JP2015059484A - Structure of cylinder head of engine and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a cylinder head of an engine which facilitates the formation of an oil passage while improving a design freedom of the oil passage, and can reduce a cost.SOLUTION: In a structure of a cylinder head 31 of an engine 30 in which oil passages 4, 5, 14 and 15 for supplying oil to hydraulic operation devices 9, 19 are formed in a cylinder row direction, the oil passages 4, 5, 14 and 15 are formed as internal spaces of first to fourth pipe members 61 to 64 at least whose ends 61d to 64d are offset with respect to base parts 61a to 64a, and the first to fourth pipe members 61 to 64 are integrally cast into a raw material of the cylinder head 31 so as to extend up to a rear terminal end from a front terminal end of the cylinder head 31 in the cylinder row direction.

Description

  The present invention relates to an engine cylinder head structure, and more particularly to an oil passage formed in a cylinder row direction for supplying oil to a hydraulic actuator.

  2. Description of the Related Art Conventionally, a so-called main gallery oil passage for supplying hydraulic pressure to a hydraulic lash adjuster (HLA) is formed in a cylinder head. Oil discharged from an oil pump is supplied to the oil passage, and oil is supplied to the HLA through the oil passage. The HLA is provided for each intake valve and exhaust valve arranged in each cylinder. Therefore, the oil passage is formed to extend in the cylinder row direction over each cylinder.

  For this reason, the length of the oil passage is very long with respect to the diameter. According to gun drilling, the processing time becomes very long, and the drill is easily broken.

  As another method for forming the oil passage, for example, Patent Document 1 shows that a straight pipe member is integrally cast in a casting member attached to a cylinder head. According to this method, gun drilling can be eliminated and productivity can be improved.

JP 59-229014 A

  In recent years, a hydraulic HLA with a valve stop mechanism has been adopted as a valve operating device for an engine in order to improve fuel efficiency. A second oil passage for operating the valve stop mechanism is connected to the HLA with a valve stop mechanism. The second oil passage extends in parallel with the oil passage and is formed so as to extend in the cylinder row direction across each cylinder. In addition, an oil control valve (OCV: Oil Control Valve) for controlling the supply of valve stop hydraulic pressure to the second oil passage is connected to one end of the second oil passage.

  By the way, as described above, the oil passage having a conventional structure, that is, the oil passage formed by gun drilling or casting of a pipe member is linear, and thus the degree of freedom in design is small. For example, when there is an obstacle on the straight line of the second oil passage and it cannot be connected to the OCV on the straight line of the second oil passage, as shown in FIG. 9 and FIG. It is necessary to form a hole by drilling to bypass the second oil passage and communicate with the OCV at a position avoiding the obstacle. As a result, the second oil passage becomes complicated, and the processing becomes complicated, for example, a sealing process is performed by appropriately providing a plug in a horizontal hole, an oblique hole, etc., and the cost increases.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides an engine cylinder head structure and a method of manufacturing the same that can be easily formed and reduced in cost while improving the degree of freedom in designing an oil passage. The purpose is to obtain.

  In order to solve the above problems, the present invention is configured as follows.

  The invention according to claim 1 of the present application is an engine cylinder head structure in which an oil passage for supplying oil to a hydraulic actuator is formed in a cylinder row direction, and at least an end of the oil passage is a bent portion. Is formed as an internal space of the pipe member that is offset with respect to the base portion, and the pipe member is integrated with the material of the cylinder head so as to extend in the cylinder row direction from one end portion to the other end portion of the cylinder head. It is characterized by being cast.

  According to a second aspect of the present invention, in the first aspect of the present invention, the cylinder head is an aluminum alloy casting, and the pipe member is an aluminum alloy pipe.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the hydraulic actuator is a hydraulic lash adjuster including a valve clearance adjustment mechanism and a valve stop mechanism, The passages are a first oil passage for operating the valve clearance adjustment mechanism and a second oil passage for operating the valve stop mechanism, and the first oil passage extends from above the one end side. The first pipe member that is oiled and forms the first oil passage is sealed at the end on the one end side, and the end on the other end side is offset upward with respect to the base. The second pipe member forming the second oil passage is the same member as the first pipe member, and is arranged so that the end portion on the one end side is offset with respect to the base portion. And features.

