JP5587380B2 - Cylinder head water jacket structure - Google Patents

Description

  The present invention relates to a water jacket structure for a cylinder head, and more particularly to a water jacket structure for a cylinder head in which an exhaust collecting portion for collecting a plurality of exhaust ports is integrally formed.

  2. Description of the Related Art As a cylinder head, one in which an exhaust collecting portion that collects a plurality of exhaust ports extending from a plurality of combustion chambers is integrally formed is known. In such a cylinder head, an exhaust water jacket for cooling the exhaust port and the exhaust collecting portion is provided in addition to the combustion chamber water jacket for cooling the combustion chamber in order to sufficiently cool the exhaust collecting portion that is likely to become high temperature. It has been.

  Further, an opening serving as an outlet for the coolant flowing in the exhaust water jacket and an opening serving as an outlet for the coolant flowing in the combustion chamber water jacket are formed on one side surface of the cylinder head in the cylinder row direction. In addition, a water outlet for supplying the coolant discharged from the opening to a radiator, a heater, or the like is attached. The plurality of openings are formed at a predetermined interval in the width direction of one side surface, and a single space where the coolant discharged from the plurality of openings joins is formed inside the water outlet. (For example, refer to Patent Document 1).

Japanese Patent No. 4337851

  However, since the space portion described in Patent Document 1 is formed in a substantially constant vertical cross-sectional area along the width direction of one side surface, the coolant flowing in from the exhaust water jacket and the combustion chamber water jacket flow in. The cooled liquid easily collides in the space, and the flow of the cooling liquid in the space is disturbed. For this reason, the cooling liquid tends to stay in the space, and as a result, the flow rate of the cooling liquid flowing in each water jacket may decrease.

  This invention is made in view of such a problem, and makes it a subject to provide the water jacket structure of the cylinder head which can suppress the flow velocity fall of the cooling fluid which flows through each water jacket.

A water jacket structure of a cylinder head according to the present invention includes a plurality of combustion chamber top portions formed on a bottom surface of the cylinder head, a plurality of exhaust ports communicating with each of the plurality of combustion chamber top portions, and an inside of the cylinder head. An exhaust collecting portion that collects the plurality of exhaust ports, a combustion chamber water jacket that cools the top of the combustion chamber, and an upper side in the cylinder axial direction with respect to the exhaust collecting portion, to cool the exhaust collecting portion An upper exhaust water jacket, a lower exhaust water jacket that is disposed on the lower side in the cylinder axial direction with respect to the exhaust collecting portion, and that cools the exhaust collecting portion, on one side surface of the cylinder head in the cylinder row direction A first outlet opening that opens and serves as an outlet for cooling liquid flowing in the upper exhaust water jacket; Opening on one side of the cylinder row of the head, a second outlet opening serving as an outlet for the coolant flowing in the lower exhaust water jacket, and opening on one side of the cylinder head in the cylinder row, A third outlet opening serving as an outlet for the coolant flowing through the water jacket for the combustion chamber, and the cooling attached to one side surface of the cylinder head in the cylinder row direction and discharged from the first to third outlet openings. A water outlet for supplying liquid to other components, and the first outlet opening and the second outlet opening are predetermined in the width direction of one side surface in the cylinder row direction with respect to the third outlet opening. A single space portion is formed in the water outlet and communicated with the first to third outlet openings, and the space portion is formed in the first outlet opening. Provided in a position corresponding to the first outlet and the second outlet opening, mainly provided in a position corresponding to the third outlet opening, a first space for supplying the coolant to the radiator, and mainly cooled to the heater. A second space for supplying a liquid, and the first outlet opening and the second outlet opening, and the third outlet opening; the first space and the second outlet; And a diaphragm portion having a smaller vertical cross-sectional area than the space portion.
Note that “up and down in the cylinder axis direction” means that the upper side is the upper side and the lower side is the lower side with respect to the cylinder orthogonal plane that is a plane orthogonal to the cylinder axis.

According to the present invention, the space formed inside the water outlet is provided at a position corresponding to the first outlet opening and the second outlet opening, and the first space that mainly supplies the coolant to the radiator; A second space provided at a position corresponding to the third outlet opening and mainly supplying the coolant to the heater, and a position corresponding to the first outlet opening and between the second outlet opening and the third outlet opening. And the first space portion and the throttle portion having a smaller vertical cross-sectional area than the second space portion, and the radiator from the upper and lower exhaust water jackets through the first space portion with the throttle portion as a boundary. And a flow from the combustion chamber water jacket to the heater through the second space. This makes it difficult for the coolant flowing in from the upper and lower exhaust water jackets and the coolant flowing in from the combustion chamber water jacket to collide in the space, and the flow of the coolant in the space is stabilized. Therefore, it becomes difficult for the cooling liquid to stay in the space, and as a result, a decrease in the flow rate of the cooling liquid flowing in each water jacket can be suppressed.
Further, when a structure that blocks between the first space portion and the second space portion is adopted, the coolant flowing into the second space portion from the combustion chamber water jacket cannot be guided to the radiator. Since the throttle part is provided, the inflow of the cooling liquid from the second space part to the first space part is allowed without greatly affecting the flow of the cooling liquid between the first space part and the second space part. Is done. Thereby, the coolant flowing in from the upper and lower exhaust water jackets and the coolant flowing in from the combustion chamber water jacket are merged in a well-balanced manner, and a sufficient amount of coolant supplied to the radiator can be secured.
That is, according to the present invention, it is possible to achieve both the suppression of the collision between the coolants flowing in from the respective water jackets and the preferable merging of the coolants flowing from the respective water jackets.

