JP6747759B2 - Exhaust turbocharger - Google Patents

Description

The present invention relates to an exhaust turbocharger provided in an internal combustion engine for automobiles and the like.

The exhaust turbocharger rotates a compressor with a turbine driven by exhaust gas, the turbine and the compressor are connected by a rotating shaft, and includes a housing having a turbine chamber and a compressor chamber.

The turbine is arranged in a turbine housing, and the turbine housing has a turbine-side scroll portion in which a turbine-side scroll space that surrounds the turbine from the outer periphery is formed, and an exhaust gas introduction passage that communicates with the start end of the turbine-side scroll space. An inlet tube portion is formed, a flange is provided in the opening of the inlet tube portion, and the flange is fixed to the cylinder head or the exhaust manifold.

The housing of the exhaust turbocharger is generally made of cast steel to ensure heat resistance. It is mainly separated into three parts: a turbine housing and a compressor housing, and an intermediate housing (bearing housing) located between them. However, Patent Document 1 discloses that a cooling water jacket is provided in the turbine side scroll portion and the inlet and outlet of the cooling water are arranged near the opening of the inlet tube portion.

On the other hand, in Patent Document 2, a turbine housing, an intermediate housing, and a compressor housing are integrally formed of aluminum, and a cooling water jacket for cooling the turbine-side scroll portion, the bearing portion, and the compressor-side scroll portion is provided therein. It is disclosed.

Micro-film of No. 58-152528 International publication WO2014/103570

The cooling water jacket of Patent Document 1 is formed only at the end of the scroll portion on the turbine side opposite to the flange, and it is unknown how the cooling water inlet and outlet are connected to the cooling water jacket. However, in any case, since the turbine housing, the intermediate housing, and the compressor housing are separate bodies, it is presumed that each housing is made of cast steel. Therefore, it is presumed that even if the cooling water jacket is provided, no strength problem will occur with respect to the inlet tube portion.

On the other hand, in Patent Document 2, the cooling water jacket formed in the turbine housing surrounds the turbine side scroll space over the entire circumference, but no description of cooling the exhaust gas introduction passage is found, so the inlet cylinder It is presumed that the cooling water jacket is not formed in the portion, and therefore, even in Patent Document 2 in which the housing is made of aluminum, it is presumed that there is no strength problem regarding the inlet tube portion.

Now, in the exhaust turbocharger, the exhaust gas first flows into the exhaust gas introduction passage formed in the inlet cylinder, so that the inlet cylinder needs to be cooled highly. The inlet cylinder is fixed to the cylinder head and exhaust manifold, and heat is also transferred from the cylinder head and exhaust manifold.Therefore, it is not necessary to cool the inlet cylinder when the turbine housing is made of lightweight aluminum. It can be said that it will be particularly high.

However, as described above, in any of the patent documents, there is no reference to the necessity of cooling the inlet tube portion, ensuring the strength when a cooling water jacket is provided in the inlet tube portion, and the exhaust turbocharger is water-cooled. Therefore, it can be said that there is a technical gap in this regard.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an improved water-cooled exhaust turbocharger.

The exhaust turbocharger of the present invention is
It has a turbine and a compressor that are concentrically rotated by being connected by a horizontal rotary shaft,
A turbine housing in which the turbine is arranged, a turbine-side scroll portion in which a turbine-side scroll space that surrounds the turbine from the outer periphery is formed; A tubular portion is formed, and a flange that is fixed to the cylinder head or the exhaust manifold is provided in the opening of the inlet tubular portion.

And in Claim 1, in the said basic structure,
A cooling water jacket that surrounds the exhaust gas introduction passage from at least below is formed in the inlet tubular portion in a state of being divided by a lower partition wall extending in the longitudinal direction at the lower end portion of the exhaust gas introduction passage, and A downward rib that vertically overlaps with the lower partition wall is formed on the lower surface of the inlet cylinder so as to extend in the longitudinal direction of the inlet cylinder.

In claim 2, in claim 1,
The cooling water jacket, with both communicates integrally and a portion formed on the turbine side scroll portion and the inlet tube portion forming portions, which is formed on the inlet cylindrical portion On the other hand, the rib is connected to the flange and the turbine-side scroll portion.

