JP2001303962A - Turbine housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbine housing capable of preventing stress concentration in a scroll part without enlarging the heat capacity of the scroll part or without blowing a traveling wind in traveling a vehicle against the scroll part. SOLUTION: This turbine housing 11 is provided with the scroll part 12 dividedly formed into a first scroll part 16 and a second scroll part 17, a cover part 13 having a first cover part 22 and a second cover part 23, and a flange part 14. The end of the first scroll part 16 is slidably fitted to a pipe enlargement part 29 of the second scroll part 17. The high-temperature exhaust gas introduced into the scroll part 12 via an exhaust gas guide port 19 expands the scroll part 12 by the heat to generate a stress, however, the stress is distributed by the slide mechanisms of the first scroll part 16 and the second scroll part 17 to prevent stress concentration on the scroll part 12.

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, the one shown in FIGS. 5 and 6 is known. FIG. 5 is a front view showing a conventional turbine housing, and FIG. 6 is a longitudinal sectional view showing a conventional turbine housing.

As shown in FIGS. 5 and 6, this turbine housing 101 is a casting having a scroll portion 102 forming a spiral exhaust gas flow path, and is integrally formed. An exhaust gas inlet 1 for introducing exhaust gas into the scroll part 102 is provided in the turbine housing 101.
03, a bypass passage 104 for bypassing and discharging excess exhaust gas in the scroll portion 102, an exhaust gas outlet 105 for discharging exhaust gas flowing in the scroll portion 102, and a turbine (not shown) for insertion. Is formed. Further, the scroll part 102 of the turbine housing 101 includes a scroll part 102.
Tongue 10 for guiding a part of the exhaust gas flowing through the inside
6 are formed to project.

In the turbine housing 101, an exhaust manifold (not shown) is connected to the exhaust gas inlet 103 side, and an elbow (not shown) is connected to the exhaust gas outlet 105 and the outlet side of the bypass flow passage 104. Has become. Further, one end of a center housing (not shown) is connected to the insertion hole 107 side, and a compressor housing (not shown) is connected to the other end of the center housing.

In the exhaust gas discharged (introduced) from the exhaust manifold through the exhaust gas inlet 103 into the scroll portion 102, excess exhaust gas is discharged to the elbow side via the bypass flow passage 104. Exhaust gas that has been adjusted and not adjusted for emission (circulated in the scroll portion 102) is set to drive a turbine (not shown) and to be exhausted to the elbow side via the exhaust gas outlet 105 at the same time. Here, scroll unit 1
Exhaust gas flowing through the inside of the scroll part 02 is guided by the inner surface of the scroll part 102 and the tongue part 106.

[0006]

However, in the above-described conventional turbine housing 101, the scroll portion 102 thermally expands due to the high temperature (for example, 900 ° C.) exhaust gas flowing through the scroll portion 102. There is a possibility that stress concentrates on a part of the scroll part 102. For this reason, the durability and reliability of the turbine housing 101 are significantly reduced.

Therefore, in order to prevent the concentration of stress in the scroll portion, the heat capacity of the scroll portion is increased to reduce the temperature rise of the scroll portion, or the temperature of the scroll portion is increased by applying the traveling wind during vehicle running to the scroll portion. However, the weight of the turbine housing (scroll portion) increases, the temperature of exhaust gas flowing through the scroll portion decreases, and the catalyst generally disposed on the downstream side of the turbine housing may be used. There is a problem that activation becomes difficult or the like.

Further, since the turbine housing 101 is an integrally formed casting, in consideration of the strength of the tongue portion 106 of the scroll portion 102, the thickness of the tongue portion 106 must be relatively thick. Moreover, it is difficult to form the tongue portion 106 in a tongue shape. Therefore, the tongue portion 10 of the scroll portion 102
In No. 6, a peeling boundary layer was easily generated, which had a bad influence on the flow of exhaust gas flowing in the scroll portion 102.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and its main purpose is to increase the heat capacity of the scroll portion and to prevent the scroll portion from being exposed to the traveling wind during vehicle running. Another object of the present invention is to provide a turbine housing capable of preventing stress concentration in a scroll portion.

It is another object of the present invention to provide a turbine housing capable of suppressing generation of a separation boundary layer in a tongue portion of a scroll portion and maintaining good flow of exhaust gas in the scroll portion. is there.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, a scroll portion forming a spiral exhaust gas flow path is divided into a plurality of scroll portions,
The gist is that the scroll portion is formed to be slidable.

