JP5225736B2 - Turbine housing - Google Patents

Description

  The present invention relates to a housing (commonly referred to as a turbine housing) for an exhaust turbine wheel, which is one of the main components of a turbocharger.

  Generally, the turbine housing is made of a casting, but the casting housing has a drawback that it is heavy and has a large heat capacity. Therefore, in recent years, in order to reduce the thickness of the turbine housing (and thus reduce the weight and heat capacity), there is a non-casting turbine housing in which all or part of the scroll portion is formed by sheet metal processing or hydroforming of a metal plate material. It has been proposed (see, for example, Patent Document 1). 1 and 2 show one conventional example of such a non-cast turbine housing.

  The turbine housing shown in FIGS. 1 and 2 includes a scroll portion 10 including a scroll main body portion 11 and a gas introduction portion 12, and an inlet flange 13, an outlet flange 14, and a center housing side flange (not shown) with respect to the scroll portion 10. It is constituted by fixing. The scroll main body 11 defines a substantially annular gas flow path in which a winding start position and a winding end position are connected. The gas introduction part 12 is a conduit for guiding the exhaust gas taken in from the gas inlet 13 a corresponding to the inlet flange 13 to the winding start position of the scroll main body part 11.

  In particular, as shown in FIG. 2, the gas introduction part 12 joins the first half part 21 and the second half part 22, and the overlapping joint parts 23 on both the left and right sides when joining both half parts. (See FIG. 2 (a)). Further, a current plate 24 separate from the first and second half parts 21 and 22 is attached to the inner wall portion of the gas introduction portion 12. This rectifying plate 24 arranges the gas flow at the junction of the exhaust gas introduced from the gas inlet 13a and the exhaust gas that has recirculated through the scroll main body 11, and newly introduced exhaust gas and recirculated exhaust gas. It is provided to avoid an increase in exhaust resistance due to interference.

The rectifying plate 24 is a member that is particularly necessary with the non-casting of the turbine housing, and corresponds to a tongue portion that is integrally cast so as to be located at an extension of the inner wall of the scroll portion in the cast turbine housing. To do. The guide member (9) shown in FIG. 3 of Patent Document 1 corresponds to the current plate 24 in the non-cast turbine housing.
JP 2007-224827 (see FIG. 3 etc.)

  However, if the rectifying plate 24 is separate, as in the turbine housing shown in FIGS. 1 and 2, there is a risk that the cost increases due to an increase in the number of parts and an increase in the number of welding processes. Moreover, the welding position (position of the weld bead) of the first and second halved parts 21 and 22 and the welding position (position of the weld bead) when the rectifying plate 24 is welded into the gas introduction part 12 are close to each other. In such a case, since the welding strength may be reduced by unnecessary heat input, it is desired to further improve the durability reliability of the turbine housing.

  An object of the present invention is to provide a turbine housing capable of reducing the number of parts, reducing the number of welding steps, and improving the durability reliability as compared with the prior art. Another object of the present invention is to provide a turbine housing that hardly causes exhaust interference between exhaust gas newly introduced into a scroll portion and recirculated exhaust gas.

According to the first aspect of the present invention, the scroll main body section that defines the substantially annular gas flow path in which the winding start position and the winding end position are connected, and the exhaust gas taken in from the gas inlet is provided at the winding start position of the scroll main body section. A turbine housing with a gas inlet for guiding,
At least the gas introduction part is formed by joining the first divided part and the second divided part that can be joined to each other, and both the divided parts are butt joined at one end position in the cross section of the gas introduction part. And at the opposite end position in the cross section of the gas introduction part is formed by overlapping and joining the two divided parts,
Either one of the first and second divided parts, the exhaust gas introduced from the gas inlet to the winding start position of the scroll body at the opposite end position where the two divided parts are overlapped and joined , A rectifying part for rectifying the exhaust gas flow is integrally formed at the junction with the recirculated exhaust gas from the winding end position toward the winding start position through the scroll body part,
The rectifying part integrally formed at the opposite end position of either one of the first and second divided parts is beyond the joining boundary when these divided parts are mutually joined. It is characterized in that it has entered inside the other.

