CYLINDER HEAD AND ENGINE

Abstract

The cylinder head 3 includes: a lower part 21; a wall portion including an upper part and a lower part; an upper part provided above the lower part so as to face the lower part and forming a cooling water flow space 30 between the lower part and the upper part; and a wall portion formed between the lower part and the upper part and having a valve bore forming wall 40 forming an intake valve bore 41 and an exhaust valve bore 42 opening into a lower surface of the lower part.The lower part includes: a cooling water introduction hole 23 extending in a vertical direction through the lower part so as to extend in the circumferential direction of a virtual circle VC surrounding a valve hole forming wall in plan view; and a rib 24 provided to be arranged in the circumferential direction of the virtual circle with respect to the cooling water introduction hole and protruding from an upper surface 21a of the lower part so as to extend in the circumferential direction.

Description

[Technical field]

[0001] The present invention relates to a cylinder head and an internal combustion engine. [State of the art]

[0002] Patent Document 1 discloses a cylinder head bolted to an upper portion of a cylinder block of an internal combustion engine, and having a cooling water flow space (head cylinder jacket) inside the cylinder head. In such a cylinder head, a bottom portion located on the cylinder block side and constituting a cooling water flow space is exposed to high temperatures. Therefore, it has been considered to efficiently cool the bottom portion by forming the bottom portion with a thin wall.

[0003] In the cylinder head of Patent Document 1, ribs for reinforcing the bottom portion are formed on the bottom portion (bottom wall) of the cylinder head located on the cylinder block side and constituting the cooling water flow space. Regarding the flow of cooling water in the cooling water flow space, the rib extends from the valve bore forming wall (intake wall portion) corresponding to a predetermined cylinder in a cylinder arrangement direction in which a plurality of cylinders are arranged.

[0004] Further designs of cylinder heads having a rib are disclosed in the documents JP 2008-75 504 A, WO 2015 / 098 705 A1 and DE 102 51 360 A1. [Prior art document][Patent specification]

[0005] Patent Document 1: JP 2012-12959 A. [Overview of the invention][Problems to be solved by the invention]

[0006] However, in the cylinder head of Patent Document 1, the ribs extend from the valve bore forming wall in the radial direction of the cylinder. Therefore, the flow of cooling water around the valve bore forming wall is obstructed by the ribs. In this case, the cooling of the valve bore forming wall caused by the cooling water becomes insufficient.

[0007] The present invention is provided to solve the foregoing problem, and the present invention provides a cylinder head in which the rigidity of a lower deck can be improved and a wall forming a valve bore can be efficiently cooled by cooling water, and an internal combustion engine provided therewith. [Means of solving the problem]

[0008] To solve the problem, a cylinder head according to claim 1 is provided. A cylinder head according to a first aspect of the present disclosure includes: a lower portion; an upper portion provided above the lower portion so as to face the lower portion and form a cooling water flow space between the lower portion and the upper portion; a wall portion formed between the lower portion and the upper portion and including a valve bore forming wall forming an intake valve bore and an exhaust valve bore open in a lower surface of the lower portion.The lower part includes: a cooling water introduction hole extending vertically through the lower part so as to extend in a circumferential direction of a virtual circle enclosing the valve hole forming wall when viewed in plan view; and a rib provided so as to be arranged in the circumferential direction of the virtual circle with respect to the cooling water introduction hole and protruding from an upper surface of the lower part so as to extend in the circumferential direction.

[0009] The internal combustion engine according to the present disclosure includes: the cylinder head; and a cylinder block having a cylinder bore forming a cylinder and covered by the cylinder head from above, wherein the virtual circle is a circle corresponding to a plan view of the cylinder bore. [Effect of the invention]

[0010] According to the invention, the rigidity of the lower part of the cylinder head can be improved, and the valve bore forming wall can be efficiently cooled by the cooling water. [Brief description of drawings] Fig. 1 is a sectional view showing an internal combustion engine having a cylinder head according to an embodiment of the present invention. Fig. 2 is a plan view of the internal combustion engine of the Fig. 1 when viewed from above. Fig. 3 is a cross-sectional view along the line III-III of the Fig. 1. Fig. 4 is a cross-sectional view along the line IV-IV of the Fig. 2. Fig. 5 is a cross-sectional view along the line VV of the Fig. 1 and Fig. 4. Fig. 6 is a sectional view along the line VI-VI of the Fig. 1 and Fig. 4. [METHOD OF CARRYING OUT THE INVENTION]

[0011] With reference to Fig. 1 to Fig. 6, an embodiment of the present invention will now be described in detail. As in Fig. 1 and Fig. 4, a cylinder head 3 according to the present embodiment, together with a cylinder block 2, forms an internal combustion engine 1. The internal combustion engine 1 of the present embodiment is a diesel engine.

[0012] In Fig. 1 to 6, a direction in which the cylinder block 2 and the cylinder head 3 are arranged is defined as a Z-axis direction. Further, a first perpendicular direction perpendicular to the Z-axis direction is defined as a Y-axis direction. Furthermore, a second perpendicular direction perpendicular to the Z-axis direction and the Y-axis direction is defined as an X-axis direction. <zylinderblock>

[0013] As in Fig. 1 and Fig. 4, the cylinder block 2 has a cylinder bore 11a forming a cylinder 11. The cylinder 11 is a space in which the piston 4 ( Fig. 1). The cylinder 11 is open to an upper surface 2a of the cylinder block 2. The piston 4 performs a reciprocating movement in the vertical direction (Z-axis direction) by receiving pressure from a combustion gas that has been ignited in the cylinder 11. As shown in Fig. 2, the cylinder block 2 of the present embodiment includes a plurality of (in the example shown in the drawings: three) cylinders 11. The plurality of cylinders 11 are aligned in a line along a first vertical direction (Y-axis direction) perpendicular to the vertical direction. In the following description, the first vertical direction in which a plurality of cylinders 11 are arranged is also referred to as a cylinder arrangement direction.

