JP2015078660A - Turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste gate valve where a seal area of a poppet valve has no unsymmetrical contact pressure.SOLUTION: A waste gate valve 9 includes a turning shaft 11, and a poppet valve 13. The poppet valve 13 is formed with an insertion hole 17. The turning shaft 11 includes a valve arm 12 on which the poppet valve 13 is assembled. The valve arm 12 is provided with an insertion part 18 to be inserted into the insertion hole 17 at a clearance α therefrom. Valve closing torque imparted to the turning shaft 11 is transmitted via a contact area C between the insertion hole 17 and the insertion part 18 to the poppet valve 13. The contact area C is provided in the center of the poppet valve 13, and so a pressure point β is formed near the center of the poppet valve 13. Thus, the contact pressure of a seal area B of the poppet valve 13 can be equalized to suppress valve leakage.

Description

  The present invention relates to a turbocharger that opens and closes a passage hole for exhaust gas by a valve device, and relates to a technique suitable for use in, for example, a wastegate valve.

(Conventional technology)
As an example of a valve device mounted on a turbocharger, a wastegate valve 9 shown in FIGS. 10A and 10B is known (see, for example, Patent Document 1).
The wastegate valve 9 is a valve device that opens and closes an exhaust gas bypass hole 10 that bypasses the turbine impeller, and rotates integrally with the rotating shaft 11 that is rotated from the outside. And a poppet valve 13 assembled at the tip of the valve arm 12.

The poppet valve 13 includes an umbrella part 13a having a substantially disk shape and a valve shaft 13b extending in the vertical direction from the disk center of the umbrella part 13a.
A through hole X is formed at the tip of the valve arm 12, and the valve shaft 13b is inserted and assembled with the through hole X with a gap α therebetween.

Specific assembly examples are:
(I) Insert the tip (head) of the valve shaft 13b from one end side of the through hole X of the valve arm 12,
(Ii) The washer Y is fitted to the tip of the valve shaft 13b exposed to the outside from the other end side of the through hole X,
(Iii) The washer Y is fixed to the tip of the valve shaft 13b by caulking or welding.
By providing in this way, the poppet valve 13 is assembled to the valve arm 12, and the valve closing torque applied to the rotating shaft 11 is applied to the poppet valve 13 via the contact surface (pressure surface) C with the valve arm 12. Reportedly.

(Problem 1 of the prior art)
The poppet valve 13 is seated on the valve seat A around the bypass hole 10 to close the bypass hole 10.
At this time (when the valve is closed), when the sealing surface B of the poppet valve 13 is tilted and contacts the valve seat A, the gap α described above absorbs the inclination of the poppet valve 13 and the sealing surface B of the poppet valve 13 is moved to the valve seat. Match A.

However, in the prior art, the contact surface C for transmitting the valve closing torque from the valve arm 12 to the poppet valve 13 is a ring surface around the valve shaft 13b as shown by hatching in FIG.
For this reason, when the sealing surface B of the poppet valve 13 is inclined and contacts the valve seat A, and the inclination is absorbed by the gap α, the pressurization of the contact surface C is biased. Specifically, a local pressurization point β is generated at the end of the contact surface C away from the center of the poppet valve 13 (specifically, the center of the umbrella portion 13a viewed from the axial direction of the valve shaft 13b). As a result, the surface pressure of the seal surface B in the poppet valve 13 is biased, and there is a concern that valve leakage may occur.

(Problem 2 of the prior art)
The prior art uses the washer Y only for the purpose of retaining the valve shaft 13b.
Use of the washer Y causes an increase in the number of parts.
In addition, by using the washer Y, it is necessary to secure a space for ensuring the rotation range of the washer Y inside the turbine housing.

Japanese Patent Laid-Open No. 07-019065

  The present invention has been made in view of the above-described problems, and its purpose is to provide a state in which the seal surface of the poppet valve is inclined to contact with the valve seat when the valve is closed, and the inclination is absorbed by the gap. Another object of the present invention is to provide a turbocharger equipped with a valve device that does not cause uneven pressure on the sealing surface of the poppet valve.