The cooling water jacket divided through the lower partition wall may be integrally connected at the upper end portion, but at the upper end, the cooling water jacket may be divided into right and left portions by the upper partition wall. When the cooling water jacket is also formed on the turbine side scroll portion as in claim 2, the cooling water jacket of the turbine side scroll portion should also be divided into left and right by a partition wall continuous with the partition wall formed in the inlet tube portion. You can

Since the exhaust turbocharger is in a state of overhanging from the flange, the weight of the turbine side scroll space, the intermediate housing and the compressor housing acts as a downward moment on the inlet cylinder, and the vibration of the engine As a result, the moment acts in small increments, so that a large downward load acts on the inlet tube portion.

Therefore, if the cooling water jacket is simply formed in the inlet cylinder so as to surround the exhaust gas introduction passage, the strength of the inlet cylinder must be weakened. It must be very large, but if it is made thicker, the purpose of weight reduction cannot be sufficiently achieved even if it is made of aluminum, for example.

On the other hand, in the present invention, in the inlet tube portion, the cooling water jacket is divided into the left and right sides by the lower partition wall, and the ribs are arranged below the lower partition wall. Since it exerts a strong resistance to a load, it is possible to secure the necessary strength even if it is thin. Therefore, when the housing is made of aluminum, it is possible to significantly suppress thermal deformation and contribute to weight saving while ensuring quality and durability. It is more preferable to divide the cooling water jacket at the upper end into left and right parts by the upper partition wall, because the strength of the inlet tube portion is further increased.

If the configuration of claim 2 is adopted, first, since the cooling water jacket is open at the end of the inlet tube portion, casting of the turbine housing becomes easy. That is, in casting, the hollow portion is composed of a sand core, but it is necessary that the core be firmly held by the mold and that the sand be easily removed after casting. When the hollow cooling water jacket is opened at the end of the inlet cylinder as shown in 2, the end face of the core can be supported by the sand-shaped frame, so that the core can be stably held, and Therefore, it is easy to remove the sand after casting.

In addition, in the invention of claim 2, since the cooling water jacket is also formed at the location of the turbine side scroll portion, the turbine housing is more reliably cooled, the effect of preventing thermal deformation is further enhanced, and the heat to the bearing portion is increased. The effect of can be greatly suppressed.

Further, in the invention of claim 2, since the ribs are connected to the flange and the turbine side scroll portion, the resistance of the inlet cylinder portion against a load (moment) from above is remarkably high. Therefore, the reinforcing effect can be perfect.

It is a vertical section front view of an embodiment. It is a separation vertical section front view of an embodiment. FIG. 3 is a view showing the embodiment, (A) is a perspective view of the housing as seen from the front, and (B) is a rear view as seen from the BB view direction of (A) (as seen from the cylinder head side). It is a figure which shows the housing of embodiment, (A) is a top view, (B) is a bottom view. (A) is a sectional view taken along line AA of FIG. 2, and (B) is a sectional view taken along line BB of (A) . It is a schematic diagram which shows the flow of cooling water. (A) is a schematic diagram showing another example of the flow of cooling water, and (B) is another example diagram of the same portion as FIG. 5(B).

(1). Outline and Turbine Housing Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline will be described. In the present embodiment, the wording "front and rear" and "right and left" is used to clarify the direction, but this means that the longitudinal direction of the rotating shaft is the left-right direction, and the horizontal direction orthogonal to this is the front-back direction. The direction is front. As a precaution, the direction is clearly shown in FIG.

As shown in FIG. 1, the exhaust turbocharger includes a blade-type turbine 1 and a compressor 2, both of which are integrally fixed by a rotary shaft 3 in a horizontal posture. Further, the exhaust turbocharger has a turbine housing 4 and a compressor housing 5, and an intermediate housing 6 located between the turbine housing 4 and the compressor housing 5. The turbine housing 4 and the intermediate housing 6 are cast aluminum products. Manufactured in one piece. The compressor housing 5 is an aluminum die cast product or a cast product.

In the turbine housing 4, a turbine chamber 7 in which the turbine 1 is rotatably arranged, and a turbine-side scroll space 8 communicating with the outer peripheral portion of the turbine chamber 7 are formed. The turbine-side scroll space 8 has a spiral shape in which the cross-sectional area at the start end is larger than the cross-sectional area at the end and is close to an annular shape, and at the start end (upper end) thereof, as shown in FIG. An exhaust gas introduction passage 9 extending in a tangential direction of the start end portion of 8 communicates.