  According to this configuration, in one of the first and second divided parts forming the gas introduction portion, the exhaust gas flow is rectified at the junction of the exhaust gas newly introduced from the gas inlet and the recirculated exhaust gas. Are integrally formed. For this reason, compared with the conventional example in which the current plate is separated, it is possible to reduce the number of parts and the number of welding processes, and avoid the deterioration of the durability due to the approach of the weld bead. Can be improved.

The invention according to claim 2 is the turbine housing according to claim 1, wherein a part of the rectifying portion that has entered the inside of the other divided part is fixed by welding to the inner wall of the other divided part. It is characterized by that.

According to a third aspect of the present invention, in the turbine housing according to the first or second aspect, the first and second divided parts are each formed by sheet metal processing of a metal plate material, and are welded to the mutual joints of these divided parts. To form a main body part of the gas introduction part.
As described above, when the main body portion of the gas introduction portion is integrated by welding the joint portions of the two divided parts made of sheet metal processing (that is, when it is a non-cast product), the present invention The usefulness and necessity of is particularly recognized.

In the turbine housing, when the flow passage cross-sectional area at the winding end position of the scroll body portion when the rectifying portion does not exist in the turbine housing is Ae, 28 to 38% of the Ae is caused by the rectifying portion. As a result, it is preferable that the rectifying unit is provided so that the flow path cross-sectional area at the winding end position of the scroll main body unit is 62 to 72% of the Ae .

  Thus, the flow passage cross-sectional area at the winding end position of the scroll main body portion is 62 to 72% of Ae (the flow passage cross-sectional area at the winding end position of the scroll main body portion when the rectifying portion is not present in the turbine housing). By providing a rectifying unit to reduce the exhaust interference at the junction of the newly introduced exhaust gas and the recirculated exhaust gas regardless of the shape of the rectifying plate, the supercharging performance due to the exhaust interference Can be prevented. Incidentally, if the flow passage cross-sectional area at the winding end position of the scroll body is less than 62% of Ae, the flow resistance of the recirculated exhaust gas becomes excessive, and the supercharging performance may be lowered. On the other hand, when the cross-sectional area of the flow path at the end of winding exceeds 72% of Ae, it becomes close to the case where there is no rectification part, and the exhaust interference between the newly introduced gas and the reflux gas becomes noticeable and the supercharging performance decreases. There is a risk.

  According to the turbine housing of the present invention, the number of parts, the number of welding steps, and the durability reliability can be improved as compared with the conventional case. Further, it is possible to make it difficult for exhaust interference between the exhaust gas newly introduced into the scroll portion and the recirculated exhaust gas to occur.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 3 and 4, the turbine housing includes a scroll portion 10, and an inlet flange 13, an outlet flange 14, and a center housing side flange (not shown) are fixed to the scroll portion 10. The scroll unit 10 includes a scroll main body 11 and a gas introduction unit 12 (also referred to as a “running unit”) connected thereto.

  Inside the scroll body 11, a substantially annular tunnel-shaped gas flow path 11a in which a winding start position and a winding end position are connected is defined. Such a scroll main body 11 is a sheet metal processed product obtained by welding a half-part (two) obtained by press-molding a metal plate material such as a stainless steel plate, for example, by overlapping joining or butt joining, Alternatively, it is provided as a hydroformed product obtained by hydroforming a hollow metal material.

  A substantially ring-shaped outlet flange 14 is provided on the front side of the center of the scroll body 11. The outlet flange 14 is a joint portion for connecting an external pipe (for example, elbow, not shown) downstream of the turbine housing to the turbine housing, and the exhaust gas circulated in the scroll main body 11 is outside the turbine housing. A gas outlet 14a is provided for escaping. On the other hand, a center housing side flange (not shown) is provided on the back side (not shown) of the central part of the scroll body 11. The center housing side flange serves as a joint portion when the turbine housing is connected and fixed to the center housing (also referred to as a bearing housing) of the turbocharger.