  A turbocharger valve device (for example, a wastegate valve) includes a rotating shaft and a poppet valve, and forms an insertion hole in the poppet valve. On the other hand, the rotation shaft is provided with a valve arm to which the poppet valve is assembled, and an insertion portion to be inserted into the insertion hole with a gap is provided in the valve arm. As a result, the valve closing torque applied to the rotating shaft is transmitted to the poppet valve via the contact surface between the insertion hole and the insertion portion.

By adopting the above configuration, it is possible to provide a contact surface (pressurizing surface) for transmitting the valve closing torque from the valve arm to the poppet valve at the center of the poppet valve (the center of the umbrella portion viewed from the vertical direction of the seal surface). it can. That is, the distance from the center of the poppet valve to the end of the contact surface can be set shorter than in the prior art.
For this reason, even if the sealing surface of the poppet valve is inclined to contact with the valve seat and the inclination is absorbed by the gap, a pressure point is generated near the center of the poppet valve. Thereby, the surface pressure of the sealing surface in the poppet valve can be equalized, and valve leakage can be suppressed.

(Example 1) which is sectional drawing of a turbocharger. (Example 1) which is explanatory drawing of a waste gate valve. It is a comparison figure of the contact surface in a prior art and Example 1. FIG. (Example 2) which is explanatory drawing of the wastegate valve | bulb using a protrusion piece. (Example 2) which is explanatory drawing of the retaining process using a protrusion piece. (Example 3) which is explanatory drawing of the retaining process using an enlarged diameter part. (Example 4) which is explanatory drawing which provided the processus | protrusion inside the insertion hole. It is shape explanatory drawing of a valve arm (modification 1). It is shape explanatory drawing of a valve arm (modification 2). It is explanatory drawing of a wastegate valve | bulb (conventional example).

  EMBODIMENT OF THE INVENTION Below, the form for inventing is demonstrated in detail based on drawing.

  The embodiment disclosed below discloses a specific example, and it goes without saying that the present invention is not limited to the embodiment.

[Example 1]
Embodiment 1 will be described with reference to FIGS.
The turbocharger is mounted on an engine for vehicle travel (an internal combustion engine that generates rotational power by combustion of fuel: a gasoline engine, a diesel engine, etc., a reciprocating engine, a rotary engine, etc.).

The turbocharger is a supercharger that pressurizes intake air sucked into the engine by the energy of exhaust gas discharged from the engine.
A turbine impeller 1 that is rotationally driven by exhaust gas discharged from the engine;
A spiral-shaped turbine housing 2 that houses the turbine impeller 1;
A compressor impeller 3 driven by the rotational force of the turbine impeller 1 to pressurize the intake air;
A spiral compressor housing 4 that houses the compressor impeller 3;
A shaft 5 that transmits the rotation of the turbine impeller 1 to the compressor impeller 3;
A center housing 6 that supports the shaft 5 so as to freely rotate at high speed;
Is provided.

The turbocharger is configured by coupling the turbine housing 2, the compressor housing 4, and the center housing 6 in the axial direction using coupling means such as a V band (retaining ring), a snap ring, and a bolt.
The turbocharger of this embodiment is provided with first and second exhaust scrolls 7 and 8 for blowing exhaust gas toward the turbine impeller 1 inside the turbine housing 2.

The turbocharger includes a waste gate valve 9 that guides exhaust gas upstream of the turbine impeller 1 to the downstream region of the turbine by bypassing the turbine impeller 1.
Specifically, the turbine housing 2 is provided with a bypass hole 10 (an example of a passage hole) that guides exhaust gas upstream of the turbine impeller 1 to the turbine downstream area by bypassing the turbine impeller 1. . The bypass hole 10 is opened and closed by a movable portion of a wastegate valve 9 that is rotatably assembled to the turbine housing 2.

The operation of the wastegate valve 9 is opened when the amount of exhaust gas discharged per unit time of the engine is excessive, such as at high engine speed, and a part of the exhaust gas upstream of the turbine impeller 1 is exhausted. Is bypassed downstream of the turbine.
Thereby, it is possible to prevent the exhaust gas pressure supplied to the turbine impeller 1 from being increased excessively and to improve the turbine efficiency.

