JP2018087555A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an exhaust gas bypassing from a waste gate passage exactly abut on a catalyst, and to surely raise a temperature of the catalyst in an early stage.SOLUTION: An exhaust turbocharger has an exhaust gas discharge cylinder part 10 connected to a turbine-side scroll change 8, and a catalyst case is connected to a terminal end of the exhaust gas discharge cylinder part 10 in a posture in a vertical longitudinal direction. An exhaust gas main passage 12 progressing toward the turbine-side scroll chamber 8 and an inlet-side portion 13a of a waste gate passage 13 are formed at an exhaust gas introduction cylinder part 9 of a turbine housing 3 in parallel with each other. The waste gate passage 13 has an outlet-side portion constituted of a pipe-shaped part 13b. The pipe-shaped part 13b is opened toward an upper face of the catalyst. The exhaust gas flows into the waste gate passage 13 with linearity, and the exhaust gas flowing into the waste gate passage 13 is injected to a surface of the catalyst with linearity. By this constitution, a temperature of the catalyst can be raised in an early stage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an internal combustion engine equipped with an exhaust turbocharger.

  For the first time in an automobile internal combustion engine, it is widely practiced to provide an exhaust turbocharger in the internal combustion engine. An exhaust turbocharger drives a turbine with exhaust gas and drives a compressor with the turbine. The necessity and degree of supercharging varies depending on the load of the internal combustion engine. A wastegate passage that bypasses the turbine is provided, and the amount of exhaust gas flowing through the wastegate passage is controlled by a wastegate valve.

  On the other hand, in particular, an internal combustion engine (gasoline engine) for automobiles is provided with a catalytic purification device in the exhaust passage in order to purify the exhaust gas. However, the efficiency of the catalyst is poor unless the temperature is raised to a certain level (active) There is a problem that In this case, since the only heat source for raising the temperature of the catalyst is exhaust gas, it is effective to apply exhaust gas as hot as possible directly to the catalyst in order to raise the temperature of the catalyst early.

  Therefore, in Patent Document 1, when a waste gate introduction passage is formed in the exhaust gas introduction passage formed in the turbine housing in the shape of a horizontal hole, a rotary waste gate valve is also used as an exhaust gas guide member, It is disclosed that the exhaust gas flowing into the passage goes straight toward the catalyst case.

WO2013-145278

  When starting (particularly during warm-up operation), there is often no need for supercharging. Therefore, when exhaust gas flowing into the wastegate passage is applied to the catalyst as in Patent Document 1, the temperature of the catalyst rises faster than in the past. However, Patent Document 1 is thought to be insufficient in the effect of rapidly raising the catalyst temperature due to three problems.

  The first problem is that since the wastegate passage opens from the exhaust gas passage like a horizontal hole, the inflow property of exhaust gas to the wastegate passage is poor, and therefore the effect of rapid temperature rise of the catalyst is sufficient. It is not. In addition, the flow rate decreases when the exhaust gas changes direction from the exhaust gas introduction passage to the waste gate passage. At this time, heat is taken away by the turbine housing, so that the temperature of the exhaust gas hitting the catalyst tends to decrease. Is also a problem. In addition, the inflow property of the exhaust gas to the wastegate passage also affects the responsiveness of the supercharging pressure control.

  The second problem of Patent Document 1 is that when the wastegate valve is opened, the exhaust gas collides with the wastegate valve and diffuses when the direction is changed from the exhaust gas introduction passage and flows into the wastegate passage. As the straightness toward the catalyst is reduced, the heat is taken away by the turbine housing and the wastegate valve, and the temperature of the exhaust gas is lowered.For this reason, the heat exchange from the exhaust gas to the catalyst becomes insufficient, This is that the effect of early temperature rise of the catalyst tends to be insufficient.

  Furthermore, the third problem of Patent Document 1 is that the wastegate flow direction changes depending on the opening of the wastegate valve because the wastegate valve is used as a guide for the flow of exhaust gas. The exhaust gas contact condition is not stable, and as a result, there is a possibility that the effect of rapid temperature rise of the catalyst may be insufficient.

  The present invention has been made to improve the current situation.

