JP6566134B2 - Variable flow rate valve mechanism and turbocharger - Google Patents

Description

  The present disclosure relates to a variable flow valve mechanism and a supercharger.

  Conventionally, a flow rate variable valve mechanism that adjusts the flow rate of a working fluid supplied to a turbine of a supercharger is known (see, for example, Patent Document 1). This variable flow rate valve mechanism includes a bearing portion provided in a turbine housing that houses a turbine, a stem rotatably supported by the bearing portion, and a valve body connected to one end side of the stem. In the variable flow rate valve mechanism, the flow rate of the working fluid supplied to the turbine is adjusted by opening and closing a variable flow rate passage that bypasses the turbine with a valve element.

JP 2006-291882 A

  In the conventional supercharger, the pulsation of the working fluid is transmitted to the valve body, and the valve body may vibrate and the stem may vibrate. The present disclosure describes a variable flow rate valve mechanism and a supercharger capable of suppressing stem vibration.

One aspect of the present disclosure is a variable flow rate valve mechanism that opens and closes an opening of a gas flow rate variable passage, the stem being rotatably supported with respect to the housing, and being inserted into a through hole of the housing. A bearing portion rotatably supported around the shaft center, and a valve portion provided on the first end side of the stem to open and close the opening, and the outer peripheral surface of the stem is first from the second end side of the stem. A conical first inclined surface that approaches the axial center of the stem toward the end side, and an inner peripheral surface of the bearing portion includes a conical second inclined surface that contacts the first inclined surface of the stem, The valve portion includes a valve portion inclined surface facing the gas flow rate variable passage, and the valve portion inclined surface extends from the axial center in the direction in which the stem extends from the second end side of the stem toward the first end side. It is separated.

  According to one aspect of the present disclosure, it is possible to provide a variable flow rate valve mechanism and a supercharger that can suppress stem radial movement and suppress stem vibration.

FIG. 1 is a cross-sectional view illustrating a supercharger according to a first embodiment of the present disclosure. FIG. 2 is a side view of the supercharger shown in FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a view showing the waste gate valve according to the first embodiment from one end side of the stem. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a cross-sectional view showing the gas flow rate variable passage and the valve inclined surface. FIG. 7 is a cross-sectional view showing the gas flow rate variable passage and the valve inclined surface of the wastegate valve according to the second embodiment. FIG. 8 is a cross-sectional view showing the gas flow rate variable passage and the valve inclined surface of the wastegate valve according to the third embodiment. FIG. 9 is a cross-sectional view showing a waste gate valve according to the fourth embodiment.

  One aspect of the present disclosure is a variable flow rate valve mechanism that opens and closes an opening of a gas flow rate variable passage, the stem being rotatably supported with respect to the housing, and being inserted into a through hole of the housing. A bearing portion rotatably supported around the shaft center, and a valve portion provided on the first end side of the stem to open and close the opening, and the outer peripheral surface of the stem is first from the second end side of the stem. A first inclined surface that approaches the axis of the stem toward the end side, an inner peripheral surface of the bearing portion includes a second inclined surface that contacts the first inclined surface of the stem, and the valve portion includes a gas flow rate The valve portion inclined surface includes a valve portion inclined surface facing the variable passage, and the valve portion inclined surface is separated from the axial center in the direction in which the stem extends from the second end side of the stem toward the first end side.

  In this variable flow rate valve mechanism, in a state in which the valve portion closes the opening, the valve portion inclined surface is pressed by the pressure of the gas in the opening, and a force is generated in the direction in which the stem extends (axial direction). . In the axial direction of the stem, the inclined surface of the valve portion is inclined so as to be away from the axial center as it goes from the second end side to the first end side, so that the force acting on the valve portion is in the axial direction of the stem. The force is directed from the second end side to the first end side. Thereby, a force acts on the stem in a direction in which the stem is shifted from the second end side to the first end side. Since the outer peripheral surface of the stem is provided with a first inclined surface that approaches the axial center from the second end side toward the first end side, the stem is pushed from the second end side to the first end side. And the 1st inclined surface of a stem approaches the 2nd inclined surface of a bearing part. Therefore, the outer peripheral surface of the stem and the inner peripheral surface of the bearing portion can be continuously brought into contact in the circumferential direction of the stem. That is, by making a line contact in the circumferential direction of the stem, the movement of the stem in the radial direction is suppressed, and the vibration of the stem is suppressed. In addition, when it contacts with a predetermined width, it becomes surface contact instead of line contact. When the contact area between the first inclined surface and the second inclined surface increases, the movement of the stem is more effectively suppressed, and the vibration of the stem is suppressed.