  The invention according to claim 4 is the invention according to claim 3, wherein the first pipe member is disposed above the second pipe member, and the other end of the first pipe member The other end of the second pipe member is covered with a cover structure, and the cover structure is formed with an orifice that communicates the first oil passage and the second oil passage. It is characterized by that.

  The invention according to claim 5 is a method for manufacturing a cylinder head of an engine, wherein a plurality of oil passages for supplying oil to the hydraulic actuator are formed in a cylinder row direction, and the pipes forming the oil passages A plurality of pipe members, at least ends of which are offset from the base by bent portions, a pipe preparation step, and a set capable of positioning and integrally assembling the plurality of pipe members A pipe setting step, a plurality of pipe members in the set state are assembled to a mold of a cylinder head, and a plurality of the pipe members in the set state by the mold. And a casting process in which the material is integrally cast on the cylinder head material.

  The invention according to claim 6 is the invention according to claim 5, wherein the hydraulic actuator is a hydraulic lash adjuster including a valve clearance adjustment mechanism and a valve stop mechanism, and the oil passage is A first oil passage for operating the valve clearance adjusting mechanism and a second oil passage for operating the valve stop mechanism, and the pipe preparation step includes a first pipe that forms the first oil passage. A step of preparing a member and a second pipe member that forms the second oil passage, wherein the pipe setting step places the first pipe member in a set state located above the second pipe member. Including a process.

  The invention according to claim 7 further includes a cover step of covering the one end portion side of the first pipe member and the second pipe member with a cover member in the invention according to claim 6. It is characterized by.

  According to the invention of each claim of the present application, the following effects can be obtained by the above configuration.

  First, according to the invention described in claim 1, by forming an oil passage as an inner diameter portion of a pipe member having a bent portion, an oil passage having a bent portion without providing a horizontal hole or an oblique hole, It can be easily formed in the cylinder head. That is, the oil passage in the cylinder head is not limited to a straight line and can be freely laid out, so the degree of freedom in designing the oil passage can be improved. Further, as a result of improving the degree of freedom in designing the oil passage, the degree of freedom in the layout of the OCV or the like connected to the oil passage can also be improved.

  In addition, it is not necessary to form a horizontal hole or a slanted hole by processing, and a plug to the horizontal hole or the slanted hole can be eliminated, so that the processing cost of the oil passage having a bent portion can be reduced.

  According to the second aspect of the present invention, since the cylinder head and the pipe member are both made of an aluminum alloy, when the pipe member is integrally cast into the cylinder head material, the pipe to the cylinder head material is used. The adhesion of the member can be increased.

  Further, since the cylinder head and the pipe member are of the same material, the linear expansion coefficient is substantially the same, so that the difference in thermal expansion between the cylinder head and the pipe member can be suppressed even when the cylinder head is at a high temperature during engine operation. As a result, it is possible to suppress the generation of thermal stress due to the difference in the amount of thermal expansion, and to ensure the durability of the cylinder head.

  According to the third aspect of the invention, when the engine is stopped, the oil in the first oil passage is blocked by the end offset upward, and the oil can remain in the first oil passage. . As a result, when the engine is started, the oil filling in the first oil passage can be accelerated, the hydraulic pressure in the oil passage can be increased, and the valve clearance adjustment mechanism can be operated in a short time.

  In addition, by disposing one end portion of the second oil passage so as to be offset with respect to the base portion, it is possible to improve the degree of freedom in the layout of hydraulic equipment such as OCV connected to the other end portion of the second oil passage.

  According to the fourth aspect of the present invention, the first oil passage and the second oil passage can be easily communicated by covering the other ends of the first and second oil passages with the cover structure. Moreover, by providing an orifice structure in the cover structure, the orifice can be easily formed without providing a separate orifice member.