According to the first aspect of the invention, when the exhaust gas flows through the scroll portion forming the spiral exhaust gas flow path, the scroll portion thermally expands due to the heat of the exhaust gas. In this case, since the scroll portion of the turbine housing is formed so as to be divided into a plurality of portions and is slidable, the stress is dispersed by sliding even when thermally expanded, and the stress is not concentrated on the scroll portion. Disappears. Therefore, a remarkable decrease in durability and reliability of the turbine housing is prevented.

According to a second aspect of the present invention, in the turbine housing according to the first aspect, the scroll portion is formed of a first pipe and a second pipe, and the first pipe and the second pipe are connected to each other. Are fitted so as to be slidable.

According to the second aspect of the invention, in addition to the operation of the first aspect, the scroll portion is formed of the first tube and the second tube, and the scroll portion is formed of the first tube. And the second pipe are slidably fitted to each other. Therefore, even when stress occurs in the scroll portion, the first tube and the second tube slide to disperse the stress, so that stress concentration on the scroll portion is prevented.

According to a third aspect of the present invention, in the turbine housing according to the second aspect, by bending one end of the first tube and the second tube, a radius of curvature at the end is obtained. The gist is that the tongue portion is formed to have a tongue shape on the smaller side of the tongue.

According to the third aspect of the present invention, in addition to the function of the second aspect of the present invention, only by bending one end of the first pipe and the second pipe, the end is formed. A tongue-shaped tongue portion is easily formed on the side of the portion where the radius of curvature is small. Also, due to the tongue formed in the shape of a tongue,
Since the exhaust gas is guided in a state in which the separation boundary layer does not or hardly occurs in the tongue portion, the flow of the exhaust gas in the scroll portion is maintained in a good state.

Furthermore, since the tongue portion is formed by one end of the first tube and the second tube, the thickness of the tongue portion is relatively thick like the tongue portion made of a casting in the prior art. Even if it is not formed, the strength of the tongue portion is ensured, and the thickness of the tongue portion can be reduced.

According to a fourth aspect of the present invention, a tubular body having a tongue-shaped tongue is provided on an inner surface of a scroll part forming a spiral exhaust gas flow path, and an end of the tubular body is provided. Is formed so as to be slidable.

According to the fourth aspect of the present invention, when the exhaust gas flows through the tubular body provided on the inner surface of the scroll portion forming the spiral exhaust gas flow path, the exhaust gas is caused by the heat of the exhaust gas. Then, the tubular body thermally expands. In this case, since the end of the tubular body is formed so as to be slidable, the stress is dispersed by sliding even when thermally expanded, and the stress is not concentrated on the tubular body.

Further, since a part of the scroll portion is protected by the tubular body, stress generated in the scroll portion is reduced. That is, even when the exhaust gas flows through the scroll portion and a stress is generated in the scroll portion, the stress is transmitted to the tubular body and relieved, so that stress concentration on the scroll portion is prevented. As a result, a remarkable decrease in the durability and reliability of the turbine housing is prevented.

Further, the exhaust gas is guided by the tongue-shaped tongue portion of the tubular body in a state in which a separation boundary layer is not generated or hardly generated in the tongue portion, so that the exhaust gas flows in the tubular body and the scroll portion. Is maintained in a good state.

In addition, since the tongue portion is formed by the tubular body, the strength of the tongue portion can be reduced even if the tongue portion is not formed to have a relatively large thickness unlike the tongue portion made by casting in the prior art. Is secured, and the thickness of the tongue portion is reduced.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front view showing a turbine housing according to the present embodiment, and FIG. 2 is a longitudinal sectional view showing the turbine housing according to the present embodiment. FIG. 3 is a cross-sectional view showing a bypass flow channel according to the present embodiment, and is a cross-sectional view taken along line AA of FIG.

As shown in FIGS. 1 and 2, a turbine housing 11 of the turbocharger driven by an exhaust turbine is provided with a scroll portion 12 made of stainless steel having excellent heat resistance and corrosion resistance. And a cover portion 13 formed in the same manner. In the present embodiment, the turbine housing 11 has a double pipe structure of the scroll part 12 and the cover part 13, and the scroll part 12 is covered by the cover part 13 with a gap. .