  The first inclined surface may be configured to be disposed on the second end side of the stem in the direction in which the stem extends. The second end side of the stem has a greater force acting in the radial direction of the stem than the first end side of the stem. By providing the first inclined surface on the second end side of the stem, vibration can be suitably suppressed.

  The valve part inclined surface may be configured to be formed in the entire region corresponding to the opening. Thus, by providing the valve inclined surface in the entire area corresponding to the opening, the pressure of the gas inside the opening can be reliably received, the stem is easily displaced in the axial direction of the stem, and the outer peripheral surface of the stem The first inclined surface easily comes into contact with the second inclined surface of the inner peripheral surface of the bearing portion. Therefore, the vibration of the stem can be suitably suppressed.

  The valve portion inclined surface may be formed in a part of a region corresponding to the opening, and may be formed only in a portion on the first end side in the direction in which the stem extends. Thereby, the vibration of the stem can be suitably suppressed even with a simple configuration.

  A supercharger according to the present disclosure is a supercharger including the above-described variable flow rate valve mechanism, and includes a turbine and a compressor that is driven by a rotational driving force transmitted by the turbine. Open and close the opening of the gas flow rate variable passage that bypasses.

  Since this supercharger includes the above-described variable flow rate valve mechanism, the valve portion is pushed from the second end side to the first end side in the axial direction of the stem by the pressure of the gas in the opening. When the stem moves from the second end side to the first end side, the first inclined surface of the outer peripheral surface of the stem makes line contact with the second inclined surface of the inner peripheral surface of the bearing portion. Thereby, the movement of the stem in the radial direction is suppressed, and the vibration of the stem is suppressed.

  Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same part or an equivalent part, and the overlapping description is abbreviate | omitted.

(Supercharger)
A supercharger 1 shown in FIGS. 1 to 3 is a supercharger for a vehicle, and compresses air supplied to an engine using exhaust gas discharged from an engine (not shown). The supercharger 1 includes a turbine 2 and a compressor (centrifugal compressor) 3. The turbine 2 includes a turbine housing 4 and a turbine impeller 6 housed in the turbine housing 4. The compressor 3 includes a compressor housing 5 and a compressor impeller 7 housed in the compressor housing 5.

  The turbine impeller 6 is provided at one end of the rotating shaft 14, and the compressor impeller 7 is provided at the other end of the rotating shaft 14. A bearing housing 13 is provided between the turbine housing 4 and the compressor housing 5. The rotating shaft 14 is rotatably supported by the bearing housing 13 via a bearing 15.

  The turbine housing 4 is provided with an exhaust gas inlet 8 and an exhaust gas outlet 10. Exhaust gas discharged from the engine flows into the turbine housing 4 through the exhaust gas inlet 8, rotates the turbine impeller 6, and then flows out of the turbine housing 4 through the exhaust gas outlet 10.

  The compressor housing 5 is provided with a suction port 9 and a discharge port 11. When the turbine impeller 6 rotates as described above, the rotating shaft 14 and the compressor impeller 7 rotate. The rotating compressor wheel 7 sucks external air through the suction port 9, compresses it, and discharges it from the discharge port 11. The compressed air discharged from the discharge port 11 is supplied to the engine.

  As shown in FIGS. 1 and 3, a part of the exhaust gas introduced from the exhaust gas inlet 8 is led into the turbine housing 4 to the exhaust gas outlet 10 side by bypassing the turbine impeller 6. A bypass passage (see FIG. 3) 17 is formed. The bypass passage 17 is a gas flow rate variable passage for making the flow rate of the exhaust gas supplied to the turbine impeller 6 side variable.