[0014] As in Fig. 1 and Fig. 4, a cooling water flow space 12 (hereinafter referred to as a block-side flow space 12) surrounding each of the cylinder bores 11a is formed in the cylinder block 2. Cooling water that cools the cylinder bore 11a flows through the block-side flow space 12. The block-side flow space 12 opens into the upper surface 2a of the cylinder block 2.

[0015] As in Fig. 1, a crankshaft 5 for driving a rocker arm 47, described later, is arranged inside the cylinder block 2. The crankshaft 5 extends along the cylinder arrangement direction. The crankshaft 5 rotates in response to the reciprocating motion of the piston 4. <zylinderkopf>

[0016] The cylinder head 3 is arranged to overlap with the upper surface 2a of the cylinder block 2 such that an upper opening of the cylinder 11 is covered.

[0017] As in Fig. 1 and Fig. As shown in Figure 4, the cylinder head 3 includes a lower deck 21 and an upper deck 22. The lower deck 21 and the upper deck 22 are each formed in the shape of a plate. The lower deck 21 is a portion of the cylinder head 3 arranged to overlap with the upper surface 2a of the cylinder block 2. The upper deck 22 is provided above the lower deck 21 so as to face the lower deck 21. In other words, the lower deck 21 and the upper deck 22 are spaced apart from each other in the vertical direction (Z-axis direction). The upper deck 22 forms a cooling water flow space 30 (hereinafter referred to as a "head-side flow space 30") between the lower deck 21 and the upper deck 22.

[0018] A cooling water introduction hole 23 is formed in the lower part 21. The cooling water introduction hole 23 extends through the lower part 21 along its plate thickness direction (vertical direction). The cooling water introduction hole 23 connects the block-side flow space 12 of the cylinder block 2 with the head-side flow space 30 of the cylinder head 3. Further, ribs 24 are formed on the lower part 21, protruding from the upper surface 21a of the lower part 21, which forms an inner surface of the head-side flow space 30. Details of the cooling water introduction hole 23 and the ribs 24 will be described later. <Ventilbohrung bildende Wand>

[0019] As in Fig. 1 and 3 to 6, the cylinder head 3 includes a valve bore forming wall 40 which extends from the lower part 21 to the upper part 22.

[0020] As in Fig. 1, Fig. 3 and Fig. As shown in Fig. 5, the valve bore forming wall 40 is provided with an intake valve bore 41 and an exhaust valve bore 42 opening into the lower surface 21b of the lower part 21. The lower surface 21b of the lower part 21 is a surface facing the upper surface 2a of the cylinder block 2. The intake valve bore 41 and the exhaust valve bore 42 are formed in a lower end portion of the valve bore forming wall 40 located on the lower part 21 side. The intake valve bore 41 and the exhaust valve bore 42 are each communicated with the cylinder 11 of the cylinder block 2.

[0021] As in Fig. 3 to 6, a central bore 43, through which a fuel injection unit 44 (injector) is inserted in the vertical direction, is formed in the valve bore forming wall 40. The fuel injection unit 44 extends vertically through the cylinder head 3. In other words, the fuel injection unit 44 protrudes from the lower surface 21b of the lower part 21 and from the upper surface 22a of the upper part 22. As shown in Fig. 3 and Fig. 5, the intake valve bore 41 and the exhaust valve bore 42 are arranged at a distance from each other around the central bore 43 in the circumferential direction.

[0022] As in Fig. 1 and Fig. 2, the valve bore forming wall 40 is provided with an intake valve 45 for opening and closing each of the intake valve bores 41 so as to be movable in the vertical direction. A portion of the intake valve 45 protrudes from the upper surface 22a of the upper part 22. Furthermore, in the same manner as the intake valve 45, an exhaust valve 46 for opening and closing each of the exhaust valve bores 42 is provided in the valve bore forming wall 40. The structure and arrangement of the exhaust valve 46 are the same as those of the intake valve 45.

[0023] The intake valve 45 and the exhaust valve 46 are controlled by oscillating the valve levers 47 provided on the upper surface 22a of the upper part 22. The valve lever 47 is oscillated by moving the push rod 48, which extends vertically through the cylinder head 3, in the vertical direction in accordance with the rotation of the crankshaft 5.

[0024] As in Fig. 3, Fig. 5 and Fig. 6, in this embodiment, a plurality of (in the example shown in the drawings: three) valve bore forming walls 40 are arranged in a line with a spacing in the first vertical direction (Y-axis direction) perpendicular to the vertical direction (Z-axis direction), that is, in the cylinder arrangement direction. The plurality of valve bore forming walls 40 are positioned to be associated with the plurality of cylinders 11, respectively. In this embodiment, two intake valve bores 41 and one exhaust valve bore 42 correspond to a single cylinder 11. <Einlassanschluss bildender Bereich>

[0025] As in Fig. 1 and 3 to 6, the cylinder head 3 includes an intake port forming portion 51 connected to the valve bore forming wall 40. The intake port forming portion 51 is located on one side (positive side of the X-axis direction) of the valve bore forming wall 40 in the second perpendicular direction, which is perpendicular to the vertical direction and to the first perpendicular direction. The intake port forming portion 51 is integrally formed on a lower surface of the upper part 22 and is disposed above the lower part 21 with a space therebetween. A space between the lower part 21 and the intake port forming portion 51 forms the head-side flow space 30.