Further, the turbine housing 11 of the present embodiment has a flange portion 14 shown in FIGS. 1 and 2 and a flange portion 15 shown in FIG. The cover 13 is joined by welding. The flange portions 14 and 15 are castings formed of cast steel having excellent heat resistance and corrosion resistance.

As shown in FIG. 2, the scroll unit 12
It has a first scroll part 16 as a first pipe and a second scroll part 17 as a second pipe, and is formed in a spiral shape. The first scroll portion 16 is joined to the flange portion 14 by welding. The first scroll portion 16 and the second scroll portion 17 are each formed in a predetermined shape by hydraulic bulge forming.

As shown in FIG. 3, the first scroll portion 16 is joined by welding to a substantially cylindrical opening 18 vertically protruding from the first scroll portion 16. Further, as shown in FIG. 2, the first scroll portion 16 has an exhaust gas inlet 19 for introducing exhaust gas,
A bypass passage 20 for discharging and adjusting excess exhaust gas is formed, and a discharge port 21 for discharging exhaust gas is formed in the second scroll portion 17. As shown in FIG. 1, an insertion hole 31 for inserting a turbine (not shown) is formed in the center of the turbine housing 11.

As shown in FIGS. 1 and 2, an exhaust manifold (not shown) is connected to the flange portion 14 on the exhaust gas inlet 19 side in the turbine housing 11 of the present embodiment. Further, one end of a center housing (not shown) is connected to the insertion hole 31 side, and a compressor housing (not shown) is connected to the other end of the center housing. Further, an elbow (not shown) is connected to the flange portion 15 of the turbine housing 11 shown in FIG.

In the exhaust gas discharged (introduced) from the exhaust manifold into the scroll portion 12 through the exhaust gas inlet 19, excess exhaust gas is discharged to the elbow side through the bypass passage 20. Adjusted,
Exhaust gas that has not been adjusted for emission (circulated in the scroll portion 12) is set to drive a turbine (not shown) and to be exhausted to the elbow side via the exhaust gas outlet 21 at the same time.

As shown in FIG. 1 to FIG.
Are formed separately and include a first cover portion 22 and a second cover portion 23. The first cover portion 22 is joined to the flange portions 14 and 15 by welding, and the second cover portion 23 is joined to the first cover portion 22 by welding. In this case, a part of the second cover portion 23, that is, the seal portion 24 is welded from the outside of the first cover portion 22 in a superimposed state, and the sealability of the cover portion 13 is maintained by the seal portion 24. It has become.

As shown in FIG. 3, the flange 15 has
A waste gate port 25 is formed. The waste gate port 25 is opened by a waste gate valve (not shown) when the flow rate of the exhaust gas in the scroll portion 12 is excessive. Conversely, when the flow rate of the exhaust gas is not excessive, the waste gate valve 25 is opened. It is to be closed by.
By controlling the waste gate valve, the flow rate of the exhaust gas flowing through the scroll portion 12 is set to be maintained in a good state.

The peripheral wall 26 and the holding portion 2 projecting from the peripheral wall 26 are provided on the opening 18 side of the flange 15.
7 are formed, and the peripheral wall portion 26 and the holding portion 2
7, an annular SUS mesh 28 is accommodated.
The SUS mesh 28 is made of a material having excellent heat resistance and corrosion resistance and has flexibility, and is fixed to the peripheral wall 26 by spot welding.

In this embodiment, the first scroll section 16
Is communicated with the waste gate port 25 of the flange portion 15, thereby forming an exhaust gas bypass flow path 20. As described above, the bypass flow path 20 is a flow path for bypassing a part of the exhaust gas flowing in the scroll portion 12 and exhausting the waste gas from the waste gate port 25 to the elbow side.

In the first scroll portion 16 of the present embodiment, an opening 18 thereof is slidably supported. That is, the opening 1 of the first scroll portion 16
8 is supported in contact with the SUS mesh 28 accommodated in the peripheral wall portion 26 and the holding portion 27, and the opening 1
A gap is formed between 8 and the holding portion 27. With this structure, the opening 18 can be slid vertically and horizontally in FIG.