The internal combustion engine of the present invention is
A turbine side scroll chamber in which a turbine that is rotationally driven by exhaust gas is disposed, a compressor driven by the turbine, an exhaust gas main passage that guides exhaust gas to the turbine side scroll chamber, and an exhaust gas on the turbine side A waste gate passage that bypasses the scroll chamber and an exhaust passage through which the exhaust gas that has passed through the turbine-side scroll chamber and the exhaust gas that has passed through the waste gate passage flow in, and the exhaust passage incorporates a catalyst The basic configuration is that the catalyst case is inserted.

And, the invention of claim 1 is the above basic configuration,
While the inlet of the exhaust gas main passage and the inlet of the waste gate passage are opened in the same direction, the exhaust gas discharged from the exhaust manifold or the cylinder head flows into the waste gate passage,
At least an outlet portion of the waste gate passage is a pipe-like portion, and an outlet of the pipe-like portion opens toward the inside of the catalyst case.

The invention of claim 2 is the invention according to claim 1,
The entirety of the wastegate passage including the pipe-shaped portion is formed in the turbine housing together with the turbine-side scroll chamber and the exhaust gas main passage, and further, the turbine housing is provided with respect to the outlet end surface of the pipe-shaped portion. A wastegate valve that rotates so that the valve lid closely contacts and separates is provided.

The invention of claim 3 is the invention of claim 2,
The entire wastegate passage including the pipe-shaped portion is formed in the turbine housing together with the turbine-side scroll chamber and the exhaust gas main passage, and at least one of the exhaust gas main passages is formed in the turbine housing. A cooling water jacket is formed to surround at least a part of the part and the wastegate passage.

  In the present invention, the inlet of the exhaust gas main passage and the inlet of the wastegate passage may be separated or integrated. When they are integrated, they branch off from the middle, but in this case as well, the exhaust gas flows straight into the entrance of the wastegate passage and goes toward the exit of the wastegate passage while keeping straightness.

  According to the present invention, since the exhaust gas discharged from the exhaust manifold or the cylinder head goes to the waste gate passage, it is possible to ensure intake of the exhaust gas into the waste gate passage. Further, since the exhaust gas is directed to the catalyst while having straightness by the guide action of the wastegate passage, it hardly diffuses and the heat dissipation is low. Furthermore, since at least the exit part of the wastegate passage is a pipe-like part and the exit is open toward the catalyst, the exhaust gas can be reliably applied to the catalyst.

  Eventually, in the present invention, exhaust gas can be firmly taken into the wastegate passage, diffusion of exhaust gas can be prevented or suppressed to maintain the directionality of the exhaust gas flow (straightness), and exhaust gas temperature can be reduced. In combination with the ability to suppress the exhaust gas and the exhaust gas can be reliably applied to the catalyst, the early temperature rise effect of the catalyst can be improved. As a result, the exhaust gas purification performance can be improved. Further, since the exhaust gas can be taken into the wastegate passage, there is an advantage that the responsiveness in controlling the supercharging pressure can be improved.

  In addition, when at least the outlet portion of the wastegate passage is a pipe-like portion, the exit of the wastegate passage can be brought close to the catalyst case. Even when the gate valve opens and closes, the exhaust gas hitting the waste gate valve can be applied to the catalyst before diffusing. For this reason, regardless of the opening degree of the wastegate valve, the exhaust gas can be accurately applied to the catalyst, and the early temperature rise of the catalyst can be further ensured.

  If the wastegate valve is configured to rotate so that the wastegate valve comes into contact with and separates from the outlet end face of the pipe-like portion, the rotation shaft of the wastegate valve is exposed to the flow of exhaust gas. Therefore, the reliability and high durability of the opening and closing of the wastegate valve can be ensured. In addition, heat is exchanged from the exhaust gas to the valve lid, and the member such as the valve lid is heated. However, since the valve lid is disposed in a space close to the catalyst, the catalyst is heated by the radiant heat of the member such as the valve lid. Can do. Therefore, it can be said that there is almost no heat loss.

  If the structure of Claim 3 is employ | adopted, the heat of exhaust gas can be heat-exchanged with cooling water, and it can contribute to warming-up promotion of an engine. It is also easy to reduce the weight by making the turbine housing aluminum.

