JP3714057B2 - EGR valve device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an EGR valve device used in an exhaust gas recirculation device that recirculates exhaust gas in an exhaust passage of an internal combustion engine to an intake passage side.
[0002]
[Prior art]
An exhaust gas recirculation device that recirculates a part of the exhaust gas to the intake side in order to reduce NO _x that is a harmful component in the exhaust gas of the engine is known. For example, the exhaust gas recirculation device shown in FIG. 3 connects the engine exhaust passage 110 and the intake passage 120 with an EGR valve device driven by a diaphragm actuator to adjust the exhaust gas recirculation amount according to the operating state of the engine 100. It is provided in an exhaust gas recirculation path (hereinafter simply referred to as EGR path) 130.
[0003]
The EGR valve device includes a valve housing 140 through which recirculated exhaust gas (hereinafter simply referred to as EGR gas) flows, and the valve housing 140 is provided at a valve seat at an intermediate portion between the exhaust gas inlet and the exhaust gas outlet of the EGR passage 130. 150 is provided. A valve shaft 160 is slidably supported on the valve housing 140 via a sliding guide member, and a valve body 170 for increasing / decreasing the valve opening area in cooperation with the valve seat 150 is provided at the lower end of the valve shaft 160. Installed. A negative pressure responsive valve actuator 180 is disposed at an upper end portion of the valve shaft 160 protruding to the outside of the valve housing 140, and the valve actuator 180 is supported by a bracket 190 that is fastened to the valve housing 140. . The valve actuator 180 includes press-molded upper and lower casings 200 and 210, a large-diameter first diaphragm 220 having an outer peripheral edge sandwiched between outer peripheral flanges of both casings, and an opening in a lower casing through which the valve shaft 160 is inserted. And a second diaphragm 230 having an outer peripheral edge fixed thereto. Both of these diaphragms are made of rubber, and each inner peripheral edge portion is fixed to each facing portion on the valve shaft 160 in a state of maintaining a sealing property.
[0004]
A return sbling 250 is contracted between the press plate 240 joined to the lower surface of the first diaphragm 220 and the bottom wall of the lower casing 210, so that the first diaphragm 220 is always upward or the valve body 170 is It is elastically biased in the closing direction. A negative pressure chamber 260 is formed by the first and second diaphragms 220 and 230 and the lower casing 210, and a negative pressure introduction pipe 270 is connected to the negative pressure chamber. The upper casing 200 is provided with an air opening 280, and atmospheric pressure acts on the upper surface of the l-th diaphragm.
[0005]
In such an EGR valve device, the upward closing valve force ps on the valve body 170 and the valve shaft 160 side, the atmospheric pressure received by the first diaphragm 220 in the negative pressure chamber, and the operation of the engine 100 A downward valve opening force pc corresponding to the differential pressure from the control negative pressure corresponding to the state is basically applied, and the upward exhaust differential pressure due to the differential pressure between the exhaust passage side pressure and the intake passage side pressure is applied to the valve body 170. Add pg. For this reason, the valve body 170 moves down to a position where these acting forces are substantially balanced, that is, pc (= ps + pg), and the valve body 170 moves away from the valve seat 150 to the EGR passage 130. Is opened. Thereby, a part of the exhaust gas passes through the exhaust gas passage in the valve housing 140 and is recirculated to the intake passage, so that a known NOx reduction effect is obtained. In this case, the flow rate of the EGR gas substantially depends on the opening degree of the EGR valve and the pressure difference between the exhaust gas pressure and the intake pressure.
[0006]
[Problems to be solved by the invention]
By the way, when the opening degree of the valve body 170 becomes relatively small, the squeezing action in the EGR passage 130 acts greatly, the pressure difference between the exhaust gas pressure and the intake pressure becomes large, and a large exhaust differential pressure pg acts on the valve body 170. . Here, the exhaust pressure pulsates greatly when the engine 100 is driven, the exhaust differential pressure pg fluctuates greatly, and the valve body 170 of the minute lift easily changes its valve opening to cause hunting, and the flow rate of EGR gas. Becomes unstable, and the desired NOx reduction effect cannot be obtained. In particular, the EGR gas flow rate required in each engine operating range is, for example, as shown in FIG. 4, in a situation where the operating range sequentially moves from the medium speed / medium load range E1 side to the high speed / high load range E2 side. Therefore, the EGR gas flow rate control is required such that the EGR gas flow rate q is sequentially reduced to q1>qa>qb> q2 (= 0). However, in the conventional EGR valve device, the valve body 170 cannot be stably held in the minute lift region, the flow rate of the EGR gas becomes unstable, and it is practically used in such a minute lift in the middle and high load region. It becomes difficult, and the supply flow rate q cannot be reduced to zero sequentially, which is a problem in suppressing the generation of NOx and smoke.
