WO2017098622A1

WO2017098622A1 - Valve device

Info

Publication number: WO2017098622A1
Application number: PCT/JP2015/084600
Authority: WO
Inventors: 明良前林; 拓朗頭井; 裕彦加藤
Original assignee: 三菱電機株式会社
Priority date: 2015-12-10
Filing date: 2015-12-10
Publication date: 2017-06-15
Also published as: JP6644085B2; JPWO2017098622A1

Abstract

There is a demand for easier transmission of the pressing force of an elastic body to a seal than in conventional valve devices to further improve sealing while providing durability and without changing the magnitude of the force of the elastic body. A valve device is configured so that provided therein are: a housing with a fluid passage through which fluid passes; a valve shaft slidably provided in the housing and having valves for opening and closing the fluid passage by sliding; and a sealing part provided between the housing and the valve shaft so as to surround the valve shaft in the radial direction and having a seal with a recess in the axial direction of the valve shaft that deforms with pressure and an elastic body provided in the seal recess that presses the seal in the radial direction of the valve shaft. The sealing part is configured so that a first range of thicknesses for the base of the valve shaft-side side surface of the seal recess is thinner than a second range of thicknesses for the portion of the valve shaft-side side surface of the seal recess that contacts the valve shaft.

Description

Valve device

The present invention relates to a valve device having a seal that suppresses fluid leakage.

In the conventional valve device, the valve shaft in the housing is slid while being supported by a bearing by an actuator or the like, and the valve attached to the valve shaft opens and closes the fluid passage in the housing, thereby controlling the flow rate of the fluid. It is adjusting.

However, in the conventional valve device, fluid leaks to an unnecessary portion from between the valve shaft and the bearing.

As this improvement measure, the conventional exhaust gas circulation valve device is provided with a seal portion comprising 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. The seal portion press-fits the plug into the housing, and the elastic body presses and expands in the radial direction, thereby pressing the seal against the valve shaft and the elastic body pressing the seal against the plug. Since the conventional exhaust gas circulation valve device is configured as described above, the exhaust gas, foreign matter, moisture, etc. from the gap between the valve shaft and the bearing are not affected by the exhaust pressure, Leakage to the actuator part that drives 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, the pressure of the elastic body can be easily transmitted to the seal, and the durability can be improved, and the sealing performance can be improved more than the conventional exhaust gas circulation valve device without changing the magnitude of the force of the elastic body. Is required.

The present invention has been made in order to solve the above-described problems, and makes it easy to transmit the pressing force of the elastic body to the seal, while maintaining durability, without changing the magnitude of the force of the elastic body. Another object of the present invention is to provide a valve device that further improves sealing performance.

The valve device according to the present invention includes a housing having a fluid passage through which a fluid passes, a valve shaft that is slidably provided in the housing and that opens and closes the fluid passage by sliding, and between the housing and the valve shaft. And a seal that has a recess in the axial direction of the valve shaft and deforms by pressure, and an elastic body that is provided in the recess of the seal and presses the seal in the radial direction of the valve shaft. A seal portion, and the seal portion is a second portion of the portion where the first thickness group of the base of the side surface on the valve shaft side of the concave portion of the seal contacts the valve shaft on the side surface on the valve shaft side of the concave portion of the seal Thinner than the thickness group.

According to the valve device of the present invention, since the seal is easily deformed, the pressure of the elastic body can be easily transmitted to the seal, and the valve shaft can be maintained without changing the magnitude of the force of the elastic body while maintaining durability. The followability of the seal to the can be improved and the sealability can be improved.

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. It is an expanded axial sectional view of the filter of the exhaust gas circulation valve device including the valve device according to Embodiment 1 of the present invention. It is an expanded axial direction sectional view of the seal part of the exhaust gas circulation valve device containing the valve device concerning Embodiment 1 of the present invention.

