JP2002349276A - Turbine housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbine housing capable of improving durability and reliability of a turbine, and capable of reducing the size and weight preventing unnecessary rotation of the turbine even if a waist gate valve is not used. SOLUTION: This turbine housing 11 has a scroll part 12, a cover part 13, and flange parts 15 and 16, houses the turbine 18 inside, and rotates the turbine 18 by applying exhaust gas flowing in the scroll part 12 to a turbine blade 17. This turbine housing 11 has a first exhaust gas passage for allowing the exhaust gas striking on the turbine blade 17 after flowing in the scroll part 12 to follow a passage for exhaust as it is after the gas rotates the turbine 18, and a second exhaust gas passage for allowing the exhaust gas to follow the passage for exhaust after flowing in a clearance between the scroll part 12 and the cover part 13 via a circular hole 33 in mid course of rotating the turbine 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine housing of an exhaust turbine driven supercharger.

[0002]

2. Description of the Related Art Conventionally, as a turbine housing of this type, for example, those shown in FIGS. 9 to 11 are known. A supercharger provided with this turbine housing controls a supercharging pressure. To be mounted on a vehicle for use. FIG. 9 is a front view showing a turbine housing according to the related art. FIG. 10 is a rear view showing a turbine housing according to the related art. FIG.
FIG. 10 is a cross-sectional view showing a turbine housing according to the related art, and is a cross-sectional view taken along line AA of FIG. 9.

As shown in FIGS. 9 to 11, a turbine housing 101 includes a metal scroll portion 102 forming a spiral exhaust gas flow path, and a scroll portion 10 formed of a metal.
2 made of a metal cover 103 enclosing the cover 2 with a gap
And flange portions 104, 105, and 106 to which the scroll portion 102 and the cover portion 103 are attached.
Further, a turbine 108 having a turbine blade 107 indicated by a two-dot chain line in FIG. 11 is housed inside the turbine housing 101.

[0004] As shown in FIG.
Between the turbine blade 107 and the turbine 108
A small clearance is set to enhance the performance of the. The cover part 103 is formed from two divided members, which are joined by welding and integrated. Both ends of the scroll portion 102 and the cover portion 103 are fixed to the flange portions 105 and 106 by welding.

As shown in FIGS. 9 to 11, the turbine housing 101 has an exhaust gas inlet 109 for introducing exhaust gas into the scroll portion 102 and a bypass for excess exhaust gas in the scroll portion 102. A bypass passage 110 for exhausting the waste gas from the waste gate port 113, an exhaust gas exhaust port 111 for exhausting exhaust gas flowing through the scroll portion 102, and an insertion hole 112 for inserting the turbine 108 are formed.

In the turbine housing 101, an exhaust manifold (not shown) is connected to the flange 104 on the exhaust gas inlet 109 side, and an elbow (not shown) is connected to the flange 105 on the exhaust gas outlet 111 and the wastegate port 113 side. Are connected. Further, the flange portion 106 on the insertion hole 112 side is used.
Is connected to one end of a center housing (not shown), and the other end of the center housing is connected to a compressor housing (not shown).
The supercharger according to the prior art includes a turbine housing 101,
A turbine 108, a center housing, a compressor housing, a wastegate valve and the like are provided.

In the exhaust gas introduced from the exhaust manifold into the scroll section 102 through the exhaust gas inlet 109, excess exhaust gas is exhausted from the waste gate port 113 to the elbow side through the bypass passage 110. Exhaust gas that has been adjusted and not adjusted (flowed in the scroll portion 102) hits the turbine blade 107 to rotate (drive) the turbine 108, and at the same time, is exhausted to the elbow side via the exhaust gas exhaust port 111. Is set.

Here, the wastegate port 113 is
It is not shown when the flow rate of the exhaust gas in the scroll portion 102 is excessive (when the supercharging pressure of the supercharger is excessive), for example, when the engine speed of the vehicle is in a high rotation range (for example, 4000 rpm or more). When the exhaust gas flow rate is not excessive (when the supercharging pressure of the supercharger is not excessive), for example, the engine speed of the vehicle is in a low rotation range (for example, when the exhaust gas flow rate is not excessive). In the case of less than 4000 rpm), it is set so as to be closed by the waste gate valve. Such control of the wastegate valve allows the turbine 10
8 is prevented from rotating more than necessary, and the flow rate of the exhaust gas flowing through the scroll portion 102 is maintained in a good state. That is, the supercharging pressure of the supercharger provided with the turbine housing is controlled to be in a favorable state.