  The total flow rate of the coolant flow rate F1 discharged from the first outlet opening and the coolant flow rate F2 discharged from the second outlet opening is discharged from the third outlet opening. It is preferable that the relationship is set such that F1 + F2> F3, which is greater than the flow rate F3 of the coolant.

  According to such a configuration, the total flow rate of the coolant flow F1 discharged from the first outlet opening and the coolant flow F2 discharged from the second outlet opening is discharged from the third outlet opening. Since the relationship of F1 + F2> F3, which is larger than the flow rate F3 of the coolant, is set, a sufficient amount of coolant supplied to the radiator can be secured.

  ADVANTAGE OF THE INVENTION According to this invention, the water jacket structure of the cylinder head which can suppress the flow rate fall of the cooling fluid which flows through each water jacket can be provided.

It is sectional drawing of the internal combustion engine which has the water jacket structure of the cylinder head which concerns on this embodiment. It is a perspective view of a cylinder head and a water outlet. It is the perspective view drawn through seeing through the exhaust gathering part inside a cylinder head, and a head side water jacket. It is the perspective view which decomposed | disassembled and showed the head side water jacket and the exhaust_gas | exhaustion gathering part up and down. FIG. 6 is a bottom view of an intake water jacket, a combustion chamber water jacket, and an upper exhaust water jacket. It is a bottom view of the water jacket for lower exhaust. It is the front view which looked at the head side water jacket and the exhaust gas collection part from the front. It is a perspective view of a water outlet. It is a front view which shows the state which looked at the water outlet from the front side. It is a rear view which shows the state which looked at the water outlet from the back side. It is a disassembled perspective view for demonstrating the flow of the cooling fluid from the block side water jacket to the water jacket for intake. It is a disassembled perspective view for demonstrating the flow of the cooling fluid from the block side water jacket to the lower water jacket for exhaust. It is the bottom view which overlapped and drew the head side water jacket and the block side water jacket on the gasket. It is a bottom view for demonstrating the flow of the cooling fluid of the water jacket for intake, the water jacket for combustion chambers, the water jacket for upper side exhaust, and the water outlet. It is a bottom view for demonstrating the flow of the cooling fluid of the water jacket for lower side exhaust, and a water outlet.

  An embodiment of the present invention will be described in detail with reference to FIGS. In the description, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the direction will be described based on the front, rear, left, right, top and bottom in a state where the internal combustion engine E is installed in the vehicle, as shown in each drawing.

FIG. 1 is a cross-sectional view of an internal combustion engine having a water jacket structure for a cylinder head according to the present embodiment.
As shown in FIG. 1, an internal combustion engine E to which the present invention is applied includes a cylinder block 1 in which four cylinders 1 a (only one is shown in FIG. 1) are arranged in series, and are integrally provided. The cylinder head 2 is coupled to the upper end of the cylinder, the gasket 3 is installed between the cylinder block 1 and the cylinder head 2, and the head cover (not shown) is coupled to the upper end of the cylinder head 2. Equipped with an engine body.

The internal combustion engine E is a multi-cylinder internal combustion engine that includes four cylinders 1a, pistons 4 that are reciprocally fitted to the cylinders 1a, and crankshafts 6 that are connected to the pistons 4 via connecting rods 5. The vehicle is mounted in a horizontal arrangement in which the rotation center line of the crankshaft 6 is directed in the left-right direction. The internal combustion engine E is disposed with the intake side facing the rear of the vehicle and the exhaust side facing the front of the vehicle.
For each cylinder 1a, a combustion chamber 7 is formed between the piston 4 and the cylinder head 2 between the piston 4 and the cylinder head 2 in the cylinder axis direction that is parallel to the cylinder axis Lc of the cylinder 1a. Is done.
In the present embodiment, the internal combustion engine E is installed so that the cylinder axis Lc and the vertical axis direction (that is, the vertical direction) coincide with each other. However, the present invention is not limited to this, and for example, the cylinder axis The internal combustion engine E may be installed such that Lc is inclined with respect to the vertical axis direction.

  The cylinder block 1 includes a block-side water jacket 10 that serves as a coolant flow path for cooling the cylinder 1a, in addition to the cylinder 1a and the crankcase (not shown). The block-side water jacket 10 is a concave groove-like space that continuously surrounds the entire four cylinders 1a, and is open on the upper surface of the cylinder block 1 (see FIGS. 11 and 12). A coolant cooled by a radiator (not shown) is supplied to one end side of the block-side water jacket 10. The block-side water jacket 10 communicates with an intake water jacket 50 and a lower exhaust water jacket 90, which will be described later, through the through holes 32, 35 and the like of the gasket 3, and supplies coolant to both. ing. The block side water jacket 10 and the gasket 3 will be described in detail later.

  FIG. 2 is a perspective view of the cylinder head and the water outlet. FIG. 3 is a perspective view illustrating the exhaust collecting part and the head-side water jacket inside the cylinder head. In addition, in FIG. 3, the external shape of the cylinder head 2 is drawn with the virtual line (two-dot chain line).

  The cylinder head 2 is a metal member manufactured by casting using a core. As shown in FIGS. 1 to 3 (mainly FIG. 1), the cylinder head 2 includes four combustion chamber tops 21 (only one is shown in FIG. 1) constituting the top of the combustion chamber 7, and each combustion chamber 7. An intake port 22 for introducing air into the exhaust chamber, an exhaust port 23 for exhausting combustion gas from each combustion chamber 7, an exhaust collecting portion 24 for collecting a plurality of exhaust ports 23 inside the cylinder head 2, and for cooling them The head side water jacket 40 is mainly included. Further, the cylinder head 2 has a valve operating chamber 25 for accommodating a part of the valve operating mechanism (not shown) at the upper part thereof.

