JP2006063851A - Turbocharger built-in cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head with a built-in turbocharger capable of reducing the size of an engine equipped with a turbocharger.
A turbine wheel 21 is disposed in an exhaust port 13 of a cylinder head main body 1 formed by combining a first cylinder head member 1X and a second cylinder head member 1Y at a dividing surface A. And the compressor wheel 23 are arranged in parallel with the cylinder arrangement direction β, and the first cylinder head member 1X and the second cylinder head member 1Y are joined at the dividing plane A. To do.
[Selection] Figure 2

Description

  The present invention relates to a turbocharger built-in cylinder head in which a turbocharger is built into a cylinder head of an engine.

  In general, a turbocharger is configured such that a turbine wheel housed in a turbine housing and a compressor wheel housed in a compressor housing are connected together by a shaft as a connecting member and rotate together. Then, the rotational energy of the turbine wheel due to the exhaust gas of the engine is transmitted to the compressor wheel through the shaft and the compressor wheel is rotated to compress the intake air, and the compressed intake air is forced into the engine combustion chamber. I have to. In the turbocharger, the output of the engine is improved by supercharging the intake air by using the energy of the exhaust gas.

  An engine equipped with such a turbocharger is disclosed in Patent Document 1, for example. This is because the exhaust manifold is connected to the exhaust port of each cylinder, and the turbine of the turbocharger is arranged in the middle of the exhaust pipe connected to the exhaust manifold, the intake manifold is connected to the intake port, and This is a so-called turbocharger external engine in which a turbocharger compressor is arranged in the middle of a connected intake pipe.

JP-A-9-264201

  By the way, in an engine externally attached to a turbocharger as described in the above-mentioned Patent Document 1, the turbine housing has an exhaust gas inlet side end portion at an exhaust gas outlet side end portion of the exhaust manifold. Connected via other exhaust pipe, if necessary. That is, the exhaust gas discharged from the combustion chamber flows into the turbine housing through an exhaust passage such as an exhaust port of the cylinder head and an exhaust manifold. Therefore, due to the large length and volume of the exhaust passage from the combustion chamber of the engine to the turbine housing, there is a problem that if the turbocharger is mounted, the physique of the engine as a whole must be large.

  Accordingly, an object of the present invention is to provide a cylinder head with a built-in turbocharger that solves the above problems and makes it possible to reduce the size of an engine equipped with a turbocharger.

  In order to solve the above-mentioned problems, a turbocharger built-in cylinder head according to one aspect of the present invention is an exhaust of a cylinder head body formed by combining a first cylinder head member and a second cylinder head member with divided surfaces. A turbine wheel is disposed at the port, a connecting member between the turbine wheel and the compressor wheel is disposed in parallel with the arrangement direction of the cylinders, and the first cylinder head member and the second cylinder head member are joined at the dividing surface. It is characterized by comprising.

  According to another aspect of the present invention, in the above-described aspect, a turbine wheel is disposed on a downstream side of a joining portion that joins a plurality of exhaust ports, and a discharge direction of the exhaust gas flowing into the turbine wheel is the direction of the turbine wheel. The exhaust port is formed so as to be in the axial direction.

  According to one aspect of the present invention, since the turbocharger is incorporated in the cylinder head using the cylinder head body itself as a turbine housing, the length and volume of the exhaust passage from the combustion chamber to the turbine wheel are reduced, and the turbocharger is mounted. However, it is possible to reduce the size of the engine.

  Further, according to another aspect of the present invention, the turbine wheel is disposed downstream of the joining portion that joins the plurality of exhaust ports, so that the exhaust gas from the plurality of exhaust ports flows to one turbine wheel. Therefore, the number of parts can be reduced and the influence of the timing of exhaust to the exhaust port can be ignored. Furthermore, since the exhaust direction of the exhaust gas flowing into the turbine wheel is set to the axial direction of the turbine wheel, the exhaust gas can be efficiently received by applying the blade shape of the conventionally used turbine wheel. .

  Hereinafter, a preferred embodiment of a cylinder head incorporating a turbocharger according to the present invention will be described in detail with reference to the accompanying drawings.