[0009]

However, in the above-described turbine housing 101 according to the prior art, unless the flow rate of the exhaust gas is controlled by using a waste gate valve or the like, the turbine 108 is rotated more than necessary by the exhaust gas. In some cases. In such a case, the turbine 108 is likely to be damaged or deteriorated, and the durability and reliability of the turbine 108 will be significantly reduced. In addition, since it is necessary to provide a wastegate valve, a wastegate port, and the like in the turbine housing 101, the turbine housing 101 and, consequently, the turbocharger are increased in size and weight.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to prevent the turbine from rotating more than necessary without using a wastegate valve or the like, thereby improving the durability and reliability of the turbine. It is an object of the present invention to provide a turbine housing capable of improving the performance and reducing the size and weight.

[0011]

In order to achieve the above object, the invention according to the first aspect of the present invention is directed to a metal scroll portion forming a spiral exhaust gas flow path and a state in which the scroll portion has a gap. A metal cover wrapped with the above, a scroll part and a flange part to which the cover part is attached, accommodating a turbine having turbine blades therein and flowing through the scroll part. In a turbine housing that rotates the turbine by applying exhaust gas to the turbine blades, exhaust gas flowing through the scroll portion and hitting the turbine blades follows a flow path that is exhausted as it is after rotating the turbine. Exhaust gas flowing through the first exhaust gas flow path and the inside of the scroll portion and impinging on the turbine blade rotates the turbine. And as its gist in that it comprises a second exhaust gas passage following the by the passage evacuated from the in circulation the gap between the cover portion and the scroll portion in the middle to.

According to the first aspect of the present invention, when the exhaust gas flows through the metal scroll portion forming the spiral exhaust gas flow path, the scroll portion is caused by the heat of the exhaust gas. The thermal expansion occurs outward, and the exhaust gas impinges on the turbine blades of the turbine housed in the turbine housing to rotate (drive) the turbine.

In this case, when the flow rate of the exhaust gas flowing through the scroll portion is not excessive, that is, when the rotational speed of the engine of the vehicle is in a low rotation range (for example, less than 4000 rpm), the exhaust gas is mainly supplied to the first exhaust gas passage. When the flow rate of the exhaust gas flowing through the scroll portion is excessive, that is, when the rotation speed of the engine of the vehicle is in a high rotation range (for example, 4000 rpm or more), one of the exhaust gas during the rotation of the turbine is discharged. The part is exhausted through the second exhaust gas flow path, and the exhaust gas not flowing through the second exhaust gas flow path is exhausted through the first exhaust gas flow path after rotating the turbine. .

In other words, when the flow rate of the exhaust gas flowing through the scroll portion is not excessive, most of the exhaust gas is used for the force for flowing the first exhaust gas flow path to rotate the turbine, and the flow rate in the scroll portion is increased. When the flow rate of the exhaust gas is excessive, the excess exhaust gas is bypassed to the second exhaust gas flow path while rotating the turbine, and the force for rotating the turbine is dispersed. Therefore, the turbine is prevented from rotating more than necessary, so that the turbine is not damaged or easily deteriorated, and the durability and reliability of the turbine are improved.

As described above, in the turbine housing of the present invention, only the first exhaust gas passage and the second exhaust gas passage are provided, and the scroll can be provided without using a waste gate valve or the like as in the prior art. It is possible to adjust the flow rate of the exhaust gas flowing through the inside of the section and maintain the state in a good state.

Further, as described above, since the turbine can be prevented from rotating more than necessary, the wastegate valve and wastegate port used in the prior art become unnecessary, and the turbine housing and, consequently, the turbocharger can be reduced in size and weight. Is achieved. In addition, since there is no need to provide a wastegate valve and a wastegate port in the turbine housing, the degree of freedom in designing the turbine housing is increased.

Furthermore, a gap is formed between the metal scroll part and the metal cover part, and the scroll part is covered with the cover part, so that the gap functions as a heat insulating layer. At the same time, the cover part serves to maintain the temperature of the exhaust gas. As a result, the heat of the exhaust gas is less likely to be transmitted to the outside (it is less likely to be robbed),
Effective utilization of the heat energy of the exhaust gas is achieved. That is, by using the thermal energy of the exhaust gas, it is possible to reduce the time required to reach the activation temperature of the catalyst disposed downstream of the turbine housing immediately after the start of the engine of the vehicle. .