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

Embodiment 1 FIG.
FIG. 1 shows an axial sectional view of an exhaust gas circulation valve device 1 including a valve device according to Embodiment 1 of the present invention. The exhaust gas circulation valve device 1 according to Embodiment 1 of the present invention adjusts the flow rate of exhaust gas. The exhaust gas circulation valve device 1 includes a housing 2 having a passage through which a fluid passes, a valve shaft 3 in the housing 2, a bearing 4 that supports the valve shaft 3, an actuator 5 that slides the valve shaft 3, a

valve Valves

6, 7 attached to the shaft 3 for opening and closing the passage of the housing 2, valve seats 8, 9 contacting the

valves

6, 7, and a spring receiving seat 10 contacting the end of the valve shaft 3 on the actuator 5 side , An urging body 11 that urges the spring seat 10, a filter 12 that removes deposits on the surface of the valve shaft 3, a seal portion 13 that seals between the housing 2 and the valve shaft 3, and a bearing 4 A fixing portion 14 that fixes the filter 12 and the seal portion 13 to the housing 2, a shaft end receiver 15 that supports an end of the valve shaft 3 opposite to the actuator 5, and a lid body 16 that covers the shaft end receiver 15. It has.

The housing 2 is provided with an inlet 17 into which exhaust gas flows from a pipe (not shown) communicating with the housing 2 and

outlets

18 and 19 through which the exhaust gas flows into a pipe (not shown) communicated with the housing 2. The inflow port 17 and the

outflow ports

18 and 19 communicate with each other through a passage in the housing 2.
In addition, the housing 2 is provided with a protrusion 27 for fixing the bearing 4, the filter 12, and the seal portion 13 with the fixing portion 14.

The valve shaft 3 has a cylindrical shape and is provided in the housing 2 so as to be slidable in the axial direction.
The valve shaft 3 is not limited to this as long as the valve shaft 3 is not cylindrical but can be slid in the axial direction.

The bearing 4 has a cylindrical shape whose diameter is larger than that of the valve shaft 3. The bearing 4 is provided in the housing 2 and is provided with a through hole through which the valve shaft 3 passes in the axial direction, and supports the valve shaft 3 so as to be slidable in the axial direction. That is, the radial cross section of the bearing 4 has an annular shape.
The bearing 4 has a cylindrical shape, but the present invention is not limited to this as long as a through hole through which the valve shaft 3 passes is provided and the valve shaft 3 can be supported. Moreover, although the cross section of the radial direction of the bearing 4 was carrying out the annular shape, if it can support the valve shaft 3, it will not restrict to this.

The actuator 5 is attached to the end surface of the housing 2. The actuator 5 includes an actuator shaft 20 that presses the valve shaft 3 in the axial direction. The actuator shaft 20 slides the valve shaft 3 by pressing the valve shaft 3 via the spring seat 10.
The actuator 5 is, for example, a motor.

The

valves

6 and 7 have a disk shape whose diameter is larger than that of the valve shaft 3, and a through hole through which the valve shaft 3 passes is provided. The

valves

6 and 7 have an annular cross section in the radial direction, and a cross section in the axial direction has a trapezoidal shape with left and right corners cut so that the valve seats 8 and 9 can be easily brought into contact with each other. Yes.
The

valves

6 and 7 are attached to the valve shaft 3 through the valve shaft 3 through the through holes, and move in the housing 2 as the valve shaft 3 slides. In this way, the

valves

6 and 7 are attached to the valve shaft 3 so as to be able to open and close the passages where the inlet 17 and the

outlets

18 and 19 of the housing 2 communicate with each other.
The

valves

6 and 7 have a circular cross section in the radial direction, and the cross section in the axial direction has a trapezoidal shape with left and right corners cut so that the valve seats 8 and 9 can be easily brought into contact with each other. However, a through-hole through which the valve shaft 3 passes is provided, and the passage through which the inflow port 17 and the

outflow ports

18 and 19 of the housing 2 communicate can be opened and closed by contacting the valve seats 8 and 9. The shape is not limited to this as long as it is a shape to be made.

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 ring shape. The valve seats 8 and 9 are formed in the housing 2 so that the

valves

6 and 7 seal against the

valves

6 and 7 when the

valves

6 and 7 block the passages where the inlet 17 and the

outlets

18 and 19 of the housing 2 communicate with each other. It is attached. The valve seats 8 and 9 are, for example, resin seals. By making the valve seats 8 and 9 a resin seal, the sealing performance is enhanced when the

valves

6 and 7 block the passages where the inlet 17 and the

outlets

18 and 19 of the housing 2 communicate with each other.
Although the valve seats 8 and 9 are annular, when the

valves

6 and 7 block the passages where the inlet 17 and the

outlets

18 and 19 of the housing 2 communicate with each other, However, the shape is not limited to this as long as the shape is in contact with 7 and seals.