  By forming the orifice, oil can be supplied from the first oil passage to the second oil passage through the orifice even when the valve stop mechanism is inoperative. As a result, when the valve stop mechanism is operated, the oil filling time in the second oil passage can be shortened to increase the oil pressure in the oil passage, and the valve stop mechanism can be operated in a short time. Can do. As a result, since the engine operating state can be switched to the reduced cylinder state in a short time, the engine control response can be improved.

  Further, according to the invention described in claim 5, it is possible to manufacture a cylinder head in which a pipe member having a bent portion is integrally cast in a cylinder head material. The effect of is realized.

  Further, according to the invention described in claim 6, the cylinder head described in claim 3 can be suitably manufactured, whereby the effect of the invention described in claim 3 is realized.

  Further, according to the invention described in claim 7, the cylinder head described in claim 4 can be preferably manufactured, and thereby the effect of the invention described in claim 4 is realized.

  That is, according to the cylinder head structure of an engine and the manufacturing method thereof according to the present invention, it is possible to facilitate the formation of the oil passage and improve the cost while improving the degree of freedom in designing the oil passage.

It is a block diagram showing a schematic structure of an oil supply system concerning an embodiment of the present invention. It is sectional drawing which shows schematic structure of the cylinder head which concerns on embodiment of this invention. It is the schematic explaining the operation state of the valve stop mechanism of a hydraulic lash adjuster. It is IV-IV sectional drawing of FIG. It is a front view of an engine. It is a rear view of an engine. It is VII-VII sectional drawing of FIG. It is a perspective view which shows the casting_mold | template of a cylinder head. It is a figure which shows the example of a process of the oil path of the cylinder head of a conventional structure. It is a figure which shows the other example of a process of the oil path of the cylinder head of a conventional structure.

The engine according to the present invention is provided with an oil supply system for supplying oil to each part of the cylinder head. By the oil supply system, the oil discharged from the oil pump is supplied to each sliding part of the valve system, a hydraulic lash adjuster (HLA), etc., which are arranged in the cylinder head. Hereinafter, the oil supply system 1 will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of an oil supply system 1 according to an embodiment of the present invention. For convenience of description, the longitudinal direction of the engine 30, the first cylinder 30 ₁ side as the front side of the engine 30 and other components, the fourth cylinder 30 ₄ side and the rear side of the engine 30 and other components.

As shown in FIG. 1, the engine 30 is an in-line four-cylinder engine in which _first to _fourth cylinders 30 ₁ to 304 are arranged in order from the front side (right side in the figure). The engine 30 is roughly divided into an oil pan 33, a cylinder block 32, and a cylinder head 31 in order from the bottom, and a chain case 34 is disposed across the front end surfaces of the cylinder head 31 and the cylinder block 32. In the chain case 34, an endless chain 56 (FIG. 5) transmits the rotation of a crankshaft (not shown) to an intake cam sprocket 54 (see FIG. 5) and an exhaust cam sprocket 55 (see FIG. 5). Reference) is provided.

  Oil in the oil pan 33 is discharged to the oil supply system 1 by an oil pump 35 provided in the cylinder block 32. The oil supplied to the oil supply system 1 is first supplied to the distribution oil passage 2 and then to the intake side first and second oil passages 4 and 5 and the exhaust side first and second oil passages 14 and 15. It is configured to be supplied after being divided.

Here, the cylinder head 31, HLA36 and a valve clearance adjusting mechanism 36a and the valve stop mechanism 36b (hereinafter, referred to as the valve stop mechanism with HLA) is the first intake and exhaust of the fourth cylinder ₃₀ 1, 30 ₄ HLA 37 (hereinafter simply referred to as HLA) that is disposed corresponding to valves 42 and 43 (see FIG. 2) and includes only valve clearance adjustment mechanism 37a is an intake / exhaust valve of _second and third cylinders 30 ₂ and 30 ₃ 42 and 43 are arranged.

  The intake side and exhaust side first oil passages 4 and 14 are connected to both the HLA 36 and HLA 37 with a valve stop mechanism, and the intake side and exhaust side second oil passages 5 and 15 are connected only to the HLA 36 with a valve stop mechanism. ing.