In the present embodiment, the following structure is employed to prevent stress concentration on the scroll portion 12. That is, as shown in FIG.
Is divided into a first scroll portion 16 and a second scroll portion 17, and the first scroll portion 16 is fitted to the second scroll portion 17. More specifically, at the end of the second scroll portion 16, an expanded tube portion 29 having a slightly enlarged diameter is formed.
The end of the scroll part 16 is fitted. The first scroll portion 16 and the second scroll portion 17 are set to be slidable by this fitting state.

In this embodiment, the scroll unit 1
The following structure is adopted in order to keep the flow of the exhaust gas inside 2 in a good state. That is, as shown in FIG. 2, a tongue portion 30 that guides a part of the exhaust gas is provided on the side of the end portion of the first scroll portion 16 where the radius of curvature is small.
Are formed. The tongue portion 30 is formed in a tongue-like shape, and is formed by bending the end of the first scroll portion 16 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 30. The exhaust gas flowing through the scroll section 12 is generated by the scroll section 1.
The inner surface 2 and the tongue portion 30 are guided in a good state.

According to the present embodiment described in detail above, the following effects can be obtained.

In the present embodiment, the scroll portion 12 is divided into the first scroll portion 16 and the second scroll portion 17, and the first scroll portion 16 is formed with respect to the expanded portion 29 of the second scroll portion 17. 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 16 and the second scroll part 17 can slide and disperse the stress. Concentration of stress on the scroll portion 12 can be prevented. Therefore, it is possible to prevent a remarkable decrease in durability and reliability of the turbine housing 11.

In the present embodiment, the concentration of stress in the scroll portion 12 is prevented without increasing the heat capacity of the scroll portion as in the related art or applying the traveling wind during vehicle running to the scroll portion. be able to.

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
7, an expanded portion 29 is formed at the end portion, and the end portion of the first scroll portion 16 is fitted to the expanded portion 29 in a slidable manner. For this reason, the first scroll part 1 with respect to the second scroll part 17 is
6 can be easily and reliably fitted.

According to the present embodiment, by simply bending the end of the first scroll portion 16 by hydraulic bulge forming, the tongue portion 30 having a tongue-like shape is formed on the side of the end having the smaller radius of curvature. It can be easily formed.

In the present embodiment, the tongue portion 30 is formed in a tongue shape. This tongue part 30
Thereby, since the exhaust gas can be guided in a state in which the separation boundary layer does not or hardly occur in the tongue portion 30 of the scroll portion 12, the flow of the exhaust gas in the scroll portion 12 can be maintained in a good state. Become.

According to the present embodiment, since the tongue portion 30 is formed by the end of the first scroll portion 16, the thickness of the tongue portion 30 is thinner than that of the prior art casting. Can be

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.

The turbine housing 11 of the present embodiment
As compared with the prior art integrally formed casting, the thickness of the turbine housing 11 is reduced due to its thin wall thickness, gaps, and the like, so that the weight of the turbine housing 11 can be reduced.

According to the present embodiment, since the opening 18 of the first scroll portion 16 is slidably supported, even if the opening 18 thermally expands due to the heat of the exhaust gas. In addition, the stress can be dispersed by sliding the opening 18, and concentration of the stress on the opening 18 can be prevented.

According to the present embodiment, since stress can be prevented from being concentrated on the opening 18, cracks, breakage, and the like are prevented from occurring on the opening 18 and the flange 15 of the first scroll portion 16. it can.

In this embodiment, the first scroll unit 1
A gap is formed between the opening 18 of FIG. 6 and the holding portion 27 of the flange 15. This gap can prevent the opening 18 from interfering with the holding portion 27 even when the opening 18 of the first scroll portion 16 is thermally expanded.

According to the present embodiment, the flange portion 15
Since the flexible SUS mesh 28 is interposed between the peripheral wall portion 26 and the opening 18 of the first scroll portion 16, stress is generated in the opening 18 due to heat of the exhaust gas. Even in such a case, the stress can be transmitted to the SUS mesh 28 and relieved, and the SUS mesh 28 can also prevent the stress concentration on the opening 18.

In this embodiment, a gap is formed between the scroll portion 12 and the cover portion 13 and the scroll portion 12 is covered with 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 in 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, by using the thermal energy of the exhaust gas, for example, immediately after the start of the engine of the vehicle, the activation temperature of the catalyst generally disposed downstream of the turbine housing 11 Can be reduced.

