JP2018087556A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an exhaust gas bypassing to a waste gate passage exactly abut on a catalyst, and to surely raise a temperature of the catalyst in an early stage.SOLUTION: A waste gate passage 21 is formed in a position separated from an exhaust gas main passage 12 for driving a turbine 2, and mostly constituted of a pipe 22. An inlet part 22a of the pipe 22 reaches an L-shaped joint part 13 from an exhaust gas discharge port 11, and an outlet part 22b is opened toward a catalyst 14 in the L-shaped joint part 13. Since the flow-in performance of an exhaust gas to the pipe 22 is excellent, and the exhaust gas flowing in the pipe 22 abuts on an upper face of the catalyst 14 without being diffused, an early rise of a temperature of the catalyst 14 can be promoted.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 wastegate main passage formed in a turbine housing has a wastegate passage formed in a lateral hole shape, a wastegate gate valve is also used as an exhaust gas guide member, and a wastegate is provided. 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 its direction from the exhaust gas main 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 waste gate valve is opened, the exhaust gas collides with the waste gate valve and diffuses when the direction is changed from the exhaust gas main passage and flows into the waste gate 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 driven to rotate by exhaust gas is disposed, a compressor driven by the turbine, an exhaust gas main passage for guiding 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 structure is such that the catalyst case is inserted.

  The invention according to claim 1 is the above-described basic configuration, wherein the wastegate passage is a dedicated passage separated from the exhaust gas main passage, and at least a part of the wastegate passage is constituted by a pipe. Is opened toward the inside of the catalyst case.

  According to a second aspect of the present invention, in the first aspect, at least a portion of the wastegate passage that is closer to the upstream side is constituted by a pipe, and a valve arrangement space is formed at a portion that is located upstream of the pipe. In the valve arrangement space, a rotary wastegate valve is arranged.

  In the present invention, since the wastegate passage is separated from the exhaust gas main passage, the exhaust gas is allowed to go straight to the wastegate passage by opening the start end of the wastegate passage to the exhaust manifold gathering portion or the outlet hole of the cylinder head. Can be made. Therefore, it is excellent in the inflow property of the exhaust gas to the wastegate passage. In addition, since the exhaust gas does not diffuse and travels toward the catalyst through the inside of the wastegate passage made of a pipe, the high-temperature exhaust gas can be reliably applied to the catalyst.

  As described above, according to the present invention, exhaust gas can be firmly taken into the wastegate passage and exhaust gas can be reliably applied to the catalyst, so that the early temperature raising 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, since at least a part of the wastegate passage is constituted by a pipe, the housing can be easily manufactured and the shape of the wastegate passage can be selected as compared with the case where the whole is formed inside the cast housing. The freedom is improved. In addition, if at least the downstream portion is formed of a pipe, it is easy to bring the outlet of the pipe closer to the catalyst case. Therefore, the contact of exhaust gas to the catalyst is further improved, and the catalyst can be heated quickly. Can be assured.

  The whole or most of the wastegate passage can be constituted by a pipe. Alternatively, at least a part of the upstream side may be constituted by a pipe, at least one part on the downstream side may be constituted by a pipe, and the middle part may be constituted by a pipe. Further, the entire pipe can be exposed to the outside of the turbine housing, or at least a part of the pipe can be cast into the turbine housing.

  If the entire pipe is arranged outside the turbine housing, the shape of the pipe can be set arbitrarily, so that it is easy to handle even if the position of the catalyst case is varied, and is excellent in versatility and freedom of design. On the other hand, when at least a part of the pipe is cast into the turbine housing, the mounting strength is excellent, and the labor of connection can be saved. If the pipe is made of a material having a small heat capacity, it is possible to further contribute to the early temperature rise of the catalyst and the early warm-up of the engine by suppressing heat dissipation.

  If the wastegate valve is arranged at the upstream end of the wastegate passage as in claim 2, it is further ensured that exhaust gas rectified (in the pipe) in the wastegate passage is applied to the catalyst without diffusing. Therefore, the early temperature rise of the catalyst can be further ensured.