  The combustion chamber top 21 is a substantially conical recess provided on the bottom surface 2 a of the cylinder head 2. The intake port 22 communicates each combustion chamber top 21 with the rear surface 2b of the cylinder head 2. The exhaust port 23 communicates each combustion chamber top portion 21 and the exhaust collecting portion 24. Two intake ports 22 and two exhaust ports 23 are provided for each combustion chamber top 21. The intake port 22 and the exhaust port 23 are provided with an intake valve and an exhaust valve (not shown).

  As shown in FIG. 2, the exhaust collecting portion 24 has one opening 24 a that opens at a substantially central portion in the left-right direction of the front surface 2 c of the cylinder head 2. The exhaust collecting portion 24 is provided in a portion of the cylinder head 2 that projects forward from the cylinder block 1 (see FIG. 1). The valve operating chamber 25 is a concave space formed in the upper surface 2 d of the cylinder head 2. The valve operating chamber 25 accommodates a part of a valve operating mechanism such as a camshaft, a rocker arm, and a valve (not shown). Further, on the left side surface 2e of the cylinder head 2, outlet openings 63, 83, and 93 serving as coolant outlets of the head side water jacket 40 described later are formed. A water outlet 100 that distributes the coolant discharged from the outlet openings 63, 83, and 93 to the heater and the radiator is attached to the left side surface 2e of the cylinder head 2. The outlet openings 63, 83, 93 and the water outlet 100 will be described in detail later.

  The front surface 2c of the cylinder head 2 has two support holes 2f formed by connecting portions that connect the core installed in the cavity during casting and the baseboard supported by the mold. The support hole 2f is closed with a cap attached later.

  As shown in FIGS. 1 and 3, the head-side water jacket 40 is a space serving as a coolant flow path, and cools the intake water jacket 50 for cooling the intake port 22 and the combustion chamber top 21. A combustion chamber water jacket 60 and an exhaust water jacket 70 for cooling the exhaust port 23 and the exhaust collecting portion 24.

  As shown in FIG. 1, the intake water jacket 50 is provided below the intake port 22. The combustion chamber water jacket 60 is provided immediately above the combustion chamber top 21 and between the intake port 22 and the exhaust port 23. The exhaust water jacket 70 includes an upper exhaust water jacket 80 disposed above the exhaust port 23 and the exhaust collecting portion 24, and a lower exhaust water jacket disposed below the exhaust port 23 and the exhaust collecting portion 24. 90.

  The intake water jacket 50 communicates with the block-side water jacket 10 and also with the combustion chamber water jacket 60 (see the broken line in FIG. 1). The combustion chamber water jacket 60 communicates with the block-side water jacket 10 and also communicates with the upper exhaust water jacket 80. The lower exhaust water jacket 90 communicates with the block-side water jacket 10. The lower exhaust water jacket 90 does not communicate with the intake water jacket 50, the combustion chamber water jacket 60, and the upper exhaust water jacket 80. That is, the upper exhaust water jacket 80 and the lower exhaust water jacket 90 form independent flow paths inside the cylinder head 2.

  Next, regarding the detailed structure of the exhaust collecting portion 24 and the head side water jacket 40 (that is, the intake water jacket 50, the combustion chamber water jacket 60, the upper exhaust water jacket 80, and the lower exhaust water jacket 90), This will be described with reference to FIGS.

FIG. 4 is a perspective view showing the head-side water jacket and the exhaust collecting part in an exploded manner. FIG. 5 is a bottom view of an intake water jacket, a combustion chamber water jacket, and an upper exhaust water jacket. FIG. 6 is a bottom view of the lower exhaust water jacket. FIG. 7 is a front view of the head side water jacket and the exhaust collecting portion as viewed from the front.
Here, in FIG. 4 to FIG. 7, for convenience of explanation, the exhaust collecting portion 24 and the head-side water jacket 40 that are spaces are drawn as if they existed (that is, cores corresponding to them).

  As shown in FIG. 4, the exhaust collecting portion 24 includes a first collecting portion 24 b that collects two exhaust ports 23 communicating with each combustion chamber 7 into one, and four first collecting portions 24 b that are openings. And a second collection unit 24c that collects in one place immediately before 24a. The second collecting portion 24c and the opening 24a are provided at a substantially central portion in the left-right direction of the cylinder head 2. Of the four first collecting portions 24b, the right and left first collecting portions 24b are longer than the two first collecting portions 24b in the middle of the two. The front side surface of the right and left first collecting portions 24b is a protrusion 81 of an upper exhaust water jacket 80 and a protrusion 91 of a lower exhaust water jacket 90 (see FIGS. 1, 4 to 6). ) Constitutes the downstream side portion 24d of the exhaust collecting portion 24 to be cooled. The downstream side portion 24d is inclined so as to be positioned on the front side as it approaches the central opening portion 24a from the exhaust ports 23 at both left and right ends in plan view.

  As shown in FIGS. 4 and 5 (mainly FIG. 5), the intake water jacket 50 is a portion for cooling the intake port 22 (see FIG. 1), and traverses the lower side of each intake port 22 in the left-right direction. It is extended while meandering. The intake water jacket 50 has eight intake-side inflow portions 51 that open to the bottom surface 2 a of the cylinder head 2 (see FIG. 2) below each intake port 22. The intake water jacket 50 and the combustion chamber water jacket 60 are located at positions corresponding to each other between the adjacent cylinders 1a (hereinafter sometimes referred to as “between cylinder shafts”) and outside the left and right cylinders 1a. It has the communication part 52 which connects. Below the communication portion 52 between the three cylinder shafts, an inter-axis inflow portion 53 that opens to the bottom surface 2a of the cylinder head 2 is provided.