(Waste gate valve)
The turbine housing 4 is provided with a waste gate valve 20 as one of variable flow valve mechanisms. The waste gate valve 20 is a valve that opens and closes the opening of the bypass passage 17.

  The waste gate valve 20 includes a stem 21 that is rotatably supported on the outer wall (wall body) of the turbine housing 4, a swing piece 22 that projects from the stem 21 in the radial direction of the stem 21, and a swing piece 22. And a supported valve body (valve part) 23.

  A support hole (through hole) 24 penetrating in the thickness direction of the outer wall is formed in the outer wall of the turbine housing 4. A cylindrical bearing portion 25 is inserted into the support hole 24. The bearing portion 25 is press-fitted and fixed to the support hole 24 in the outer wall of the turbine housing 4. An opening (insertion hole) through which the stem 21 is inserted is formed in the bearing portion 25.

Here, as shown in FIG. 5, an inclined surface (first inclined surface) 21 a is formed on the outer peripheral surface of the stem 21. Specifically, the stem 21 includes a conical portion (a truncated conical portion), and an outer peripheral surface of the conical portion forms an inclined surface 21a. This conical portion is reduced in diameter in the direction of the axis L ₂₁ of the stem 21 (direction in which the axis extends) from the other end side (second end side) toward one end side (first end side). That is, the inclined surface 21a of the stem 21, toward the one end side from the other end, are inclined so as to approach the axis of the stem 21 (axis) L _21. The inclined surface 21a, in cross-section along the axis L _21, are formed linearly.

In the axial _{L 21} direction, on both sides of the conical portion of the stem 21, the cylindrical portion 21c, 21d are provided. Partial cylindrical portion 21c in the axial L ₂₁ direction of one end is a part rocking pieces 22 are attached, the cylindrical portion 21d of the other end, which protrudes from the turbine housing 4, the link member 28 to be described later is attached It is. For example, the cylindrical portion 21c on one end side is provided with a locking portion in order to suppress the movement of the swing piece 22 relative to the stem 21. An uneven shape can be used as the locking portion.

  As shown in FIG. 4, the swing piece 22 includes a cylindrical portion 22 a attached to the column portion 21 c of the stem 21, and an overhang portion 22 b that is connected to the cylindrical portion 22 a and projects outward in the radial direction of the cylindrical portion 22 a. I have. The overhang portion 22b has, for example, a plate shape. A mounting hole for supporting the valve body 23 is provided at the end of the overhanging portion 22b opposite to the cylindrical portion 22a. The swing piece 22 swings with the rotation of the stem 21 and moves the valve body 23.

The valve body 23 can be brought into contact with and separated from the peripheral edge portion of the opening portion of the bypass passage 17 (see FIG. 6), and has, for example, a disk shape. The valve body 23 forms a seat surface that contacts the opening end surface of the bypass passage 17. The valve body 23 is provided with a valve shaft 26 that protrudes on the side opposite to the opening of the bypass passage 17. The valve shaft 26 is inserted through a mounting hole at the tip of the swing piece 22. A stopper 27 is fixed to the end of the valve shaft 26 opposite to the valve body 23, and the valve shaft 26 inserted through the mounting hole is held by the stopper 27. Incidentally, the axis L ₂₆ of the valve shaft 26, with respect to the axis L ₂₁ of the stem 21, may be arranged to be orthogonal, it may be arranged to be inclined relative to the axis L _21.

As shown in FIG. 6, an inclined surface (hereinafter referred to as “valve portion inclined surface”) 23 a is provided on the surface of the valve body 23 facing the bypass passage 17. The valve portion inclined surface 23a, in the axial L ₂₁ direction of the stem 21, toward the one end side from the other end of the stem 21 is inclined so as to be separated from the axis L _21. That is, the valve body 23 protrudes in the direction of the axis L ₂₁ of the stem 21 so that a portion farther from the side closer to the wall of the turbine housing 4 is separated from the axis L ₂₁ of the stem 21. The valve portion inclined surface 23a is inclined relative to the axis _{L 21} and the axis _{L 26} of the valve shaft 26 of the stem 21.