The spring seat 10 has a shape in which a flange extending in the radial direction and a convex portion are provided on the side opposite to the actuator 5 side. The spring seat 10 is attached to the valve shaft 3 so that the convex portion of the spring seat 10 abuts against the end of the valve shaft 3 on the actuator 5 side.
The spring seat 10 has a shape that is provided with a flange extending in the radial direction and a convex portion on the opposite side of the actuator 5 side. However, a disc shape or the like is formed at the end of the valve shaft 3 on the actuator 5 side. If there is a part which contacts, it will not restrict to this.

The urging body 11 is provided in a compressed state between the housing 2 and the flange extending in the radial direction of the spring seat 10. Since the biasing body 11 is provided in a compressed state between the housing 2 and the spring receiving seat 10, the spring receiving seat 10 is biased toward the actuator 5 by the biasing force of the biasing body 11. The valve shaft 3 to which the spring seat 10 is attached slides toward the actuator 5, and the

valves

6 and 7 attached to the valve shaft 3 are urged in the direction in which they abut against the valve seats 8 and 9.
The biasing body 11 is, for example, a coil spring. The spring is not limited to a coil spring as long as the spring seat 10 can be biased. In addition, the urging body 11 is provided in a compressed state between the housing 2 and the flange extending in the radial direction of the spring receiving seat 10, but when the spring receiving seat 10 has a disk shape, It does not have to be. The biasing body 11 may be provided anywhere as long as the spring seat 10 can be biased.

FIG. 2 shows 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 ridge extending in the radial direction reaching the housing 2 and a convex portion on the side opposite to the actuator 5 are provided. The filter 12 is provided on the passage side where the inflow port 17 and the

outflow ports

18 and 19 of the housing 2 communicate with each other.
The filter 12 can scrape off deposits such as exhaust gas soot adhering to the valve shaft 3. By scraping off deposits such as soot from the exhaust gas, the deposits are attached to the valve shaft 3 and the radial direction of the valve shaft 3 is increased, thereby preventing sliding troubles.
The filter 12 includes a holder 21, a net 22, and a pressing plate 23.

The holder 21 has a flange extending in the radial direction reaching the housing 2 at the end on the bearing 4 side, and a convex portion having a bottom at the end opposite to the bearing 4. A through hole through which the valve shaft 3 passes is provided at the bottom. Note that the bottom is not necessarily flat and may be a closed shape such as a sharp shape.

The net 22 has a rod shape and is provided in the holder 21. The net 22 is first longer than the depth from the ridge of the holder 21 to the bottom of the convex portion. The net 22 has a through hole through which the valve shaft 3 passes.
The net 22 is, for example, a wire net. In addition, it is not restricted to a wire mesh.

The holding plate 23 is provided with a through hole through which the valve shaft 3 passes, and has an annular shape. When the presser plate 23 is provided in the holder 21, the presser plate 23 presses the net 22 against the holder 21 by bringing the presser plate 23 into contact with the flange of the holder 21. Thereby, the net | network 22 deform | transforms so that a through-hole may be shrunk | reduced, and contact | abuts to the valve stem 3 surface accurately. Further, the holding plate 23 prevents the net 22 from damaging the seal portion 13.
Although the pressing plate 23 has an annular shape, the pressing plate 23 is not limited to this as long as the net 22 can be pressed against the holder 21.
Furthermore, for example, when the seal portion 13, the bearing 4, and the filter 12 are present in the order from the actuator side, the pressing plate 23 may not be used.

FIG. 3 is an enlarged axial sectional view of the seal portion 13 of the exhaust gas circulation valve device 1 including the valve device according to Embodiment 1 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 further provided between the housing 2 and the valve shaft 3 in the radial direction. The seal portion 13 seals the gap between the housing 2 and the valve shaft 3.
The seal part 13 includes a seal 24, an elastic body 25, and a plug 26.
The seal portion 13 is provided between the bearing 4 and the filter 12 in the axial direction of the valve shaft 3, but is not limited thereto. For example, the seal portion 13 may be present on the actuator side with respect to the bearing 4.