  First, a first embodiment in which a turbocharger built-in cylinder head according to the present invention is applied to an in-line three-cylinder four-valve engine will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a perspective conceptual view of a turbocharger built-in cylinder head 100 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of one cylinder of the cylinder head 100. However, both FIG. 1 and FIG. 2 are simplified by omitting the intake valve and the exhaust valve for easy understanding. The present invention does not limit the number of cylinders and the number of valves.

  The turbocharger built-in cylinder head 100 of the first embodiment has a cylinder head main body 1, and a turbine wheel 21, a turbine shaft 22, and a compressor wheel 23 are disposed therein as will be described later. Composed. Hereinafter, the configuration in which these are arranged and the method thereof will be described. Since the intake and exhaust ports corresponding to each cylinder have the same configuration, the common configuration will be described by taking the intake and exhaust ports related to one cylinder as a representative. .

  An intake port 11 and an exhaust port 13 are formed in the cylinder head body 1 so as to be divided into two branches corresponding to the number of intake valves and exhaust valves (not shown) and communicate with the combustion chamber 12. The intake manifold 11 is connected to the intake port 11 of one cylinder at the end opposite to the combustion chamber 12, while the exhaust port 13 is connected to the exhaust port (not shown) at the end opposite to the combustion chamber 12. The manifold is made connectable.

  In the exhaust port 13, the exhaust port 13 is connected to each other by a communication path 13 b on the downstream side of the joining portion 13 a where the flow path that is branched into the bifurcated branch communicated with the combustion chamber 12 is joined. Further, the cylinder head body 1 communicates with a wastegate port 14 formed at the longitudinal end of the cylinder head body 1. The waste gate port 14 has a waste gate valve 14a, and is adjacent to and parallel to the exhaust port 13 of the cylinder located at one end in the longitudinal direction among the three cylinders arranged in series. It is formed so as to be orthogonal to the passage 13b. Further, as will be described in detail later, a turbine accommodating portion 13c in which the turbine wheel 21 is disposed is formed on the downstream side of the merging portion 13a. On the other hand, a compressor housing portion 16 having a compressor accommodating portion 16a in which a compressor wheel 23 is disposed is disposed at the end opposite to the one end where the wastegate port 14 of the cylinder head body 1 is formed in the longitudinal direction. The head body 1 is integrally formed. In the present embodiment, a turbine wheel 21 is provided for each exhaust port 13 of each cylinder so that the number of turbine wheels 21 and the number of cylinders correspond one-to-one.

  Here, the configuration of the turbine accommodating portion 13c described above and the configurations of the turbine shaft accommodating portion 15 and the compressor accommodating portion 16a related thereto will be described with reference to FIG. FIG. 2 is a cross-sectional view of the cylinder head main body 1 relating to one cylinder, which is a cross-sectional view of the cylinder head main body 1 cut along a dashed line BB in FIG. In order to accommodate each turbine wheel 21 in each turbine housing part 13c, each turbine shaft 22 in each turbine shaft housing part 15, and further the compressor wheel 23 in the compressor housing part 16a, the cylinder head body 1 is a first cylinder head member. 1X and the second cylinder head member 1Y are divided and formed.

  As shown in FIG. 2, the first cylinder head member 1 </ b> X and the second cylinder head member 1 </ b> Y are vertically below the central axis of the exhaust port 13 and longitudinally cut a hollow portion inside the exhaust port 13 in the longitudinal direction. Thus, it has a dividing surface A (indicated by a dotted line in FIG. 2) for dividing the cylinder head body 1 in the axial direction of the exhaust port 13. The dividing surface A is also a surface that divides the cylinder head body 1 so that the inner wall surface of the exhaust port 13 becomes the surface of the first cylinder head member 1X and the second cylinder head member 1Y, respectively. The port 13 includes a virtual surface portion. That is, the exhaust port 13 is formed in the cylinder head main body 1 by combining the first cylinder head member 1X and the second cylinder head member 1Y with the dividing surface A in contact. The turbine accommodating portion 13c of the exhaust port 13 has a cross section so that the substantially upper half of the turbine wheel 21 is positioned in the flow path of the exhaust port 13 and the substantially lower half is rotatably embedded in the first cylinder head member 1X. Is formed as a semicircular recess.