  An inlet flange 13 is provided at the distal end of the gas introduction part 12 occupying one side of the scroll part 10. The inlet flange 13 is a joint portion when an external pipe (not shown) on the upstream side of the turbine housing is connected to the turbine housing, and provides an inlet (gas inlet 13a) for exhaust gas to be introduced into the turbine housing. To do. The gas introduction part 12 serves as a conduit that guides the exhaust gas taken in from the gas inlet 13 a to the winding start position of the scroll body 11.

  As shown in FIG. 4A, the gas introduction part 12 has a cylindrical shape with a substantially circular cross section, and a diameter line (indicated by a two-dot chain line in the drawing) that substantially horizontally crosses the substantially circular cross section. It is formed of two halved parts (that is, a first divided part 31 and a second divided part 32) which are divided into two vertically along the joining boundary 15). The first and second divided parts 31 and 32 are formed as separate parts by sheet metal processing (for example, press processing) of a metal plate material (for example, stainless steel plate). In the present embodiment, a curved plate-shaped rectifying part 33 is integrally formed with the divided part main body part in the second divided part 32 constituting the lower half of the gas introducing part 12 in FIG. This rectification unit 33 arranges the gas flow at the junction of the exhaust gas introduced from the gas inlet 13a and the exhaust gas that has recirculated through the scroll body 11, and newly introduced exhaust gas and recirculated exhaust gas The increase in exhaust resistance due to the interference is avoided.

  In the present embodiment, the first divided part 31 and the second divided part 32 are joined to each other, and the divided parts 31 and 32 are integrated by welding the joint part. That is, in FIG. 4A, both divided parts 31 and 32 are butt-joined at the right end position of the gas introduction part 12, and welding W1 is applied to the butt-joint part. Further, the split parts 31 and 32 are overlapped and joined at the left end position of the gas introducing portion 12, and welding W2 is applied to the overlapped joint portion.

  In the present embodiment, the rectifying unit 33 formed integrally with the second divided part 32 enters the inside of the first divided part 31 beyond the joint boundary 15 between both divided parts (see FIG. 4A). ). Applying welding W3 to the front end portion of the rectifying portion 33 that has entered the inside of the first divided part 31 or the vicinity thereof, and fixing the front end portion or the vicinity thereof to the inner wall surface of the first divided part 31 by welding. Is preferred. By performing welding W3, the support of the rectification | straightening part 33 in a scroll part becomes reliable, and the durable reliability of a turbine housing further improves.

  The turbine housing of this embodiment has a flow path cross-sectional area as shown in the graph of FIG. That is, the flow path cross-sectional area of the gas introduction part 12 is narrowed down from the gas inlet 13a (cross-sectional area S1) toward the winding start position (cross-sectional area S2) of the scroll main body part 11. On the other hand, the flow passage cross-sectional area of the scroll body 11 has a tendency to gradually decrease from the winding start position to the winding end position, although it does not change as steeply as in the gas introduction section. In particular, when the flow passage cross-sectional area at the winding end position of the scroll main body 11 when the rectifying portion 33 does not exist in the turbine housing is Ae (in the case of the thick broken line in FIG. 5), in this embodiment, rectification is performed. About 1/3 (that is, about 33%) of the Ae is closed by the portion 33, and as a result, the flow passage cross-sectional area at the end of winding of the scroll body 11 is about 2/3 (that is, about 67%) of the Ae. ) Is set.

  According to the present embodiment, the exhaust gas newly introduced from the gas inlet 13a and the recirculated exhaust gas are supplied to one of the first and second divided parts 31 and 32 (that is, the second divided part 32) forming the gas introduction part 12. A rectifying unit 33 for rectifying the exhaust gas flow is integrally formed at the junction with the gas. For this reason, compared with the conventional turbine housing (FIGS. 1 and 2) in which the current plate 24 is separated, the number of parts and the number of welding processes can be reduced. Further, the welding W1 and W2 for joining the first and second divided parts 31 and 32 need only be welded at positions along the joining boundary 15, and welding of the current plate 24 as in the conventional example is unnecessary. As compared with the conventional example, it is possible to avoid a decrease in durability due to the approach of the weld bead.