  Part of the oil supplied to the intake-side first oil passage 4 is diverted, and the valve-operating system such as a bearing portion of the intake-side camshaft 52 (see FIG. 2) passes through the intake-side shower oil passage 6. Supplied to each sliding part. Similarly, a part of the oil supplied to the exhaust-side first oil passage 14 is diverted and the valve-operating valve such as a bearing portion of the exhaust-side camshaft 53 (see FIG. 2) is passed through the exhaust-side shower oil passage 16. Supplied to each sliding part of the system.

  Oil supply to the intake side and exhaust side second oil passages 5 and 15 is performed via oil control valves (OCV) 9 and 19 disposed in the chain case 34. Specifically, first, oil is supplied from the distribution oil passage 2 to the intake side OCV supply oil passage 7 and the exhaust side OCV supply oil passage 17 through the OCV supply oil passage 3 of the chain case 34. Next, oil is supplied to the intake-side second oil passage 5 via the intake-side OCV 9 connected to the intake-side OCV supply oil passage 7. Similarly, oil is supplied to the exhaust side second oil passage 15 via the exhaust side OCV 19 connected to the exhaust side OCV supply oil passage 17.

  Here, the intake-side OCV 9 is a well-known solenoid valve, and when energized, the intake-side OCV supply oil passage 7 and the intake-side second oil passage 5 communicate with each other to supply oil to the intake-side second oil passage 5. In a state where the supply is performed and the power is not supplied, the intake-side second oil passage 5 and the intake-side OCV discharge oil passage 8 are communicated to discharge the oil in the intake-side second oil passage 5. Similarly, when the exhaust side OCV 19 is energized, it supplies oil from the exhaust side OCV supply oil passage 17 to the exhaust side second oil passage 15, and when not energized, the exhaust side OCV 19 supplies the exhaust side OCV 19 to the exhaust side OCV exhaust oil passage 18. The oil in the exhaust side second oil passage 15 is discharged.

  Further, the rear end portion of the intake side first oil passage 4 and the rear end portion of the intake side second oil passage 5 are communicated with each other via an intake side orifice 10. Similarly, the rear end portion of the exhaust side first oil passage 14 and the rear end portion of the exhaust side second oil passage 15 are communicated with each other via the exhaust side orifice 20.

Next, the schematic configuration of each component of the oil supply system 1 will be specifically described with reference to FIGS. Figure 2 is a sectional view showing a first cylinder 30 ₁ of the valve system showing a schematic configuration of the cylinder head 31, FIG. 3 is valved stop mechanism according to A arrow view of FIG. 2 showing the operation of the valve stop mechanism with HLA36 4 is a sectional view of the HLA 36. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2 showing the intake side first and second oil passages 4, 5. FIG. 5 is a front view of the engine 30 as viewed in the direction of arrow B in FIG. 6 is a rear view of the engine 30 as viewed in the direction of arrow C in FIG. 4, and FIG. 7 is a sectional view taken along line VII-VII in FIG.

  As shown in FIG. 2, the cylinder head 31 is provided with an intake valve 42 and an exhaust valve 43 that open and close the intake port 31a and the exhaust port 31b, respectively, and a cam provided on the outer periphery. The intake side camshaft 52 and the exhaust side camshaft 53 for opening the intake and exhaust valves 42 and 43 through the portions 52a and 53a are rotatable between the upper portion of the cylinder head 31 and the cam cap 44 coupled to the upper surface thereof. It is supported.

The intake / exhaust valves 42 and 43 are urged in the closing direction by return springs 45 and 46, and the pressing force by the cam portions 52a and 53a is converted into a swinging motion through the swing arms 47 and 48 to open. It is supposed to be. An HLA arrangement hole 38 is formed corresponding to each of the intake and exhaust valves 42 and 43 formed in the cylinder head 31. First, fourth cylinder ₃₀ 1, 30 ₄ of HLA arrangement hole ₃₈ 1, 38 ₄ valve stop mechanism with HLA36 in is provided, the 2, HLA arrangement hole ₃₈ 2 of the third cylinder ₃₀ 2, 30 _3, 38 ₃ is provided with an HLA 37.