It is the partially broken front view which looked at the exhaust turbo supercharger of the embodiment from the direction orthogonal to the exhaust side of the cylinder head. FIG. 2A is a plan view of an exhaust turbocharger, and FIG. 2B is a sectional view taken along the line IIA-IIA in FIG. It is a figure which shows 2nd Embodiment, (A) is a top view, (B) is BB sectional drawing of (A). It is a figure which shows 3rd Embodiment which is another example of a wastegate valve | bulb, and 4th Embodiment.

(1). First Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. First, the first embodiment shown in FIGS.

  As shown in FIG. 1, the exhaust turbocharger 1 has a turbine housing 3 in which a turbine 2 is built, a compressor housing 5 in which a compressor 4 is built, and a bearing housing 6 positioned between the two. ing. One end of the rotating shaft 7 is fixed to the turbine 2, and the compressor 4 is fixed to the other end of the rotating shaft 7. In the bearing housing 6, the rotating shaft 7 is rotatably held via the floating metal 8.

  A turbine-side scroll chamber 9 is formed in the turbine housing 3 so as to surround the turbine 2, and the turbine-side scroll chamber 9 has an exhaust gas main passage 10 facing the tangential direction thereof (see FIG. 2A). And the exhaust-gas discharge port 11 (refer FIG. 1) opened to the axial center direction of the turbine 2 is connecting. A catalyst case 12 is connected to the exhaust gas discharge port 11 via an L-shaped joint portion 13. The L-shaped joint portion 13 has a flange 13a, and the flange 13a is fixed to the turbine housing 3 with bolts. Note that the L-shaped joint portion 13 can also be regarded as a part of the exhaust passage.

  The catalyst case 12 has a configuration in which tapered cone portions 12b are provided above and below the straight portion 12a, and the catalyst 14 is disposed inside the straight portion 12a. The catalyst case 12 is arranged with the axis line in a substantially vertical posture.

  The exhaust gas main passage 10 is formed in the exhaust gas introduction cylinder portion 15, and a flange-like manifold portion 17 fixed to the cylinder head 16 is integrally provided at the tip of the exhaust gas introduction cylinder portion 15. Although only a part of the manifold portion 17 is illustrated in FIG. 1, an exhaust gas passage 18 that opens toward the cylinder head 16 is formed in the horizontal direction so that the exhaust gas passage 18 is formed in the cylinder head 16. Are connected to an exhaust outlet hole 19 and an exhaust gas main passage 10 which are opened on the exhaust side surface of the exhaust gas.

  Although only one exhaust outlet hole 19 is shown in the figure, it is arranged in the horizontal direction by the number of cylinders. Further, the exhaust gas introduction cylinder portion 15 is connected to the left side portion of the manifold portion 17 when viewed from the front direction orthogonal to the exhaust side surface of the cylinder head 16, but is connected to the left and right intermediate portion and right side portion of the manifold portion 17. May be.

  A hollow auxiliary protrusion 20 that is integrally connected to the exhaust gas introduction cylinder 15 is formed on the side of the catalyst case 12 with the exhaust gas introduction cylinder 15 interposed between the front surfaces of the manifold portion 17. One end portion (inlet portion) 22a of a circular pipe 22 constituting the wastegate passage 21 is connected to the portion 20 by press fitting. The other end portion (exit portion) 22 b of the pipe 22 is connected to the corner portion of the L-shaped joint portion 13 from above. The L-shaped joint portion 13 is provided with a boss portion 13 b for holding the pipe 22.

  The pipe 22 may be connected to the auxiliary protrusion 20a and the L-shaped joint 13 by welding, brazing, flange connection, or the like. In this embodiment, most of the wastegate passage 21 excluding the upstream end portion is constituted by the pipe 22.

  As shown by a one-dot chain line in FIG. 1, the outlet portion 22 b of the pipe 22 can be inserted into the L-shaped joint portion 13. In this case, the penetration dimension of the pipe 22 can be set arbitrarily. The outlet portion 22b can be inserted to the cone portion 13a to approach the catalyst 14. The outlet 22b of the pipe 22 can also be formed in a downwardly expanding taper shape or a trumpet shape.

