concave portion of the seal 24 as h. Base 28, the pressing is not much hanging of the elastic member 25, the pressing of the valve shaft 3 is a portion which is not used directly. However, base 28, when the from the bottom of the recess of the seal 24 to the end of the opening of the seal 24 is h, but from the bottom of the recess of the seal 24 was in the range of h / 4, for example, h / 3 and h / 5, etc. But well, not limited to this.

  In addition, the thickness group of the root 28 of the side surface of the concave portion of the seal 24 on the valve shaft 3 side is smaller than the thickness group of the portion 29 of the concave surface of the seal 24 that is in contact with the valve shaft 3 on the side of the valve shaft 3. However, here, for example, the thickness group of the base 28 of the side surface on the valve shaft 3 side of the concave portion of the seal 24 is 0.5 mm, and the valve shaft on the side surface of the concave portion of the seal 24 on the valve shaft 3 side. 3 thickness groups of the portion 29 of contact and 2.1mm from 2mm and a side thickness group aspects of root 28 in the valve shaft 3 side of the recess of the seal 24 is in the valve shaft 3 side of the recess of the seal 24 Of the thickness of the portion 29 in contact with the valve shaft 3 is set to half or less. However, the numerical values are only examples, and are not limited thereto.

  Furthermore, even if the above has been the thickness of group aspects of root 28 in the valve shaft 3 side of the recess of the seal 24 to 0.5mm and uniform, to have a width, for example, from 0.48mm to 0.5mm and the value Good. Also at this time, the thickness group of the base 28 of the side surface of the concave portion of the seal 24 on the valve shaft 3 side is in the range of 0.48 mm to 0.5 mm, and the contact with the valve shaft 3 of the side surface of the concave portion of the seal 24 on the valve shaft 3 side. The thickness group of the portion 29 to be changed from 2 mm to 2.1 mm, and the thickness group of the base 28 of the side surface on the valve shaft 3 side of the concave portion of the seal 24 is the side valve shaft on the valve shaft 3 side of the concave portion of the seal 24. 3 or less than half of the thickness group of the portion 29 in contact with 3. Conversely, the thickness of group portion 29 which contacts the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 was 2.1mm from 2mm, or may be, for example, 2mm and uniformity. In this case, the thickness of the group of the side surface of the base 28 in the valve shaft 3 side of the recess of the seal 24 is 0.5 mm, the portion 29 in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 The thickness group is 2 mm, and the thickness group of the base 28 of the side surface of the concave portion of the seal 24 on the valve shaft 3 side is the thickness of the portion 29 in contact with the valve shaft 3 of the side surface of the concave portion of the seal 24 on the valve shaft 3 side. Less than half of the group. That is, the thickness group of the root 28 of the side surface of the concave portion of the seal 24 on the valve shaft 3 side is less than half the thickness group of the portion 29 of the concave surface of the seal 24 in contact with the valve shaft 3 on the side surface of the valve shaft 3. if so will the value of the thickness can be uniform even if the width. Here, the above numerical values are merely examples, and are not limited thereto.

  Seal 24, the portion 29 in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 in the axial direction of the cross section, in the shape of a curved surface. The seal 24 has a better sealing property as the contact area with the valve shaft 3 is larger. Here, in the conventional seal, it seems that the entire side surface of the concave portion of the seal on the valve shaft side is in wide surface contact with the valve shaft. When an inclination or a gap occurs, a part of the side surface of the concave portion of the seal on the valve shaft side tends to contact the valve shaft only in a narrow range such as a line contact. On the other hand, the seal 24 of the exhaust gas recirculation valve device 1 includes a valve device according to a first embodiment of the present invention, the valve shaft 3 and the contact portion 29 is axial side on the valve shaft 3 side of the recess of the seal 24 Has a curved surface, the valve shaft 3 is located on the valve shaft 3 side of the concave portion of the seal 24 even if an inclination or a gap occurs due to a dimensional error during assembling or manufacturing. A portion 29 of the side surface which comes into contact with the valve shaft 3 extends along the valve shaft 3 to facilitate surface contact. That is, if the inclination or gap is formed in the valve shaft 3, the seal 24 of the exhaust gas recirculation valve device 1 includes a valve device according to a first embodiment of the present invention are stable, the housing 2 and the valve shaft 3 to seal the gap between.

