JP6882039B2 - Exhaust turbocharger - Google Patents

Description

The present invention relates to an exhaust turbocharger used in an internal combustion engine.

In an exhaust turbocharger used for an internal combustion engine, the turbine housing in which the turbine is arranged is exposed to high-temperature exhaust gas. Therefore, it has been proposed to form a cooling water jacket on the turbine housing to make it a water-cooled type, and an example thereof is disclosed in Patent Documents 1 to 3.

The exhaust turbocharger has a turbine housing in which a turbine is arranged, a compressor housing in which a compressor blade is arranged, and an intermediate housing located between the two. Patent Document 1 describes these three housings. Is integrally cast with aluminum to form a cooling water jacket in each housing.

On the other hand, in Patent Document 2, the cooling water jacket is formed only in the turbine housing, and the cooling water jacket is integrally continuous with the outer part of the scroll chamber and the periphery of the inlet passage for sending the exhaust gas to the scroll chamber. It is formed in a state of being separated from each other or in a state of being separated from each other. This Patent Document 2 also discloses that the turbine housing is made of aluminum.

It is necessary to provide a cooling water inlet and a cooling water outlet in the cooling water jacket. In Patent Document 1, in the turbine housing, of the left and right inner peripheral portions sandwiching the scroll chamber, the inner peripheral portion on the exhaust outlet side. Is provided with a cooling water inlet, and a cooling water outlet is provided on the inner peripheral portion on the side of the intermediate housing. On the other hand, Patent Document 2, although ports seems the inlet or outlet of the cooling water in FIG 4,5,15 is displayed, in fact do coolant how flows of unknown.

International Publication WO2014 / 103570 Japanese Unexamined Patent Publication No. 2016-75287

In the cooling water jacket, its structure is closely related to the cooling performance. For example, a waistgate passage is usually formed in a turbine housing, but since the waistgate passage is exposed to exhaust gas, the side of the turbine housing where the waistgate passage is provided is strongly cooled. The structure should be designed. In addition, the cooling water inlet and the cooling water outlet should be arranged so that the cooling water flows smoothly without stagnation.

However, Patent Documents 1 and 2 merely disclose the cooling water jacket, and it is difficult to find the structure of the cooling water jacket corresponding to the difference in the amount of heat received depending on the location. In particular, how to properly cool the part that becomes hot due to the Westgate passage is important, but no useful disclosure can be found in this regard.

The present invention has been made in view of such a situation, and an object of the present invention is to provide an exhaust turbocharger having excellent cooling performance and high reality.

The exhaust turbo supercharger of the present invention has "a scroll chamber for rotationally driving a turbine with exhaust gas in a turbine housing, an inlet passage for sending exhaust gas to the scroll chamber, and cooling water surrounding the scroll chamber and the inlet passage. A jacket is formed, and the cooling water jacket is provided with a cooling water inlet at the lower end located below the scroll chamber and the entrance passage, and the upper end located above the scroll chamber and the entrance passage. The basic configuration is that a cooling water outlet is provided in the section.

The invention of claim 1 is based on the above basic configuration.
"The waistgate passage branches off from the inlet passage, and the cooling water jacket extends so as to surround the waistgate passage from at least both the upper and lower sides, and the cooling water inlet is located below the scroll chamber. The cooling water outlet is provided at a position near the waistgate passage and at a position shifted toward the front of the cooling water inlet when viewed from the front-rear direction, which is the flow direction of exhaust gas passing through the inlet passage. ,
In addition, horizontally long partition walls that divide the cooling water jacket into upper and lower parts are formed on both front and rear sides of the scroll chamber when viewed from the front-rear direction. "
It has the feature.

According to the present invention , the upward protrusion functions as a tank for collecting cooling water, and the cooling water flowing through the cooling water jacket is collected at the upward protrusion and then discharged from the cooling water outlet. Therefore, it is possible to impart a flow direction to the cooling water so that the cooling water can flow smoothly. As a result, the cooling performance can be improved. Furthermore, since heat has the property of escaping upward, if an upward protrusion is provided as in the present invention, the received cooling water is discharged to the cooling water outlet via the upward protrusion, and heat is trapped. It does not occur, which ensures high cooling performance.