  The combustion chamber water jacket 60 is a portion that cools the combustion chamber top 21 (see FIG. 1), and extends above the combustion chamber top 21 in the left-right direction. The combustion chamber water jacket 60 is formed wider in the front-rear direction than the intake water jacket 50 and surrounds a spark plug (not shown). The combustion chamber water jacket 60 has two combustion chamber side inflow portions 61 that open to the bottom surface 2a of the cylinder head 2 at the right end (see FIG. 7). In addition, the combustion chamber water jacket 60 has a communication portion 62 that communicates with the upper exhaust water jacket 80 at a position corresponding to between the exhaust ports 23 (see FIG. 1). Further, the combustion chamber water jacket 60 has an outlet opening 63 that opens to the left side surface 2e of the cylinder head 2 and serves as an outlet for the coolant at the left end (see FIG. 2). The outlet opening 63 is formed wider in the front-rear direction than the combustion chamber water jacket 60 and extends to the front side.

  As shown in FIGS. 4, 5, and 7 (mainly FIG. 5), the upper exhaust water jacket 80 is provided so as to cover the upper sides of the exhaust ports 23 and the exhaust collecting portion 24. The upper exhaust water jacket 80 has a wider width in the front-rear direction and a smaller thickness in the vertical direction than the intake water jacket 50 and the combustion chamber water jacket 60 (FIG. 1). reference). The upper exhaust water jacket 80 has a projecting portion 81 projecting downward from the front end portion (see FIG. 1). The protruding portion 81 is disposed so as to face the downstream side portion 24 d of the exhaust collecting portion 24. In addition, the protrusion part 81 is not provided in the part 82 corresponding to the opening part 24a of the exhaust gas collection part 24 among the front side edge parts of the upper water jacket 80 for exhaust. The upper exhaust water jacket 80 has, at the left end, an outlet opening 83 that opens to the left side surface 2e of the cylinder head 2 and serves as a coolant outlet (see FIG. 2).

  Incidentally, with reference to FIG. 5, the intake port 22 is installed in a portion 55 between the intake water jacket 50 and the combustion chamber water jacket 60. In addition, a spark plug (not shown) is installed in a portion 65 of the combustion chamber water jacket 60 corresponding to the center position of the cylinder 1a. Further, an exhaust valve (not shown) is installed in a portion 67 between the combustion chamber water jacket 60 and the upper exhaust water jacket 80.

  As shown in FIGS. 4, 6, and 7 (mainly FIG. 6), the lower exhaust water jacket 90 is provided so as to cover the lower sides of the exhaust ports 23 and the exhaust collecting portion 24. The lower exhaust water jacket 90 is formed flat so as to have the same thickness as the upper exhaust water jacket 80 (see FIG. 1). The lower exhaust water jacket 90 has a protrusion 91 that protrudes upward from the front end (see FIG. 1). The protruding portion 91 is disposed so as to face the downstream side portion 24 d of the exhaust collecting portion 24. In addition, the protrusion 91 is not provided in the part 92 corresponding to the opening part 24a of the exhaust gas collection part 24 among the front edge parts of the lower exhaust water jacket 90. The lower exhaust water jacket 90 has an outlet opening 93 that opens to the left side surface 2e of the cylinder head 2 and serves as an outlet for cooling liquid at the left end (see FIG. 2). The lower exhaust water jacket 90 has eight exhaust-side inflow portions 94 that open to the bottom surface 2a of the cylinder head 2 at positions corresponding to the lower ends of the exhaust ports 23 at the rear end. . Thus, since the exhaust-side inflow portion 94 is provided immediately below the exhaust port 23, the exhaust port 23 can be efficiently cooled. An additional inflow portion 95 is provided between the two exhaust side inflow portions 94 on the side farthest from the outlet opening 93 (that is, the upstream side).

  The exhaust collecting portion 24 and the head-side water jacket 40 include a second water jacket core 300, an exhaust core 400, and a first water jacket core 200, which are sand molds as shown in FIG. The cylinder head 2 is formed by being installed in this order from below in a cavity of a casting mold (not shown). That is, since the installation of the core is completed simply by arranging the three cores so as to be stacked in order from the bottom, complication of the installation work of the core is suppressed.

  Next, the outlet openings 63, 83, 93 and the water outlet 100 will be described with reference to FIGS. 2 and 8 to 10. FIG. FIG. 8 is a perspective view of the water outlet. FIG. 9 is a front view showing a state in which the water outlet is viewed from the front side. FIG. 10 is a rear view showing a state in which the water outlet is viewed from the back side. In addition, the hatching of FIG. 10 has shown the attachment surface with the cylinder head 2. FIG.

  As shown in FIG. 2, the outlet opening 83 and the outlet opening 93 are formed side by side. The outlet opening 83 and the outlet opening 93 are formed at a predetermined distance from the outlet opening 63 in the width direction of the left side surface 2e (forward). The outlet opening 83 constitutes a first outlet opening referred to in the claims, the outlet opening 93 constitutes a second outlet opening referred to in the claims, and the outlet opening 63 is claimed. The 3rd exit opening part in the range of is comprised.