[0026] An intake port 53 communicating with the intake valve bore 41 is formed in the intake port forming portion 51. The intake port 53 extends from the intake valve bore 41 to one side in the second vertical direction. In other words, the intake port 53 is configured to draw air from the intake side of the cylinder head 3, which is one side of the second vertical direction.

[0027] A plurality of (in the example shown in the drawings: three) intake port forming portions 51 are arranged in a first vertical direction at a distance from each other so as to correspond to the plurality of valve bore forming walls 40. Two intake ports 53, each communicating with the two intake valve bores 41 formed in each of the valve bore forming walls 40, are formed in each of the intake port forming portions 51. <Auslassanschluss bildender Bereich>

[0028] As in Fig. 4 and Fig. As shown in Fig. 5, the cylinder head 3 includes an exhaust port forming portion 52 connected to each of the valve bore forming walls 40. The exhaust port forming portion 52 is disposed on the other side (negative side of the X-axis direction) in the second perpendicular direction with respect to the valve bore forming wall 40. The exhaust port forming portion 52 is disposed above the lower part 21 and below the upper part 22 at a distance from the lower part 21 and the upper part 22. A space between the lower part 21 and the exhaust port forming portion 52 and a space between the upper part 22 and the exhaust port forming portion 52 respectively constitute the head-side flow space 30.

[0029] An exhaust port 54 communicating with the exhaust valve bore 42 is formed in the exhaust port forming portion 52. The exhaust port 54 extends from the exhaust valve bore 42 to the other side in the second vertical direction. In other words, the exhaust port 54 is configured to discharge air to an exhaust side of the cylinder head 3, which is the other side in the second vertical direction.

[0030] A plurality of (in the example shown in the drawings: three) outlet port forming regions 52 are arranged at a distance from one another in the first vertical direction such that they are associated with each of the plurality of valve bore forming walls 40. <Außenumfangswand>

[0031] As in Fig. 3, Fig. 5 and Fig. 6, the cylinder head 3 further includes an outer peripheral wall 60 provided on the outer periphery side of the plurality of valve bore forming walls 40 described above. The outer peripheral wall 60 extends from the lower part 21 to the upper part 22 such that the plurality of valve bore forming walls 40 are enclosed, and together with the lower part 21 and the upper part 22, forms the head-side flow space 30.

[0032] Two lateral walls 61, 62 and an end wall 63 are provided on the outer peripheral wall 60.

[0033] As in Fig. 4 and Fig. 5, the second lateral walls 61, 62 extend in the first perpendicular direction (the Y-axis direction) at the two ends of the cylinder head 3 in the second perpendicular direction (the X-axis direction). The intake port forming portion 51 described above is integrally formed on an intake-side lateral wall 61 located on the intake side (the positive side of the X-axis direction) of the two lateral walls 61, 62. An intake port 53 extends through the intake-side lateral wall 61. The exhaust port forming portion 52 described above is integrally formed on an exhaust-side lateral wall 62 located on an exhaust side (the positive side of the X-axis direction) of the two lateral walls 61, 62. An exhaust port 54 extends through the exhaust-side lateral wall 62. Further, a push rod 48 ( Fig. 1), described above, through the outlet-side lateral wall 62 in the vertical direction. A plurality of push rods 48 are arranged spaced apart from one another in the first vertical direction.

[0034] As in Fig. 3, Fig. 5 and Fig. 6, the one end wall 63 extends in the second vertical direction over first ends of the two lateral walls 61, 62 in the first vertical direction.

[0035] A second end of each of the two lateral walls 61, 62 is open. A cooling water discharge portion 65 is provided on the second end side of the two lateral walls 61, 62 (the end portion on one side of the arrangement direction of the plural valve hole forming walls 40). The cooling water flowing through the head-side flow space 30 is discharged into the cooling water discharge portion 65. <Schraubenbohrung bildende Wand>

[0036] As in Fig. 3, Fig. 5 and Fig. 6, the cylinder head 3 further includes bolt hole forming walls 71, 72 extending from the lower part 21 to the upper part 22. Bolt holes 73 for fastening the cylinder head 3 to the cylinder block 2 are formed in the bolt hole forming walls 71, 72. Each bolt hole 73 opens into the lower surface 21b of the lower part 21 and the upper surface 22a of the upper part 22. In other words, the bolt hole 73 extends through the cylinder head 3 in its vertical direction. In the present embodiment, a single bolt hole 73 is formed in the same bolt hole forming walls 71, 72.

[0037] A plurality of screw hole forming walls 71, 72 (four in the example shown in the drawings) are arranged in a circumferential direction of each of the valve hole forming walls 40 so as to surround the valve hole forming walls 40, respectively. Furthermore, the plurality of screw hole forming walls 71, 72 (four in the example shown in the drawings) are arranged in the first perpendicular direction on the inlet side and the outlet side of the valve hole forming wall 40, respectively, so as to be located on both sides of the same valve hole forming wall 40 in the first perpendicular direction. A part of the screw hole forming wall 71 (a first screw hole forming wall 71) of the plurality of screw hole forming walls 71, 72 is spaced apart from the outer peripheral wall 60 described above.In the present embodiment, the first screw hole forming wall 71 is located between two valve hole forming walls 40 adjacent to each other in the first perpendicular direction on the outlet side of the valve hole forming wall 40. The first screw hole forming wall 71 is located between the valve hole forming wall 40 and the outlet-side lateral wall 62 in the second perpendicular direction. The remaining screw hole forming wall 72 (second screw hole forming wall 72) is integrally formed on the outer peripheral wall 60.