According to a second aspect of the present invention, in the turbine housing according to the first aspect, a hole is formed in a shroud portion of the scroll portion which is provided closer to the turbine blade, and the inside of the scroll portion and the cover are formed. The gist is that a part of the second exhaust gas passage is formed by making the inside of the part communicate with the inside.

According to the second aspect of the present invention, in addition to the function of the first aspect, a hole is formed in a shroud portion of the scroll portion which is provided closer to the turbine blade, and the inside of the scroll portion is formed. A part of the second exhaust gas passage can be easily formed only by making the inside of the cover and the inside of the cover communicate. In addition, the holes formed in the shroud portion of the scroll portion ensure that excess exhaust gas is introduced into the gap between the scroll portion and the cover portion.

According to a third aspect of the present invention, in the turbine housing according to the first or second aspect, the second aspect is provided.
The gist is that a resistor for adjusting the flow rate of the exhaust gas flowing through the exhaust gas passage is provided outside one end of the scroll portion.

According to the third aspect of the present invention, in addition to the functions of the first and second aspects of the invention, it is also possible to adjust the flow rate of the exhaust gas flowing through the second exhaust gas passage. Since the resistor is provided outside the one end of the scroll portion, the flow of the exhaust gas flowing through the second exhaust gas flow path is reliably adjusted by the resistor. That is, by adjusting the density of the resistor in advance, it becomes difficult for the exhaust gas to flow through the second exhaust gas flow path, or the exhaust gas becomes easier to flow through the second exhaust gas flow path (resistor When the density of the resistor increases, it becomes difficult for the exhaust gas to flow through the second exhaust gas passage, and conversely, when the density of the resistor decreases,
Exhaust gas easily flows through the second exhaust gas passage).

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view showing a turbine housing according to the present embodiment, and is a cross-sectional view taken along line CC of FIG. FIG. 2A is a cross-sectional view schematically illustrating a first exhaust gas flow path of the present embodiment, and FIG. 2B is a cross-sectional view schematically illustrating a second exhaust gas flow path of the present embodiment. FIG. FIG. 3 shows B surrounded by a small circle in FIG.
FIG. 4 is an enlarged cross-sectional view showing a portion of FIG. FIG. 4 is a front view showing the turbine housing according to the present embodiment. FIG. 5 is a longitudinal sectional view showing the turbine housing in the present embodiment, and is a sectional view taken along line DD of FIG. FIG. 6 is a side view showing the turbine housing according to the present embodiment. FIG. 7 is a rear view showing the turbine housing in the present embodiment. FIG. 8 is a side view showing the turbine housing in the present embodiment.

As shown in FIGS. 1 to 8, a turbine housing 11 according to the present embodiment has a scroll portion 12 made of a small heat capacity stainless steel having excellent heat resistance and corrosion resistance, and a stainless steel. The formed cover portion 13 and the scroll portion 12 and the cover portion 13
And flange portions 14, 15, and 16 to which are attached. A turbine 18 having a turbine blade 17 indicated by a two-dot chain line in FIG. 1 is housed in the turbine housing 11. In the present embodiment, the turbine housing 11 has a double pipe structure of a scroll part 12 corresponding to an inner pipe and a cover part 13 corresponding to an outer pipe.
Is enclosed with a gap.

The turbine housing 11 of the present embodiment
Has three flange portions 14, 15, and 16,
The cover part 13 and the scroll part 12 are joined to these flange parts 14, 15, 16 by welding. The flange portions 14, 15, 16 are castings formed of stainless steel cast steel having excellent heat resistance and corrosion resistance.

As shown in FIG. 5, the scroll section 12
It is formed in a spiral shape and is divided into a first scroll portion 12a and a second scroll portion 12b. First
The scroll part 12a is joined to the flange part 14 by welding. The first scroll part 12a and the second scroll part 12b are each formed in a predetermined shape by hydraulic bulge molding, and the first scroll part 12a is fitted to the second scroll part 12b. In this case, an expanded portion 19 having a slightly enlarged diameter is formed at the end of the second scroll portion 12b, and the end of the first scroll portion 12a is fitted to the expanded portion 19. The first scroll portion 12a and the second scroll portion 12b are set to be slidable by this fitting state.