The valve portion inclined surface 23 a is formed in the entire region corresponding to the opening portion of the bypass passage 17 in the direction of the axis L ₂₁ of the stem 21.

The bypass passage 17 extends in a direction orthogonal to the axis L ₂₁ of the stem 21 as shown in FIG. Periphery 17a, 17b forming the opening of the bypass passage 17, the cut surface along the axis _{L 21} of the stem 21 to form a plane parallel to the axis _{L 21.} The peripheral portion 17 a is a peripheral portion closer to the wall of the turbine housing 4, and the peripheral portion 17 b is a peripheral portion far from the wall of the turbine housing 4. The peripheral edge portion 17 a is disposed at a position closer to the axis L ₂₁ than the peripheral edge portion 17 b in the direction orthogonal to the axis L ₂₁ of the stem 21.

  And the valve body 23 is equipped with the seal surfaces 23b and 23c which contact | abut to the peripheral parts 17a and 17b of the bypass channel 17 on the outer side of the valve part inclined surface 23a. The valve body 23 is formed with seal surfaces 23b and 23c that abut against the peripheral edge portions 17a and 17b of the bypass passage 17 on the entire circumference of the valve shaft 26 in the circumferential direction.

  Then, the valve body 23 comes into contact with the peripheral edge portions 17a and 17b of the opening portion of the bypass passage 17, and the waste gate valve 20 is closed, and the valve body 23 is separated from the peripheral edge portions 17a and 17b of the opening portion of the bypass passage 17. The waste gate valve 20 is opened.

  As shown in FIG. 5, a plate-like link member 28 that projects in the radial direction of the stem 21 is fixed to the cylindrical portion 21 d on the other end side of the stem 21. As shown in FIG. 2, an attachment hole into which the connection pin 29 is inserted is formed at the distal end portion of the link member 28, and the connection pin 29 is inserted into the attachment hole. The tip 51 b of the operating rod 51 of the actuator 50 is connected to the link member 28 via the connecting pin 29.

As shown in FIG. 5, an inclined surface (second inclined surface) 25 a that contacts the inclined surface 21 a of the stem 21 is formed on the inner peripheral surface of the opening of the bearing portion 25. The inner peripheral surface of the bearing portion 25 includes an inclined surface 25 a that faces the conical portion of the stem 21. The opening of the bearing portion 25 has a tapered shape whose diameter decreases from the other end side of the stem 21 toward the one end side in the direction of the axis L ₂₁ of the stem 21. That is, the inclined surface 25 a of the bearing portion 25 is inclined so as to approach the axis (axis) L ₂₁ of the stem 21 from the other end side toward the one end side. The inclined surface 25a, in cross-section along the axis L _21, are formed linearly. The inclined surface 25 a on the inner peripheral surface of the bearing portion 25 is inclined at the same angle as the inclined surface 21 a on the outer peripheral surface of the stem 21. The inclined surfaces 21 a and 25 a are formed on the entire circumference in the circumferential direction of the stem 21.

  Next, the operation of the supercharger 1 will be described.

  The exhaust gas flowing in from the exhaust gas inlet 8 passes through the turbine scroll passage 4a and is supplied to the inlet side of the turbine impeller 6. The turbine impeller 6 generates rotational force using the pressure of the supplied exhaust gas, and rotates the rotating shaft 14 and the compressor impeller 7 integrally with the turbine impeller 6. Thereby, the air sucked from the suction port 9 of the compressor 3 is compressed using the compressor impeller 7. The air compressed by the compressor impeller 7 passes through the diffuser channel 5a and the compressor scroll channel 5b and is discharged from the discharge port 11. The air discharged from the discharge port 11 is supplied to the engine.