Therefore, the turbine housing 4 has an inlet tube portion 4a in which an exhaust gas introduction passage 9 is formed, and a flange 12 fixed to the cylinder head 11 (or the exhaust manifold) with a bolt (and a nut) at the tip thereof. Is formed. Therefore, the turbine housing 3 has the inlet tubular portion 4a and the turbine-side scroll portion 4b as main elements, and the inlet tubular portion 4a is in a horizontally long posture that is approximately horizontal. As shown in FIG. 5, in the present embodiment, the exhaust side surface 11a of the cylinder head 11 is slightly tilted backward so that the space between the exhaust side surface 11a and the vertical line 13 increases as it goes upward.

The exhaust gas flowing from the exhaust gas introduction passage 9 into the turbine side scroll space 8 is discharged in the axial direction while rotatingly driving the turbine 1 while flowing in the circumferential direction of the turbine side scroll space 8. Therefore, in the turbine housing 4, a cylindrical exhaust outlet 14 for exhausting exhaust gas is opened toward the axial direction of the rotating shaft 3, and an exhaust pipe or a catalyst case is connected to the exhaust outlet 14. ..

Further, as partially shown in FIG. 1, a bypass passage 15 is formed in the turbine housing 4 near the exhaust outlet 14 to allow exhaust gas to escape from the exhaust gas introduction passage 9 to the exhaust outlet 14. The bypass passage 15 is located above the exhaust outlet 14. Therefore, as can be easily understood from FIG. 4, the turbine housing 4 is provided with an expanded portion 16 connected to the inlet cylinder portion 10, the exhaust outlet 14, and the turbine side scroll portion 4b, and the bypass passage 15 is formed in the expanded portion 16. And a waste gate valve placement space 17 (see FIG. 1) communicating with the waste gate valve placement space 17 is formed.

The waste gate valve arrangement space 17 communicates with the exhaust outlet 14 and opens in the axial direction of the rotating shaft 3, and the waste gate valve is inserted from the opening direction of the exhaust outlet 14 and is supported by the support shaft to form the turbine housing 4. Connected to. Reference numeral 18 in FIG. 3 denotes a hole through which the support shaft is inserted.

In the turbine housing 4, an inside jacket 19 surrounding the turbine side scroll space 8 and the exhaust gas introduction passage 9 from the side of the intermediate housing 6 and a turbine side scroll space 8 and the exhaust gas introduction passage 9 are exhausted as cooling means by cooling water. An outside jacket 20 that surrounds the outlet 14 is formed, and the inside jacket 19 and the outside jacket 20 are divided into left and right parts by an upper partition wall 21a and a lower partition wall 21b. Therefore, the upper and lower partition walls 21a and 21b extend along the surface that divides the inlet tube portion 4a and the turbine-side scroll portion 4b into two in the left and right (axial direction), and at the front end portion on the opposite side of the flange 12. It is connected.

As shown in FIG. 3(B) and FIG. 4(B), the inside jacket 19 and the outside jacket 20 are open to the rear surface of the inlet tube portion 4a. Further, the inside jacket 19 and the outside jacket 20 have a single flow at the location of the inlet tube portion 4a, but are annular at the location of the turbine side scroll portion 4b. A side view shape of the jacket 19, 20 is schematically shown in FIG. 6 (A).

There can be several modes of cooling water flow between the inside jacket 19 and the outside jacket 20. An example thereof is schematically shown in FIGS. 6(A) and (B) and FIG. 7(A). In the example shown in FIG. 6(A), the inner jacket 19 and the outer jacket 20 are provided at the front end of the turbine side scroll portion 4b by separating the front ends of the upper and lower partition walls 21a and 21b from each other without connecting them. And a communication portion 22 is formed, and cooling water is flowed from the inside jacket 19 to the outside jacket 20. Therefore, in this example, the rear end of the inside jacket 19 is the cooling water inlet 22a, and the rear end of the outside jacket 20 is the cooling water outlet 22b.