In the present embodiment, a tongue portion 20 for guiding a part of the exhaust gas is formed in a tongue shape on the side of the end of the first scroll portion 12a having a small radius of curvature. The end of the first scroll portion 12a is formed by bending by hydraulic bulging. Here, the tongue shape is a shape in which the flow of exhaust gas can be rectified in a state in which a separation boundary layer does not or hardly occur in the tongue portion 20. Exhaust gas flowing through the scroll portion 12 is guided in a good state by the inner surface of the scroll portion 12 and the tongue portion 20.

As shown in FIGS. 1 and 3, at one end of the second scroll portion 12b, a throat portion 21 extending in the axial direction of the turbine 18 and the diameter thereof is gradually reduced from the throat portion 21. An inclined portion 22 is formed. Outside the throat portion 21, a SUS mesh 23 as a resistor for adjusting the flow rate of exhaust gas flowing through a second exhaust gas flow path Rb (see FIG. 2B) described later is provided. And is formed in an annular shape. Here, the SUS mesh is formed by braiding a SUS metal wire to have a predetermined shape, and is in a state in which exhaust gas can flow. The SUS mesh 23 is fixed to the inner surface of the flange portion 15 by welding, and the ring member 24 made of stainless steel is attached to the throat portion 2 of the second scroll portion 12b.
1 is welded to the inner surface.

More specifically, the throat portion 21 of the second scroll portion 12b is interposed between the SUS mesh 23 and the ring member 24. The ring member 24 also slides in the same direction in conjunction with sliding in the axial direction (left-right direction in the figure).
In this case, a gap is set such that even if the throat portion 21 and the ring member 24 slide in the axial direction of the turbine 18 (rightward in the figure), they do not contact the flange portion 15.

The ring member 24 is attached to the throat 21
The second scroll portion 12 b is joined to the turbine blade 17 close to the turbine blade 17, that is, the turbine blade 17 of the shroud portion 25.
The movement to the side is regulated. Shroud portion 25 of second scroll portion 12b and turbine blade 17
In order to enhance the performance of the turbine 18, a minute clearance is set.

Further, as shown in FIG. 5, an exhaust gas inlet 26 for introducing exhaust gas is provided in the first scroll portion 12a.
Is formed, and an exhaust gas exhaust port 27 for exhausting exhaust gas is formed in the second scroll portion 12b.
In addition, the first scroll part 12a and the second scroll part 1
2b between the scroll portion 12 and the cover portion 13 for maintaining a gap between the scroll portion 12 and the cover portion 13 at a predetermined interval.
US mesh 28 is interposed. As shown in FIG. 1, an insertion hole 29 for inserting (accommodating) the turbine 18 indicated by a two-dot chain line in the figure is formed in the turbine housing 11.

As shown in FIGS. 4 to 8, in the turbine housing 11 of the present embodiment, an exhaust manifold (not shown) is connected to the flange portion 14 on the exhaust gas inlet 26 side. Also, as shown in FIGS. 1, 4, 6, and 8, the flange portion 16 on the insertion hole 29 side is used.
Is connected to one end of a center housing (not shown), and the other end of the center housing is connected to a compressor housing (not shown).
Further, the turbine housing 1 shown in FIGS.
An elbow (not shown) is connected to the first flange portion 15, that is, the flange portion 15 on the exhaust gas exhaust port 27 side. The supercharger according to the present embodiment includes a turbine housing 11, a turbine 18, a center housing, a compressor housing, and the like.

As shown in FIG. 1 and FIG.
Are formed so as to be half-split, and include a first cover portion 13a and a second cover portion 13b. The first cover portion 13a is joined to the flange portions 14 and 16 by welding, and the second cover portion 13b is connected to the first cover portion 1.
3a is joined by welding. In this case, a part of the second cover portion 13b, that is, the seal portion 30 is welded from the outside of the first cover portion 13a in a superposed state, and the sealability of the cover portion 13 is secured by the seal portion 30. It has become.