[0038] The valve bore forming wall 40, the outer peripheral wall 60 and the screw bore forming wall 71, 72 described above are part of a wall portion formed between the lower part 21 and the upper part 22. <Kühlwassereinführbohrung>

[0039] As in Fig. 3, the cooling water introduction hole 23 formed in the base 21 extends in the circumferential direction of a virtual circle VC that encloses the valve bore forming wall 40 in plan view. The virtual circle VC, in the present embodiment, is a circle corresponding to a planar observed shape of the cylinder bore 11a of the cylinder 11. Furthermore, the virtual circle VC is a circle centered on a central hole 43 (fuel injection unit 44) formed in the valve bore forming wall 40. The cooling water introduction hole 23 is located outside the virtual circle VC (cylinder bore) in the radial direction. Furthermore, the cooling water introduction hole 23 is spaced apart from the valve bore forming wall 40.

[0040] A plurality of cooling water introduction holes 23 (in the example shown in the drawings: three) are arranged at a distance from each other in the circumferential direction of the virtual circle VC with respect to the same valve bore forming wall 40. The cooling water introduction holes 23 formed in the same valve bore forming wall 40 include an inlet-side introduction hole 23A provided adjacent to the inlet-side valve bore forming wall 40 and an outlet-side introduction hole 23B provided adjacent to the outlet side of the valve bore forming wall 40.

[0041] The intake-side insertion hole 23A is located between the valve-bore forming wall 40 and the intake-side lateral wall 61 in the second perpendicular direction. The number of intake-side insertion holes 23A is two for a single virtual circle VC in the present embodiment. The two intake-side insertion holes 23A are shifted toward the two sides of the center of the virtual circle VC (the central hole 43, the power injection unit 44) in the first perpendicular direction. For example, the number of intake-side insertion holes 23A may be one, or may be three or more, for example.

[0042] As in Fig. 1 and Fig. 3, the inlet-side insertion hole 23A is arranged below the inlet port forming portion 51 in the vertical direction. In other words, the inlet-side insertion hole 23A is covered by the inlet port forming portion 51. However, as shown in Fig. 3 and Fig. 5, a part of the inlet-side insertion hole 23A may not necessarily be covered by the inlet port forming portion 51.

[0043] As in Fig. 3, the exhaust-side insertion hole 23B is arranged between the valve-hole forming wall 40 and the exhaust-side lateral wall 62 in the second perpendicular direction. The number of the exhaust-side insertion holes 23B is one for a single virtual circle VC in the present embodiment. The exhaust-side insertion hole 23B is shifted toward the end wall 63 side of the outer peripheral wall 60 (the outer side in the arrangement direction of the plurality of valve-hole forming walls 40) with respect to the center of the virtual circle VC in the first perpendicular direction. For example, a plurality of exhaust-side insertion holes 23B may be provided.

[0044] As in Fig. 3 and 4, the outlet-side insertion hole 23B is located vertically below the outlet port forming portion 52. In other words, the outlet-side insertion hole 23B is covered by the outlet port forming portion 52. Furthermore, a part of the outlet-side insertion hole 23B may not necessarily be covered by, for example, the outlet port forming portion 52. <rippe>

[0045] As in Fig. 3, the ribs 24 formed on the upper surface 21a of the base 21 are provided so as to be arranged in the circumferential direction of the virtual circle VC with respect to the cooling water introduction hole 23. Further, the rib 24 is provided so as to extend in the circumferential direction of the virtual circle VC. In the present embodiment, both ends of the ribs 24 in the extending direction are in contact with the wall portion (the valve hole forming wall 40, the outer peripheral wall 60, and the screw hole forming wall 71, 72). The ribs 24 of the present embodiment will be described in more detail below.

[0046] The ribs 24 of the present embodiment include inlet-side ribs 24A provided on the inlet side from the center of the virtual circle VC in the second vertical direction (the X-axis direction), and outlet-side ribs 24B provided on the outlet side from the center of the virtual circle VC.

[0047] The intake-side ribs 24A extend mainly in the second perpendicular direction from the second screw-hole forming wall 72 integrally formed on the intake-side lateral wall 61 of the outer peripheral wall 60 to the valve-hole forming wall 40 between the two valve-hole forming walls 40 adjacent in the first perpendicular direction (Y-axis direction). In other words, both ends of each intake-side rib 24A are in contact with the valve-hole forming wall 40 and the second screw-hole forming wall 72 in the extending direction. Thus, the intake-side ribs 24A are arranged to be located in the circumferential direction of each virtual circle VC with respect to the two intake-side insertion holes 23A located on both sides of the corresponding intake-side rib 24A in the first perpendicular direction.

[0048] In the cylinder head 3 of the example shown in the drawings, the number of intake-side ribs 24A is two since the number of valve bore forming walls 40 is three.

[0049] A region in which a first end of the intake-side rib 24A in the extending direction contacts the valve bore forming wall 40 lies within the virtual circle VC in the radial direction. Therefore, the intake-side rib 24A extends in the radial direction across the inside and outside of the imaginary circle VC.

[0050] In the present embodiment, the first end of the inlet-side rib 24A in the extension direction is aligned with the valve-bore forming wall 40 of the two valve-bore forming walls 40 adjacent to each other in the first perpendicular direction, as shown in the drawing, which is on the cooling water discharge portion 65 side. For this reason, the inlet-side ribs 24A are inclined toward the cooling water discharge portion 65 in the first perpendicular direction while facing the valve-bore forming wall 40 from the second screw-bore forming wall 72 in the second perpendicular direction.