Next, a specific example of the wastegate valve 9 will be described.
The wastegate valve 9 (an example of a valve device) adjusts the amount of exhaust gas blown to the turbine impeller 1 by opening and closing the bypass hole 10 formed in the turbine housing 2 as described above. A rotation shaft 11 that is rotated from the outside of the turbine housing 2, and a poppet valve 13 that is assembled to the tip of a valve arm 12 that rotates integrally with the rotation shaft 11.

As shown in FIG. 1, the rotating shaft 11 is rotatably supported via a bearing 14 inside a cylindrical portion provided in the turbine housing 2, and is externally assembled to the outside of the turbine housing 2. The actuator is rotated through the arm 15.
An external arm 15 is fixed to the outside of the rotating shaft 11 (outside of the turbine housing 2). The external arm 15 is a member (for example, a link plate) that extends radially outward from the rotation center of the rotation shaft 11, and the rotation shaft 11 is rotated when the external arm 15 is rotated by an actuator. Move.

A valve arm 12 is integrally provided inside the rotating shaft 11 (inside the turbine housing 2).
The valve arm 12 is a rotation arm that extends radially outward from the rotation center of the rotation shaft 11, and the rotation of the rotation shaft 11 causes the poppet valve 13 assembled at the tip of the valve arm 12 to move. Draw an arc to rotate.

The poppet valve 13 is assembled at the tip of the valve arm 12, and the poppet valve 13 rotates to open and close the bypass hole 10 by rotating the valve arm 12.
The poppet valve 13 includes a substantially disc-shaped umbrella portion 13 a that sits on a valve seat A (a plane formed in the turbine housing 2) around the bypass hole 10 and closes the bypass hole 10 when the poppet valve 13 is closed. Hereinafter, the seating surface on the side of the poppet valve 13 that is seated on the valve seat A when the valve is closed will be referred to as a sealing surface B.

The poppet valve 13 is provided with an insertion hole 17 having a hole shape.
The insertion hole 17 is a through hole that passes through the center of the poppet valve 13 (the center of the umbrella portion 13a as viewed from the vertical direction of the seal surface B). The insertion hole 17 is formed in parallel to the seal surface B. ing.
As a specific example, the insertion hole 17 is a square hole having a substantially rectangular cross-sectional shape, and a plane close to the seal surface B (a contact surface C with the insertion portion 18 described later) of the square hole is a seal. It is provided parallel to the surface B.

On the other hand, the valve arm 12 is provided with an insertion portion 18 to be inserted into the insertion hole 17. A gap α is provided between the insertion hole 17 and the insertion portion 18, and the poppet valve 13 is assembled to the valve arm 12 in a state in which the play due to the gap α is allowed.
As a specific example, the insertion portion 18 is a square shaft having a substantially rectangular cross-sectional shape, and when the valve is closed, one plane of the square shaft forming the insertion portion 18 contacts the inner surface of the insertion hole 17 and rotates. The valve closing torque applied from the moving shaft 11 to the valve arm 12 is transmitted to the poppet valve 13 through the contact surface C (the surface through which the insertion portion 18 and the insertion hole 17 contact to transmit the valve closing torque).

(Effect 1 of Example 1)
The seal surface B of the poppet valve 13 may be inclined and contact the valve seat A when the valve is closed due to factors such as assembly errors and thermal expansion differences due to high-temperature exhaust gas.
In that case, the gap α intentionally provided between the insertion hole 17 and the insertion portion 18 absorbs the inclination of the poppet valve 13, and makes the seal surface B of the poppet valve 13 coincide with the valve seat A.

Here, in the wastegate valve 9 of the first embodiment, the contact surface C (rectangular pressure surface) for transmitting the valve closing torque from the valve arm 12 to the poppet valve 13 is shown by hunting in FIG. The poppet valve 13 is provided at the central portion (specifically, the central portion of the umbrella portion 13a when the seal surface B is viewed from the vertical direction). That is, in the first embodiment, the distance from “the center of the poppet valve 13” to “the end of the contact surface C” is set shorter than that in the prior art.
For this reason, even if the sealing surface B of the poppet valve 13 is inclined and contacts the valve seat A, and the inclination is absorbed by the gap α, the pressurization point β is generated near the center of the poppet valve 13. Thereby, the surface pressure of the sealing surface B in the poppet valve 13 can be equalized, and valve leakage can be suppressed.