It is the front view which looked at the exhaust turbo supercharger of the embodiment from the direction orthogonal to the exhaust side of the cylinder head. It is the rear view which looked at the exhaust gas turbocharger from the opposite side to FIG. (A) is a principal part top view, (B) is the BB partial fragmentary sectional view of (A) in the state which closed the wastegate valve, (C) is the state in which the wastegate passage was opened (B). FIG. FIG. 4 is a partial cross-sectional view taken along the line IV-IV in FIG.

  Next, an embodiment of the present invention will be described with reference to the drawings. The exhaust turbocharger 1 has a turbine housing 3 in which a turbine 2 is built, a compressor housing 4 in which a compressor (not shown) is built, and a bearing housing 5 positioned therebetween. As shown in FIG. 4, one end of the rotating shaft 6 is fixed to the turbine 2, and a compressor (not shown) is fixed to the other end of the rotating shaft 6.

  As shown in FIG. 4, the bearing housing 5 is configured to rotatably hold the rotating shaft 6 via the floating metal 7. In this embodiment, the turbine housing 3 and the bearing housing 5 are integrated as an aluminum casting product. Is manufactured.

  As shown in FIG. 4, a turbine side scroll chamber 8 is formed in the turbine housing 3 so as to surround the turbine 2, and the turbine side scroll chamber 8 includes an exhaust gas introduction cylinder portion 9 and an exhaust gas discharge cylinder portion 10. And communicate with each other. The exhaust gas discharge cylinder portion 10 constitutes a part of the exhaust passage. An inlet side flange 9a is integrally formed at the front end (opening end) of the exhaust gas introduction tube portion 9, and this inlet side flange 9a is fixed to the collective portion 11 of the exhaust manifold or the cylinder head.

  The exhaust gas introduction tube portion 9 includes an exhaust gas main passage 12 that guides the exhaust gas to the turbine side scroll chamber 8 and a waist that bypasses the exhaust gas to the exhaust gas discharge tube portion 10 without passing through the turbine side scroll chamber 8. An entrance side portion 13a of the gate passage 13 is formed. That is, in the present embodiment, the inlet side portion 13 a of the wastegate passage 13 communicates integrally with the exhaust gas main passage 12. Therefore, there is only one opening hole in the exhaust gas introducing cylinder portion 9.

  As shown in FIG. 2, the inlet of the exhaust gas main passage 12 and the inlet side portion 13a of the waste gate passage 13 are arranged in the horizontal direction, and the opening area of the inlet of the exhaust gas main passage 12 is the waste gate. The opening area of the inlet side portion 13a of the passage 13 is larger. For this reason, the opening hole of the exhaust gas introduction cylinder part 9 is not a perfect circle, but has a shape connecting a large diameter circle and a small diameter circle.

  As shown in FIG. 3, the exhaust gas introduction tube portion 9 and the exhaust gas discharge tube portion 10 are L-shaped in a plan view and are partially connected. The wastegate passage 13 has an outlet side portion that is separated from the exhaust gas introduction tube portion 9 and faces the tip of the exhaust gas discharge tube portion 10, and this exit side portion is formed in the pipe-shaped portion 13b. Yes.

  The front end (opening end) of the exhaust gas discharge cylinder portion 10 is inclined at an angle of approximately 45 degrees so as to face obliquely downward when viewed from the front, and an outlet side flange 14 is integrally provided at the front end to provide an outlet side flange. 14 is connected to the catalyst case 15. The catalyst case 15 has a shape in which tapered cone portions 15b are provided at both upper and lower ends of the straight main body portion 15a, and a joint portion 15c provided in the upper cone portion 15b is bolted or welded to the outlet side flange 14. It is fixed. The joint portion 15c also constitutes an exhaust passage. The catalyst case 15 has a substantially vertical posture.

  And the pipe-shaped part 13b of the above-mentioned wastegate channel | path 13 inclines in planar view and front view, and is opening toward the inside of a catalyst case. To be precise, the upper surface of the catalyst (not shown) is located on the extension of the axial center of the pipe-like portion 13b. Accordingly, the exhaust gas ejected from the pipe-like portion 13b hits the upper surface of the catalyst. In addition, it is preferable to set the pipe-shaped part 13b so that it may go to the center part of a catalyst. In addition, it is preferable to open the pipe-shaped part 13b toward the central part of the catalyst as much as possible.