  The swing arms 47 and 48 have cam followers 49 and 50 that are rotatably provided substantially in the center and are in sliding contact with the outer peripheral surfaces of the cam portions 52a and 53a, respectively, and one end portion of each of the intake and exhaust valves 42 and 43. The other end is in contact with the end of the valve clearance adjusting mechanism 36a of the HLA 36 with a valve stop mechanism. The swing arms 47 and 48 swing as a whole at the contact point with the pivot portion of the HLA 36 with a valve stop mechanism as a swing fulcrum. As a result, the intake and exhaust valves 42 and 43 are opened.

  As shown in FIG. 3, the HLA 36 with a valve stop mechanism includes a valve clearance adjustment mechanism 36a and a valve stop mechanism 36b. The valve clearance adjusting mechanism 36a is configured to automatically adjust the valve clearance by hydraulic pressure, and is operated by oil supplied from the intake side and exhaust side first oil passages 4 and 14.

  The valve stop mechanism 36b is provided with an outer cylinder 361 that accommodates the valve clearance adjustment mechanism 36a so as to be able to protrude and retract, and a through hole 361a that is provided facing the side peripheral surface of the outer cylinder 361 so as to protrude and retract. A pair of lock pins 362 capable of switching the clearance adjustment mechanism 36a to the outer cylinder 361 to be locked or unlocked, a lock spring 363 for urging these lock pins 362 radially outward, and a valve clearance adjustment mechanism 36a And a lost motion spring 364 for urging the upper side of the upper side.

  As shown in FIG. 3B, the lock pin 362 is fitted in the through hole 361a of the outer cylinder 361 and the valve clearance adjusting mechanism 36a is locked to the outer cylinder 361, as shown in FIG. When the oil supplied from the intake side and exhaust side second oil passages 5, 15 acts on the outer end surface of the lock pin 362, the lock pin 362 resists the urging force of the lock spring 363 and moves inwardly of the outer cylinder 361. The valve clearance adjusting mechanism 36a is unlocked with respect to the outer cylinder 361 by being pressed to the side and disengaged from the through hole 361a.

  In this state, the swinging motion of the swing arms 47 and 48 is absorbed by the protruding and retracting operation of the valve clearance adjusting mechanism 36a urged by the lost motion spring 364, and the intake and exhaust valves 42 and 43 stop opening.

  The supply of oil to the valve stop mechanism 36 b of the HLA 36 with a valve stop mechanism disposed corresponding to the intake valve 42 is controlled by the intake side OCV 9 connected to the intake side second oil passage 5. Similarly, the oil supply to the valve stop mechanism 36 b of the HLA 36 with a valve stop mechanism disposed corresponding to the exhaust valve 43 is controlled by the exhaust side OCV 19 connected to the exhaust side second oil passage 15.

In the present embodiment, in the first cylinder 30 ₁ and the fourth cylinder 30 _4, the valve stop mechanism with HLA36 is mounted, when not operated valve stop mechanism 36b are first to fourth cylinders 30 ₁ 30 ₄ all-cylinder operation is performed by, when actuating the valve stop mechanism 36b includes first cylinder 30 ₁ and the fourth cylinder 30 ₄ and the second cylinder 30 ₂ by cylinder deactivation third cylinder 30 Reduced-cylinder operation in which operation is performed with only ₃ is performed. That is, the engine 30 is configured to be able to select all-cylinder operation and reduced-cylinder operation by controlling the intake side and exhaust side OCVs 9 and 19.

The HLA 37 provided corresponding to the intake and exhaust valves 42 and 43 of the second and third cylinders 30 ₂ and 30 ₃ includes a valve clearance adjusting mechanism 37a.