In the example shown in FIG. 6B, the inside jacket 19 and the outside jacket 20 are completely separated, cooling water inlets 22a are formed at the lower ends of both jackets 19 and 20, respectively, and a cooling water outlet 22b is provided at the rear. Formed on the edge. In the example shown in FIG. 7(A), the inside jacket 19 and the outside jacket 20 are connected at their lower front ends by a communicating portion 22, and the communicating portion 22 is provided with a cooling water inlet 22a. The rear ends of both jackets 19 and 20 are cooling water outlets 22b.

As shown in FIG. 2, the outside jacket 20 surrounds the periphery of the turbine side scroll space 8 in a range of about 1/4. The inside jacket 19 has a substantially symmetrical shape with the outside jacket 20, but the inner circumference of the inside jacket 19 may be extended to the vicinity of the inner hole 23 into which the rotating shaft 3 is fitted. As shown in FIGS. 1 and 2, a plurality of annular grooves 24 are formed in a portion of the rotary shaft 3 that is fitted into the inner peripheral hole 23 of the turbine housing 4, and the oil seal 24 a is fitted into the annular grooves 24. Has been.

Further, as shown in FIG. 3, FIG. 4(B) and FIG. 5, reinforcing ribs 25 extending from the flange 12 to the turbine side scroll portion 4b are provided on the lower surface of the inlet cylinder portion 4a so as to project downward. The rib 25 vertically overlaps with the lower partition wall 21b formed in the lower portion of the inlet tube portion 4a. The rib 35 is plate-shaped and has a substantially equal vertical width over the entire length in the front and rear, but the vertical width may be gradually different in the front-rear direction, or the lower end may be arched in a side view. It can also be formed. The upper partition 21a is located on the lower partition 21b and the rib 25.

(2). Compressor housing/intermediate housing Just in case, the compressor part and the intermediate housing 6 are also explained. As shown in FIGS. 1 and 2, the compressor housing 5 is formed with a compressor chamber 26 in which the compressor 2 is rotatably arranged and a compressor-side scroll space 27 located outside the compressor chamber 26. Are connected by a communication passage 28. The compressor side scroll space 27 is formed in a state close to an annular shape, and the cross-sectional area increases from the start end to the end end. The end of the compressor-side scroll space 27 faces the tangential direction, and the discharge port 29 is connected to this end. Reference numeral 30 in FIG. 1 indicates a mounting boss of the diaphragm type actuator.

A lid member 31 is fitted into the compressor housing 5 from the intermediate housing 6 side, and the compressor housing 5 and the lid member 31 form a compressor-side scroll space 27. Further, the compressor chamber 26 and the communication passage 28 are formed between the lid member 31 and the intermediate housing 6 (thus, to be exact, the compressor housing 5 is composed of the main body portion and the lid member 31). ..).

As shown in FIGS. 1 and 2, a bearing portion 33 into which the rotary shaft 3 is rotatably fitted is formed in the intermediate housing 6, and a hollow floating metal 34 is arranged in the bearing portion 33 via an oil layer. The middle part of the rotating shaft 3 is rotatably fitted inside the floating metal 34. The floating metal 34 is non-rotatably held by a stopper 35 fitted or screwed into the bearing portion 33 from below.

An oil inlet 36 that penetrates in the up-down direction is formed in the upper portion of the bearing portion 33. A hollow oil outlet space 37 is formed below the bearing portion 33. As shown in FIG. 5A, the oil outlet space 37 has a semicircular shape in a side view. Further, first and second oil splash spaces 38, 39 are formed on both left and right sides of the bearing portion 33 of the intermediate housing 6, and the oil splash spaces 38, 39 communicate with the oil outlet space 37. ing.

As shown largely in FIG. 2, a first oil seal 40 made of metal is attached to an end portion of the bearing portion 33 on the compressor housing 5 side. The cross-sectional display (hatching) of the first oil seal 40 is omitted. Further, the left end of the intermediate housing 6 has a large opening, and a metal retainer ring 41 is fixed to this large-diameter opening. The first oil seal 40 is fitted to the retainer ring 41 via the second oil seal 41 a, and the second oil seal 41 a is fixed to the first oil seal 40. The end of the rotary shaft 3 is fixed to the compressor 2 with a nut 42.