  When the supercharging pressure (pressure of air discharged from the discharge port 11) reaches the set pressure during operation of the supercharger 1, the actuator 50 is driven and the operating rod 51 is pushed out. The pushing force (driving force) by the actuating rod 51 is transmitted to the valve body 23 via the link member 28, the stem 21 and the swing piece 22 connected to the actuating rod 51. As a result, the valve body 23 moves away from the peripheral edge of the opening of the bypass passage 17, and the waste gate valve 20 is in the open state. At this time, part of the exhaust gas flowing in from the exhaust gas inlet 8 passes through the bypass passage 17 and bypasses the turbine impeller 6. Therefore, the flow rate of the exhaust gas supplied to the turbine impeller 6 can be reduced.

On the other hand, when the supercharging pressure becomes lower than the set pressure during operation of the supercharger 1, the pushing force by the operating rod 51 is released and the operating rod 51 is pushed back. As a result, the link member 28 swings about the stem 21, the stem 21 rotates about its axis L ₂₁ , and the swing piece 22 swings. And the valve body 23 approaches the opening part of the bypass channel | path 17, and is pressed by the peripheral parts 17a and 17b of an opening part, and the waste gate valve 20 will be in a closed state. That is, in the turbine 2, the exhaust gas is not bypassed by the bypass passage 17.

  In the supercharger 1, for example, exhaust gas in the bypass passage 17 may also pulsate due to pulsation of exhaust gas from the engine, and the closed valve body 23 may vibrate.

In the waste gate valve 20, the pressure of the exhaust gas in the bypass passage 17 acts on the valve portion inclined surface 23 a of the valve body 23 when the valve is closed. The valve portion inclined surface 23a is toward the one end side from the other end of the stem 21, the inclination to have away from the axis L ₂₁ of the stem 21, the pressure of the exhaust gas in the bypass passage 17 acts, the valve A force is applied to the body 23 from the other end side to the one end side in the direction of the axis L ₂₁ of the stem 21. By this force, the valve body 23, the swing piece 22, and the stem 21 move along the direction of the axis L ₂₁ of the stem 21.

  As a result, the stem 21 moves from the other end side to the one end side, and the larger outer diameter of the stem 21 is shifted to the smaller inner diameter of the bearing portion 25. The inclined surface 21a of the stem 21 It is in close contact with the inclined surface 25a of the portion 25 and makes line contact so as to be continuous in the circumferential direction of the stem 21. Therefore, the movement of the stem 21 in the radial direction is suppressed, and the vibration of the stem 21 is suppressed. In addition, when it contacts with a predetermined width, it becomes surface contact instead of line contact. When the contact area between the inclined surface 21a and the inclined surface 25a increases, the movement of the stem 21 is more effectively suppressed, and the vibration of the stem 21 is suppressed.

Since the valve portion inclined surface 23a is formed in the entire region corresponding to the opening portion of the bypass passage 17, it is possible to reliably receive the pressure of the gas inside the opening portion of the bypass passage 17, and the stem 21 is suitably positioned on the axis. L ₂₁ can be shifted in the direction.

(Second Embodiment)
Next, with reference to FIG. 7, the waste gate valve 20 of 2nd Embodiment is demonstrated. The second embodiment is different from the first embodiment in that the direction in which the bypass passage 17B extends is different. In the second embodiment, the opening of the bypass passage 17B extends in a direction intersecting the axis L ₂₆ of the valve shaft 26 of axis L ₂₁ and the valve body 23 of the stem 21. Incidentally, the peripheral portions 17a, 17b of the opening of the bypass passage 17, as in the first embodiment, are formed parallel to the axis _{L 21} of the stem 21.

  The turbocharger provided with the waste gate valve 20 of the second embodiment also has the same effects as the first embodiment.

(Third embodiment)
Next, a waste gate valve 20B of the third embodiment will be described with reference to FIG. The waste gate valve 20B of the third embodiment is different from the waste gate valve 20 of the first embodiment in that the shape of the valve portion inclined surface 23d of the valve body 23B is different. In the third embodiment, the position of the peripheral edge portion 17 c of the opening of the bypass passage 17 is formed at the same distance from the axis L _{21 on} the entire circumference in the circumferential direction of the valve shaft 26.