[0007]
In addition, instead of adjusting the opening of the EGR valve with a diaphragm actuator driven by negative pressure, it is also possible to adjust the opening of the valve with a stepper motor. Although there is a problem that the valve opening degree can be adjusted with a DC servo motor, there is a problem that a position sensor or the like is required in this case, and the cost is likely to increase.
[0008]
Based on the above-mentioned problems, the invention of claim 1 is an EGR valve device driven by a diaphragm actuator, and when the valve body is sequentially switched to a plurality of minute openings, the EGR gas flow rate is sequentially changed to a plurality of minute flow rates. An object of the present invention is to provide an EGR valve device that can be stably switched and held.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a negative pressure sensitive type valve opening control diaphragm which is attached to one end of the valve shaft and applies a valve opening force in the valve lift direction to the valve shaft. And an EGR valve device in which the valve body at the other end of the valve shaft adjusts the cross-sectional area of the exhaust gas recirculation path of the internal combustion engine by operating the valve shaft and a return spring that applies a valve closing biasing force in the valve lift decreasing direction to the valve shaft. A first negative pressure chamber that houses a diaphragm attached to one end of the valve shaft, a second negative pressure chamber disposed at the uppermost position in the valve axial direction of the first negative pressure chamber, and the second A main portion that pushes the valve shaft in the valve opening direction by the operation of the first lift diaphragm housed in the negative pressure chamber, and an umbrella portion that is expanded in the width direction from the main portion at a position above the main portion; a shaft opposite the stopper formed of, between the first negative pressure chamber and the second negative pressure chamber The third negative pressure chamber and, the contact with the shaft to the bevel portion is moved to the third and the second negative pressure chamber side by the operation of the second lift diaphragms housed in the negative pressure chamber formed in the a movable stopper which the second lifting diaphragm is arranged to lie a predetermined gap against the umbrella portion of the shaft opposite the stopper when inoperative while restricting the amount of movement of the counter stopper, the second negative pressure chamber And the third negative pressure chamber, restricting the amount of movement of the movable stopper toward the second negative pressure chamber , and when the second lift diaphragm is inactive , A fixed stopper disposed with a gap smaller than the gap, the second negative pressure chamber is driven with negative pressure, and the umbrella portion of the shaft-facing stopper moves in the valve lift direction to contact the movable stopper. The valve shaft side to the first lift position When the third negative pressure chamber is driven with negative pressure together with the second negative pressure chamber, the movable stopper operates in the valve lift decreasing direction and comes into contact with the fixed stopper. The shaft-facing stopper in a state is characterized in that the valve shaft side is positioned at a second lift position that is smaller than the first lift position .
[0010]
Here, when the second negative pressure chamber is supplied with negative pressure, the shaft-facing stopper contacts the movable stopper, thereby positioning the valve body on the valve shaft side that contacts the shaft-facing stopper at the first lift position, When a negative pressure is supplied to both the second negative pressure chambers, the valve stopper on the valve shaft side is moved from the first lift position to the second lift position of the small lift by bringing the movable stopper, which the shaft facing stopper contacts, into contact with the fixed stopper. Can be positioned. For this reason, even if the first lift position and the second lift position are the minute lift positions, the valve shaft is positioned by the movable stopper shaft and the fixed stopper via the shaft-facing stopper at each position, and the valve shaft side is vibrated. Displacement can be reliably suppressed, minute valve openings at a plurality of stages according to the operating state of the engine can be secured stably, and the EGR gas flow rate can be sequentially switched and held at a plurality of minute flow rates.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an exhaust gas recirculation device for an internal combustion engine employing an EGR valve device to which the present invention is applied. The exhaust gas recirculation device includes an exhaust gas recirculation passage (hereinafter simply referred to as an EGR passage) 4 connecting the exhaust passage 2 and the intake passage 3 of the engine 1, and an EGR valve device 5 in the middle of the EGR passage 4. The EGR valve device 5 includes a valve housing 6 in which a part of the EGR passage 4 is provided.