  Further, a portion 29 of the concave portion of the seal 24 which is in contact with the valve shaft 3 on the side surface on the valve shaft 3 side comes into broader surface contact with the valve shaft 3, so that the pressure with which the seal 24 presses the valve shaft 3 is reduced. If the valve shaft, for example, tilt or gap in errors of assembly or during production time dimension occurs, the portion which contacts the pressing of the elastic body F, a valve shaft side on the valve shaft side of the recess of the conventional seal Assuming that the contact area with S1 is S1, the pressure P1 at this time is P1 = F / S1. Using the same elastic member, when the portion 29 in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 to a curved surface, the pressing of the elastic body 25, like F, embodiments of the present invention Assuming that the contact area between the seal 24 and the valve shaft 3 of the exhaust gas circulation valve device 1 including the valve device according to 1 is S2, the pressure P2 at this time is P2 = F / S2. Here, since S1 <S2, P1> P2. The smaller the pressure, the smaller the friction, so the wear of the seal 24 is slowed down, which leads to a longer life.

  Seal 24 is, for example, resin or rubber. The seal 24 is preferably made of a resin such as polytetrafluoroethylene (PTFE), which has heat resistance, lubricity, and corrosion resistance, is hardly worn, and has a long service life. The material is if those deformed by the pressure of the elastic body 25 is not limited to this.

The thickness of the root portion 28 of the side surface of the seal 24 on the valve shaft 3 side of the concave portion of the seal 24 is larger than the thickness group of the portion 29 of the concave portion of the seal 24 in contact with the valve shaft 3 on the side surface of the concave portion of the seal 24 on the valve shaft 3 side. by also thin, the seal 24 tends to be deformed, easily convey the pressing of the elastic body 25 to the seal 24, the seal 24 into close contact with the more the valve shaft 3. With the above configuration, it is possible to improve the sealing property without changing the size of the force of the elastic body 25. Although the seal 24 by contact with the valve shaft 3 occurs wear due to rub the valve stem 3, a portion 29 in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 seal 24 By making it thicker than the base 28 of the seal 24, the durability can be maintained even if it is worn more than when all the side surfaces of the concave portion of the seal 24 on the valve shaft 3 side are made thinner. Furthermore, when using the same as a conventional elastic body 25, the seal portion 13 for easily convey the pressing of the elastic body 25 to the seal 24 the pressure for pressing into the housing 2 and the valve shaft 3 is increased. Therefore, even if a gap is Akidashi between the seal 24 and the valve stem 3 seals 24 are worn, since the easily transmitted pressing of the elastic body 25, elastic body 25 presses the seal 24, more sealability good. That is, the thickness group of the portion 29 of the concave portion of the seal 24 which is in contact with the valve shaft 3 on the side of the valve shaft 3 in the concave portion of the seal 24 becomes thinner due to wear and a gap is provided between the valve shaft 3 and the seal 24. Time can be delayed, leading to a longer life.
Further, the elastic body 25, even with small force of the elastic body 25 than the prior art, can be the same sealing performance as the conventional. By using those forces of the elastic body 25 is small, it reduces the pressure seal 24 presses the valve shaft 3. Because better pressure is less friction becomes smaller, blunted wear of the seal 24, leading to a long-life.