The valve portion inclined surface 23d of the valve body 23B is in the axial L ₂₁ direction of the stem 21, and is formed in a portion of a region corresponding to the opening of the bypass passage 17. Specifically, the valve portion inclined surface 23d is in the axial L ₂₁ direction, are formed only in a portion of the one end side. Part valve portion inclined surface 23d is not formed, it forms a plane parallel to the axis L ₂₁ of the example the stem 21.

Regions valve portion inclined surface 23d is formed in the direction rocking pieces 22 extends (a direction perpendicular to the axis L ₂₁ and axial L _26), it may be the same or may be different. For example, the valve portion inclined surface 23d is formed around the axis L _26, may be formed along the conical. In a state where the peripheral portion of the valve body 23B is in contact with the peripheral portion 17c of the opening of the bypass passage 17, the valve portion inclined surface 23d may be disposed so as to enter the inside of the opening. In FIG. 8, there is shown a cross-section taken along a plane parallel to the axis L ₂₁ of the street stem 21B the axis L ₂₆ of the valve shaft 26.

  Also in the waste gate valve 20B of the third embodiment, the stem 21 can be moved to one end side by applying the pressure of the exhaust gas to the valve portion inclined surface 23d of the valve body 23B. Thereby, the inclined surface 21 a of the stem 21 is in line contact with the inclined surface 25 a of the inner peripheral surface of the bearing portion 25 continuously in the circumferential direction of the stem 21. Therefore, since the movement of the stem 21 in the radial direction is suppressed, the vibration of the stem 21 is suppressed. In the waste gate valve 20B, a valve portion inclined surface 23d is formed in a part of a region corresponding to the opening portion of the bypass passage 17. Thereby, the vibration of the stem 21 can be suitably suppressed even with a simple configuration.

(Fourth embodiment)
Next, a waste gate valve 20C of the fourth embodiment will be described with reference to FIG. The waste gate valve 20C of the fourth embodiment is different from the waste gate valve 20 of the first embodiment in that the arrangement of the inclined surface 21e on the outer peripheral surface of the stem 21B is different, and the inclined surface of the inner peripheral surface of the bearing portion 25. The arrangement of 25b is different.

As shown in FIG. 9, the stem 21B of the waste gate valve 20C includes a cylindrical portion (parallel surface 21f) and a conical portion (inclined surface 21e) in a region supported by the bearing portion 25. Cylindrical portion and the conical portion is adjacent in the axial L ₂₁ direction, the cylindrical portion is disposed at one end, a conical portion is disposed at the other end. The outer peripheral surface of the cylindrical portion forms a plane parallel 21f in the axis _{L 21} of the stem 21B, an outer circumferential surface of the conical portion is formed an inclined surface 21e that is inclined relative to the axis _{L 21} of the stem 21B. The inclined surface 21e is in the axial _{L 21} of the stem 21B, toward the one end side from the other end, are inclined so as to approach the axis _{L 21.} In the stem 21B, in the region supported by the bearing portion 25, the inclined surface 21e is formed only in the portion on the other end side.

The inner peripheral surface of the opening of the bearing portion 25 of the waste gate valve 20C includes a plane 25c parallel to the axis _{L 21,} and an inclined surface 25b which is inclined relative to the axis _{L 21.} The parallel surface 25c is a surface facing the outer peripheral surface of the cylindrical portion of the stem 21B, and the inclined surface 25b is a surface facing the outer peripheral surface of the conical portion of the stem 21B.

Also in the waste gate valve 20C of the fourth embodiment, the pressure acts in the exhaust gas in the bypass passage 17 in the valve portion inclined surface 23a, the stem 21B is at one end from the other end in the axial L ₂₁ direction Moving. As a result, the inclined surface 21e of the stem 21B moves to one end side, and the portion with the larger outer diameter of the stem 21B moves to the smaller inner diameter of the inclined surface 25b of the bearing portion 25. Therefore, the inclined surface 21e of the stem 21B and the inclined surface 25b of the bearing portion 25 can be continuously contacted in the circumferential direction of the stem 21B. That is, it is possible to suppress the vibration of the stem 21B by making a line contact in the circumferential direction of the stem 21B and suppressing the radial movement of the stem 21B.