  In the present embodiment, the total flow rate of the coolant flow rate F1 discharged from the outlet opening 83 and the coolant flow rate F2 discharged from the outlet opening 93 is equal to the coolant flow rate F3 discharged from the outlet opening 63. The relationship of more than F1 + F2> F3 is set. Further, the flow rate S1 of the coolant discharged from the outlet opening 93, the flow rate S2 of the coolant discharged from the outlet opening 83, and the flow rate S3 of the coolant discharged from the outlet opening 63 are S1> S2. > S3 is set. That is, the flow rate of the coolant flowing in the upper and lower exhaust water jackets 80 and 90 is set higher than the flow rate of the coolant flowing in the combustion chamber water jacket 60. Note that the vertical cross-sectional areas of the upper exhaust water jacket 80 and the lower exhaust water jacket 90 are made smaller than the vertical cross-sectional areas of the exhaust water jacket 70, respectively, or the opening areas of the outlet opening 83 and the outlet opening 93 are made to be outlet openings. A difference in flow velocity between the upper and lower exhaust water jackets 80 and 90 and the combustion chamber water jacket 60 is generated by reducing the opening area of the portion 63.

  The water outlet 100 is a metal member manufactured by casting using a core. As shown in FIGS. 8 to 10 (mainly FIG. 10), the water outlet 100 has an outlet 110, a plurality of connecting portions 120a to 120g, and a plurality of fastening portions 130.

  As shown in FIG. 10, the outlet 110 serving as a space extends along the front-rear direction (the width direction of the left side surface 2e), and the coolant discharged from the outlet openings 63, 83, 93 is supplied to a radiator, a heater, or the like. A single space to supply. The outlet 110 includes a first space part 111, a second space part 112, and a throttle part 113.

  The first space 111 is a space that is provided at a position corresponding to the outlet openings 83 and 93 and into which the coolant in the upper exhaust water jacket 80 and the lower exhaust water jacket 90 mainly flows. An opening 111 a that communicates with the outlet openings 83 and 93 is formed on the back surface of the first space 111.

  The second space portion 112 is provided at a position corresponding to the outlet opening 63 and is a portion into which mainly the coolant in the intake water jacket 50 and the combustion chamber water jacket 60 flows. An opening 112 a that communicates with the outlet opening 63 is formed on the back surface of the second space 112.

  The throttle portion 113 is a space that is provided at a position corresponding to between the outlet openings 83 and 93 and the outlet opening 63 and has a smaller vertical cross-sectional area than the first space portion 111 and the second space portion 112. The diaphragm 113 is narrowed so as to be narrowed up and down. Specifically, the upper wall inner surface 114 forming the outlet 110 is inclined to the lower surface as it goes from the first space portion 111 to the second space portion 112, and the first space portion 112 to the first space portion 112. In addition to providing an inclined surface 114b that is inclined so as to be positioned on the lower side toward the space portion 111, the lower wall inner surface 115 that forms the outlet 110 has a position corresponding to the vicinity of the boundary between the inclined surfaces 114a and 114b in the vertical direction. The narrowed portion 113 is formed by providing a protrusion 115a that protrudes a predetermined length above the other portion. The restrictor 113 is configured to flow from the upper exhaust water jacket 80 and the lower exhaust water jacket 90 to the radiator through the first space 111, and from the intake water jacket 50 and the combustion chamber water jacket 60 to the second space. 112 has a function of easily generating a flow toward the heater via 112. Further, by providing the throttle portion 113, the flow from the second space portion 112 to the first space portion 111 is not significantly affected between the first space portion 111 and the second space portion 112 without greatly affecting the flow of the coolant. Coolant inflow is allowed.

  As shown in FIGS. 8 and 9, the connecting portions 120 a to 120 g are formed to protrude outward from the surface (outer surface) of the water outlet 100 and are cylindrical portions to which pipes or water temperature sensors (not shown) are connected. The connection parts 120a to 120e communicate with the first space part 111 and are provided biased forward. The connection portion 120f communicates with the second space portion 112 and is provided biased rearward. The connection portion 120g communicates with the second space portion 112 and is provided at the center portion in the front-rear direction. The vertical cross-sectional area (outflow cross-sectional area) of the connecting part 120a communicating with the radiator is formed larger than the vertical cross-sectional areas of the other connecting parts 120b-120g. Thereby, the flow volume of the cooling fluid supplied to a radiator can be increased. As shown in FIG. 10, the opening 120 a 1 facing the first space 111 of the connecting portion 120 a is provided so as to face the outlet openings 83 and 93 (see FIG. 2) of the cylinder head 2. Moreover, the opening part (illustration omitted) which faces the 2nd space part 112 of the connection part 120g is provided so that it may be substantially orthogonal to the exit opening part 63 of the cylinder head 2 (refer FIG. 2, FIG. 8).

  With such a configuration, as shown in FIG. 8, the coolant in the first space 111 is supplied to the radiator through the connecting portion 120a and the piping. In addition, the coolant in the first space 111 is supplied to the CVT warmer through the connection part 120b and the pipe, and is supplied to the expansion tank through the connection part 120c and the pipe. Further, the coolant in the first space 111 is supplied to the thermostat through the connecting part 120d and the pipe. On the other hand, the coolant in the second space 112 is supplied to the throttle body through the connection portion 120f and the piping, and is supplied to the heater through the connection portion 120g and the piping. Note that a water temperature sensor (not shown) for detecting the temperature of the cooling water is attached to the connecting portion 120e.