The seal 24 is provided in the plug 26. The seal 24 is provided with a through hole through which the valve shaft 3 passes so as to surround the valve shaft 3 through the valve shaft 3. Further, the seal 24 has a recess in which the elastic body 25 is provided 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 value range of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is the thickness value of the portion 29 in contact with the side valve shaft 3 on the valve shaft 3 side of the concave portion of the seal 24. It is thinner than the range. Hereafter, the “thickness value range” will be referred to as a “thickness group”. Further, the sealing performance can be further improved by the pressure of the exhaust gas expanding the seal 24.

The root 28 is, for example, in a range of h / 4 from the bottom of the recess of the seal 24, where h is from the bottom of the recess of the seal 24 to the end of the opening of the seal 24. The base 28 is a place where the elastic body 25 is not pressed so much and is not directly used for pressing the valve shaft 3. However, the root 28 has a range of h / 4 from the bottom of the recess of the seal 24, where h is from the bottom of the recess of the seal 24 to the end of the opening of the seal 24. For example, h / 3, h / 5, etc. But it is not limited to this.

Further, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is thinner than the thickness group of the portion 29 that contacts the side valve shaft 3 on the valve shaft 3 side of the concave portion of the seal 24. In this case, for example, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is 0.5 mm, and the side valve shaft on the valve shaft 3 side of the concave portion of the seal 24 The thickness group of the portion 29 in contact with 3 is 2 mm to 2.1 mm, and the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is the side surface of the concave portion of the seal 24 on the valve shaft 3 side. The thickness of the portion 29 in contact with the valve shaft 3 is less than half of the thickness group. However, the numerical value is merely an example, and is not limited thereto.

In addition, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is made uniform to 0.5 mm. However, for example, even if the value is widened from 0.48 mm to 0.5 mm, Good. Also at this time, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is 0.48 mm to 0.5 mm, and contacts with the valve shaft 3 on 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 is from 2 mm to 2.1 mm, and the thickness group of the side base 28 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 is less than half of the thickness group of the portion 29 in contact with 3. On the contrary, the thickness group of the portion 29 in contact with the valve shaft 3 on the side surface of the concave portion of the seal 24 on the side of the valve shaft 3 is set to 2 mm to 2.1 mm. At this time, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is 0.5 mm, and the portion 29 of the concave portion of the seal 24 in contact with the side valve shaft 3 on the valve shaft 3 side. The thickness group is 2 mm, and the thickness of the portion 29 where the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 contacts the side valve shaft 3 on the valve shaft 3 side of the concave portion of the seal 24. It will be less than half of the group. That is, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is less than half the thickness group of the portion 29 that contacts the valve shaft 3 on the side surface of the concave portion of the seal 24 on the valve shaft 3 side. The thickness value may be wide or uniform. Here, the above numerical values are merely examples, and are not limited thereto.

The seal 24 has a curved surface in a cross section in the axial direction of a portion 29 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. The seal 24 has better sealing performance when the contact area with the valve shaft 3 is wider. Here, in the conventional seal, the entire side surface on the valve shaft side of the concave portion of the seal seems to be in wide surface contact with the valve shaft. However, the valve shaft is, for example, due to a dimensional error during assembly or manufacturing. When an inclination or a gap occurs, a part of the side surface on the valve shaft side of the concave portion of the seal tends to come into contact with the valve shaft only in a narrow range such as line contact. On the other hand, in the seal 24 of the exhaust gas circulation valve device 1 including the valve device according to Embodiment 1 of the present invention, the portion 29 that contacts the valve shaft 3 on the side surface on the valve shaft 3 side of the recess of the seal 24 is axial. In the cross section, the curved shape of the valve shaft 3 is on the valve shaft 3 side of the recess of the seal 24 even if an inclination or a gap occurs due to a dimensional error during assembly or manufacturing. A portion 29 in contact with the valve shaft 3 on the side surface extends along the valve shaft 3 so as to facilitate surface contact. That is, when an inclination or a gap is generated 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 stabilizes the housing 2 and the valve shaft 3. Seal the gap between them.