A valve seat 9 is disposed at an intermediate portion between the exhaust gas inlet 7 and the exhaust gas outlet 8 of the EGR passage 4, and a valve shaft 12 is slidably inserted into a sliding guide member 11 mounted on the valve housing 6. ing. A disc-shaped valve member 13 that controls the valve opening area in cooperation with the valve seat 9 is integrally attached to the lower end portion of the valve shaft 12.
[0012]
A U-shaped or cup-shaped support member 14 is fixed on the valve housing 6. The support member 14 includes a valve actuator 15, a second stopper device 16 on the upper side, and a first stopper device 17 on the upper side. It is supported by overlapping each other. The valve housing 6, the valve shaft 12 and the valve seat 9 slidably supported by the valve housing 6, and the valve actuator 15 connected to the upper end of the valve shaft 12 form an EGR valve component 18. .
[0013]
The valve actuator 15 has a cup-shaped lower casing 20 having a hole 19 into which the valve shaft 12 is inserted, and a central hole 23 ′ mounted on the upper end flange portion of the lower casing 20 with its outer peripheral flange portion overlapped. A thick plate casing 21, a rubber valve opening degree control diaphragm 22 sandwiched by outer peripheral flange portions of the lower casing 20 and the thick plate casing 21, and these outer peripheral portions and a second stopper device 16 described later. A tightening belt 23 that integrally tightens and couples these members, including a member on the side, and a lower seal diaphragm 25 sandwiched between a lower end peripheral portion 201 of the lower casing 20 and a ring member 24 and fixed to each other.
[0014]
The lower seal diaphragm 25 is sandwiched at its center by upper and lower holders 26 and 27, and the valve opening degree control diaphragm 22 having a relatively large pressure-receiving area has upper and lower press plates 28 and 29 at its center. And is fixed to the upper end portion of the valve shaft 12 by a holder 26 and a tightening nut 30. The negative pressure chamber 31 is limited by the valve opening control diaphragm 22, the lower casing 20, and the lower seal diaphragm 25, whereby the valve opening control diaphragm 22 is configured as a negative pressure sensitive diaphragm. Note that atmospheric pressure always acts on the upper surface of the valve opening control diaphragm 22 through a vent hole (not shown) provided in the thick plate casing 21.
[0015]
In the negative pressure chamber 31, a return spring 32 that is contracted between the lower presser plate 29 and the lower casing 20 is accommodated, and one end of a negative pressure introduction pipe 33 is connected to the lower casing 20. . The negative inlet pipe 33 is connected to a negative pressure source 34 via a duty control valve 35, and the duty control valve 35 is driven and controlled by the controller 36 to generate a control negative pressure corresponding to the operating state of the engine 1.
On the upper surface of the outer peripheral edge of the thick plate casing 21, the outer peripheral edges of the second lift diaphragm 37 made of rubber, the stepped cylindrical upper casing 38, and the inner casing 39 inside thereof are sequentially overlapped and integrated by the fastening belt 23. Are tightly coupled. The second lift diaphragm 37 is sandwiched between the lower ring piece 40 and the upper annular fitting 41, and is integrally coupled. A central opening 42 in which the valve shaft 12 is loosely fitted is formed at the center thereof.
[0016]
The upper annular metal fitting 41 sandwiches the second spring 43 with the inner casing 39 positioned above the upper annular metal fitting 41, and when the negative pressure is not applied due to this elastic force, the upper surface of the second lift diaphragm 37 is placed on the thick plate casing. 21 is pressed against the upper surface. Further, the upper annular metal fitting 41 is integrally joined with an annular movable stopper 44 at an annular portion outside the portion where the central opening 42 is formed. The movable stopper 44 is formed with an outer peripheral protruding portion e1 and a stopper portion e2 on the upper side, and the central edge portion of the sealing diaphragm 45 is sandwiched between the outer peripheral protruding portion e1 and the annular bead r of the upper annular metal fitting 41 opposed thereto. Yes. The outer peripheral edge of the sealing diaphragm 45 is sandwiched between the inner casing 39 and the upper casing 38 together with the annular plate-like fixing stopper 46. Thus, the negative pressure chamber 47 is limited by the inner casing 39, the second lift diaphragm 37, the sealing diaphragm 45, and the upper annular fitting 41, whereby the second lift diaphragm 37 serves as a negative pressure sensitive diaphragm. It is configured.