  Since the exhaust gas introduction tube portion 9 and the exhaust gas discharge tube portion 10 are orthogonal to each other in plan view, the wastegate passage 13 is curved from the inlet side portion 13a communicating with the exhaust gas main passage 12, and is piped. It reaches the shape part 13b. Therefore, although the direction of the exhaust gas flowing into the wastegate passage 13 changes in the middle, the direction change portion is curved, so that the exhaust gas flows with straightness in the whole wastegate passage 13.

  As shown in FIGS. 3B and 3C, a wastegate valve 16 for opening and closing the wastegate passage 13 is attached to the exhaust gas discharge cylinder portion 10 of the turbine housing 3. The wastegate valve 16 has an operation shaft 17 that rotates around an axis, and a valve lid 19 that is provided at the tip of the operation shaft 17 via a bracket 18. When the operation shaft 17 is rotated low, The valve lid 19 rotates (swings), contacts (adheres to) the tip (opening end) of the pipe-shaped portion 13b, and moves away from the pipe-shaped portion 13b.

  The operation shaft 17 is displayed as a simple line in FIGS. The exhaust gas discharge cylinder portion 10 is formed with a bearing cylinder 20 that rotatably holds the operation shaft 17. Although not shown, a link is integrally fixed to a base end portion of the shaft 17 exposed to the outside of the exhaust gas discharge cylinder portion 10, and a diaphragm actuator (provided in the compressor housing 4) is attached to the link. A rod driven by (not shown) is connected. Therefore, the wastegate valve 16 is operated by the actuator via the rod (the operation shaft 17 can be rotated by an electric motor or the like).

  As shown in FIG. 3, a first cooling water jacket 21 is formed in the exhaust gas introduction cylinder portion 9. On the other hand, as shown in FIG. 4, a pair of second cooling water jackets 23 partitioned right and left by a partition wall 22 are formed on the outer and outer sides of the turbine side scroll chamber 8. The first cooling water jacket 21 is preferably provided with a partition wall or a bridge portion for reinforcement. Further, the first cooling water jacket 21 and the second cooling water jacket 23 can be communicated with each other.

  As shown in FIG. 2, a cooling water port 24 for supplying and draining water to the first cooling water jacket 21 is divided into the left and right sides and opens in the inlet side flange 11. One of the left and right ports 24 may be used as an inlet and the other as an outlet. The inlet port and the outlet port of the first cooling water jacket 21 can be provided on the outer peripheral portion of the exhaust gas introducing cylinder portion 9.

  As can be easily understood from the above description, when the wastegate valve 16 is fully closed, the exhaust gas flows from the main passage 12 to the turbine-side scroll chamber 8 to drive the turbine 2. The exhaust gas is discharged from the exhaust gas discharge cylinder 10 to the catalyst case 15.

  On the other hand, when the wastegate valve 16 is fully opened, a considerable amount of the exhaust gas that has flowed into the exhaust gas introduction cylinder portion 9 passes through the wastegate passage 13 and flows into the catalyst case 15. In this case, since the exhaust gas flows straight into the inlet side portion 13a of the waste gate passage 13, intake of the exhaust gas into the waste gate passage 13 can be ensured.

  Further, since the wastegate passage 13 is only gently curved in the middle and the exhaust gas does not change direction at right angles, the exhaust gas travels straight over the entire wastegate passage 13. For this reason, high-temperature exhaust gas can be jetted from the pipe-shaped part 13b to the upper surface of the catalyst while suppressing the heat release of the exhaust gas. Therefore, it is possible to quickly activate the catalytic action of raising the temperature of the catalyst early and removing harmful components from the exhaust gas.

  The amount of exhaust gas flowing through the wastegate passage 13 changes according to the opening of the wastegate valve 16, but the tip of the pipe-like portion 13 b can be brought close to the catalyst, so that it changes its direction by hitting the exhaust gas or the valve lid 19. Even so, the exhaust gas can be quickly applied to the catalyst. That is, the exhaust gas hits the catalyst before diffusing, so that the exhaust gas can be applied to the upper surface of the catalyst regardless of the opening degree of the waste gate valve 16.