In particular, if the upward protrusion is formed so as to spread across the turbine side scroll chamber, the waist gate passage, and the inlet passage, the temperature rises through the portion that strongly receives the heat of the exhaust gas and the cooling water is cooled. Is discharged quickly, so that the part that receives the heat of the exhaust gas can be appropriately cooled to ensure high durability and reliability. Therefore, it can be said that it can greatly contribute to the practical use of the aluminum turbine housing.

Further, in the present invention , since the cooling water inlet is arranged below the scroll chamber (turbine side scroll chamber) (preferably directly below or in the vicinity thereof), the cooling water flows separately on both sides of the scroll chamber. Therefore, the cooling water can be distributed throughout the cooling water jacket. Since the cooling water outlet is provided at a portion close to the waist gate passage, the cooling water that has passed through the portion where the waist gate passage is provided is quickly discharged after heat transfer. Therefore, it is possible to ensure a high cooling performance by preventing heat cage forest.

It is an overall view of the exhaust turbocharger according to the embodiment, (A) is a perspective view seen from the direction of an intake inlet, and (B) is a perspective view seen from the direction of an exhaust gas inlet. (A) is a plan view of the exhaust turbocharger, and (B) is a front view. FIG. 2 is a sectional view taken along line III-III of FIG. 2 (A). (A) is a plan view of the turbine housing, (B) is a plan view of the cooling water jacket displayed by a solid line and the outer shape of the turbine housing is displayed by a chain line, and (C) is a solid line of the exhaust gas passage of the turbine. It is a top view which showed the outer shape of the housing by the alternate long and short dash line. (A) is a front view of the turbine housing, and (B) is a front view of the cooling water jacket displayed by a solid line and the outer shape of the turbine housing displayed by a chain line. (A) is a right side view of the turbine housing, and (B) is a right side view of the cooling water jacket displayed by a solid line and the outer shape of the turbine housing displayed by a chain line. (A) is a bottom view of the turbine housing, (B) is a left sectional view of VIIB-VIIB of FIG. 4 (A), and (C) is a left side view of the cooling water jacket. (A) is a sectional view taken along line VIIIA-VIIIA of FIGS. 4 (A) and 5 (A), (B) is a sectional view taken along line BB of FIG. , (C) are schematic cross-sectional views taken along the line VIIIC-VIIIC of FIGS. 4 (A), 6 (A) and 7 (B). (A) is an IX-IX sectional view taken along the line 4 (A) and FIG. 7 (B), and FIG. 6B is an IXB-IXB sectional view taken along the line 6 (A) and FIG. 8 (A).

(1). Outline Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline will be described with reference to FIGS. 1 to 3. In the present embodiment, the words front-back, left-right, and up-down are used to clarify the direction, but the longitudinal direction of the rotation axis is the left-right direction, and the direction orthogonal to this is the front-back direction. The direction facing from the cylinder head is the front. The vertical direction is the vertical direction. Just in case, the direction is clearly shown in Figures 1 and 2.

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

The turbine housing 4 is formed with a turbine chamber 7 in which the turbine 1 is rotatably arranged, and a turbine-side scroll chamber 8 communicating with the outer peripheral portion of the turbine chamber 7. The turbine-side scroll chamber 8 has a spiral shape in which the distance from the rotation axis of the turbine 1 gradually decreases from the start end to the end end, and the inlet passage shown in FIG. 1 (B) is at the start end (upper end). 9 is in communication.

Therefore, the turbine housing 4 has a circular portion 4a in which the turbine-side scroll chamber 8 is formed and an inlet cylinder portion 4b in which the inlet passage 9 is formed, and protrudes to the opposite side to the intermediate housing 6. The side overhanging portion 4c is formed in a state of being integrally connected to the circular portion 4a and the inlet cylinder portion 4b. At the rear end of the inlet cylinder portion 4b, an inlet side flange 12 that is bolted to the cylinder head (or the gathering portion of the exhaust manifold) is formed.