  The fastening portion 130 is a portion that is provided at an appropriate position of the water outlet 100 and fastened to the cylinder head 2 with a bolt (not shown). As shown in FIGS. 8 to 10, the fastening portion 130 is formed with an insertion hole 130 a through which a bolt is inserted. The insertion hole 130a is provided at a position corresponding to the insertion hole 2e1 formed in the left side surface 2e of the cylinder head 2 (see FIGS. 2 and 8).

FIG. 11 is an exploded perspective view for explaining the flow of the coolant from the block-side water jacket to the intake water jacket. FIG. 12 is an exploded perspective view for explaining the flow of the coolant from the block-side water jacket to the lower exhaust water jacket. FIG. 13 is a bottom view in which a head side water jacket and a block side water jacket are overlapped with a bottom view of the gasket.
In FIG. 11 and FIG. 12, for convenience of explanation, portions of the head-side water jacket 40 other than the inflow portion are drawn with virtual lines (two-dot chain lines). In FIG. 13, the gasket 3 is hatched with dots and the opening of the block-side water jacket 10 is drawn with a virtual line (thick broken line). Furthermore, in FIG. 13, the water outlet 100 is schematically drawn.

  As shown in FIGS. 11, 12, and 13, the block-side water jacket 10 is formed so as to entirely surround the four cylinders 1a. The block-side water jacket 10 has a coolant introduction portion 11 that is wider than other portions on the front side of the rightmost cylinder 1a. A partition member 11a is inserted into the introduction portion 11, and regulates the direction in which the coolant flows. In the present embodiment, the coolant pipe P is connected to the left side of the partition member 11a of the introduction portion 11. Further, the block-side water jacket 10 has a constricted portion 12 at a portion corresponding to between the cylinders 1a (between the cylinder shafts). In addition, a concave groove-shaped inter-axis slit 13 is formed between the cylinder shafts so that the front and rear constricted portions 12 communicate with each other.

  As shown in FIGS. 11, 12, and 13 (mainly FIG. 13), the gasket 3 is a metal plate-like member that seals the coupling portion between the cylinder block 1 and the cylinder head 2. The gasket 3 has four cylinder openings 31 corresponding to the four cylinders 1 a of the cylinder block 1. The gasket 3 includes an intake-side through hole 32 and an inter-axis through hole 33 formed at positions corresponding to the intake-side inflow portion 51 and the inter-axis inflow portion 53 of the intake water jacket 50, and a combustion chamber water jacket 60. The combustion chamber side through hole 34 formed at a position corresponding to the combustion chamber side inflow portion 61 and the exhaust gas formed at positions corresponding to the exhaust side inflow portion 94 and the additional inflow portion 95 of the lower exhaust water jacket 90. A side through hole 35 and an additional through hole 36 are provided. These intake side through hole 32, inter-shaft through hole 33, combustion chamber side through hole 34, exhaust side through hole 35 and additional through hole 36 are all formed at positions corresponding to the opening of block side water jacket 10. Yes. The intake-side through-hole 32 and the exhaust-side through-hole 35 have some exceptions, but the hole located on the right side (the hole far from the outlet openings 63, 83, 93) is formed with a large diameter. ing. In particular, the combustion chamber side through hole 34 is formed to have a larger diameter than the other through holes 32, 33, 35, and 36. Thereby, the vertical flow described later is easily formed.

Next, the flow of the coolant in the block-side water jacket 10 and the head-side water jacket 40 will be described with reference to FIGS.
FIG. 14 is a bottom view for explaining the flow of the coolant in the intake water jacket, the combustion chamber water jacket, the upper exhaust water jacket, and the water outlet. FIG. 15 is a bottom view for explaining the flow of coolant in the lower exhaust water jacket and the water outlet. In FIGS. 14 and 15, the water outlet 100 is schematically illustrated.

  As shown in FIGS. 11 and 12, the coolant (arrow Y1) that has flowed into the introduction portion 11 from the coolant pipe P flows in the left direction along the block-side water jacket 10 (arrow Y2). Then, after making a U-turn at the left end (arrow Y3), the rear side of the cylinder 1a flows rightward along the block-side water jacket 10 (arrow Y4), and reaches the right end (arrow Y5). Further, the coolant flows from the front constricted portion 12 toward the rear constricted portion 12 through the inter-axis slit 13 (arrow Y6).

  As shown in FIG. 12, a part of the coolant (arrow Y2) flowing in the left direction along the block side water jacket 10 in the front side of the cylinder 1a is formed in the exhaust side through hole 35 and the additional through hole formed in the gasket 3. 36 and flows into the inside of the lower exhaust water jacket 90 from the exhaust side inflow portion 94 and the additional inflow portion 95 (arrow Y7). That is, the flow of the coolant in the present embodiment is a so-called exhaust-preceding flow in which the coolant flows into the lower exhaust water jacket 90 prior to the intake water jacket 50. As a result, the exhaust port 23 and the exhaust collecting portion 24 can be efficiently cooled.

  Further, as shown in FIG. 11, a part of the coolant (arrow Y 4) flowing in the right direction on the rear side of the cylinder 1 a along the block side water jacket 10 passes through the intake side through hole 32 formed in the gasket 3. Then, the air flows into the intake water jacket 50 from the intake-side inflow portion 51 (arrow Y8a). In addition, the coolant (arrow Y6) passing through the inter-axis slit 13 merges with the constricted portion 12 on the rear side, passes through the inter-axis through hole 33 formed in the gasket 3, and passes through the inter-axis inflow portion 53 for intake. It flows into the inside of the water jacket 50 (arrow Y8b). Further, the coolant (arrow Y5) that has reached the right end portion of the block-side water jacket 10 passes through the combustion chamber-side through hole 34 formed in the gasket 3 and from the combustion chamber-side inflow portion 61 to the combustion chamber water jacket 60. (Arrow Y9).