  In the present embodiment, the flow passage cross-sectional area at the winding end position of the scroll main body portion 11 is provided with the rectifying portion 33, so that the scroll main body portion 11 at the winding end position when the rectifying portion 33 does not exist in the turbine housing is provided. It is set to be about 2/3 of the channel cross-sectional area Ae. By arranging the flow straightening portion 33 and setting the flow path cross-sectional area at the end of winding, it is possible to effectively prevent a decrease in supercharging performance due to exhaust interference, which is often found in non-cast turbine housings. In particular, exhaust interference when the engine rotates in a state close to the maximum output and the exhaust gas has a high flow rate can be avoided very effectively.

  In addition, as a result of accumulating many trial experiments until the completion of the present invention, the rectifying action of the rectifying unit 33 in the non-cast turbine housing is caused by the difference in the shape of the rectifying unit 33 (specifically, the rectifying unit 33). Is much larger than the size of the flow straightening section 33 so that the cross-sectional area of the flow path at the end of the winding can be made larger than the difference between the straight plate shape and the smooth curved plate shape). Turned out to be affected. Based on such technical knowledge, the rectifying unit 33 of the present embodiment is closed by about 1/3 of the Ae by the rectifying unit 33, and as a result, the cross-sectional area of the flow path at the winding end position of the scroll body 11. Is set to be about 2/3 of the Ae. Such a dimension setting seems to be the best dimension setting of the rectifying unit 33, but it goes without saying that a slight dimension width is allowed around this dimension.

[Modification] In the above-described embodiment of FIGS. 3 to 5, the rectifying unit 33 is integrally formed on the second divided part 32 side. However, the rectifying unit 33 may be integrally formed on the first divided part 31 side. .

(Delete)

The front view of the conventional turbine housing. 1 shows the vicinity of a gas introduction part of the turbine housing of FIG. 1, (a) is a cross-sectional view (cross-sectional view) taken along line AA in (b), and (b) is a cross-sectional view taken along line BB in (a). Figure (plan view). 1 is a front view of a turbine housing according to an embodiment of the present invention. FIG. 3 shows the vicinity of a gas introduction part of the turbine housing of FIG. 3, (a) is a cross-sectional view (cross-sectional view) taken along line AA in (b), and (b) is a cross-sectional view taken along line BB in (a). Figure (plan view). The graph which shows the change condition of the flow-path cross-sectional area in the turbine housing of FIG.

DESCRIPTION OF SYMBOLS 10 ... Scroll part, 11 ... Scroll main-body part, 11a ... Substantially annular tunnel-shaped gas flow path, 12 ... Gas introduction part, 13a ... Gas inlet, 14a ... Gas outlet, 15 ... Joining boundary, 31 ... 1st division | segmentation part , 32 ... second divided parts, 33 ... rectifying unit.

Claims (3)

A scroll main body section that defines a substantially annular gas flow path in which a winding start position and a winding end position are connected, and a gas introduction section that guides exhaust gas taken from the gas inlet to the winding start position of the scroll main body section. A turbine housing comprising:
At least the gas introduction part is formed by joining the first divided part and the second divided part that can be joined to each other, and both the divided parts are butt joined at one end position in the cross section of the gas introduction part. And at the opposite end position in the cross section of the gas introduction part is formed by overlapping and joining the two divided parts,
Either one of the first and second divided parts, the exhaust gas introduced from the gas inlet to the winding start position of the scroll body at the opposite end position where the two divided parts are overlapped and joined , A rectifying part for rectifying the exhaust gas flow is integrally formed at the junction with the recirculated exhaust gas from the winding end position toward the winding start position through the scroll body part,
The rectifying part integrally formed at the opposite end position of either one of the first and second divided parts is beyond the joining boundary when these divided parts are mutually joined. A turbine housing characterized in that it enters the other inside.   2. The turbine housing according to claim 1, wherein a part of the rectifying portion that has entered the inside of the other divided part is fixed to the inner wall of the other divided part by welding.   The first and second divided parts are each formed by sheet metal processing of a metal plate material, and are integrated by welding the mutual joints of these divided parts to form the main body portion of the gas introduction part. The turbine housing according to claim 1 or 2.

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