  On the other hand, the turbine shaft accommodating portion 15 is not shown in FIG. 2, but is a concave portion having a semicircular cross section along the dividing surface A of the first cylinder head member 1X and the second cylinder head member 1Y. It is formed as. In other words, these are combined to form a hollow portion having a circular cross section. Further, the compressor housing portion 16 having the compressor accommodating portion 16a in which the compressor wheel 23 is disposed is also equally divided with the dividing surface A as a boundary so that the compressor wheel 23 compresses the intake air in the compressor accommodating portion 16a. It has a shape that can be rotated.

  The turbine housing portion 13c, the turbine shaft housing portion 15 and the compressor housing portion 16a are provided continuously, and the turbine shaft housing portion 15 connects the three turbine wheels 21 and the compressor wheel 23 via the turbine shaft 22. Three are provided to be rotatable as a unit. These turbine shaft accommodating portions 15 are arranged so that the turbine shaft 22, which is a connecting member for connecting the turbine wheel 21 and the compressor wheel 23, is in a parallel relationship with the cylinder arrangement direction β, that is, the axial direction α is the cylinder arrangement. It is positioned so as to have a parallel relationship with the direction β.

  In addition, although not shown in detail, bushings 15 c that support the turbine shaft 22 are disposed at both ends of the turbine shaft housing portion 15 of the cylinder head body 1. A lubricant supply port 15a and a lubricant discharge port 15b are formed so that the lubricant can be supplied to them. A lubricating oil passage (not shown) is formed in the cylinder head body 1 so that the lubricating oil supplied for lubricating the camshaft and the like is supplied to the lubricating oil supply port 15a. On the other hand, the lubricating oil discharge port 15b communicates with a lubricating oil passage formed in the cylinder block. It is possible to prevent leakage of the lubricating oil to the exhaust port 13 and the turbine accommodating portion 13c by the bushing 15c that supports the turbine shaft 22, but it may be sealed by further providing a packing.

  Further, as shown in FIG. 2, the exhaust port 13 has a large diameter at the upstream portion 13X, which is a connection location with the combustion chamber 12, and has the largest diameter at the midstream portion 13Y in which the turbine accommodating portion 13c is provided. The inner diameter of the exhaust port 13 is made smaller from the upstream portion 13X to the midstream portion 13Y so as to decrease. On the other hand, the exhaust port 13 has an inner diameter that increases from the midstream portion 13Y to the downstream portion 13Z.

  Furthermore, the cylinder head main body 1 having the above configuration, that is, the first cylinder head member 1X and the second cylinder head member 1Y is made of an aluminum alloy from the viewpoint of thermal conductivity, that is, heat dissipation. The turbine wheel 21, the turbine shaft 22, and the compressor wheel 23 are also made of an aluminum alloy. This does not exclude that the turbine wheel 21, the turbine shaft 22, and the compressor wheel 23 are not made of aluminum alloy but are made of cast iron or the like. Further, in order to sufficiently cool the cylinder head 100, the cylinder head 100 can be cooled by a head water jacket (not shown).

  Next, a manufacturing method including the incorporation of the turbocharger 2 into the cylinder head body 1 will be described according to the flow of time. First, the above-described first cylinder head member 1X and second cylinder head member 1Y are each produced by ordinary casting. The turbine wheel 21 is provided in each turbine accommodating portion 13c of the exhaust port 13 of the first cylinder head member 1X, the turbine shaft 22 is provided with bushings 15c at both ends of each turbine shaft accommodating portion 15, and the compressor shaft is further compressed. The compressor wheel 23 is disposed in the accommodating portion 16a so that the rotation axis α of the turbine shaft 22 is parallel to the cylinder arrangement direction β. In this state, the first cylinder head member 1X is combined with the second cylinder head member 1Y, that is, the first cylinder head member 1X and the second cylinder head member 1Y are brought into contact with each other at the dividing surface A. And the 1st cylinder head member 1X and the 2nd cylinder head member 1Y are joined by this division surface A which is contact | abutting. Specifically, diffusion bonding is performed. Thus, the turbocharger 2 is incorporated into the cylinder head body 1 using the cylinder head body 1 as a housing.