Furthermore, the pressure at which the seal 24 pushes the valve shaft 3 is reduced because the portion 29 of the concave portion of the seal 24 that is in contact with the valve shaft 3 on the side of the valve shaft 3 is more in surface contact with the valve shaft 3. For example, when the valve shaft is tilted or has a gap due to dimensional errors during assembly or manufacturing, the elastic body is pressed F, and the valve shaft on the side surface on the valve shaft side of the concave portion of the conventional seal If the contact area with is S1, the pressure P1 at this time is P1 = F / S1. When the same elastic body is used to form a curved surface portion 29 that contacts the valve shaft 3 on the side of the valve shaft 3 of the recess of the seal 24, the pressing of the elastic body 25 is similarly F, and the embodiment of the present invention. When the contact area between the seal 24 of the exhaust gas circulation valve device 1 including the valve device 1 and the valve shaft 3 is S2, the pressure P2 at this time is P2 = F / S2. Here, since S1 <S2, P1> P2. Since the friction is smaller when the pressure is smaller, wear of the seal 24 is dulled, leading to a longer life.

The seal 24 is, for example, resin or rubber. The seal 24 is preferably made of polytetrafluoroethylene (PTFE), which has heat resistance, lubricity, and corrosion resistance, is not easily worn, and extends the life of the seal 24. The material is not limited to this as long as it can be deformed by the pressure of the elastic body 25.

In the seal 24, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is more than the thickness group of the portion 29 in contact with the side valve shaft 3 on the valve shaft 3 side of the concave portion of the seal 24. Since the seal 24 is more easily deformed by reducing the thickness, the pressure of the elastic body 25 is easily transmitted to the seal 24, and the seal 24 is more closely attached to the valve shaft 3. With the above configuration, the sealing performance can be improved without changing the magnitude of the force of the elastic body 25. Further, wear due to wear of the seal 24 against the valve shaft 3 due to contact with the valve shaft 3 occurs, but a portion 29 of the concave portion of the seal 24 that contacts the valve shaft 3 on the side of the valve shaft 3 is sealed 24. By making it thicker than the base 28, the durability is maintained even if it is worn more than when all the side surfaces on the valve shaft 3 side of the concave portion of the seal 24 are thinned. Furthermore, when the same elastic body 25 is used as the conventional one, it is easy to transmit the pressure of the elastic body 25 to the seal 24, so that the pressure that the seal portion 13 presses against the housing 2 and the valve shaft 3 is increased. For this reason, even if the seal 24 is worn and a gap is generated between the seal 24 and the valve shaft 3, the pressing of the elastic body 25 is easy to be transmitted. Therefore, the elastic body 25 presses the seal 24 and the sealing performance is further improved. Good. That is, the thickness group of the portion 29 in contact with the valve shaft 3 on the side surface of the concave portion of the seal 24 on the side of the valve shaft 3 becomes thinner due to wear, leaving a gap between the valve shaft 3 and the seal 24. Can be delayed, leading to a longer life.
Furthermore, even if the elastic body 25 is a member having a smaller force than the conventional elastic body 25, the same sealing performance as that of the conventional one can be obtained. The pressure with which the seal 24 pushes the valve shaft 3 is reduced by using the elastic body 25 having a small force. Since the friction is smaller when the pressure is smaller, wear of the seal 24 is dulled, leading to a longer life.

The elastic body 25 is provided in the concave portion of the seal 24 and is provided so as to surround the valve shaft 3 in the same manner as the seal 24. The cross section in the axial direction of the elastic body 25 has a shape that is bent in two. The elastic body 25 presses the seal 24 in the radial direction of the valve shaft 3 to press the seal 24 against the valve shaft 3 and press the seal 24 against the plug 26.
The elastic body 25 is not limited to this as long as it has a shape that presses the seal 24 in the radial direction of the valve shaft 3, presses the seal 24 against the valve shaft 3, and presses the seal 24 against the plug 26.
The elastic body 25 is a metal spring having effects of corrosion resistance and heat resistance, for example. The elastic body 25 is preferably a stainless steel spring having an effect of corrosion resistance and heat resistance, among metal springs. The material is not limited to this.