As shown in FIG. 1, in the turbine housing 11 of the present embodiment, ridges 31, 32 are formed to project from the flanges 15, 16 so that the ridge 32 and the first cover 13a are formed. Are welded to each other in such a manner that the mating surface of the protrusion 31 and the mating surface of the ridge 31 and the second cover 13b are flush with each other. Flange part 15,
By forming the protruding portions 31 and 32 on the base member 16, heat generated at the time of welding does not adversely affect the peripheral portion of the welded portion, and the heat generated by the first cover portion 13a, the second cover portion 13b, and the second scroll portion 12b is not affected. The welding will be performed in a good condition.

In the turbine housing 11 of the present embodiment, the following structure is employed to prevent the turbine 18 from rotating more than necessary.

That is, the turbine housing 11 in the present embodiment is schematically shown by a first exhaust gas passage Ra schematically shown by an arrow in FIG. 2A and by an arrow shown in FIG. 2B. A second exhaust gas passage Rb. Also,
As shown in FIGS. 1, 2A, and 2B, in the turbine housing 11 of the present embodiment, a plurality of shrouds 25 (where the second scroll portion 12b is located closer to the turbine blade 17) are provided. In the present embodiment, eight) circular holes 33 are formed at predetermined intervals. Through these circular holes 33, the inside of the second scroll portion 12b and the cover portion 1 are formed.
3, a part of the second exhaust gas passage Rb is formed.

More specifically, the first exhaust gas flow path Ra follows a flow path in which the exhaust gas flowing through the scroll portion 12 and hitting the turbine blade 17 is directly exhausted after rotating the turbine 18. And is formed by a part of the second scroll portion 12b and the exhaust gas outlet 27 of the flange portion 15. In addition, the second exhaust gas flow path Rb forms a gap between the second scroll part 12 b and the cover part 13 while the exhaust gas flowing through the scroll part 12 and hitting the turbine blade 17 rotates the turbine 18. It follows a flow path that is exhausted after the circulation, and is part of the second scroll part 12b, the circular hole 33 of the shroud part 25, the second scroll part 12b, and the cover part 1.
3, SUS mesh 23, flange 15
Is formed by the exhaust gas exhaust port 27 of FIG.

Here, when the flow rate of the exhaust gas flowing through the scroll portion 12 is not excessive, that is, when the rotational speed of the engine of the vehicle is in a low rotation range (for example, less than 4000 rpm), the exhaust gas is mainly the first exhaust gas. When the flow rate of the exhaust gas exhausted through the flow passage Ra and flowing through the scroll portion 12 is excessive, that is, when the rotation speed of the engine of the vehicle is in a high rotation range (for example, 4000 rpm or more),
Part of the exhaust gas during the rotation of the turbine 18 is the second
Exhaust gas that is exhausted through the exhaust gas flow path Rb and does not flow through the second exhaust gas flow path Rb is
8 is rotated and then exhausted through the first exhaust gas passage Ra. In addition, even when the flow rate of the exhaust gas flowing in the scroll portion 12 is not excessive, the exhaust gas may flow through the second exhaust gas flow path Rb,
The flow rate of the exhaust gas is very small and does not cause any problem.

In other words, when the flow rate of the exhaust gas flowing through the scroll section 12 is not excessive, most of the exhaust gas is used for the force for flowing the first exhaust gas flow path Ra to rotate the turbine 18, When the flow rate of the exhaust gas flowing in the scroll portion 12 is excessive, the excess exhaust gas is bypassed to the second exhaust gas flow path Rb while rotating the turbine 18 so that the force for rotating the turbine 18 is dispersed. It has become.

In the turbine housing 11 of the present embodiment, when the exhaust gas flows from the exhaust manifold into the scroll portion 12 through the exhaust gas inlet 26, the scroll portion 12 is caused by the heat of the exhaust gas.
Are thermally expanded outward, and the exhaust gas impinges on the turbine blades 17 of the turbine 18 housed inside the turbine housing 11 to rotate (drive) the turbine 18.

In this case, when the flow rate of the exhaust gas flowing through the scroll section 12 is not excessive, the exhaust gas is exhausted through the first exhaust gas flow path Ra forming the main flow path and flows through the scroll section 12. When the flow rate of the exhaust gas is excessive, the exhaust gas passes through the first exhaust gas flow path Ra that forms the main flow path.
And a second exhaust gas flow path Rb serving as a sub flow path. Then, the first exhaust gas flow path R
The exhaust gas exhausted through the second exhaust gas passage Rb and the exhaust gas is exhausted to the elbow side via the exhaust gas exhaust port 27.