[0051] Furthermore, the first end of the inlet-side rib 24A in the extension direction may be in contact with the valve bore forming wall 40 located on the end wall 63 side of the outer peripheral wall 60, among the two valve bore forming walls 40 adjacent to each other in the first perpendicular direction. Furthermore, a second end of the inlet-side rib 24A in the extension direction may be in contact with, for example, the inlet-side lateral wall 61 instead of the second screw bore forming wall 72.

[0052] The exhaust-side ribs 24B are arranged between the valve-bore forming wall 40 and the exhaust-side lateral wall 62 in the second vertical direction. The exhaust-side ribs 24B extend mainly in the first vertical direction (the arrangement direction of the plurality of valve-bore forming walls 40). Both ends of the exhaust-side rib 24B in the extension direction are in contact with the exhaust-side lateral wall 62 and the screw-bore forming wall 71, 72.

[0053] Specifically, a first end of the outlet-side rib 24B in the extension direction contacts the screw hole forming wall 71, 72 that is closer to the cooling water discharge portion 65 side than the corresponding valve hole forming wall 40 in the first vertical direction. On the other hand, a second end of the outlet-side rib 24B in the extension direction contacts a portion that is closer to the end wall 63 of the outer peripheral wall 60 of the outlet-side lateral wall 62 in the first vertical direction than the center of the virtual circle VC. For this reason, the outlet-side ribs 24B are inclined toward the inlet side in the second vertical direction while being directed toward the cooling water discharge portion 65 side from the outlet-side lateral wall 62 in the first vertical direction.Thus, the portion of the outlet-side rib 24B on the first end side (on the side where the screw hole forming wall 71, 72 is present) is arranged to be located in the circumferential direction of the virtual circle VC with respect to the corresponding outlet-side insertion hole 23B. Further, a portion of the outlet-side rib 24B on the second end side (on the side where the outlet-side lateral wall 62 is present) is arranged to be located outside the virtual circle VC with respect to the corresponding outlet-side insertion hole 23B in the radial direction.

[0054] A plurality of exhaust-side ribs 24B are provided to correspond to the plurality of valve-bore forming walls 40. In other words, the number of exhaust-side ribs 24B corresponds to the number of valve-bore forming walls 40 (in the example shown in the drawings: three).

[0055] As further stated in Fig. 1, Fig. 3 and Fig. 4, each of the outlet-side ribs 24B is provided below the corresponding outlet port forming portion 50. <Kopfseitiger Durchflussraum>

[0056] As in Fig. 1 and 3 to 6, in the cylinder head 3 of the present embodiment, the head-side flow space 30 is separated by the first partition wall 81 ( Fig. 3) and the second partition wall 82 ( Fig. 1 and Fig. 4) divided into two sub-spaces 31, 32.

[0057] As in Fig. 1, Fig. 3 and Fig. As shown in Fig. 4, the first partition wall 81 divides the lower portion of the head-side flow space 30, which is located on the base 21 side in the vertical direction, into an inlet-side space and an outlet-side space. The first partition wall 81 is configured to connect the adjacent valve-hole forming walls 40 to each other and to connect the valve-hole forming walls 40 arranged at both ends of the plurality of valve-hole forming walls 40 in the arrangement direction and the outer peripheral wall 60.

[0058] As in Fig. 1, Fig. 4 and Fig. 5, the second partition wall 82 divides the space on the exhaust side, which is located closer to the exhaust side than the valve bore forming wall 40, and the first partition wall 81 in the second vertical direction (X-axis direction), into a lower divided space including the lower side of the exhaust port forming portion 52 and an upper divided space including the upper side of the exhaust port forming portion 52 in the vertical direction.

[0059] The head-side flow space 30 is divided by the first partition wall 81 and the second partition wall 82 into a first dividing space 31 containing the space on the inlet side and an upper subspace on an outlet side, and a second dividing space 32 containing the lower subspace on an outlet side.

[0060] As in Fig. 3, the inlet-side insertion port 23A and the inlet-side insertion port 24A are arranged in the space on the inlet side of the first partition space 31. On the other hand, an outlet-side insertion hole 23B and an outlet-side rib 24B are arranged in the second partition space 32. In the present embodiment, the upper partition space ( Fig. 5) on the outlet side of the first dividing chamber 31 and the second dividing chamber 32 ( Fig. 3) in the cooling water discharge portion 65. In other words, the space on the inlet side of the first partition space 31 is connected to the cooling water discharge portion 65 via the upper subspace on the outlet side. Therefore, the cooling water that has flowed into the space on the inlet side of the first partition space 31 through the inlet-side introduction hole 23A passes through the upper subspace on the outlet side of the partition space 31 and is then discharged into the cooling water discharge portion 65. On the other hand, the cooling water that has flowed into the second partition space 32 through the outlet-side introduction hole 23B is directly discharged into the cooling water discharge portion 65.

[0061] As further stated in Fig. 5 and Fig. 6, a first through-hole 83 connecting the upper compartment on the outlet side of the first compartment 31 and the second compartment 32 is formed in the second partition wall 82. The first through-hole 83 is formed to extend vertically through the second partition wall 82. The first through-hole 83 is arranged to contact each of the plurality of valve-bore forming walls 40. In other words, the number of first through-holes 83 is equal to the number of valve-bore forming walls 40. By forming the first through-hole 83, part of the cooling water that has flowed into the second compartment 32 through the outlet-side introduction hole 23B flows through the first through-hole 83 into the upper compartment on the outlet side of the first compartment 31.