The plug 26 is provided between the housings 2 and has a cylindrical shape having a through hole through which the valve shaft 3 passes and a concave portion in which the seal 24 is provided. The plug 26 is press-fitted and brought into close contact with the housing 2. The plug 26 prevents the seal 24 from moving in the axial direction by sliding of the valve shaft 3 by providing the seal 24 between the plug 26 and the filter 12.
Note that the plug 26 may be formed integrally with the bearing 4. By doing so, the number of parts is reduced. Moreover, the assemblability by the reduction of the number of parts is further improved.
Further, the plug 26 can be formed integrally with the housing 2 when the seal portion 13 is present on the actuator side with respect to the bearing 4. By doing so, the number of parts is reduced. Moreover, the assemblability by the reduction of 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. The fixing portion 14 fixes the bearing 4, the filter 12, and the seal portion 13 to the housing 2 by sandwiching the bearing 4, the filter 12, and the seal portion 13 between the protrusions 27 of the housing 2.
The fixing portion 14 is used in the case where the bearing 4 is made of a material such as carbon that is cracked and damaged when pressed. The bearing 4 made of a material that cracks and breaks when press-fitted such as carbon is fixed by the fixing portion 14 because the bearing 4 cannot be press-fitted and fixed to the housing 2. On the other hand, when the bearing 4 is a press-fit material such as copper, it can be fixed only by the bearing 4, so the fixing portion 14 may not be used.

The shaft end receiver 15 has a shape provided with a through hole for passing and supporting and fixing the valve shaft 3 and a flange extending in the radial direction reaching the housing 2. The shaft end receiver 15 is provided at an end portion of the housing 2 and slidably supports an end portion of the valve shaft 3 opposite to the actuator 5 side through a through hole.
The shaft end receiver 15 has a shape that is provided with a radial hole that reaches the housing 2 and a through-hole that allows the valve shaft 3 to pass through and is supported and fixed. A recess or the like may be used as long as the end opposite to the side can be slidably supported.

The lid body 16 is provided with a convex portion on the side opposite to the actuator 5 side, and the outer periphery has a shape that is pressed in the radial direction so as to be caught by the housing 2. The lid 16 is provided on the end surface of the housing 2 opposite to the actuator 5 so as to contact the housing 2 with the shaft end receiver 15 and cover the shaft end receiver 15. The lid body 16 bulges outside to ensure a sliding range of the valve shaft 3. Here, the lid 16 bulges outside in order to secure the sliding range of the valve shaft 3, but is not limited thereto.

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 the passage where the inflow port 17 and the

outflow ports

18 and 19 of the housing 2 communicate with each other is blocked. 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 seat 10 is attached slides toward the actuator 5 side. At this time, the valve shaft 3 slides while being supported by the bearing 4. As the valve shaft 3 slides, the

valves

6 and 7 attached to the valve shaft 3 are urged in a direction in contact with the valve seats 8 and 9, and the

valves

6 and 7 are in contact with the inlet 17 and outlet 18 of the housing 2. The passage which each communicates with 19 is blocked. At this time, the filter 12 scrapes off exhaust gas soot and the like 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. In the seal 24, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is more than the thickness group of the portion 29 in contact with the side valve shaft 3 on the valve shaft 3 side of the concave portion of the seal 24. Therefore, the seal 24 is easily deformed by pressing the elastic body 25, and the seal portion 13 seals between the housing 2 and the valve shaft 3. Further, the pressure of the exhaust gas pushes the seal 24 to expand the sealing performance. 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 opening the passage where the inlet 17 and the

outlets

18 and 19 of the housing 2 communicate with each other, the actuator 5 is driven. The actuator 5 presses the actuator shaft 20 to the side opposite to the actuator 5 side, and presses the spring seat 10 to which the valve shaft 3 is attached to the side opposite to the actuator 5 side. Accordingly, the valve shaft 3 to which the spring seat 10 is attached slides on the side opposite to the actuator 5 side. At this time, the valve shaft 3 slides while being supported by the bearing 4. Since the biasing body 11 is provided in a compressed state between the housing 2 and the spring receiving seat 10, the spring receiving seat 10 is biased toward the actuator 5 by the biasing force of the biasing body 11. However, the force by which the actuator 5 presses the actuator shaft 20 to the side opposite to the actuator 5 side is superior to the biasing force of the biasing body 11. As the valve shaft 3 slides, the

valves

6, 7 attached to the valve shaft 3 are urged away from the valve seats 8, 9, so that the

valves

6, 7 are in the inlet 17 and

outlets

18, 19 of the housing 2. Open the passages that communicate with each other. At this time, the filter 12 scrapes off exhaust gas soot and the like 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. In the seal 24, the thickness group of the side base 28 on the valve shaft 3 side of the concave portion of the seal 24 is more than the thickness group of the portion 29 in contact with the side valve shaft 3 on the valve shaft 3 side of the concave portion of the seal 24. Therefore, the seal 24 is easily deformed by pressing the elastic body 25, and the seal portion 13 seals between the housing 2 and the valve shaft 3. Further, the pressure of the exhaust gas pushes the seal 24 to expand the sealing performance. 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 between the housing 2 and the valve shaft 3 regardless of opening and closing of the passage where the inlet 17 and the

outlets

18 and 19 of the housing 2 communicate with each other.