(Effect 2 of Example 1)
In the first embodiment, as described above, the contact surface C between the insertion hole 17 and the insertion portion 18 is provided on a plane parallel to the seal surface B when the valve is closed.
For this reason, the area of the contact surface C is securable.
Specifically, the area of the contact surface C of the prior art shown by hunting in FIG. 3A and the area of the contact surface C of Example 1 shown by hunting in FIG. Can be provided. Thereby, abrasion of the contact surface C can be suppressed over a long period of time.

[Example 2]
A second embodiment will be described with reference to FIGS. In the following embodiments, the same reference numerals as those in the first embodiment indicate the same functional objects.
The second embodiment shows a technique for retaining the poppet valve 13 at the tip of the valve arm 12 while ensuring the clearance α between the insertion hole 17 and the insertion portion 18.

As in the first embodiment, the insertion hole 17 is a square hole-shaped through hole that opens on both sides in the axial direction. Similarly to the first embodiment, the insertion portion 18 is also a square shaft, and includes an exposed portion 19 that is inserted from one end side of the insertion hole 17 and exposed to the outside from the other end side of the insertion hole 17.
Then, the insertion portion 18 is prevented from being removed from the insertion hole 17 by plastically deforming the exposed portion 19.

Specifically, two protrusion pieces 20 that can be plastically deformed by pressing are provided on the exposed portion 19 (the tip of the insertion portion 18 that is exposed from the insertion hole 17 and is plastically deformed) in the second embodiment. .
After the insertion portion 18 is inserted into the insertion hole 17, the protruding piece 20 is plastically deformed outward by pressing as shown in FIG. Thereby, the protruding piece 20 after plastic deformation functions as a retaining piece, and the insertion portion 18 can be prevented from being removed from the insertion hole 17 while the clearance α between the insertion hole 17 and the insertion portion 18 is secured. .

(Effect of Example 2)
Thereby, the washer used by the prior art can be abolished and the number of parts of the wastegate valve 9 can be reduced.
In addition, since the washer is eliminated, it is not necessary to provide a space for ensuring the rotation range of the washer inside the turbine housing 2. That is, the volume (dead space) necessary for moving the wastegate valve 9 inside the turbine housing 2 can be reduced.

[Example 3]
Embodiment 3 will be described with reference to FIG.
As in the second embodiment, the third embodiment shows a technique for retaining the poppet valve 13 at the tip of the valve arm 12 while ensuring the clearance α between the insertion hole 17 and the insertion portion 18.

In the central portion of the tip of the exposed portion 19 (the tip of the insertion portion 18 exposed from the insertion hole 17 and plastically deformed) of the third embodiment, a diameter expansion hole 22 into which the diameter expansion die 21 is pushed is formed. Yes.
After inserting the insertion portion 18 into the insertion hole 17, as shown in FIG. 6, the distal end of the insertion portion 18 is expanded by plastic deformation by pushing the diameter-expansion die 21 into the diameter-expansion hole 22. An enlarged diameter portion 23 is formed at the tip of 18. As a result, the enlarged diameter portion 23 formed by plastic deformation functions as a retaining, and the insertion portion 18 is prevented from being removed from the insertion hole 17 while the clearance α between the insertion hole 17 and the insertion portion 18 is secured. Can do.

  Thereby, the washer for retaining used in the prior art can be abolished, and the same effect as in the second embodiment can be obtained.

[Example 4]
Embodiment 4 will be described with reference to FIG.
The poppet valve 13 of the fourth embodiment is provided with a protrusion 24 inside the insertion hole 17.
The protrusion 24 is provided at the center of the poppet valve 13 (specifically, the center of the umbrella portion 13a when the seal surface B is viewed from the vertical direction), and the valve closing torque applied to the rotating shaft 11 is provided. Then, it is transmitted to the poppet valve 13 through the contact surface C of the insertion portion 18 and the protrusion 24.

Specifically, the protrusion 24 reduces the area of the contact surface C between the insertion hole 17 and the insertion portion 18 so that the contact surface C is concentrated on the center portion of the poppet valve 13, and from the “center of the poppet valve 13” to the “contact surface”. The distance to the “end of C” is shortened.
Thereby, the valve closing torque applied from the valve arm 12 to the poppet valve 13 can be reliably applied to the center portion of the poppet valve 13. As a result, the surface pressure of the seal surface B of the poppet valve 13 can be further equalized, and valve leakage can be more reliably suppressed.