[0062] Furthermore, the first through-hole 83 is arranged adjacent to the outlet port forming portion 52 on the side of the cooling water discharge portion 65 in the first vertical direction (Y-axis direction). Therefore, the outlet port forming portion 52 prevents the cooling water flowing into the upper subspace on the outlet side of the first partition space 31 from the second partition space 32 ( Fig. 3) flows through the first through-hole 83 in the direction away from the cooling water discharge portion 65 in the first vertical direction. In other words, the cooling water flows along the outlet port forming portion 52 and along the valve bore forming wall 40. Subsequently, a flow directed in the second vertical direction of the cooling water flowing into the upper subspace on the outlet side of the first partition space 31 from the second partition space 32 through the first through-hole 83 can be guided by the outlet port forming portion 52 in the first vertical direction so as to be guided toward the cooling water discharge portion 65.

[0063] Furthermore, the second partition wall 82 of the present embodiment extends into the cooling water discharge region 65. In other words, the second partition wall 82 also divides an interior space of the cooling water discharge region 65 in the vertical direction. A second through-hole 84 connecting two spaces in the cooling water discharge region 65 is formed in a portion of the second partition wall 82 located within the cooling water discharge region 65. Therefore, it is possible for the cooling water flowing from the head-side flow space 30 into the cooling water discharge region 65 to flow through both spaces in the cooling water discharge region 65. Specifically, the cooling water flowing into a lower partition space of the second partition wall 82 in the cooling water discharge region 65 from the second partition space 32 flows through the second through-hole 84 to an upper partition space of the second partition wall 82 in the cooling water discharge region 65.In the present embodiment, the cooling water flowing into the cooling water discharge portion 65 is discharged to the outside of the cooling water discharge portion 65 via the discharge port 66 formed in the upper portion of the cooling water discharge portion 65, but the present invention is not limited thereto.

[0064] As in Fig. 1, Fig. 2 and Fig. As shown in Fig. 4, a rocker arm housing 6 is integrally formed in the cylinder head 3 of the present embodiment. The rocker arm housing 6 is formed to extend upward (in the positive direction of the Z axis) with respect to the cylinder head 3 at the peripheral edge of the upper surface 22a of the top 22 (of the cylinder head 3), and enclose the rocker arm 47 and the like provided in the upper surface 22a of the top 22.

[0065] As further stated in Fig. 1, 2, and 4 to 6, an intake manifold 7 is integrally formed in connection with the cylinder head 3 of the present embodiment. The intake manifold 7 is connected to an intake-side lateral wall 61 of the cylinder head 3. The intake manifold 7 extends in the first vertical direction so as to be connected to each of the plurality of intake ports 53 in which an internal space is formed in the first vertical direction. <Funktion und Wirkungen>

[0066] In the cylinder head 3 of the present embodiment, as shown in Fig. 3, the outlet-side ribs 24B are formed to be arranged in the circumferential direction of the virtual circle VC with respect to the outlet-side introduction holes 23B. Therefore, the cooling water flowing into the second partition space 32 of the head-side flow space 30 through the outlet-side introduction hole 23B is guided by the outlet-side rib 24B and flows relatively smoothly in the circumferential direction of the virtual circle VC around the valve-bore forming wall 40. Since the cooling water flows in this way, the valve-bore forming wall 40 is cooled.

[0067] Furthermore, the outlet-side rib 24B extends in the first vertical direction (the arrangement direction of the plurality of valve-hole forming walls 40). Therefore, the cooling water that has flowed from the outlet-side introduction hole 23B into the second partition space 32 is guided by the outlet-side rib 24B and flows relatively smoothly in the first vertical direction. Consequently, the cooling water flowing through the second partition space 32 flows relatively smoothly to the cooling water discharge portion 65. The cooling water flowing in this way passes through a lower side of the outlet port forming portion 52, thereby cooling the outlet port forming portion 52.

[0068] As further stated in Fig. 5 and Fig. 6, the first through hole 83 formed in the second partition wall 82 and connecting the first partition space 31 and the second partition space 32 in the vertical direction is disposed adjacent to the cooling water discharge portion 65 side of the outlet port forming portion 52 in the first vertical direction. Therefore, the cooling water flowing from the second partition space 32 through the first through hole 83 into the upper partition space on the outlet side of the first partition space 31 flows relatively unobstructed to the cooling water discharge portion 65 in the first vertical direction via the outlet port forming portion 52. The cooling water flowing in this way passes through an upper side of the outlet port forming portion 52, thereby cooling the outlet port forming portion 52.

[0069] Furthermore, in the cylinder head 3 of the present embodiment, as shown in Fig. 3, the inlet-side ribs 24A are formed to be arranged in the circumferential direction of the virtual circle VC with respect to the inlet-side introduction holes 23A. Therefore, the cooling water flowing through the inlet-side introduction hole 23A into the space on the inlet side of the first partition space 31 in the head-side flow space 30 flows relatively smoothly in the circumferential direction of the virtual circle VC around the valve-bore forming wall 40. Since the cooling water flows in this way, the valve-bore forming wall 40 is cooled.

[0070] As in Fig. 3, Fig. 5 and Fig. 6, the inlet-side rib 24A extends from the inlet-side lateral wall 61 toward the valve bore forming wall 40. Therefore, the cooling water that has flowed from the inlet-side introduction hole 23A into the space area on the inlet side flows relatively smoothly to the upper divided space on the outlet side of the first partition space 31 along the inlet-side rib 24A.