  Next, the intake side first and second oil passages 4 and 5 and the exhaust side first and second oil passages 14 and 15 will be described. As shown in FIG. 2, the cylinder head 31 has first to fourth pipe members 61 to 64 made of aluminum alloy extending in the cylinder row direction from the front end portion to the rear end portion of the cylinder head 31. The cylinder head 31 is integrally cast. The intake-side first oil passage 4 is defined as the inner diameter portion of the first pipe member 61, the intake-side second oil passage 5 is defined as the inner diameter portion of the second pipe member 62, and the exhaust-side first oil passage 14 is defined as the third inner diameter portion. The exhaust member side second oil passage 15 is defined as the inner diameter portion of the fourth pipe member 64.

As shown in FIG. 4, the first pipe member 61 includes a base portion 61a extending in the cylinder row direction from the front end surface to the fourth cylinder 30 ₄ of the cylinder head 31, portion bent at the rear side of the fourth cylinder 30 ₄ And an offset portion 61d bent upward in a crank shape via 61b and 61c. A ball 65 is press-fitted into the front end opening of the base 61 a and sealed, and a communication hole 61 e communicating with the distribution oil passage 2 (see FIG. 1) is formed from above the cylinder head 31 on the rear side of the ball 65. Has been.

The base 61a is in a positional relationship where HLA arrangement hole ₃₈ 1-38 ₄ and the side of the first to fourth cylinders ₃₀ 1 to 30 ₄ is duplicated in the overlapping portion ₆₁ 1-61 _4, the base portion 61a HLA arrangement The holes 38 _{1 to} 38 ₄ (see FIG. 2) communicate with each other.

On the other hand, the second pipe member 62 is the same member as the first pipe member 61, and rotates the first pipe member 61 downward by approximately 180 degrees while making the first pipe member 61 reverse to the longitudinal direction. The cylinder head 31 is integrally cast so as to be positioned below the cylinder head 31. Nachi Suwa, second pipe member 62, through a base portion 62a extending in the cylinder row direction from the rear end surface to the first cylinder 30 ₁ of the cylinder head 31, the bent portion 62b and 62c in the first cylinder 30 ₁ of the front And an offset portion 62d bent downward in a crank shape. The front end opening of the offset portion 62d communicates with the intake side OCV supply oil passage 7 (see FIG. 1) provided in the chain case 34 via the intake side OCV9.

The base 62a is a 1, HLA arrangement hole ₃₈ 1 of the fourth cylinder ₃₀ 1, 30 _4, 38 ₄ located in the overlapping positional relationship (see FIG. 2), in said overlap portion ₆₂ 1, 62 _4, the base portion 62a and the 1, a fourth cylinder ₃₀ 1, 30 ₄ of HLA arrangement hole ₃₈ 1, 38 ₄ are communicated.

  Here, in the front view of the engine 30 shown in FIG. 5, the base portion 62a of the second pipe member 62 is overlapped with the intake side cam sprocket 54, but the offset portion 62d positioned below the base portion 62a is provided. By connecting to the chain case 34, the intake side second oil passage 5 can be connected to the intake side OCV 9 while avoiding interference with the intake side cam sprocket 54. The intake side OCV 9 is attached to the chain case 34, and the intake side second oil passage 5, the intake side OCV supply oil passage 7, and the intake side OCV discharge oil passage 8 are connected to each other.

  Returning to FIG. 4, a cover structure 70 is attached to the rear end portion of the cylinder head 31. The cover structure 70 covers the rear end opening of the first pipe member 61 and the rear end opening of the second pipe member 62. The cover structure 70 includes a cover member 71 and a seal member 72 disposed between the cover member 71 and the rear end portion of the cylinder head 31. The seal member 72 is formed of a multilayer gasket, and a slit 721a is formed in the gasket layer 721 facing the cylinder head 31 so as to communicate the intake side first oil passage 4 and the intake side second oil passage 5. Has been. As shown in FIGS. 6 and 7, the intake-side first oil passage 4 and the intake-side second oil passage 5 are communicated with each other via the slit portion 721a, and the slit portion 721a is connected to the intake-side orifice 10 (see FIG. 6). 1).

  Incidentally, the rear end portion of the first pipe member 61 is an offset portion 61d located above the base portion 61a, and the second pipe member 62 is disposed below the first pipe member 61, that is, the cylinder head 31. At the rear end, the rear end opening of the first pipe member 61 and the rear end opening of the second pipe member 62 can be separated from each other, and the length of the orifice passage by the slit portion 721a can be ensured. Therefore, it is easy to form the intake-side orifice 10 suitably.