According to the above-described embodiment, the following effects can be obtained.

According to the present embodiment, the scroll section 1
When the flow rate of the exhaust gas flowing through the inside 2 is not excessive, most of the exhaust gas can be circulated to the first exhaust gas flow path Ra and used as a force for rotating the turbine 18.

According to the present embodiment, the scroll section 1
In the case where the flow rate of the exhaust gas flowing through the inside of the turbine 2 is excessive, the force for rotating the turbine 18 can be dispersed by bypassing the excess exhaust gas on the way of rotating the turbine 18 to the second exhaust gas flow path Rb. It is possible to prevent the 18 from rotating more than necessary.

According to the present embodiment, the turbine 18 can be prevented from rotating more than necessary, so that the turbine 18 is not damaged or deteriorated easily. Performance and reliability can be improved. Therefore, the function of the turbine 18 can be maintained in a stable state for a long time.

The turbine housing 11 of the present embodiment
According to the first exhaust gas passage Ra and the second exhaust gas passage R
b, the flow rate of the exhaust gas flowing through the scroll portion 12 can be adjusted and maintained in a good state without using a waste gate valve or the like as in the related art. become.

According to the present embodiment, since the turbine 18 can be prevented from rotating more than necessary, the wastegate valve and the wastegate port used in the prior art become unnecessary, and the turbine housing 11 and, consequently, the supercharger are not used. The size and weight can be reduced.

According to the present embodiment, the turbine housing 11 does not need to be provided with a wastegate valve and a wastegate port.
Design flexibility can be increased.

In the present embodiment, a gap is formed between the scroll portion 12 and the cover portion 13 and the scroll portion 12 is covered by the cover portion 13. For this reason, the gap can serve as a heat insulating layer, and the cover portion 13 can serve to maintain the temperature of the exhaust gas flowing in the scroll portion 12. Therefore, the heat of the exhaust gas flowing through the scroll portion 12 is less likely to be transmitted to the outside (it is less likely to be robbed), and the thermal energy of the exhaust gas can be effectively used.

According to the present embodiment, the activation temperature of the catalyst disposed downstream of the turbine housing 11 is reached immediately after the start of the engine of the vehicle by utilizing the thermal energy of the exhaust gas. Time can be reduced.

According to the present embodiment, a plurality of circular holes 33 are formed in the shroud portion 25 of the second scroll portion 12b provided close to the turbine blade 17, and the inside of the second scroll portion 12b and the cover portion are formed. A part of the second exhaust gas flow path Rb can be easily formed only by making the inside of the second exhaust gas passage 13 communicate with the inside.

In the present embodiment, the second scroll unit 1
A plurality of circular holes 33 are formed in the shroud portion 25 of 2b. With these circular holes 33, excess exhaust gas can be reliably introduced into the gap between the second scroll portion 12b and the cover portion 13.

In the present embodiment, the second scroll unit 1
The SUS mesh 23 was provided outside the throat portion 21 of 2b. The SUS mesh 23 can reliably adjust the flow rate of the exhaust gas flowing through the second exhaust gas flow path Rb. That is, by adjusting the density of the SUS mesh 23 in advance, the flow state of the exhaust gas flowing through the second exhaust gas passage Rb can be adjusted (SUS mesh 2).
If the density of the third exhaust gas is set to be large, it becomes difficult for the exhaust gas to flow through the second exhaust gas passage Rb.
If the density of the exhaust gas is set to be small, it becomes easier for the exhaust gas to flow through the second exhaust gas passage Rb).

In the present embodiment, the second scroll unit 1
The 2 th throat portion 21 and the inclined portion 22 are made to have a SUS mesh 23 and a ring member 24 in the axial direction of the turbine 18.
To be slidable. For this reason, even when the second scroll portion 12b thermally expands due to the heat of the exhaust gas, the throat portion 21 and the inclined portion 22 move to the flange portion 15 side to provide an escape area. Stress that may be generated can be reduced.

According to the present embodiment, interference between the turbine blade 17 and the shroud portion 25 of the second scroll portion 12b can be prevented.

According to the present embodiment, during rotation of the turbine 18, the throat portion 21 and the inclined portion 22 of the second scroll portion 12 b move toward the flange portion 15 toward the turbine 18.
Therefore, the turbine blade 17 and the shroud portion 25 of the second scroll portion 12b can be reliably prevented from interfering with each other.