The elastic body 25 is provided in a concave portion of the seal 24, and is provided so as to surround the valve shaft 3, similarly to the seal 24. Axial cross section of the elastic body 25 is shaped as folded in two. The elastic body 25 presses the seal 24 in the radial direction of the valve shaft 3, and presses the seal 24 against the valve shaft 3 and presses the seal 24 against the plug 26.
The elastic body 25, the seal 24 is pressed in the radial direction of the valve shaft 3, the seal 24 with pressing the seal 24 in the valve shaft 3 have a shape that presses the plug 26 is not limited thereto.
The elastic body 25 is, for example, a metal spring having an effect of corrosion resistance and heat resistance. Elastic body 25, in particular corrosion resistance among metal spring, it is spring stainless steel having an effect of heat resistance. It should be noted that the material is not limited to this.

Plug 26 is provided between the housing 2, a cylindrical shape having a recess providing the through hole and seal 24 through the valve shaft 3. The plug 26 is press-fitted into the housing 2. Plug 26, by providing the seal 24 between the plug 26 and the filter 12, the seal 24 is prevented from moving in the axial direction by sliding of the valve shaft 3.
The plug 26 may be formed integrally with the bearing 4. Thus the number of parts is reduced by the. Further, assemblability is further improved due to the reduction in the number of parts.
Moreover, the plug 26, when the seal portion 13 is present on the actuator side of the bearing 4 can also be formed integrally with the housing 2. By doing so, the number of parts is reduced. Moreover, assemblability by decreasing the number of parts is further improved.

The fixing portion 14 is provided with a through hole through which the valve shaft 3 passes, and has an annular shape. Fixing unit 14 includes a bearing 4, a filter 12, by a sealing portion 13 interposed between the projections 27 of the housing 2, a bearing 4, a filter 12, to fix the seal portion 13 to the housing 2.
Note that the fixing portion 14 is used in the case where the bearing 4 is made of a material such as carbon which is broken and broken by press-fitting. The bearing 4 made of a material such as carbon or the like which is broken and broken by press-fitting is fixed by the fixing portion 14 because it is impossible to press-fit the bearing 4 into the housing 2 and fix it. Conversely, if the bearing 4 is made of a press-fittable material such as copper or the like, it can be fixed only by the bearing 4, so that the fixing portion 14 need not be used.

The shaft end bearing 15 has a shape in which a radially extending edge reaching the housing 2 and a through hole for passing, supporting, and fixing the valve shaft 3 are provided. The shaft end bearing 15 is provided at an end of the housing 2 and slidably supports an end of the valve shaft 3 on the side opposite to the actuator 5 side by a through hole.
Note that the shaft end bearing 15 has a shape in which a radially extending edge reaching the housing 2 and a through hole for passing and supporting and fixing the valve shaft 3 are provided. A concave portion or the like may be used as long as the end opposite to the side can be slidably supported.

  The lid body 16, a convex portion is provided on the opposite side of the actuator 5 side, the outer periphery is shaped to press radially as caught by the housing 2. The lid 16 is provided on an end face of the housing 2 opposite to the actuator 5 side so as to cover the shaft end receiver 15 with the shaft end receiver 15 abutting on the housing 2. The lid body 16 bulges to the outside in order to secure the sliding range of the valve shaft 3. Here, the lid 16 is swelled outward in order to secure the sliding range of the valve shaft 3, but is not limited to this.

  Next, the operation of the exhaust gas circulation valve device 1 according to Embodiment 1 of the present invention will be described.