Further, as can be understood from FIG. 3, an outlet passage 13 through which the exhaust gas discharged from the turbine chamber 7 flows and a waist gate passage 14 connecting the inlet passage 9 and the outlet passage 13 are formed in the side overhanging portion 4c. The waist gate passage 14 is opened and closed by a rotary waist gate valve 15. A shroud piece 13a for forming an inner peripheral portion of the turbine-side scroll chamber 8 is mounted on the outlet passage 13. The wastegate valve 15 is driven by the diaphragm type actuator 16 shown in FIG. The actuator 16 has a rod 17, and when the rod 17 moves back and forth, the waist gate valve 15 rotates around the axis of the support shaft 19 via the outer link 18, the support shaft 19, and the inner link 20. ..

An outlet side flange 21 is formed on the side overhanging portion 4c, and although not shown, the catalyst case is fixed to the outlet side flange 21 (the exhaust pipe may be fixed). Outlet 13b of the exhaust gas is discharged by communicating with the outlet passage 13 and wastegate passage 14 is opened diagonally downward.

As shown in FIG. 3, the compressor housing 5 is formed with an intake inlet 22 and a compressor-side scroll chamber 23 located outside the compressor blade 2, and the intake air pressurized by the compressor-side scroll chamber 23 is formed. , It is discharged to the intake system from the discharge port 24. The compressor housing 5 is connected to the intermediate housing 6 via a C-shaped or halved ring 25.

The intermediate housing 6 is formed with a bearing portion 27 that rotatably holds the rotating shaft 3 via the floating metal 26. The bearing portion 27 is formed with an oil supply hole 28 opened upward and an oil discharge hole 29 opened downward. Since the seal structure of the rotating shaft 3 has nothing to do with the present invention, the description thereof will be omitted.

(2). Cooling structure of the turbine housing The turbine housing 4 is formed with a cooling water jacket through which cooling water flows. This point will be described with reference to the drawings of FIG. 4 and below. As shown in FIGS. 7 (C) and 8 (C), the cooling water jacket 31 basically covers the circular portion 4a and the inlet cylinder portion 4b of the turbine housing 4 as a whole.

Then, in the cooling water jacket 31, the front part of the scroll chamber 8 is partitioned up and down by the front horizontally long partition wall 32a, and the rear part of the scroll chamber 8 is vertically separated by the left and right rear horizontally long partition walls 32b. It is divided into. As shown in FIG. 9A, the waist gate passage 14 is sandwiched between the upper and lower cooling water jackets 33 and 34. The front horizontally long partition wall 32a has a substantially U-shaped shape in a plan view so as to surround the scroll chamber 8 from the front left and right. It has a form that extends long in the front-rear direction, which is the axial direction.

Therefore, the cooling water jacket 31 is divided into an upper jacket 33 and a lower jacket 34 by the horizontally long partition walls 32a and 32b. The upper and lower jackets 33 and 34 are communicated with each other by one front communication portion 35 and two left and right rear communication portions 36. A cooling water inlet 37 communicates with the lower jacket 34, and a cooling water outlet 38 communicates with the upper jacket 33. The cooling water inlet 37 and the cooling water outlet 38 are formed in the boss portion, and are connected to the hose via the joint cylinders 37a and 38a as shown in FIGS. 8 and 9.

Since the communication portions 35 and 36 are divided into front and rear parts, the cooling water flows evenly through the upper and lower jackets 33 and 34 and is discharged from the cooling water outlet 38. Therefore, the entire turbine housing 4 can be cooled as evenly as possible, and the occurrence of thermal strain can be significantly suppressed.