According to the present embodiment, the ring member 24
Is joined to the inner surface of the throat portion 21 of the second scroll portion 12b without any gap, so that this ring member 24
Thereby, the movement of the shroud portion 25 of the second scroll portion 12b toward the turbine blade 17 can be reliably restricted.

According to the present embodiment, the flange portion 1
Since the ridge portions 31 and 32 are formed on the portions 5 and 16, the first cover portion 13 a, the second cover portion 13 b, and the second scroll 13 are not affected by heat generated during welding and adversely affect peripheral portions of the welded portion. The welding of the portion 12b can be performed in a good state.

According to the present embodiment, the flange portion 1
The projections 31 and 32 formed on the projections 5 and 16 facilitate positioning of the first cover 13a, the second cover 13b, and the second scroll 12b during welding.

In the present embodiment, the scroll portion 12 is divided into a first scroll portion 12a and a second scroll portion 12b, and the first scroll portion 12a is formed with respect to the expanded portion 19 of the second scroll portion 12b. The fitting was performed in a slidable state. For this reason, even when the scroll part 12 thermally expands due to the heat of the exhaust gas flowing in the scroll part 12, the first scroll part 12a and the second scroll part 12b can slide and disperse the stress, Concentration of stress on the scroll portion 12 can be prevented. Therefore, it is possible to prevent the durability and reliability of the turbine housing 11 from being improved.

In this embodiment, since stress concentration on the scroll portion 12 can be prevented, the function of the turbine housing 11 can be maintained in a stable state for a long period of time.

According to the present embodiment, the scroll unit 1
Since the stress can be prevented from concentrating on the scroll portion 2, it is possible to prevent the scroll portion 12 from being cracked or damaged.

In the present embodiment, the second scroll unit 1
An expanded portion 19 is formed at the end of 2b, and the end of the first scroll portion 12a is fitted to the expanded portion 19 in a slidable manner. For this reason, this expanded portion 19
Accordingly, when the first scroll portion 12a is fitted to the second scroll portion 12b, the first scroll portion 12a can be easily and securely fitted.

According to the present embodiment, the end of the first scroll portion 12a is simply curved by hydraulic bulge molding,
The tongue 20 in the form of a tongue can be easily formed on the side of the end having the smaller radius of curvature.

In the present embodiment, the tongue portion 20 is formed in a tongue shape. This tongue part 20
Accordingly, the exhaust gas can be guided in a state in which the separation boundary layer does not or hardly occur in the tongue portion 20 of the scroll portion 12, so that the flow of the exhaust gas in the scroll portion 12 can be maintained in a good state. Become.

According to the present embodiment, the scroll unit 1
Since the flow of exhaust gas in 2 can be maintained in a good state,
A decrease in turbine efficiency can be prevented.

According to the present embodiment, since the stainless steel material having excellent heat resistance and corrosion resistance is used as the material for forming the turbine housing 11, the turbine housing 11 is hardly affected by the heat of the exhaust gas and the like. Can be improved in durability and reliability.

According to the present embodiment, since the turbine housing 11 is formed of a stainless material having excellent heat resistance and the like, the temperature of the exhaust gas of the engine can be set to a high temperature range.

It is to be noted that the above embodiment can be modified and implemented as follows.

The turbine housing 1 of the above embodiment
In FIG. 1, the circular hole 33 is formed in the shroud portion 25 of the second scroll portion 12b. However, instead of the circular hole 33, the shroud portion 25 may be provided with an opening / closing structure such as a slide portion. Further, an opening / closing structure may be attached to the circular hole 33. That is, the first exhaust passage Ra and the second
Any structure may be used as long as the turbine housing 11 has the exhaust passage Rb.

In the above embodiment, the hole 33 is used as the hole.
However, for example, a square hole such as a triangle, a square, or a pentagon, an elliptical hole, or the like may be used.
However, the present invention is not limited to this. Further, the number of holes is not particularly limited to eight.

In the above embodiment, SU was used as the resistor.
Although the S mesh 23 is employed, for example, a porous body or the like may be employed, and the invention is not particularly limited to the SUS mesh 23. In short, anything may be used as long as the flow rate of the exhaust gas flowing through the second exhaust gas channel Rb can be adjusted. Further, the SUS mesh 23 as the resistor may be omitted.