  The actuator 5 is not driven when closing the passage where the inflow port 17 and the outflow ports 18 and 19 of the housing 2 communicate with each other. Since the urging body 11 is provided in a compressed state between the housing 2 and the spring receiving seat 10, the spring receiving seat 10 is urged toward the actuator 5 by the urging force of the urging body 11. Accordingly, the valve shaft 3 to which the spring receiving seat 10 is attached slides to the actuator 5 side. At this time, the valve shaft 3 slides while being supported by the bearing 4. By the sliding of the valve shaft 3, the valve 6, 7 mounted to the valve shaft 3 is biased in a direction in contact with the valve seat 8 and 9, the valve 6, 7 is the inlet 17 of the housing 2 outlet 18, closing the passage 19 and is communicated respectively. In this case, the filter 12, the valve shaft 3 scraped off soot or the like in the exhaust gas when the slide. Further, the seal portion 13, the elastic body 25 presses the seal 24 in the radial direction of the valve shaft 3, the seal 24 by the pressure is deformed. The thickness of the root portion 28 of the side surface of the seal 24 on the valve shaft 3 side of the concave portion of the seal 24 is larger than the thickness group of the portion 29 of the concave portion of the seal 24 in contact with the valve shaft 3 on the side surface of the concave portion of the seal 24 on the valve shaft 3 side. Since the thickness is also thin, the deformation of the seal 24 due to the pressing of the elastic body 25 is facilitated, and the seal portion 13 seals between the housing 2 and the valve shaft 3. Further, the pressure of the exhaust gas pushes and spreads the seal 24 to further enhance the sealability. The bearing 4, the filter 12, and the seal portion 13 are fixed by the fixing portion 14 and do not slide with the valve shaft 3.

  Further, when releasing the passage of the inlet 17 and the outlet 18, 19 the housing 2 are communicated with each drives the actuator 5. The actuator 5 presses the actuator shaft 20 to the side opposite to the actuator 5 side, and presses the spring receiving seat 10 to which the valve shaft 3 is attached to the side opposite to the actuator 5 side. To the valve shaft 3 the spring receiving seat 10 is attached with which it slides on the opposite side to the actuator 5 side. At this time, the valve shaft 3 slides while being supported by the bearing 4. Incidentally, the biasing member 11, by being provided in a state of being compressed between the housing 2 and the spring receiving seat 10, a spring receiving seat 10 is urged to the actuator 5 side by the biasing force of the biasing member 11 and which is the force that the actuator 5 is the actuator shaft 20 and actuator 5 side to press on the opposite side is winning the force of the Tsukezeitai 11. The sliding of the valve shaft 3 urges the valves 6, 7 attached to the valve shaft 3 in a direction away from the valve seats 8, 9, and the valves 6, 7 are moved into the inlet 17 and the outlets 18, 19 of the housing 2. Open the passages communicating with each other. At this time, the filter 12 removes soot and the like of the exhaust gas when the valve shaft 3 slides. In the seal portion 13, the elastic body 25 presses the seal 24 in the radial direction of the valve shaft 3, and the seal 24 is deformed by the pressure. The thickness of the root portion 28 of the side surface of the seal 24 on the valve shaft 3 side of the concave portion of the seal 24 is larger than the thickness group of the portion 29 of the concave portion of the seal 24 in contact with the valve shaft 3 on the side surface of the concave portion of the seal 24 on the valve shaft 3 side. Since the thickness is also thin, the deformation of the seal 24 due to the pressing of the elastic body 25 is facilitated, and the seal portion 13 seals between the housing 2 and the valve shaft 3. The pressure of the exhaust gas by pushing the seal 24, and further raising the sealability. The bearing 4, the filter 12, and the seal portion 13 are fixed by the fixing portion 14 and do not slide with the valve shaft 3. As described above, the seal portion 13 always seals the space between the housing 2 and the valve shaft 3 irrespective of the opening and closing of the passage through which the inflow port 17 and the outflow ports 18 and 19 of the housing 2 communicate.