  In the stem 21B, in the region supported by the bearing portion 25, the radial force acts more on the other end side than on the one end side. Therefore, by making the inclined surfaces 21e and 25b contact each other at the other end portion, the movement of the stem 21B in the radial direction can be restrained, and the vibration of the stem 21B can be suitably suppressed.

  The present invention is not limited to the above-described embodiments, and various modifications as described below are possible without departing from the gist of the present disclosure.

For example, the surface of the valve body 23 facing the bypass passage 17 may be inclined with respect to the rotation center line of the stem 21 by bending one end side of the stem 21. The peripheral edge of the opening of the bypass passage 17 is not limited to a plane parallel to the axis L ₂₁ of the stem 21, and may be a plane inclined with respect to the axis L ₂₁ .

The inclined surface of the stem 21, in the axial L ₂₁ direction of the stem 21, in the region supported by the bearing portion 25 may be formed only a portion of the one end side.

  The contact between the inclined surface of the stem 21 and the inclined surface of the bearing portion 25 is not limited to contact with the entire circumference in the circumferential direction of the stem 21, and may be in partial contact with the circumferential direction of the stem 21. For example, the structure in which the recessed part is partially formed in the inclined surface of the bearing part 25 may be sufficient, and the structure in which the recessed part is partially formed in the inclined surface of the stem 21 may be sufficient.

  In the said embodiment, although the supercharger 1 in which the waste gate valve 20 was employ | adopted is illustrated for vehicles, a supercharger is not limited to vehicles, You may be used for the engine for ships, Others May be used for other engines.

  According to some aspects of the present disclosure, it is possible to provide a variable flow rate valve mechanism and a supercharger that can suppress the vibration of the stem by suppressing the radial movement of the stem.

DESCRIPTION OF SYMBOLS 1 Supercharger 2 Turbine 3 Compressor 4 Turbine housing 17 Bypass passage 20, 20B, 20C Waste gate valve 21, 21B Stem 21a, 21e Stem inclined surface (first inclined surface)
23 Valve body (valve part)
23a, 23d Valve part inclined surface 25 Bearing part 25a, 25b The inclined surface (2nd inclined surface) of a bearing part
L ₂₁ stem axis (axis)

Claims (7)

A flow rate variable valve mechanism for opening and closing an opening of a gas flow rate variable passage,
A stem rotatably supported relative to the housing;
A bearing portion that is inserted through the through hole of the housing and supports the stem rotatably about the axis of the stem;
A valve portion provided on the first end side of the stem and opening and closing the opening,
The outer peripheral surface of the stem includes a conical first inclined surface that approaches the axial center of the stem from the second end side of the stem toward the first end side,
The inner peripheral surface of the bearing portion includes a conical second inclined surface that abuts on the first inclined surface of the stem,
The valve portion includes a valve portion inclined surface facing the gas flow rate variable passage,
In the direction in which the stem extends, the valve portion inclined surface is a variable flow rate valve mechanism that is separated from the shaft center from the second end side of the stem toward the first end side.   The variable flow valve mechanism according to claim 1, wherein the first inclined surface is disposed on the second end side of the stem in a direction in which the stem extends.   The flow rate variable valve mechanism according to claim 1, wherein the valve portion inclined surface is formed in an entire region corresponding to the opening.   The variable flow valve mechanism according to claim 2, wherein the valve portion inclined surface is formed in an entire area corresponding to the opening.   2. The flow rate variable according to claim 1, wherein the valve portion inclined surface is formed in a part of a region corresponding to the opening, and is formed only in a portion on the first end side in a direction in which the stem extends. Valve mechanism.   3. The variable flow rate according to claim 2, wherein the valve inclined surface is formed in a part of a region corresponding to the opening, and is formed only in a portion on the first end side in a direction in which the stem extends. Valve mechanism. A turbocharger comprising the flow rate variable valve mechanism according to any one of claims 1 to 6,
A turbine,
A compressor that is driven by a rotational driving force transmitted by the turbine, and
The said valve part is a supercharger which opens and closes the opening part of the said gas flow variable passage which bypasses the said turbine.

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