  In the engine having the cylinder head 100 having such a configuration, when exhaust gas is discharged from the combustion chamber 12 of each cylinder to the exhaust port 13, the exhaust gas passes through the merging portion 13 a of the exhaust port 13 and is turbine. It is discharged to the exhaust manifold via the accommodating portion 13c. Then, each turbine wheel 21 is rotated when the exhaust gas passes through each turbine accommodating portion 13c. When the turbine wheel 21 is thus rotated, the rotation is also transmitted to the compressor wheel 23 via the turbine shaft 22 so that the compressor wheel 23 is rotated. On the other hand, when the compressor wheel 23 is thus rotated, the intake air that has flowed into the compressor housing portion 16 a is pressurized and superposed to the combustion chamber 12 of each cylinder via the intake pipe 4 and the intake manifold 3. The intake air amount can be adjusted by controlling the opening degree of the throttle valve 41 of the intake pipe 4 connected to communicate the cylinder head body 1 and the intake manifold 3 by controlling an actuator (not shown). Has been. The discharge pressure of the compressor wheel 23 can be controlled by controlling the opening / closing of the waste gate valve 14a by an actuator (not shown) and the like, and by controlling the rotational speed of the turbine wheel 21 by bypassing the exhaust gas.

  As described above, incorporating the turbocharger 2 into the cylinder head body 1 to form the cylinder head 100 has the following effects. First, by incorporating the turbocharger 2 into the cylinder head body 1, the exhaust gas flows into the turbine housing through the exhaust port and the exhaust manifold of the cylinder head with the turbocharger externally attached as in the prior art. Compared to the case, the length and volume of the exhaust passage from the combustion chamber 12 to the turbine wheel 21 are reduced, and the physique of the engine including the turbocharger 2 can be reduced. Further, as compared with the case where an external turbocharger is provided, the turbine wheel 21 is reduced to a size suitable for the size of the exhaust port 13 and its inertial mass is reduced. It is possible to improve the responsiveness of the rotation of the 21. Further, the fact that the cylinder head body 1 is made of an aluminum alloy means that the turbine housing is made of an aluminum alloy, and as a result, the mass of the turbine housing is larger than when the turbine housing is conventionally made of cast iron. (Heat capacity) can be reduced, so that, for example, a larger amount of heat can be supplied to a catalyst provided for further downstream NOx removal and the like, and catalyst warm-up can be performed efficiently. Further, for example, in addition to narrowing the flow path through which the exhaust gas flows at the confluence portion 13a in the exhaust port 13, the exhaust port 13 is squeezed in front of the turbine wheel 21 so as to expand at the outlet of the turbine wheel 21. The turbocharger 2 can efficiently extract energy from the exhaust gas flowing through the port 13. Furthermore, since the cylinder head body 1 is a housing of the turbocharger 2, the number of parts can be reduced.

  Next, a second embodiment of the turbocharger built-in cylinder head 100 according to the present invention will be described with reference to FIG. The second embodiment is mainly different from the first embodiment in two points. First, there is only one turbine wheel 21, and the turbine wheel 21 is disposed on the downstream side of the merging portion 13 p of all the exhaust ports 13. Secondly, the exhaust gas flowing into one turbine wheel 21 flows out in the axial direction of the turbine wheel 21. In the following, the same points as those in the first embodiment will be avoided and the differences will be described. The junction 13p is formed so that a plurality of exhaust ports are used as one exhaust port, and is a junction that is different from the junction 13a that combines two forks. In the embodiment, the joining portion 13p is referred to as a second joining portion, and the joining portion 13a in the first embodiment described above is referred to as a first joining portion.