According to the present embodiment, the scroll portion 12, the cover portion 13, the flange portions 14, 15 and the SUS mesh 28 of the turbine housing 11 are formed of a material having excellent heat resistance and corrosion resistance. It is hardly affected by the heat of the exhaust gas, and the durability and reliability of the turbine housing 11 can be improved.

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

According to the present embodiment, the loss of the heat energy of the exhaust gas can be minimized.

In the present embodiment, the first cover portion 22 is welded in a state where the first cover portion 22 is overlapped by the seal portion 24 of the second cover portion 23 from the outside. With this seal portion 24,
Since the sealing property of the cover portion 13 is maintained, even if the exhaust gas leaks from the scroll portion 12 into the cover portion 13, even if the turbine housing 11 (especially the cover portion 1)
3) It is possible to prevent the exhaust gas from leaking. In addition,
Even if the exhaust gas leaks from the scroll portion 12 into the cover portion 13, the amount of the leak is small and does not cause any trouble.

According to the present embodiment, the scroll section 1
The stress generated in the scroll portion 12 can be reduced by the slide mechanism of the bypass flow path 20 as well as the slide mechanism of the slide mechanism 2 itself.

The above embodiment can be modified as follows.

The turbine housing 41 shown in FIG. 4 may be used. In the configuration and the like of the turbine housing 41, the same parts as those of the turbine housing 101 in the above-described prior art are denoted by the same reference numerals, and description thereof will be omitted. The turbine housing 41 is obtained by adding a tubular body 42 made of stainless steel to a scroll part 102 made of casting. However, the portion of the scroll portion 102 provided with the tubular body 42 shown in FIG. 4 is formed to be slightly thinner than the thickness of the scroll portion 102 shown in FIG. Accordingly, the weight of the turbine housing 41 of the embodiment shown in FIG. 4 is not larger than that of the turbine housing 101 of the embodiment shown in FIGS. 5 and 6.

As shown in FIG. 4, the turbine housing 41 has a tubular body 42 provided with a tongue-shaped tongue 43 on the inner surface of the scroll portion 102 of the turbine housing 101 shown in FIG. It is. This tubular body 4
2 is formed by hydraulic bulge forming, and the exhaust gas inlet 103 side is joined by welding, and the end of the tongue 43 side is not joined by welding so as to be slidable with the free end. Has become.

According to the turbine housing 41, when the exhaust gas flows through the tubular member 42 provided on the inner surface of the scroll portion 102 forming the spiral exhaust gas flow path, heat is generated by the heat of the exhaust gas. As a result, the tubular body 42 thermally expands. In this case, the end of the tubular body 42 on the tongue 43 side is
Since it is a free end, even when thermally expanded, it can slide to disperse the stress. Therefore, the concentration of stress on the tubular body 42 can be prevented.

Further, since a part of the scroll portion 102 is protected by the tubular member 42, the stress generated in the scroll portion 102 can be reduced. That is, the exhaust gas flows through the scroll portion 102 and the scroll portion 102
Is generated, the stress can be transmitted to the tubular body 42 and relieved, so that stress concentration on the scroll portion 102 can be prevented. As a result, a remarkable decrease in durability and reliability of the turbine housing 41 can be prevented.

Furthermore, since the tongue 43 of the tubular body 42 has a tongue-like shape, the exhaust gas can be guided in a state in which a separation boundary layer does not or hardly occur in the tongue 43. Of the exhaust gas can be maintained in a good state. According to the turbine housing 41, an effect similar to the effect of the above-described embodiment can be obtained.

In addition, in the turbine housing 41 shown in FIG. 4, since a part of the exhaust gas can be guided by the tongue portion 43, the scroll portion 102 (including the tongue portion 106) in contact with the tubular body 42 on the tongue portion 43 side is included. ) May be formed to be thinner. In this way, the weight of the turbine housing 41 can be reduced.

In the above embodiment, the scroll section 12
Is divided into the first scroll portion 16 and the second scroll portion 17, but the scroll portion 12 is
It may be divided into four parts or four parts, and the invention is not particularly limited to the two parts in the above embodiment. In short, it is only necessary that the scroll part 12 is formed so as to be slidable.

In the above-described embodiment, the first scroll portion 16 is fitted to the second scroll portion 17, but the second scroll portion is fitted to the first scroll portion. The configuration may be any.