[0071] Thereafter, the cooling water that has entered the upper subspace on the outlet side from the space on the inlet side of the first partition space 31 flows toward the cooling water outlet portion 65 side along the first perpendicular direction together with the cooling water that has flowed into the upper subspace on the outlet side through the first through-hole 83 into the first partition space 31, caused by the flow of the cooling water that has entered the upper subspace on the outlet side from the first through-hole 83. The temperature of the cooling water that has entered the upper subspace on the outlet side from the space on the inlet side is lower than the temperature of the cooling water that has entered the upper subspace on the outlet side from the first through-hole 83. Therefore, it is possible to efficiently cool the outlet port forming portion 52.

[0072] As described above, according to the cylinder head 3 of the present embodiment and in the internal combustion engine 1 provided with the same, the ribs 24 are formed to be arranged in the circumferential direction of the virtual circle VC (of the cylinder bore 11a) with respect to the cooling water introduction hole 23 in the upper surface 21a of the base 21. Therefore, it is possible to increase the rigidity of the area around the virtual circle VC of the base 21. In particular, it is possible to increase the rigidity of the area around the cooling water introduction hole 23, which has a lower rigidity, by forming the cooling water introduction hole 23 in the base 21.Therefore, even if the lower part 21 is formed with a thin wall, it is possible to ensure the surface pressure of the lower part 21 (particularly, a portion corresponding to a circumference of the cylinder bore 11a) pressing against the cylinder block 2 in a state in which the cylinder head 3 is attached to the cylinder block 2 so that the lower part 21 is pressed against the cylinder block 2 by the bolt.

[0073] Furthermore, according to the cylinder head 3 and the engine 1 of the present embodiment, the ribs 24 extend in the circumferential direction of the virtual circle VC (cylinder bore 11a). Therefore, the cooling water flows relatively smoothly in the circumferential direction of the virtual circle VC around the valve bore forming wall 40 in the head-side flow space 30. Consequently, the valve bore forming wall 40 can be efficiently cooled by the cooling water.

[0074] Furthermore, according to the cylinder head 3 and the engine 1 of the present embodiment, both ends of each of the ribs 23 in the extension direction are in contact with the wall region (the valve bore forming wall 40, the outer peripheral wall 60, and the bolt bore forming wall 71, 72) having high rigidity. Thus, the rigidity of the region near the virtual circle VC of the base 21 can be further increased.

[0075] According to the cylinder head 3 and the engine 1 of the present embodiment, the intake-side ribs 24A extend inside and outside in the radial direction of the virtual circle VC (cylinder bore 11a). Therefore, it is possible to increase the rigidity of the portion extending inside and outside of the virtual circle VC in the bottom part 21. Therefore, even if the bottom part 21 is formed with a thin wall, it is possible to further increase the surface pressure of the bottom part 21 (particularly, the portion corresponding to an edge of the cylinder bore 11a) pressed against the cylinder block 2.

[0076] According to the cylinder head 3 and the engine 1 of the present embodiment, the cooling water discharge portion 65 is further provided at an end portion on one side in the arrangement direction of the plurality of valve bore forming walls 40. Furthermore, the plurality of exhaust-side ribs 24B are provided to correspond to the plurality of valve bore forming walls 40 and extend in the arrangement direction of each of the plurality of valve bore forming walls 40. Therefore, the cooling water flowing through the head-side flow space 30 (specifically, the second partition space 32) is guided by the exhaust-side ribs 24B and can flow relatively smoothly in the arrangement direction of the plurality of valve bore forming walls 40. Furthermore, the cooling water flowing through the head-side flow space 30 flows relatively smoothly to the cooling water discharge portion 65.

[0077] Further, according to the cylinder 3 and the engine 1 of the present embodiment, the intake-side ribs 24A extend from the intake-side lateral wall 61 to the valve bore forming wall 40. Therefore, the cooling water that has flowed from the intake-side introduction hole 23A into the inlet-side space of the first partition space 31 is guided by the intake-side ribs 24A and flows relatively smoothly to the upper partition space on the exhaust side from the inlet-side space of the first partition space 31.

[0078] Furthermore, according to the cylinder head 3 and the engine 1 of the present embodiment, the first through hole 83 formed in the second partition wall 82 and connecting the first partition space 31 and the second partition space 32 in the vertical direction is arranged adjacent to the cooling water discharge portion 65 side of the exhaust port forming portion 52 in the first vertical direction. Therefore, the cooling water that has flowed from the second partition space 32 through the first through hole 83 into the upper partition space on the exhaust side of the first partition space 31 flows relatively smoothly to the cooling water discharge portion 65 in the first vertical direction due to the exhaust port forming portion 52.

[0079] Consequently, the cooling water can flow smoothly from the cooling water introduction hole 23 (the inlet-side introduction hole 23A and the outlet-side introduction hole 23B) to the cooling water discharge portion 65 in the head-side flow space 30. Therefore, it is possible to efficiently cool the valve hole forming wall 40 and the outlet port forming portion 52 by the cooling water flowing through the head-side flow space 30. <Andere Ausführungsformen>

[0080] Although embodiments of the present invention have been described above, the present invention is not limited thereto, and it can be appropriately changed without departing from the basic technical idea of ​​the present invention.

[0081] In the cylinder head of the present invention, both ends of the rib in the extending direction formed in the base are in contact with the wall portion (the valve bore forming wall, the outer peripheral wall, and the bolt bore forming wall). In this case, it is possible to increase the rigidity of the portion near the virtual circle of the base.

[0082] Further, in the cylinder head of the present invention, the ribs contact the wall portion.