  In addition, although the front-end | tip of the pipe-shaped part 13b is cut diagonally, if the position of the valve lid 19 etc. are changed, the end surface of the pipe-shaped part 13b can also be made orthogonal to an axis line. The pipe-shaped portion 13b is formed in a straight shape, but can be formed in a tapered shape or a tapered shape.

  When the cooling water jackets 21 and 23 are formed as in the present embodiment, there is an advantage that the turbine housings 3 and 5 can be made aluminum to reduce the weight while preventing heat damage. Further, since the turbine housing 3 and the bearing housing 5 are integrated, it is possible to reduce the time and effort of assembly and improve the rotational accuracy of the turbine 2 and the compressor. Only one of the first cooling water jacket 21 and the second cooling water jacket 23 can be formed.

  When the cooling water jackets 21 and 23 are provided, if the cooling water jackets 21 and 23 are configured such that the return cooling water from the radiator flows into the cooling water jackets 21 and 23, the cooling water does not flow into the cooling water jackets 21 and 23 during warm-up. In addition, heat exchange from the exhaust gas to the cooling water can be prevented, and an early temperature rise of the catalyst can be ensured.

  The present invention can be embodied in various ways other than the above-described embodiment. For example, the present invention can also be applied to an exhaust turbocharger that does not include a cooling water jacket, and an exhaust turbocharger in which a turbine housing and a bearing housing are configured as separate members. In the embodiment, the tip of the exhaust gas discharge cylinder is cut obliquely, but the exhaust gas discharge cylinder is formed in an L shape having a horizontal part and a downward part, and the catalyst case is fixed to the downward part. Also good.

  Further, the exhaust gas main passage and the waste gate passage can be completely separated, and the whole waste gate passage can be formed in a pipe-like portion. Furthermore, the wastegate valve can be arranged so as to open and close the start end of the wastegate passage, and the structure of the wastegate valve is not limited to the rotary type (swing type) in which the valve lid moves greatly. For example, a butterfly method or the like can also be employed.

  The present invention can actually be embodied in an internal combustion engine. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Exhaust turbo supercharger 2 Turbine 3 Turbine housing 4 Compressor handling 5 Bearing housing 8 Turbine side scroll chamber 9 Exhaust gas introduction cylinder part 10 Exhaust gas discharge cylinder part which comprises a part of exhaust passage 11 Exhaust manifold collection part 12 Exhaust gas main passage 13 Westgate passage 13a Inlet side portion 13b of the wastegate passage Pipe portion 15 constituting the exit side portion of the wastegate passage 15 Catalyst case 15c Connection portion constituting the exhaust passage 16 Wastegate valve 17 Operating shaft 19 Valve Lid 21 First cooling water jacket 23 Second cooling water jacket

Claims (3)

A turbine side scroll chamber in which a turbine that is rotationally driven by exhaust gas is disposed, a compressor driven by the turbine, an exhaust gas main passage that guides exhaust gas to the turbine side scroll chamber, and an exhaust gas on the turbine side A waste gate passage that bypasses the scroll chamber, and an exhaust passage through which the exhaust gas that has passed through the turbine-side scroll chamber and the exhaust gas that has passed through the waste gate passage flow in,
In the exhaust passage, a catalyst case containing a catalyst is inserted, and
While the inlet of the exhaust gas main passage and the inlet of the waste gate passage are opened in the same direction, the exhaust gas discharged from the exhaust manifold or the cylinder head flows into the waste gate passage,
At least the outlet part of the waste gate passage is a pipe-like part, and the outlet of the pipe-like part opens toward the inside of the catalyst case.
Internal combustion engine. The entirety of the wastegate passage including the pipe-shaped portion is formed in the turbine housing together with the turbine-side scroll chamber and the exhaust gas main passage, and further, the turbine housing is provided with respect to the outlet end surface of the pipe-shaped portion. A wastegate valve that rotates so that the valve lid contacts and separates,
The internal combustion engine according to claim 1. The entire wastegate passage including the pipe-shaped portion is formed in the turbine housing together with the turbine-side scroll chamber and the exhaust gas main passage, and at least one of the exhaust gas main passages is formed in the turbine housing. A cooling water jacket surrounding at least a part of the part and the wastegate passage is formed,
The internal combustion engine according to claim 1 or 2.

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