As described above, in the exhaust gas circulation valve device 1 including the valve device shown in the first embodiment, the thickness group of the base 28 of the side surface on the valve shaft 3 side of the concave portion of the seal 24 is determined. by less than the thickness group portion 29 which contacts the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24, the seal 24 is more susceptible to deformation, the pressing of the elastic body 25 to the seal 24 easier to tell, seal 24 is in close contact with the more the valve shaft 3. With the above configuration, it is possible to improve the sealing property without changing the size of the force of the elastic body 25. Also, the seal 24 comes into contact with the valve shaft 3 and wears due to friction with the valve shaft 3. However, a portion 29 of the concave portion of the seal 24 which is in contact with the valve shaft 3 on the side of the valve shaft 3 is replaced with the seal 24. By making it thicker than the base 28 of the seal 24, the durability can be maintained even if it is worn more than when all the side surfaces of the concave portion of the seal 24 on the valve shaft 3 side are made thinner. Further, when the same elastic body 25 as that of the related art is used, the pressure of the elastic body 25 is easily transmitted to the seal 24, so that the pressure of the seal portion 13 against the housing 2 and the valve shaft 3 is increased. For this reason, even if the seal 24 wears and a gap is formed between the seal 24 and the valve shaft 3, the pressing of the elastic body 25 is easily transmitted, and the elastic body 25 presses the seal 24, and the sealing property is further improved. good. In other words, the thickness of a group of part 29 in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 than before with a gap between the valve shaft 3 and the seal 24 becomes thin due to wear Time can be delayed, leading to a longer life.
Furthermore, even if the elastic body 25 has a smaller force than that of the conventional elastic body, the same sealing performance as that of the related art can be obtained. By using those forces of the elastic body 25 is small, it reduces the pressure seal 24 presses the valve shaft 3. The smaller the pressure, the smaller the friction, so the wear of the seal 24 is slowed down, which leads to a longer life.

  Further, in the valve device of the first embodiment, the seal 24 is in the valve shaft 3 portion 29 which contacts the axial cross section of the side surface on the valve shaft 3 side of the recess of the seal 24, a curved surface When the valve shaft 3 is tilted or a gap occurs, the seal 24 stably seals the gap between the housing 2 and the valve shaft 3. Seal 24, it is large contact area between the valve shaft 3 is good sealability. Here, conventional seals, the whole aspect of the valve stem side of the seal recess but seems to be contacted widely plane as the valve shaft, the valve shaft, for example during assembly and during production dimensions error or the like When an inclination or a gap occurs, a part of the side surface of the concave portion of the seal on the valve shaft side tends to contact the valve shaft only in a narrow range such as a line contact. On the other hand, the seal 24 of the exhaust gas recirculation valve device 1 includes a valve device according to a first embodiment of the present invention, the valve shaft 3 and the contact portion 29 is axial side on the valve shaft 3 side of the recess of the seal 24 Has a curved surface, the valve shaft 3 is located on the valve shaft 3 side of the concave portion of the seal 24 even if an inclination or a gap occurs due to a dimensional error during assembling or manufacturing. A portion 29 of the side surface that comes into contact with the valve shaft 3 extends along the valve shaft 3 to facilitate surface contact. That is, when a tilt or a gap occurs in the valve shaft 3, the seal 24 of the exhaust gas circulation valve device 1 including the valve device according to Embodiment 1 of the present invention stably connects the housing 2 to the valve shaft 3. to seal the gap between.

  Further, in the valve device in the first embodiment, by the portion 29 in contact with the valve shaft 3 side in the valve shaft 3 side of the recess of the seal 24 is wider surface contact with the valve shaft 3, the seal The pressure by which 24 presses valve stem 3 is reduced. If the valve shaft is inclined or a gap is generated due to, for example, an error in dimensions during assembly or manufacture, the pressure of the elastic body is changed to F, a portion of the concave portion of the conventional seal that comes into contact with the valve shaft on the side of the valve shaft on the valve shaft side. Assuming that the contact area with S1 is S1, the pressure P1 at this time is P1 = F / S1. When a portion 29 of the concave portion of the seal 24 which is in contact with the valve shaft 3 on the side of the valve shaft 3 is formed into a curved surface by using a similar elastic member, the pressing force of the elastic member 25 is similarly F. when the contact area between the seal 24 and the valve shaft 3 of the exhaust gas recirculation valve device 1 includes a valve device according to 1 and S2, the pressure P2 at this time is the P2 = F / S2. Here, <since it is S2, P1> S1 becomes P2. Because better pressure is less friction becomes smaller, blunted wear of the seal 24, leading to a long-life.