In the above-described embodiment, the expanded portion 29 is formed at the end of the second scroll portion 17, but the expanded portion 29 may be omitted.

In the above-described embodiment, the first scroll portion 16 is provided with respect to the expanded portion 29 at the end of the second scroll portion 17.
Although the fitting structure for fitting the end portions is adopted, the fitting structure is not particularly limited to the above-described embodiment.
In short, any fitting structure may be used as long as the scroll portion 12 can be slid.

In the above-described embodiment, the tongue portion 30 is formed by curving the end of the first scroll portion 16. However, the tongue portion having a tongue shape by curving the end of the second scroll portion 17 is provided. It is good also as composition which forms.

In the above embodiment, the first scroll portion 16 and the opening 18 are formed separately, but the first scroll portion 16 and the opening 18 may be formed integrally.

In the above embodiment, a material having excellent heat resistance and corrosion resistance is used. However, the material is not particularly limited to stainless steel, cast steel, and the like, which are materials having excellent heat resistance and corrosion resistance.

Further, technical ideas that are not described in each claim of the claims but are understood from the above-described embodiments and the like are described below together with their effects.

(A) The turbine housing according to any one of claims 1 to 4, further comprising an outer tube enclosing the scroll portion with a gap therebetween. housing.

According to this structure, the thermal energy of the exhaust gas can be effectively used in addition to the effects of the inventions described in the first to fourth aspects.

(B) The turbine housing according to any one of (1) to (4) and (a), wherein the scroll portion is formed of a heat-resistant material. .

With this configuration, in addition to the effects of the inventions described in claims 1 to 4 and (a), the durability and reliability of the turbine housing can be improved.

[0078]

According to the first aspect of the present invention, the concentration of stress in the scroll portion is prevented without increasing the heat capacity of the scroll portion or applying the traveling wind during vehicle running to the scroll portion. be able to. Therefore, it is possible to prevent the durability and reliability of the turbine housing from being significantly reduced.

According to the second aspect of the present invention, since the first pipe and the second pipe can slide to disperse the stress, the effect of the first aspect of the invention can be obtained.

According to the invention described in claim 3, according to claim 2
In addition to the effects of the invention described in (1), a tongue shaped like a tongue can be easily formed. Further, the generation of the separation boundary layer in the tongue portion can be suppressed, and the flow of the exhaust gas in the scroll portion can be maintained in a good state. Further, the thickness of the tongue portion can be reduced.

According to the fourth aspect of the present invention, it is possible to prevent the concentration of stress in the scroll portion without increasing the heat capacity of the scroll portion or exposing the scroll portion to running wind during vehicle travel. it can. As a result, it is possible to prevent the durability and reliability of the turbine housing from being significantly reduced. Further, the generation of the separation boundary layer in the tongue portion can be suppressed, and the flow of the exhaust gas in the scroll portion can be maintained in a good state. Further, the thickness of the tongue portion can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing a turbine housing according to the present embodiment.

FIG. 2 is a longitudinal sectional view showing the turbine housing according to the embodiment.

FIG. 3 is a sectional view showing a bypass flow path,
-A line sectional drawing.

FIG. 4 is a longitudinal sectional view showing a turbine housing according to another embodiment.

FIG. 5 is a front view showing a turbine housing according to the related art.

FIG. 6 is a longitudinal sectional view showing a turbine housing according to the related art.

[Explanation of symbols]

 Reference Signs List 11 turbine housing 12 scroll part 16 first scroll part 17 second scroll part 29 expanded part 30 tongue part 41 turbine housing 42 tongue part 43 tubular body 102 scroll part

Claims (4)

[Claims] 1. A turbine housing wherein a scroll portion forming a spiral exhaust gas flow path is divided into a plurality of portions, and the scroll portion is formed so as to be slidable. 2. The method according to claim 1, wherein the scroll portion is formed of a first tube and a second tube, and the first tube and the second tube are fitted in a slidable state. The turbine housing according to claim 1. 3. A tongue is formed on one side of the first tube and the second tube having a small radius of curvature by bending one end of the first tube and the second tube. The turbine housing according to claim 2, wherein: 4. A tubular body having a tongue-shaped tongue is provided on an inner surface of a scroll part forming a spiral exhaust gas flow path, and an end of the tubular body is slidable. A turbine housing characterized by being formed.