  As shown in FIG. 2B, the inlet portion of the pipe 22 only partially enters the auxiliary protrusion 20, and the valve arrangement space located upstream of the pipe 22 is inside the auxiliary protrusion 20. 23 is formed. A butterfly-type wastegate valve 24 is rotatably arranged in the valve arrangement space 23 via a support shaft 25.

  The support shaft 25 has a substantially vertical posture, and a bearing boss portion 26 that stably holds the support shaft 25 is formed on the auxiliary projection 20. The upper end of the support shaft 25 is exposed upward. A link 27 is fixed to the exposed portion, and a rod 28 driven by a diaphragm actuator is connected to the link 27 so as to be relatively rotatable. Although not shown, the actuator is attached to the compressor housing 5. The support shaft 25 can also be driven by an electric motor or an electromagnetic solenoid.

  In FIG. 1, a reference numeral 29 generally indicates a cylinder block, and a reference numeral 30 indicates a head cover.

  As can be easily understood from the above description, when the waste gate valve 24 is opened, an amount of exhaust gas corresponding to the opening degree flows into the catalyst case 12 through the pipe 22. For this reason, the amount of exhaust gas flowing into the exhaust gas main passage 10 changes according to the opening degree of the waste gate valve 24. Thereby, the supercharging pressure can be controlled. Even if the wastegate valve 24 is fully opened, the exhaust gas flows into the exhaust gas main passage 10. However, in this state, the torque generated in the turbine 2 is remarkably reduced, so that supercharging is substantially performed. No state.

  Since the wastegate passage 21 faces the same direction as the exhaust gas main passage 10 and opens to the exhaust gas passage 18 of the manifold portion 17, the exhaust gas flows straight into the wastegate passage 21. Moreover, even if the pipe 22 is bent, the exhaust gas proceeds in a directional direction, so that the exhaust gas can be firmly applied to the catalyst 14 at a high temperature. Thereby, the early temperature rising effect of the catalyst 14 can be improved.

  Moreover, since the pipe 22 can be bent freely, it can cope with the difference in the arrangement position of the catalyst case 12 and the like, and is excellent in versatility and design freedom. When the wastegate valve 24 is arranged at the start end of the wastegate passage 21 as in the embodiment, the exhaust gas rectified by the pipe 22 hits the catalyst 14 without diffusing, so that the early temperature rise effect of the catalyst 14 can be further improved. .

  Note that when the pipe 22 is connected to the auxiliary protrusion 20, the auxiliary protrusion 20 may be formed separately from the exhaust gas introduction cylinder portion 15. Further, the manifold portion 17 does not necessarily have to be integrated with the turbine housing 3, and the introduction portion of the wastegate passage 21 is provided integrally with the flange provided at the tip of the exhaust gas introduction cylinder portion 15, so that the flange is connected to the exhaust manifold. It is also possible to connect to a set of parts. Alternatively, when the manifold portion is built in the cylinder head, the flange may be fixed to the cylinder head.

(2) Second Embodiment Next, in the above-described embodiment, the entire pipe 22 is exposed to the outside of the turbine housing 3. However, in the second embodiment shown in FIG. 3 is cast.

  That is, in 2nd Embodiment of FIG. 3, the side meat | flesh part 3a is integrally formed in the site | part on the opposite side to the bearing housing 6 across the turbine side scroll chamber 9 among the turbine housing 3, A considerable range on the inlet side of the turbine housing 3 is cast. The pipe 22 is exposed to the exhaust gas discharge port 11 from the side meat portion 3a, and the direction of the pipe 22 is changed to the L-shaped joint portion 13 at the exhaust gas discharge port 11. Inside the shape joint portion 13, it is bent downward so as to face the catalyst 14.

  In this embodiment, the exhaust gas discharge port 11 is longer than that in the first embodiment, and the flange 13a of the L-shaped joint portion 13 is connected to a flange 11a provided at the opening edge of the exhaust gas discharge port 11 with a bolt or a weld. It is fixed with etc.