  As shown in FIG. 14, the coolant that has flowed from the combustion chamber side inflow portion 61 into the right end portion of the combustion chamber water jacket 60 flows from the right to the left toward the outlet opening 63 at the left end portion (arrow Y10). This flow (arrow Y10) forms a flow (so-called vertical flow) along the arrangement direction Lb (see FIGS. 11 and 12) of the cylinder 1a (that is, the combustion chamber top portion 21) in the water jacket 60 for the combustion chamber. Further, the coolant that has flowed into the intake water jacket 50 from the intake-side inflow portion 51 and the inter-shaft inflow portion 53 flows into the combustion chamber water jacket 60 through the communication portion 52 (arrow Y11). Join the longitudinal flow. The coolant (arrow Y10) that has flowed from right to left in the combustion chamber water jacket 60 flows into the second space 112 of the water outlet 100 from the outlet opening 63. The coolant that has flowed into the second space 112 is supplied to a heater or the like via the connection portions 120f to 120g (only the connection portion 120g is shown in FIG. 14) and piping.

  A part of the coolant flowing through the combustion chamber water jacket 60 flows into the upper exhaust water jacket 80 through the communication portion 62. The flow (arrow Y12) flowing in from each communication portion 62 merges at the front end side of the upper exhaust water jacket 80 and follows the arrangement direction Lb (see FIGS. 11 and 12) of the cylinder 1a (ie, the combustion chamber top portion 21). A flow (so-called longitudinal flow) is formed (arrow Y13). The right front portion 80a of the upper exhaust water jacket 80 is inclined so as to be positioned on the front side as it approaches the outlet opening 83, so that the coolant flowing in from the right communication portion 62 toward the front It is guided by the right front part 80 a of the exhaust water jacket 80 and flows easily toward the outlet opening 83. The coolant flowing from the right to the left in the upper exhaust water jacket 80 flows into the first space 111 of the water outlet 100 from the outlet opening 83. The coolant that has flowed into the first space portion 111 is supplied to a radiator or the like via the connection portions 120a to 120d (only the connection portion 120a is shown in FIG. 14) and piping.

  As shown in FIG. 15, the coolant (arrow Y14) that has flowed into the lower exhaust water jacket 90 from the exhaust side inflow portion 94 flows forward and joins at the front end side of the lower exhaust water jacket 90. Then, a flow (so-called vertical flow) is formed along the arrangement direction Lb (see FIGS. 11 and 12) of the cylinder 1a (that is, the combustion chamber top portion 21) (arrow Y15). Note that the right front portion 90a of the lower exhaust water jacket 90 is inclined so as to be positioned on the front side as it approaches the outlet opening 93, so that it faces forward from the right exhaust side inflow portion 94 and the additional inflow portion 95. The coolant that has flowed in is guided to the right front portion 90 a of the lower exhaust water jacket 90 and easily flows toward the outlet opening 93. The coolant (arrow Y15) that has flowed from the right to the left inside the lower exhaust water jacket 90 flows into the first space 111 of the water outlet 100 from the outlet opening 93. The coolant that has flowed into the first space portion 111 is supplied to a radiator or the like via the connection portions 120a to 120d (only the connection portion 120a is shown in FIG. 15) and piping.

As described above, according to the water jacket structure of the cylinder head according to the present embodiment, the outlet 110 formed inside the water outlet 100 is provided at a position corresponding to the outlet openings 83 and 93 and is mainly cooled to the radiator. A first space portion 111 for supplying liquid, a second space portion 112 that is provided at a position corresponding to the outlet opening 63 and mainly supplies cooling liquid to the heater, outlet openings 83 and 93, and the outlet opening 63. There are throttle portions 113 provided at positions corresponding to each other and having a smaller vertical cross-sectional area than the first space portion 111 and the second space portion 112. From the jackets 80 and 90 to the radiator through the first space 111 and the intake and combustion chamber water jackets 50 and 60 The flow directed to the heater through the second space portion 112 can be easily generated. This makes it difficult for the coolant flowing in from the upper and lower exhaust water jackets 80 and 90 and the coolant flowing in from the intake / combustion chamber water jackets 50 and 60 to collide with each other in the outlet 110. The flow of is stabilized. Therefore, it becomes difficult for the coolant to stay in the outlet 110, and as a result, a decrease in the flow rate of the coolant flowing in each of the water jackets 50, 60, 80, 90 can be suppressed.
In particular, the coolant having a relatively high flow rate flowing from the upper and lower exhaust water jackets 80 and 90 is less likely to collide with the coolant having a relatively low flow rate flowing from the intake / combustion chamber water jackets 50 and 60. Since the decrease in the flow rate is small, the coolant can be smoothly supplied to the radiator.

Further, when a structure that blocks between the first space portion 111 and the second space portion 112 is adopted, the coolant flowing into the second space portion 112 from the intake / combustion chamber water jackets 50 and 60 is guided to the radiator. However, in the present embodiment, since the throttle portion 113 is provided, the second space portion 112 is not significantly affected between the first space portion 111 and the second space portion 112 without greatly affecting the flow of the coolant. The cooling liquid is allowed to flow into the first space 111. As a result, the coolant flowing in from the upper and lower exhaust water jackets 80, 90 and the coolant flowing in from the intake / combustion chamber water jackets 50, 60 are appropriately combined in a well-balanced manner, and the amount of coolant supplied to the radiator Can be secured sufficiently.
That is, according to this embodiment, the collision suppression between the coolants flowing in from the respective water jackets 50, 60, 80, 90 and the appropriate merging of the coolants flowing from the respective water jackets 50, 60, 80, 90 are achieved. , Both can be achieved.