  In the valve device shown in the above-described embodiment, the elastic body 25 is such that the elastic body 25 and the elastic body 25 are parallel except for the bent portion in the cross section as shown in FIG. The elastic body 25 may have a shape in which the elastic body 25 moves away from the bent portion. Even thus configured valve device, it is possible to obtain the effect of the first embodiment described above.

  In the valve device described in the above-described embodiment, the seal 24 has a symmetrical shape with respect to the side surface in contact with the valve shaft 3 and the side surface in contact with the housing 2. An asymmetrical shape may be used between the contacting side surface and the side surface contacting the housing 2. For example, the side that abuts the valve shaft 3 is to reduce the base 28, in contact with the side surface on the housing 2 may be a uniform thickness group. Even with the valve device configured as described above, the effects of the first embodiment can be obtained.

  In the valve device shown in this embodiment described above, the seal 24 is in the valve shaft 3 portion 29 which contacts the axial cross section of the side surface on the valve shaft 3 side of the recess of the seal 24, the shape of the curved surface However, a flat shape may be used. Even thus configured valve device, it is possible to obtain the effect of the first embodiment described above.

  In the valve device described in the above embodiment, a gap 30 is formed between the bottom corner of the concave portion of the seal 24 and the elastic body 25, but the gap 30 is not formed. Is also good. Even thus configured valve device, it is possible to obtain the effect of the first embodiment described above.

  Valve device shown in the embodiment described above has been adapted for exhaust gas recirculation valve device 1, as long as it can adjust the flow rate of the fluid is not limited to the exhaust gas. Further, for example, if the purge solenoid valve device and the oil valve device such as a valve device which can be adapted, not limited to the exhaust gas circulation valve device 1. Even thus configured valve device, it is possible to obtain the effect of the first embodiment described above.

  However, the valve device shown in the above embodiment merely an example, as appropriate, be one that can be configured combinations and subtracting it, not limited to the embodiment alone configuration embodiment.

1 exhaust gas recirculation valve device, 2 housing, 3 valve shaft, 4 bearings,
5 Actuator, 6,7 valve, 8,9 valve seat, 10 spring seat,
11 biasing body, 12 filter, 13 seal portion 14 fixed portion,
15 shaft end, 16 lid, 17 inlet, 18, 19 outlet,
20 Actuator shaft, 21 Holder, 22 Net, 23 Holding plate,
24 seal, 25 elastic body, 26 plug, 27 protrusion,
28 root, 29 a portion in contact with the valve stem on the side face on the valve stem side of the concave portion of the seal,
30 gap.

Claims (5)

A housing having a fluid passage through which exhaust gas passes;
A valve shaft slidably provided in the housing and having a valve for opening and closing the fluid passage by the sliding;
A seal provided between the housing and the valve shaft so as to radially surround the valve shaft, having a recess in the axial direction of the valve shaft and deforming by pressure; and a valve shaft provided in the recess of the seal. and a sealing portion having an elastic member for pressing the on radial the seal,
The seal portion, the second portion first thickness group root side in the valve shaft side of the recess of the seal is in contact with the valve shaft side in the valve shaft side of the recess of the seal Not more than half the thickness of the thickness group ,
The root is set in a range of a quarter of the length from the bottom of the recess of the seal to the end of the opening of the seal , and the valve shaft on the side of the recess on the valve shaft side of the recess of the seal. shape of the portion contacting the exhaust gas recirculation valve device which is a curved surface. The seal exhaust gas recirculation valve device according to claim 1 which is a member made of resin. It said resin member, the exhaust gas recirculation valve device according to claim 2, characterized in that the PTFE. The exhaust gas circulation valve device according to claim 1, wherein the elastic body is a metal spring. The exhaust gas circulation valve device according to claim 4 , wherein the metal spring is a stainless steel spring.

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