  The three exhaust ports 13 are grouped together at a second merge section 13p on the downstream side of each first merge section 13a, and the exhaust gas merges and flows at the second merge section 13p. Yes. One turbine wheel 21 is disposed in a turbine accommodating portion 13c formed on the downstream side of the outlet 13q at the end of the second merging portion 13p. The delivery port 13q is located downstream of the combustion chamber 12 disposed at the end of the cylinder head body 1. In other words, the turbine wheel 21 is disposed closest to the compressor wheel 23 among the three cylinders and downstream of the exhaust port 13 of the cylinder at the end. Then, the exhaust gas from each exhaust port 13 of each cylinder is merged at the second merging portion 13p and flows into the turbine wheel 21 from a direction γ orthogonal to the axial direction of the turbine wheel 21, and is parallel to the axial direction of the turbine wheel 21. The exhaust port 13 is formed to be bent 90 degrees at the turbine accommodating portion 13c so as to flow out in the correct direction δ. The wastegate port 14 is provided so as to be orthogonal to the merge portion 13p, and communicates with the exhaust port 13 of the center cylinder among the three cylinders. Note that the turbine wheel 21 may be located anywhere in the exhaust port 13 of the cylinder head body 1.

  As described above, according to the second embodiment, the turbocharger 2 is incorporated into the cylinder head body 1 as in the first embodiment, so that the physique of the engine equipped with the turbocharger 2 can be reduced. Become. Since the turbine wheel 21 is disposed on the downstream side of the merging portion 13p of the exhaust port 13, the exhaust gas from the plurality of exhaust ports 13 is allowed to flow to one turbine wheel 21, thereby reducing the number of parts. In addition, it is possible to ignore the influence of the exhaust timing on the exhaust port 13. The discharge direction δ of the exhaust gas flowing into the turbine wheel 21 is set to the axial direction of the turbine wheel 21, so that the exhaust gas can be efficiently received by applying the blade shape of the turbine wheel 21 that has been conventionally used. become.

  The turbocharger built-in cylinder head according to the present invention has been described based on the first embodiment and the second embodiment, but the present invention is not limited to the above embodiment. Specifically, the number of cylinders of the engine is three, but it may be four, six, eight, or any other number. Further, the number of turbine wheels may be set regardless of the number of cylinders. The cylinder head body is divided and formed from the first cylinder head member and the second cylinder head member, but the exhaust port is provided with a turbine wheel so that the turbocharger can be incorporated into the cylinder head. If the port has a dividing surface, it may be further divided into a plurality of members. Furthermore, the division | segmentation surface should just be made so that the location provided with a turbine wheel may be located in an exhaust port, and division surfaces other than such a location do not need to pass an exhaust port. In addition, the split surface that divides at least a part of the exhaust port in the axial direction thereof may include the central axis of the exhaust port. Further, the compressor wheel may be disposed so as to be exposed from the end of the cylinder head body. In this case, it is preferable that the compressor housing of the compressor wheel is directly fixed to the cylinder head body so as to cover the compressor wheel, and substantially all of the turbocharger is incorporated in the cylinder head body. In the first and second embodiments, the intake manifold and the intake pipe that interpose the cylinder head body are described as being independent of the cylinder head. However, they may be integrated into the cylinder head body.

1 is a perspective conceptual diagram of a turbocharger built-in cylinder head according to a first embodiment of the present invention. It is a cross-sectional view regarding one cylinder of the cylinder head shown in FIG. FIG. 5 is a perspective conceptual view of a cylinder head with a built-in turbocharger according to a second embodiment of the present invention.

Explanation of symbols

1 cylinder head body 1X first cylinder head member 1Y second cylinder head member 13 exhaust port 2 turbocharger 21 turbine wheel 22 turbine shaft 23 compressor wheel α turbine shaft rotation axis β cylinder arrangement direction

Claims (2)

  A turbine wheel is disposed in the exhaust port of the cylinder head body formed by combining the first cylinder head member and the second cylinder head member on the dividing surface, and the connecting member between the turbine wheel and the compressor wheel is connected to the cylinder. A turbocharger built-in cylinder head, wherein the cylinder head is arranged in parallel with the arrangement direction and is formed by joining the first cylinder head member and the second cylinder head member at the dividing surface. The turbine wheel is disposed on the downstream side of a joining portion that joins a plurality of the exhaust ports, and the exhaust port is formed so that the exhaust gas flowing into the turbine wheel is discharged in the axial direction of the turbine wheel. The turbocharger built-in cylinder head according to claim 1.

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