[0017]
One end of a negative pressure introduction pipe 48 is connected to the inner casing 39 and the outer casing 38. The negative introduction pipe 48 is connected to the negative pressure source 34 via an open / close electromagnetic valve 49, and the open / close electromagnetic valve 49 is driven and controlled by the controller 36.
Here, the movable stopper 44 holds the stopper portion e2 at the first lift restricting position A1 when the second spring 43 abuts the thick plate casing 21 via the upper annular fitting 41, and together with the shaft facing stopper 50 described later, the valve shaft 12 is positioned (position restricted) at the first lift position P1, and when the stopper portion e2 is brought into contact with the fixed stopper 46, as shown in FIG. The valve shaft 12 is moved to the second lift position P2 by switching to the second lift restriction position A2.
[0018]
The first stopper device 17 is disposed on the upper casing 38 and the fixed stopper 46. The first stopper device 17 includes an inner casing 51 that overlaps the inner wall of the upper casing 38. The upper bent edge of the inner casing 51 is placed on its upper surface with the outer peripheral edge of the first lift diaphragm 52 and the outer peripheral edge of the upper lid 53 fitted on top of each other, and then clamped and fixed to join them together. Thus, the upper casing 38 is bent. The central portion of the first lift diaphragm 52 is screwed in a state of being sandwiched between the upper and lower presser plates 53 ′ and 54 by a protruding screw portion f of a shaft facing stopper 50 described later and a nut 55. The outer peripheral edge of the sealing diaphragm 57 is sandwiched between the lower bent edge of the inner casing 51 and the fixed stopper 46, and is integrally coupled. The central portion of the sealing diaphragm 57 is coupled through the shaft-facing stopper 50 disposed opposite to the upper end portion of the valve shaft 12. The shaft-facing stopper 50 is provided with a protruding portion g as a locking portion that expands in the radial direction on the upper side of the main portion that is in contact with and away from the upper end portion of the valve shaft 12. Note that the central portion of the sealing diaphragm 57 is sandwiched between the umbrella portion g and the lower end portion of the tubular member 56, and is coupled to each other.
[0019]
The negative pressure chamber 58 is limited by the first lift diaphragm 52, the sealing diaphragm 57, and the inner casing 51, whereby the first lift diaphragm 52 is configured as a negative pressure sensitive diaphragm. Note that a vent hole (not shown) is formed in the upper lid 53, and atmospheric pressure always acts on the first lift diaphragm 52 through the vent hole.
In the negative pressure chamber 58, a return spring 59 that is contracted between the lower presser plate 54 and the lower end portion of the inner casing 51 is accommodated, and an upper limit position is determined by a stopper 62 of the upper lid 53. One end of a negative pressure introducing pipe 60 is connected to the upper casing 38 and the inner casing 51. The negative inlet pipe 60 is connected to the negative pressure source 34 via the open / close electromagnetic valve 61, and the open / close electromagnetic valve 61 is driven and controlled by the controller 36.
[0020]
Here, when the negative pressure chamber 58 is driven with negative pressure supplied, the first lift diaphragm 52 moves the shaft-facing stopper 50 downward in the valve lift direction O to move the movable stopper 44 at the first lift restricting position A1. In this case, the valve shaft 12 side can be positioned at the first lift position P1.
In such a configuration, in FIG. 1, the valve body 13 is brought into contact with the valve seat 9 by the urging force of the return spring 32 through the valve shaft 12 in an operation state where the engine 1 is stopped or the engine does not perform EGR. The state which the valve body 13 is located in zero, ie, the fully closed position P0 is shown. During this time, the negative pressure chambers 47 and 58 of the first stopper device 17 and the second stopper device 16 are not supplied with negative pressure, and the shaft-facing stopper 50 is held in the inoperative state shown by the solid line in FIG.