  Further, the total flow rate of the coolant flow rate F1 discharged from the outlet opening 83 and the coolant flow rate F2 discharged from the outlet opening 93 is larger than the coolant flow rate F3 discharged from the outlet opening 63. Since the relationship of F1 + F2> F3 is set, the supply amount of the coolant to the radiator can be sufficiently secured.

  The water jacket structure of the cylinder head according to the present embodiment has been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and does not depart from the spirit of the present invention. Needless to say, it can be changed as appropriate.

  For example, in the present embodiment, the combustion chamber water jacket 60 is configured to communicate with the upper exhaust water jacket 80, but the present invention is not limited to this, and the upper exhaust water jacket 80 and the lower exhaust water jacket 80 are connected to the lower exhaust water jacket 80. The combustion chamber water jacket 60 may be configured to communicate with the lower exhaust water jacket 90 as long as the side exhaust water jacket 90 forms an independent flow path. Incidentally, if the combustion chamber water jacket 60 is configured to communicate with the upper exhaust water jacket 80, the vertical width of the communication portion 62 can be increased, so the first water shown in FIG. The rigidity of the jacket core 200 can be increased.

  In the present embodiment, the protrusions 81 and 91 are provided on both the upper exhaust water jacket 80 and the lower exhaust water jacket 90. However, the present invention is not limited to this, and the upper exhaust water jacket 90 is provided. Only one of the water jacket 80 and the lower exhaust water jacket 90 may be provided with a protrusion. Even in such a configuration, the downstream side portion 24d of the exhaust collecting portion 24 can be cooled while the upper exhaust water jacket 80 and the lower exhaust water jacket 90 are separated.

  In the present embodiment, the opening 24a of the exhaust collecting portion 24 is formed at a position that is substantially the center of the cylinder head 2 in the left-right direction. 24a may be formed.

  Further, the present invention has been described taking the in-line four-cylinder internal combustion engine E as an example, but the present invention is not limited to this, and is applicable to the internal combustion engine E having other cylinder numbers such as two cylinders and three cylinders. It is also possible to apply to a V-type internal combustion engine E or the like. Further, the present invention is not limited to the internal combustion engine E of an automobile, and it is needless to say that the present invention can be applied to other internal combustion engines E such as ships and general-purpose machines.

DESCRIPTION OF SYMBOLS 1 Cylinder block 1a Cylinder 2 Cylinder head 21 Combustion chamber top part 22 Intake port 23 Exhaust port 24 Exhaust collecting part 3 Gasket 10 Block side water jacket 40 Head side water jacket 50 Intake water jacket 60 Combustion chamber water jacket 70 Exhaust water jacket 70 80 Upper exhaust water jacket 90 Lower exhaust water jacket 83 Outlet opening (first outlet opening)
93 outlet opening (second outlet opening)
63 Exit opening (third exit opening)
100 Water outlet 110 Outlet (space)
111 First space portion 112 Second space portion 113 Restriction portion E Internal combustion engine Lc Cylinder axis

Claims (2)

A plurality of combustion chamber tops formed on the bottom surface of the cylinder head;
A plurality of exhaust ports communicating with each of the plurality of combustion chamber tops;
An exhaust collecting portion for collecting the plurality of exhaust ports inside the cylinder head;
A water jacket for the combustion chamber for cooling the top of the combustion chamber;
An upper exhaust water jacket that is disposed on the upper side in the cylinder axial direction with respect to the exhaust collecting portion and cools the exhaust collecting portion;
A lower exhaust water jacket that is disposed on the lower side in the cylinder axial direction with respect to the exhaust collecting portion and cools the exhaust collecting portion;
A first outlet opening that opens to one side surface of the cylinder head in the cylinder row direction and serves as an outlet for cooling liquid flowing in the upper exhaust water jacket;
A second outlet opening that opens to one side surface of the cylinder head in the cylinder row direction and serves as an outlet for the coolant flowing in the lower exhaust water jacket;
A third outlet opening that opens to one side surface of the cylinder head in the cylinder row direction and serves as an outlet for the coolant flowing through the combustion chamber water jacket;
A water outlet that is attached to one side surface of the cylinder head in the cylinder row direction and that supplies the coolant discharged from the first to third outlet openings to other components;
The first outlet opening and the second outlet opening are formed at a predetermined distance from the third outlet opening in the width direction of one side surface in the cylinder row direction,
Inside the water outlet is formed a single space communicating with the first to third outlet openings,
The space portion is
A first space that is provided at a position corresponding to the first outlet opening and the second outlet opening, and that mainly supplies the coolant to the radiator;
A second space provided at a position corresponding to the third outlet opening, and mainly supplying the coolant to the heater;
A throttle portion provided at a position corresponding to between the first outlet opening and the second outlet opening and the third outlet opening and having a smaller vertical cross-sectional area than the first space and the second space. When,
A water jacket structure for a cylinder head, characterized by comprising:   The total flow rate of the coolant flow rate F1 discharged from the first outlet opening and the coolant flow rate F2 discharged from the second outlet opening is the cooling rate discharged from the third outlet opening. 2. The water jacket structure for a cylinder head according to claim 1, wherein a relationship of F1 + F2> F3, which is larger than a flow rate F3 of the liquid, is set.

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