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 on the side surface on the valve shaft 3 side of the recess of the seal 24 is set. Since the seal 24 is more easily deformed by making it thinner than the thickness group of the portion 29 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, the pressing of the elastic body 25 is applied to the seal 24. The seal 24 is more closely attached to the valve shaft 3. With the above configuration, the sealing performance can be improved without changing the magnitude of the force of the elastic body 25. Further, wear due to wear of the seal 24 against the valve shaft 3 due to contact with the valve shaft 3 occurs, but a portion 29 of the concave portion of the seal 24 that contacts the valve shaft 3 on the side of the valve shaft 3 is sealed 24. By making it thicker than the base 28, the durability is maintained even if it is worn more than when all the side surfaces on the valve shaft 3 side of the concave portion of the seal 24 are thinned. Furthermore, when the same elastic body 25 is used as the conventional one, it is easy to transmit the pressure of the elastic body 25 to the seal 24, so that the pressure that the seal portion 13 presses against the housing 2 and the valve shaft 3 is increased. For this reason, even if the seal 24 is worn and a gap is generated between the seal 24 and the valve shaft 3, the pressing of the elastic body 25 is easy to be transmitted. Therefore, the elastic body 25 presses the seal 24 and the sealing performance is further improved. Good. That is, the thickness group of the portion 29 in contact with the valve shaft 3 on the side surface of the concave portion of the seal 24 on the side of the valve shaft 3 becomes thinner due to wear, leaving a gap between the valve shaft 3 and the seal 24. Can be delayed, leading to a longer life.
Furthermore, even if the elastic body 25 is a member having a smaller force than the conventional elastic body 25, the same sealing performance as that of the conventional one can be obtained. The pressure with which the seal 24 pushes the valve shaft 3 is reduced by using the elastic body 25 having a small force. Since the friction is smaller when the pressure is smaller, wear of the seal 24 is dulled, leading to a longer life.

Further, in the valve device according to the first embodiment, the seal 24 has a curved surface shape in a cross section in the axial direction of a portion 29 that contacts the valve shaft 3 on the side surface on the valve shaft 3 side of the recess of the seal 24. As a result, when the valve shaft 3 is inclined or has a gap, the seal 24 stably seals the gap between the housing 2 and the valve shaft 3. The seal 24 has better sealing performance when the contact area with the valve shaft 3 is wider. Here, in the conventional seal, the entire side surface on the valve shaft side of the concave portion of the seal seems to be in wide surface contact with the valve shaft. However, the valve shaft is, for example, due to a dimensional error during assembly or manufacturing. When an inclination or a gap occurs, a part of the side surface on the valve shaft side of the concave portion of the seal tends to come into contact with the valve shaft only in a narrow range such as line contact. On the other hand, in the seal 24 of the exhaust gas circulation valve device 1 including the valve device according to Embodiment 1 of the present invention, the portion 29 that contacts the valve shaft 3 on the side surface on the valve shaft 3 side of the recess of the seal 24 is axial. In the cross section, the curved shape of the valve shaft 3 is on the valve shaft 3 side of the recess of the seal 24 even if an inclination or a gap occurs due to a dimensional error during assembly or manufacturing. A portion 29 in contact with the valve shaft 3 on the side surface extends along the valve shaft 3 so as to facilitate surface contact. That is, when an inclination or a gap is generated 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 stabilizes the housing 2 and the valve shaft 3. Seal the gap between them.

Furthermore, in the valve device according to the first embodiment, the portion 29 of the concave portion of the seal 24 that contacts the valve shaft 3 on the side of the valve shaft 3 is in surface contact with the valve shaft 3 more widely. The pressure with which 24 presses the valve shaft 3 decreases. For example, when the valve shaft is tilted or has a gap due to dimensional errors during assembly or manufacturing, the elastic body is pressed F, and the valve shaft on the side surface on the valve shaft side of the concave portion of the conventional seal If the contact area with is S1, the pressure P1 at this time is P1 = F / S1. When the same elastic body is used to form a curved surface portion 29 that contacts the valve shaft 3 on the side of the valve shaft 3 of the recess of the seal 24, the pressing of the elastic body 25 is similarly F, and the embodiment of the present invention. When the contact area between the seal 24 of the exhaust gas circulation valve device 1 including the valve device 1 and the valve shaft 3 is S2, the pressure P2 at this time is P2 = F / S2. Here, since S1 <S2, P1> P2. Since the friction is smaller when the pressure is smaller, wear of the seal 24 is dulled, leading to a longer life.