[0083] The internal combustion engine of the present invention can be applied to any truck such as a dump truck, a hydraulic excavator, a dozer, an internal combustion engine forklift, or the like. [Explanation of reference symbols] 1 combustion engine, 2 cylinder block, 3 cylinder head, 11 cylinders, 11a cylinder bore, 21 Lower deck or lower part, 21a upper surface, 21b lower surface, 22 upper deck or upper part, 23 Cooling water inlet hole, 23A inlet side insertion hole, 23B outlet-side insertion hole, 24 ribs, 24A inlet side rib, 24B outlet side rib, 30 head-side flow chamber (cooling water flow chamber), 31 first division room, 32 second division room, 40 valve bore forming wall, 41 intake valve bore, 42 exhaust valve bore, 43 central hole, 44 fuel injection unit, 51 Inlet connection forming area, 52 Outlet connection forming area, 53 inlet connection, 54 outlet connection, 60 outer peripheral wall, 61, 62 lateral wall, 63 end wall, 65 Cooling water discharge area, 71, 72 screw hole forming wall, 81 first partition wall, 82 second partition wall, 83 first through hole, VC virtual circle< / rippe> < / zylinderkopf> < / zylinderblock>

Claims

A cylinder head (3), comprising: a lower part (21); an upper part (22) provided above the lower part (21) so as to face the lower part (21) and form a cooling water flow space (30) between the lower part (21) and the upper part (22); a wall portion (40, 60, 71, 72) formed between the lower part (21) and the upper part (22) and having a plurality of valve bore forming walls (40), an outer peripheral wall (60), and a plurality of screw bore forming walls (71, 72), wherein the plurality of valve bore forming walls (40) form an intake valve bore (41) and an exhaust valve bore (42) opening into a lower surface (21b) of the lower part (21) and are spaced apart from each other in a line in a first vertical direction (Y) perpendicular to the vertical direction (Z) is, the outer peripheral wall (60) is provided on an outer peripheral side of the plurality of valve bore forming walls (40) such thatthat it encloses the plurality of valve bore forming walls (40), and the plurality of screw bore forming walls (71, 72) form a screw bore (73) suitable for fastening the cylinder head (3) to a cylinder block (2) and are arranged in a circumferential direction of each valve bore forming wall (40) such that they enclose each of the valve bore forming walls (40), wherein the lower part (21) comprises: a cooling water introduction hole (23) which extends in the vertical direction (Z) through the lower part (21) such that it extends in a circumferential direction of a virtual circle (VC) which, when viewed in plan view, encloses the valve bore forming wall (40); and a rib (24) which protrudes on an upper surface (21a) of the lower part (21) such that it extends in the circumferential direction, wherein the plurality of screw bore forming walls (71,72) have a first screw hole forming wall (71) and a second screw hole forming wall (72), the first screw hole forming wall (71) is arranged at a distance from the outer peripheral wall (60) and is arranged between the valve hole forming wall (40) and the outer peripheral wall (60), and the second screw hole forming wall (72) is formed integrally on the outer peripheral wall (60), and wherein the rib (24) has inlet-side ribs (24A) provided on an inlet side starting from the center of the virtual circle (VC) and outlet-side ribs (24B) provided on an outlet side starting from the center of the virtual circle (VC), the inlet-side ribs (24A) are arranged between two valve hole forming walls (40) that are adjacent to each other,from the plurality of valve bore forming walls (40) and extend from the second screw bore forming wall (72) to the valve bore forming wall (40), both ends of each inlet-side rib (24A) in an extending direction of the inlet-side rib (24A) are in contact with the valve bore forming wall (40) and the second screw bore forming wall (72), the outlet-side ribs (24B) are arranged between the valve bore forming wall (40) and an outlet-side lateral wall (62) provided on the outer peripheral wall (60) in a second vertical direction (X) which is perpendicular to the vertical direction (Z) and to the first vertical direction (Y) and extend in an arrangement direction of the plurality of valve bore forming walls (40), and wherein a cooling water discharge region (65) which is configured to discharge cooling water flowing through the Cooling water flow chamber (30) flows,provided at an end portion on one side in the arrangement direction of the plurality of valve bore forming walls (40); a first end of the outlet-side rib (24B) in an extension direction of the outlet-side rib (24B) is in contact with the screw bore forming wall (71, 72) that is closer to the cooling water discharge portion (65) side than the corresponding valve bore forming wall (40) in the first vertical direction (Y), and a second end of the outlet-side rib (24B) in the extension direction of the outlet-side rib (24B) is in contact with a portion that is closer to the side of an end wall (63) of the outer peripheral wall (60) of the outlet-side lateral wall (62) in the first vertical direction (Y) than the center of the virtual circle (VC). The cylinder head (3) according to claim 1, wherein a central bore (43) through which a fuel injection unit (44) is inserted in the vertical direction (Z) is formed on the valve bore forming wall (40), and the virtual circle (VC) is a circle centered on the central bore (43) in plan view. The cylinder head (3) according to claim 1 or 2, wherein the rib (24) extends over an inside and an outside of the virtual circle (VC) in the radial direction. The cylinder head (3) according to one of claims 1 to 3, comprising an exhaust port forming region (52) which is connected to the valve bore forming wall (40) and forms an exhaust port (54) which is connected to the exhaust valve bore (42), wherein the exhaust port forming region (52) is arranged above the lower part (21) and below the upper part (22) at a distance from the lower part (21) and the upper part (22), and wherein the rib (24) is provided below the exhaust port forming region (52). An internal combustion engine (1), comprising:a cylinder head (3) according to any one of claims 1 to 4; anda cylinder block (2) having a cylinder bore (11a) forming a cylinder (11) and covered from above by the cylinder head (3),wherein the virtual circle (VC) is a circle corresponding to the cylinder bore (11a) in plan view.

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