  In the above embodiment, the example in which the axial direction of the rotating shaft 11 and the axial direction of the insertion portion 18 (the insertion direction with respect to the insertion hole 17) are provided in parallel is shown. The axial direction of the insertion portion 18 may not be parallel. As a specific example thereof, as shown in FIG. 8, the axial direction of the insertion portion 18 may be provided perpendicular to the axial direction of the rotating shaft 11.

  In the above embodiment, the insertion portion 18 is provided with a square axis, and the wide surface of the square axis is in contact with the insertion hole 17. However, as shown in FIG. Of these, the narrow surface may be brought into contact with the insertion hole 17.

  In the above embodiment, the valve arm 12 is provided in parallel with the valve seat A and the seal surface B when the valve is closed. However, the present invention is not limited to this, and is shown in FIGS. 9 (a) and 9 (b). Thus, the valve arm 12 may not be parallel to the valve seat A or the seal surface B when the valve is closed.

In the above embodiment, the insertion portion 18 is provided with a square shaft and the insertion hole 17 is also provided with a square hole. However, the present invention is not limited thereto. For example, the insertion portion 18 is provided with a round bar (cylindrical shaft), The insertion hole 17 may be provided as a round hole. That is, the contact surface C may be a cylindrical surface.
Alternatively, the contact portion with the insertion hole 17 in the insertion portion 18 may be provided as a spherical surface, and the contact portion with the insertion portion 18 in the insertion hole 17 may be provided as a recessed spherical surface. That is, the contact surface C may be a spherical surface.

  In the above embodiment, an example in which the present invention is applied to the wastegate valve 9 has been described. However, the flow path switching valve that opens and closes a flow path switching hole (an example of a passage hole) that guides exhaust gas to the second exhaust scroll 8. The present invention may be applied to (a valve device mounted on a turbocharger).

9 Wastegate valve (valve device)
10 Bypass hole (pass hole)
11 Rotating shaft 12 Valve arm 13 Poppet valve 17 Insertion hole 18 Insertion part α Clearance C Contact surface

Claims (5)

In a turbocharger equipped with a valve device (9) for opening and closing an exhaust gas passage hole (10),
The valve device (9) includes a rotating shaft (11) that is rotated, and a poppet valve (13) that is assembled to the tip of a valve arm (12) that rotates together with the rotating shaft (11). With
The poppet valve (13) is formed with an insertion hole (17) having a hole shape,
The valve arm (12) is provided with an insertion portion (18) to be inserted with a gap (α) between the insertion hole (17),
The valve closing torque applied to the rotating shaft (11) is transmitted to the poppet valve (13) through the contact surface (C) of the insertion hole (17) and the insertion portion (18). Turbocharger. The turbocharger according to claim 1,
When the seating surface of the poppet valve (13) seated on the valve seat (A) around the passage hole (10) when the valve is closed is the sealing surface (B),
The turbocharger, wherein a contact surface (C) of the insertion hole (17) and the insertion portion (18) is a plane parallel to the seal surface (B) when the valve is closed. In the turbocharger according to claim 1 or 2,
The insertion hole (17) is a through hole opened on both sides in the axial direction,
The insertion portion (18) includes an exposed portion (19) inserted from one end side of the insertion hole (17) and exposed to the outside from the other end side of the insertion hole (17),
A turbocharger characterized in that the insertion portion (18) is prevented from being removed from the insertion hole (17) by plastically deforming the exposed portion (19). In the turbocharger as described in any one of Claims 1-3,
The poppet valve (13) includes a protrusion (24) inside the insertion hole (17),
The valve closing torque applied to the rotating shaft (11) is transmitted to the poppet valve (13) via the contact surface (C) of the insertion portion (18) and the protrusion (24). Turbocharger. In the turbocharger as described in any one of Claims 1-4,
The passage hole (10) is a bypass hole (10) for bypassing the exhaust gas upstream of the turbine impeller (1) to the exhaust downstream side of the turbine impeller (1),
The turbocharger, wherein the valve device (9) is a wastegate valve (9) that opens and closes the bypass hole (10).

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