[0021]
Next, as shown in the map for setting the EGR gas flow rate in FIG. 4, a large amount of EGR gas flow rate q1 is required during the operation in the medium speed / medium load region E1, and in this case, the engine controller 36 has a negative pressure. The duty control valve 35 is duty-driven so as to adjust the valve body 13 to the opening degree at which the control negative pressure supplied to the chamber 31 can obtain the EGR gas flow rate corresponding to the operation region. As a result, the control negative pressure of the negative pressure chamber 31 is adjusted, and the valve opening degree control diaphragm 22 is further displaced downward in accordance with this to move the valve shaft 12 and the valve body 13 downward on the valve lift direction O side. . Therefore, a predetermined amount of exhaust gas recirculation is made in the intake passage 3 of the engine 1 according to the operating state, and NOx in the exhaust gas can be reduced.
[0022]
Next, the operating state of the engine changes, and as shown in FIG. 4, the operating range moves from the medium speed / medium load range E1 side to the high speed / high load range E2 side. The controller 36 sets the control negative pressure in accordance with the operation range, drives the duty control valve 35 to obtain the control negative pressure, and controls the valve opening degree diaphragm 22 with the control negative pressure. Driven to adjust the valve body 13 to a minute opening range. Further, the controller 36 turns on the first electromagnetic valve 61, supplies negative pressure to the negative pressure chamber 58 of the first stopper device 17, drives the first lift diaphragm 52, and the shaft facing stopper 50 is shown in FIG. The gap is lowered by a distance corresponding to the clearance t1, and comes into contact with the movable stopper 44 at the first lift restricting position A1 (see FIG. 2A). As a result, the valve shaft 12 that is about to move to the closing side due to fluctuations in exhaust pressure comes into contact with the shaft-facing stopper 50 and is stably held at the relatively small first lift position P <b> 1 regulated by the movable stopper 44. It becomes. For this reason, exhaust gas recirculation is performed in the intake passage 3 of the engine 1 at a predetermined flow rate according to the operating state, and NOx and smoke in the exhaust gas can be reduced.
[0023]
Further, when the operating state of the engine changes and the supply flow rate of EGR gas shifts from qa to qb in the operation range from qa to high-speed and high-load region E2 side as shown in FIG. 36 also turns on the second electromagnetic valve 49 together with the first electromagnetic valve 61 to supply negative pressure to both the negative pressure chambers 58 and 47 of the first stopper device 17 and the second stopper device 16, and the first and second lifts. The diaphragms 52 and 37 are driven. At this time, the movable stopper 44 is moved upward from the first lift restricting position A1 by the upward operating force of the second lift diaphragm 37 having a larger negative pressure receiving area than the first lift diaphragm 52, and the stopper portion e2 is fixed to the fixed stopper 46. And is held at the second lift restricting position A2. In conjunction with the raising operation of the movable stopper 44, the shaft-facing stopper 50 and the valve shaft 12 are also operated in the valve lift decreasing direction C, and the valve shaft 12 and the valve body are raised corresponding to the clearance t2 shown in FIG. As shown in FIG. 2B, 13 is stably held at the second lift position P2 that is smaller than the first lift position P1. For this reason, the EGR gas having a supply flow rate corresponding to the operating state is exhausted and recirculated to the intake passage 3 of the engine 1, and NOx in the exhaust gas can be reliably reduced, and the desired amount of EGR gas can be obtained. A large amount of EGR gas is prevented from being refluxed, and smoke can be prevented from increasing.
[0024]
After that, when the engine operating range shifts to the high speed and high load range E2, the controller 36 turns off all of the first solenoid valve 61, the second solenoid valve 49, and the duty control valve 35, and the shaft facing stopper 50 and the valve body. The side 13 is moved in the valve lift decreasing direction C and returned to the fully closed position P0 indicated by the solid line in FIG. 1, and the EGR gas flow rate is maintained at zero.
Accordingly, when the valve body 13 moves in two steps to the first and second lift positions P1 and P2 in the minute opening range and the lift amount decreases and displaces, the valve body 13 is oscillated and displaced slightly at each lift position. The EGR gas flow rate does not become unstable, the required EGR gas flow rate can be secured in all engine operating ranges, NOx reduction can be ensured, and the occurrence of smoke due to the increase in EGR amount can be suppressed. Can do. Further, since the valve body 13 is prevented from vibrational displacement in each of a plurality of minute opening ranges, it is possible to effectively prevent premature breakage due to vibration as in the conventional device, and the valve actuator 15 and thus the EGR valve. There is an advantage that the durability and reliability of the device 5 can be secured.