In the above embodiment, the scroll section 12
Is divided into the first scroll portion 12a and the second scroll portion 12b, but they may be integrally formed. Conversely, the scroll part 12 is divided into three parts,
It may be divided and formed more than divided.

In the above embodiment, the flange portion 15,
Although the ridges 31 and 32 are formed on the ridge 16,
2 may be omitted.

In the above embodiment, a stainless steel material having excellent heat resistance and corrosion resistance is used. However, the present invention is not limited to the stainless steel material.

[0075]

According to the first aspect of the present invention, it is possible to prevent the turbine from being rotated more than necessary without using a waste gate valve or the like, so that the turbine is likely to be damaged or deteriorated. And the durability and reliability of the turbine can be improved. Further, the size and weight of the turbine housing, and eventually the turbocharger, can be reduced. In addition, since there is no need to provide a wastegate port and a wastegate valve in the turbine housing, the degree of freedom in designing the turbine housing can be increased. Further, since the thermal energy of the exhaust gas can be effectively used, it is possible to shorten the time required to reach the activation temperature of the catalyst disposed downstream of the turbine housing immediately after the start of the engine of the vehicle.

According to the invention described in claim 2, according to claim 1
In addition to the effects of the invention described in the above, a part of the second exhaust gas passage can be easily formed. In addition, the holes make it possible to reliably introduce excess exhaust gas into the gap between the scroll portion and the cover portion.

According to the third aspect of the invention, in addition to the effects of the first and second aspects of the present invention, the flow rate of the exhaust gas flowing through the second exhaust gas flow path is ensured by the resistor. Can be adjusted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a turbine housing according to an embodiment of the present invention, which is taken along line CC of FIG.
It is a line sectional view.

FIG. 2A is a cross-sectional view schematically illustrating a first exhaust gas flow path according to one embodiment, and FIG. 2B is a cross-sectional view schematically illustrating a second exhaust gas flow path according to one embodiment. is there.

FIG. 3 is an enlarged sectional view showing a portion B surrounded by a small circle in FIG. 1;

FIG. 4 is a front view showing a turbine housing according to one embodiment.

FIG. 5 is a longitudinal sectional view showing the turbine housing in one embodiment, and is a sectional view taken along line DD of FIG. 6;

FIG. 6 is a side view showing a turbine housing in one embodiment.

FIG. 7 is a rear view showing the turbine housing according to the embodiment.

FIG. 8 is a side view showing the turbine housing in one embodiment.

FIG. 9 is a front view showing a turbine housing according to the related art.

FIG. 10 is a rear view showing a turbine housing according to the related art.

11 is a cross-sectional view showing a turbine housing according to the related art, and is a cross-sectional view taken along line AA of FIG. 9;

[Explanation of symbols]

 Reference Signs List 11 turbine housing 12 scroll part 12a first scroll part 12b second scroll part 13 cover part 13a first cover part 13b second cover part 14, 15, 16 flange part 17 turbine blade 18 turbine 23 SUS mesh (resistor) 25 shroud Part 33 circular hole (hole) Ra first exhaust gas flow path Rb second exhaust gas flow path

Claims (3)

[Claims] A metal scroll portion forming a spiral exhaust gas flow path, a metal cover portion enclosing the scroll portion with a gap therebetween, and the scroll portion and the cover portion. A turbine housing having a flange portion attached thereto and accommodating a turbine having a turbine blade therein, and rotating the turbine by applying exhaust gas flowing through the scroll portion to the turbine blade. A first exhaust gas flow path that follows the flow path through which the exhaust gas that hits the turbine blades after rotating the turbine and that hits the turbine blades passes through the scroll section and hits the turbine blades. Exhaust gas causes the gap between the scroll part and the cover part to rotate during the rotation of the turbine. A turbine housing, characterized in that it comprises a and a second exhaust gas passage following the is the channel exhausted from through. 2. A second exhaust gas flow passage, wherein a hole is formed in a shroud portion of the scroll portion provided close to the turbine blade so as to communicate between the scroll portion and the cover portion. The turbine housing according to claim 1, wherein a part of the turbine housing is formed. 3. The scroll device according to claim 1, wherein a resistor for adjusting a flow rate of the exhaust gas flowing through the second exhaust gas passage is provided outside one end of the scroll portion. 3. The turbine housing according to 2.