  In this embodiment, the outlet portion 22b of the pipe 22 is manufactured in a state exposed to the outside of the exhaust gas discharge port 11. In the assembly, when the L-shaped joint portion 13 is fitted into the exposed portion of the pipe 22 and then the L-shaped joint portion 13 is fixed to the flange 11a of the exhaust gas discharge port 11, the outlet portion 22b of the pipe 22 becomes the catalyst 14. It will be in the state which faced the upper surface. Therefore, the work of connecting the pipe 22 to the catalyst case 12 and the L-shaped joint portion 13 is not necessary, and the assembling work can be reduced accordingly.

  Further, since the pipe 22 is cast into the turbine housing 3, a portion of the pipe 22 exposed to the exhaust gas discharge port 11 and the L-shaped joint portion 13 even when the outlet 22 b of the pipe 22 is a free end. Does not fluctuate due to vibration or the like. The part upstream of the part located in the exhaust gas discharge port 11 of the pipe 22 is cast into the side meat part 3a. For example, the side meat part 3a is provided separately in two front and rear parts. Thus, the pipe 22 can be exposed between the front and rear side meat portions 3a.

(3). Other Embodiments FIG. 4 shows another example of the wastegate valve 24. Among these, in 3rd Embodiment shown to (A), the waste gate valve 24 employ | adopts the system rotated horizontally centering on one end part, and the control system is the same as that of 1st Embodiment. In this embodiment, the wastegate valve 24 has a rectangular shape, and the valve arrangement space 23 has a square cross section corresponding to this. An inward flange 31 that holds the fully closed state of the waste gate valve 24 is formed at the opening edge of the valve arrangement space 23.

  In the fourth embodiment shown in FIG. 4B, the wastegate valve 24 is configured in a swing manner. That is, a lateral arm 32 is provided on the support shaft 25, and a valve lid 33 is provided at the tip of the arm 32. Accordingly, the valve lid 33 swings around the axis of the support shaft 25. In this embodiment, an arrangement space for the arm 32 is required, so that the valve arrangement space 23 is larger than the cross-sectional area of the pipe 22.

  In order to allow the wastegate valve 24 to be fitted into the valve arrangement space 23, the valve arrangement space 23 is opened forward, and the pipe 22 is connected to a cover plate 34 that closes the valve arrangement space 23. The lid plate 34 may be fixed with bolts or may be fixed by welding. In this embodiment, since the support shaft 25 is not exposed to the flow of exhaust gas, there is an advantage that the movement of the waste gate valve 24 is smooth and the durability is excellent.

  While the embodiments of the present invention have been described above, the present invention can be embodied in various ways. For example, when the pipe is externally attached, the outlet portion may be connected to the upper cone portion of the catalyst case (it is also possible to have a shape bent downward in the upper cone portion). It is also possible to configure the entire wastegate passage with a pipe. The pipe may be composed of a plurality of members connected in series.

  Further, a waste type valve as shown in FIG. 3B is used as a wastegate valve, and this is arranged at the L-shaped joint part or the cone part of the catalyst case, and is brought into contact with and separated from the outlet end face of the pipe. A configuration can also be employed. The wastegate valve can be disposed in the middle of the wastegate passage. The range of the pipe occupying the wastegate passage can be arbitrarily set as necessary.

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

DESCRIPTION OF SYMBOLS 1 Exhaust turbocharger 2 Turbine 3 Turbine housing 3a Side wall part 5 Compressor housing 9 Turbine side scroll chamber 10 Exhaust gas main passage 11 Exhaust gas discharge port 12 Catalyst case 13 L-shaped joint part 14 Catalyst 15 Exhaust gas introduction cylinder part 16 Cylinder head 17 Manifold portion 18 Exhaust gas passage 20 Auxiliary protrusion 21 Wastegate passage 22 Pipe constituting the wastegate passage 22a Inlet portion 22b Outlet portion 23 Valve arrangement space 24 Wastegate valve 25 Support shaft

Claims (2)

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
The waste gate passage is a dedicated passage separated from the exhaust gas main passage, and at least a part thereof is constituted by a pipe, and an outlet of the waste gate passage opens toward the inside of the catalyst case. Yes,
Internal combustion engine. In the waste gate passage, at least a portion close to the upstream side is constituted by a pipe, and a valve arrangement space is formed in a portion located on the upstream side of the pipe. The waste gate valve is arranged,
The internal combustion engine according to claim 1.

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