As shown in FIGS. 3, 5, 7 (A), (B) and the like, the side overhanging portion 4c has a chevron shape protruding above the circular portion 4a and the inlet cylinder portion 4b, and exits to the highest portion. A boss 39 is formed, and a cooling water outlet 38 is formed therein. Therefore, the upper jacket 33 also has an upward protruding portion 33a, and a cooling water outlet 38 is formed at the upper end of the upper jacket 33a. Therefore, the cooling water jacket 31 has a funnel shape that is narrowed upward in the side view and the front view, and the cooling water sent from below does not stagnate in the middle and reaches the cooling water outlet 38. It is collected and surely discharged.

Further, for example, as clearly shown in FIG. 5, the cooling water inlet 37 of the cooling water jacket 31 is located directly below the turbine chamber 7 and has a tubular shape, while the cooling water outlet 38 has the outlet passage 13 and the outlet passage 13. It is biased toward the Westgate passage 14, and both are separated (offset) in the left-right direction and the front-back direction. That is, as shown in FIG. 4 (B), the cooling water outlet 38 is displaced rearward by L1 with respect to the cooling water inlet 37, and the intermediate housing 6 is displaced by L2 to the opposite side. As can be understood from 9, the cooling water outlet 38 is arranged slightly outside the waistgate passage 14 (located above the side overhang 4c).

Further, for example, as can be easily understood from FIG. 9A, both the upper and lower cooling water jackets 33 and 34 are closer to the outlet passage 13 and the waist gate passage 14 (side overhanging portion 4c) than the side of the intermediate housing 6. On the side), the volume is much larger. Therefore, it is possible to strongly cool the part exposed to high temperature and susceptible to heat damage (particularly the part surrounded by the exhaust gas passage) to prevent the temperature from rising abnormally, and it is also possible to significantly suppress the thermal strain. ..

The communication holes 35 and 36 are formed by fitting a screw-type plug 41 into a cavity 40 that opens outward. That is, by screwing the plug 41 halfway through the cavity 40, a part of the cavity 40 is formed into communication holes 35 and 36.

As can be understood from FIGS. 4 (B), 8 (A), and 9 (B), the circular portion 4a has upper and lower vertically elongated ribs 42, 43 that divide the upper jacket 33 and the lower jacket 34 into left and right. Is formed. Therefore, at the portion of the circular portion 4a, the inner and outer portions separated by the cooling water jacket 31 are connected by the front horizontally long partition wall 32a and the upper and lower vertically long ribs 42 and 43, and are connected to the front horizontally long partition wall 32a. The upper and lower vertically elongated ribs 42 and 43 form a cross-shaped shape when viewed from the front.

Since the upper and lower vertically elongated ribs 42 and 43 can also hold a rectifying function that divides the water flow into left and right, it can also contribute to smoothing the flow of cooling water. Further, since the vertically long ribs 42 and 43 also exhibit a function of heat dissipation, there is an advantage that heat retention can be suppressed. As can be understood from FIG. 8A, the upper vertically elongated rib 42 is formed approximately in the front half of the circular portion 4a, and behind the upper vertically elongated rib 42, the upper jacket 33 is integrally continuous on the left and right sides. There is. Therefore, the cooling water is smoothly collected at the cooling water outlet 38.

On the other hand, the lower vertically elongated ribs 43 are formed on both front and rear sides of the cooling water inlet 37. Therefore, the lower jacket 34 is separated to the left and right by the front and rear lower vertically elongated ribs 43 and the boss portion forming the cooling water inlet 37 at the portion of the circular portion 4a. The water flow separated to the left and right gathers at the front communication portion 35 and flows to the upper jacket 33, and the water flow separated to the left and right by the lower vertical rib 43 at the rear gathers at the lower jacket 34 at the inlet cylinder portion 4b. Then, it is divided into left and right rear communication portions 36 and flows to the upper jacket 33.