In the valve device shown in the above-described embodiment, the elastic body 25 is the one in which the elastic body 25 and the elastic body 25 are parallel except for the portion bent in the cross section as shown in FIG. The shape which the elastic body 25 and the elastic body 25 leave | separate may be sufficient as it leaves | separates from the bent location. Even with the valve device configured as described above, the effects of the first embodiment can be obtained.

In the valve device shown in the present embodiment described above, the seal 24 has a symmetrical shape between the side surface that contacts the valve shaft 3 and the side surface that contacts the housing 2, but the seal 24 contacts the valve shaft 3. An asymmetric shape may be used between the side surface in contact with and the side surface in contact with the housing 2. For example, the base 28 is thinned on the side contacting the valve shaft 3, but the side contacting 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 the above-described embodiment, the seal 24 has a curved surface shape in a section in the axial direction of the portion 29 that contacts the valve shaft 3 on the side surface on the valve shaft 3 side of the recess of the seal 24. However, it may have a planar shape. Even with the valve device configured as described above, the effects of the first embodiment can be obtained.

In the valve device shown in the above embodiment, the gap 30 is formed between the bottom corner of the recess of the seal 24 and the elastic body 25, but the gap 30 is not open. Also good. Even with the valve device configured as described above, the effects of the first embodiment can be obtained.

In the above-described valve device shown in the present embodiment, the exhaust gas circulation valve device 1 is applied, but it is not limited to exhaust gas as long as the flow rate of the fluid can be adjusted. Further, the exhaust gas circulation valve device 1 is not limited as long as the valve device can be applied, such as a purge solenoid valve device or an oil valve device. Even with the valve device configured as described above, the effects of the first embodiment can be obtained.

By the way, the valve device shown in the above-described embodiment is merely an example, and can be configured by combining or subtracting as appropriate, and is not limited to the configuration of the embodiment alone.

1 exhaust gas circulation valve device, 2 housing, 3 valve shaft, 4 bearing,
5 Actuator, 6, 7 Valve, 8, 9 Valve seat, 10 Spring receiving seat,
11 Biasing body, 12 Filter, 13 Sealing part, 14 Fixing part,
15 bearing end, 16 lid, 17 inlet, 18, 19 outlet,
20 Actuator shaft, 21 Holder, 22 Net, 23 Presser plate,
24 seal, 25 elastic body, 26 plug, 27 protrusion,
28 Root, 29 The portion that contacts the valve stem on the side of the seal recess on the valve stem side,
30 gap.

Claims

A housing having a fluid passage through which fluid flows;
A valve shaft that is slidably provided in the housing and has a valve that opens and closes the fluid passage by the sliding;
The valve shaft is provided between the housing and the valve shaft so as to surround the valve shaft in a radial direction, and has a recess in the axial direction of the valve shaft and is deformed by pressure, and is provided in the recess of the seal. An elastic body that presses the seal in the radial direction of
The seal portion is a second portion of a portion where the first thickness group of the side base on the valve shaft side of the recess portion of the seal contacts the valve shaft on the side surface on the valve shaft side of the recess portion of the seal. A valve device characterized by being thinner than the thickness group.
The valve device according to claim 1, wherein the root is a predetermined range from the bottom of the concave portion of the seal.
2. The valve device according to claim 1, wherein the first thickness group has a thickness equal to or less than half of the second thickness group.
The valve device according to claim 1, wherein a shape of a portion of the side surface of the concave portion of the seal that is in contact with the valve shaft on the valve shaft side is a curved surface.
The valve device according to claim 1, wherein the seal is a resin member.
The valve device according to claim 5, wherein the resin member is PTFE.
The valve device according to claim 1, wherein the elastic body is a metal spring.
The valve device according to claim 7, wherein the metal spring is a stainless steel spring.