[0025]
The present invention is not limited to the above embodiment, and various changes and modifications can be made to the above embodiment within the scope of the claims. For example, not only the configuration in which the valve body is disposed on the upstream side of the valve seat, but also when the valve body is disposed on the downstream side of the valve seat and the opening degree of the valve body is small, between the upstream side and the downstream side. The present invention can also be applied to cases where a large differential pressure is generated and the opening of the valve body changes in an oscillating manner.
In addition, the controller 36 drives the diaphragm 22 and the diaphragm 52 when positioning the valve body 13 at the first lift position P1, but only the diaphragm 52 is driven to regulate the first lift amount. You may control as follows.
[0026]
【The invention's effect】
As described above, according to the first aspect of the present invention, the valve body side can be sequentially positioned at the first lift position and the second lift position of a smaller lift by switching the negative pressure of the second and third negative pressure chambers. Therefore, even if the first lift position and the second lift position are minute lift positions, the valve shaft is positioned by the movable stopper shaft and the fixed stopper via the shaft-facing stopper at each position, and the vibration displacement on the valve shaft side Can be reliably suppressed, minute valve openings in a plurality of stages according to the operating state of the engine can be stably ensured, and the EGR gas flow rate can be sequentially switched to a plurality of minute flow rates.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an exhaust gas recirculation device for an internal combustion engine equipped with an EGR valve device as one embodiment of the present invention.
2A and 2B are diagrams for explaining valve switching operation characteristics of the EGR valve device of FIG. 1, in which FIG. 2A shows the position of the valve body when the movable stopper is in the first lift restricting position, and FIG. The position on the valve body side when in the second lift restricting position is shown.
FIG. 3 is a schematic configuration diagram of an exhaust gas recirculation device for an internal combustion engine equipped with a conventional EGR valve device.
FIG. 4 is a characteristic diagram of an EGR gas flow rate setting map used by an exhaust gas recirculation device for a normal internal combustion engine.
[Explanation of symbols]
1 Engine 4 EGR passage 6 Valve housing 12 Valve shaft 13 Valve body 15 Valve actuator 16 Second stopper device 17 First stopper device 22 Valve opening control diaphragm 37 Second lift diaphragm 44 Movable stopper 46 Fixed stopper 50 Axis facing stopper 52 First lift diaphragm A1 First lift restriction position A2 Second lift restriction position O Valve lift direction P1 First lift position P2 Second lift position

Claims (1)

A negative pressure sensitive diaphragm for controlling the opening of the valve, which is attached to one end of the valve shaft and applies a valve opening force in the valve lift direction to the valve shaft, and a valve closing biasing force in the valve lift decreasing direction on the valve shaft. In the EGR valve device in which the valve body at the other end of the valve shaft adjusts the cross-sectional area of the exhaust gas recirculation path of the internal combustion engine by adjusting the return spring to be applied, the diaphragm attached to the one end side of the valve shaft is accommodated. The first negative pressure chamber, the second negative pressure chamber disposed at the uppermost position in the valve axis direction of the first negative pressure chamber, and the first lift diaphragm accommodated in the second negative pressure chamber act as described above. A shaft opposing stopper formed of a main portion that pushes the valve shaft in the valve opening direction, and an umbrella portion that is expanded in the width direction from the main portion at a position above the main portion; and the first negative pressure chamber; A third negative pressure chamber formed between the second negative pressure chamber and the third negative pressure chamber; When the second lift diaphragm is inactive while restricting the amount of movement of the shaft opposite the stopper in contact with the valve head is moved in the second negative pressure chamber side by the operation of the second lifting diaphragm which is and disposed a movable stopper to lie the umbrella predetermined gap against the above shaft opposite the stopper, positioned between the second negative pressure chamber and the third vacuum chamber, the second of the movable stopper comprising the said fixed stopper second lift diaphragm is disposed with a small gap than the predetermined gap with respect to the movable stopper when inoperative while regulating the movement amount in the negative pressure chamber side, the The second negative pressure chamber is driven by negative pressure, and the umbrella portion of the shaft facing stopper moves in the valve lift direction to contact the movable stopper, thereby positioning the valve shaft side at the first lift position, and the second negative pressure chamber. And the third negative pressure chamber By the pressure driving, the movable stopper operates in the valve lift decreasing direction and contacts the fixed stopper, so that the shaft-facing stopper in contact with the movable stopper moves the valve shaft side closer to the valve shaft side than the first lift position. An EGR valve device that is positioned at a two-lift position .

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