As shown in FIG. 7B, the inlet cylinder portion 4b is inclined so that the height is slightly higher from the rear end to the front end. Therefore, as shown in FIG. 7C, the portion of the cooling water jacket 31 located at the inlet cylinder portion 4b is also slightly inclined in the side view so as to be higher toward the front. Corresponding to the form of the cooling water jacket 31, the rear horizontal partition wall 32b is inclined so as to stand up, move backward in a horizontal posture, and then lower toward the rear. Therefore, the lower jacket The upper surface of the 34 has a chevron shape in a lateral view.

Therefore, in order to surely prevent air bubbles from accumulating at the upper end of the lower jacket 34, a communication hole 44 is formed in a portion of the rear horizontally long partition wall 32b having a high height as shown in FIG. 9A. .. Therefore, even if the cooling water contains air bubbles or the cooling water boils to generate air bubbles, the air bubbles can be quickly eliminated. Therefore, high cooling performance can be ensured. Since the communication hole 44 is formed by drilling, the turbine housing 4 has a drill hole 45 concentric with the communication hole 44, but the drill hole 45 is closed by a plug (not shown).

As shown in FIG. 8, since the turbine-side scroll chamber 8 has a spiral shape, the portion of the turbine-side scroll chamber 8 sandwiched between the start end and the end of the inlet passage 9 has a thickness toward the tip. Is a thinned tongue 46. Therefore, the tongue portion 46 is exposed to the harshest thermal environment in the turbine housing 4, but in the present embodiment, the front end portion of the rear laterally elongated partition wall 32b is located substantially beside the tongue portion 46, and the rear horizontally elongated partition wall 32b is located. A communication hole 44 is formed in a portion of the tongue portion 46 located next to the tongue portion 46.

Since the cooling water flows through the communication hole 44, the heat exchange from the rear horizontally long partition wall 32b to the cooling water is remarkably promoted, so that the heat of the tongue 46 is also vigorously dissipated to the cooling water through the rear horizontally long partition wall 32b. Will be done. As a result, it is possible to prevent the tongue portion 46 from being excessively heated, and to ensure high quality. As shown in FIG. 9, the entrance passage 9 and the waist gate passage 14 are arranged side by side, and one side of the rear horizontal partition wall 32b is located between them, but a communication hole 44 is formed in the rear horizontal partition wall 32b. Since heat transfer from the waist gate passage 14 can be suppressed, it is more useful as a protective means for the tongue portion 46.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various ways. For example, the shape of the cooling water jacket can be appropriately set according to the shape of the turbine housing and the like. The intermediate housing and the turbine housing may be separate bodies.

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

1 Rotating shaft 2 Turbine 4 Turbine housing 4a Circular part 4b Inlet cylinder part 4c Side overhang 7 Turbine room 8 Turbine side scroll room 9 Inlet passage 31 Cooling water jacket 32a, 32b Horizontal partition 33 Upper jacket 34 Lower jacket 35, 36 Part 37 Cooling water inlet 39 Cooling water outlet

Claims (1)

The turbine housing is formed with a scroll chamber for rotationally driving the turbine with exhaust gas, an inlet passage for sending exhaust gas downward to the scroll chamber, and a cooling water jacket surrounding the scroll chamber and the inlet passage. The cooling water jacket is provided with a cooling water inlet at the lower end located below the scroll chamber and the inlet passage, and is formed on the cooling water jacket at the upper end located above the scroll chamber and the inlet passage. It has a configuration in which a cooling water outlet located at the upper end of the upward protrusion is provided.
The waistgate passage branches off from the inlet passage, and the cooling water jacket extends so as to surround the waistgate passage from at least both the upper and lower sides, and the cooling water inlet is located below the scroll chamber. The cooling water outlet is provided at a position close to the waist gate passage and at a position deviated from the cooling water inlet when viewed from the front-rear direction, which is the flow direction of exhaust gas passing through the inlet passage.
Further, horizontally long partition walls that divide the cooling water jacket into upper and lower parts are formed on both front and rear sides of the scroll chamber when viewed from the front and rear direction.
Exhaust turbocharger.

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