As shown in FIG. 1, the end of the intermediate housing 6 on the side opposite to the turbine housing 4 is held from the outside by a compressor housing 5, and both of them cannot be removed by an elastic C-shaped stopper ring 43. Held in.

(3). Summary The exhaust turbocharger of this embodiment is of a type that is directly attached to the cylinder head 11, and the inside jacket 19 and the outside jacket 20 are open at the rear end of the inlet tube portion 4a. .. Then, since the turbine side scroll portion 4b and the inside jacket 19 can be cooled by flowing the cooling water through the jackets 19 and 20, even if the turbine housing 4 and the intermediate housing 6 are made of aluminum, excessive thermal deformation and melting damage are caused. In this state, the smooth rotation of the turbine 1 can be ensured. Therefore, it is possible to make great progress in making the housing aluminum (lighter weight), which can contribute to improving fuel efficiency.

Since the inside jacket 19 and the outside jacket 20 are divided into the left and right by the partition walls 21a and 21b that extend over the inside jacket 19 and the turbine side scroll portion 4b, the turbine housing 4 secures high strength. In addition, since the flow path between the inside jacket 19 and the outside jacket 20 is simplified, the cooling water can be evenly flowed through the jackets 19 and 20 without causing the stagnation phenomenon of the cooling water.

Therefore, it is possible to prevent distorted thermal deformation of the turbine housing 4 and significantly suppress thermal strain. As a result, high reliability and durability can be obtained. Then, in the inlet tube portion 4a, the inside jacket 19 and the outside jacket 20 are divided by the upper and lower partition walls 21a and 21b, and the lower partition wall 21b and the ribs 25 which are vertically continuous are formed on the lower surface. , High resistance against load from above.

Therefore, while the turbine housing 4 (and the intermediate housing 6) is made of aluminum to reduce its weight, the durability can be ensured and the thickness of each inlet cylinder portion 4a can be made as thin as possible to promote the weight reduction. When the rib 25 is connected to the flange 12 and the turbine side scroll portion 4b as in the embodiment, the section modulus against the downward bending force (moment) becomes large, which can further contribute to the improvement of strength.

As shown in FIG. 7B, the inside jacket 19 and the outside jacket 20 may be divided by the inner peripheral portion of the inlet tubular portion 4a, and the rib 25 may be formed in the divided portion.

In each of the above-described embodiments, the jackets 19 and 20 are formed up to the inlet tube portion 4a, but a configuration in which the rear end of the jackets 19 and 20 does not reach the rear end of the inlet tube portion 4a can also be adopted. Either or both of the inside jacket 19 and the outside jacket 20 can be vertically divided by side partition walls.

The present invention can be embodied in an exhaust turbocharger. Therefore, it can be used industrially.

1 Turbine 2 Compressor 3 Rotating shaft 4 Turbine housing 4a Inlet cylinder part 4b Turbine side scroll part 5 Compressor housing 6 Intermediate housing 7 Turbine chamber 9 Exhaust gas introduction passage 11 Cylinder head 14 Exhaust outlet 19 Inside jacket 20 Outside jacket 21a Upper partition wall 21b Lower partition wall 22a Cooling water inlet 22b Cooling water outlet 25 Rib

Claims (2)

It has a turbine and a compressor that are concentrically rotated by being connected by a horizontal rotary shaft,
A turbine housing in which the turbine is arranged, a turbine-side scroll portion in which a turbine-side scroll space that surrounds the turbine from the outer periphery is formed; A tubular portion is formed, and a flange fixed to the cylinder head or the exhaust manifold is provided in the opening portion of the inlet tubular portion,
A cooling water jacket that surrounds the exhaust gas introduction passage from at least below is formed in the inlet tubular portion in a state of being divided by a lower partition wall extending in the longitudinal direction at the lower end portion of the exhaust gas introduction passage, and A downward rib that vertically overlaps with the lower partition wall is formed on a lower surface of the inlet tube portion so as to extend in a longitudinal direction of the inlet tube portion.
Exhaust turbocharger. The cooling water jacket, with both communicates integrally and a portion formed on the turbine side scroll portion and the inlet tube portion forming portions, which is formed on the inlet cylindrical portion While opening at the end surface of the inlet tube portion,
The rib is connected to the flange and the turbine side scroll portion,
The exhaust turbocharger according to claim 1.

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