  In addition, by forming the intake side orifice 10 with the slit portion 721a formed in the gasket layer 721, for example, by pressing the orifice member into one of the first or second pipe members 61 and 62, the intake side orifice Compared to the case of forming the portion, the number of parts can be reduced, and the orifice structure can be easily formed.

  As shown in FIG. 2, the third and fourth pipe members 63 and 64 that define the exhaust side first and second oil passages 14 and 15 are the first pipe member 61 (that is, the second pipe member 62). The third member 63 is the same member, and the third pipe member 63 is disposed such that the offset portion 63d is located at the rear end portion, and the fourth pipe member 64 is disposed such that the offset portion 64d is located at the front end portion. However, as shown in FIG. 5, the offset portion 64d of the fourth pipe member 64 is arranged offset to the intake side with respect to the base portion 64a.

  Thereby, in the front view of the engine 30 shown in FIG. 5, the base portion 64a and the endless chain 56 are overlapped, but connected to the chain case 34 via the offset portion 64d located on the intake side from the base portion 64a. Thus, the exhaust side second oil passage 15 can be connected to the exhaust side OCV 19 while avoiding interference with the endless chain 56. The exhaust side OCV 19 is attached to the chain case 34, and the exhaust side second oil passage 15, the exhaust side OCV supply oil passage 17, and the exhaust side OCV exhaust oil passage 18 are connected to each other.

  Further, as shown in FIG. 6, the cover structure 80 that covers the rear end portions of the third and fourth pipe members 63 and 64 is different from the cover structure 70 provided on the intake side, and the cover member 71 is provided with the fuel pump. 81 flange portions 82 are provided. The seal member 83 of the cover structure 80 is configured similarly to the seal member 72 of the cover structure 70, and the exhaust side first oil passage 14 and the exhaust side second oil are formed on the gasket layer 831 facing the cylinder head 31 of the seal member 83. A slit portion 831 a that communicates with the path 15 is formed. The exhaust side first oil passage 14 and the exhaust side second oil passage 15 communicate with each other through the slit portion 831a, and the slit portion 831a functions as the exhaust side orifice 20 (see FIG. 1).

  Next, a method of casting the first to fourth pipe members 61 to 64 integrally with the material of the cylinder head 31 will be described with reference to FIG. FIG. 8 is a perspective view showing the mold 90 of the cylinder head 31, with the upper die, the lower die, the left and right closing die, the water jacket core, the port core, etc. omitted.

  First, as a pipe preparation step, first to fourth pipe members 61 to 64 are prepared. As described above, the first to fourth pipe members 61 to 64 are members having the same shape, and are pipe members made of an aluminum alloy. The first to fourth pipe members 61 to 64 are pipe members formed by extruding an aluminum alloy material. However, pipe members formed by joining ends joined by winding aluminum alloy steel plates are used. May be.

  Next, as shown in FIG. 8, as the pipe setting process, the first and second pipe members 61 and 62 are disposed in the posture when they are integrally cast in the cylinder head 31, and both front end portions are While integrating with the baseboard 91, both rear ends are integrated with the baseboard 92. As a result, the first and second pipe members 61 and 62 are positioned to be in a set state that can be integrally assembled to the mold 90. The baseboards 91 and 92 may be integrally formed with a core such as shell sand, or may be integrally joined with a metal member such as an aluminum alloy material.

  Similarly, while arranging the third and fourth pipe members 63 and 64 in the posture when casted integrally with the cylinder head 31, both front end portions are integrated with the baseboard 93 and both rear end portions are arranged. Are integrated with a baseboard 94. As a result, the third and fourth pipe members 63 and 64 are positioned so that they can be assembled to the mold 90 integrally. The structure of the baseboards 93 and 94 is the same as that of the baseboards 91 and 92.

  Next, as a mold assembling step, the first and second pipe members 61 and 62 and the third and fourth pipe members 63 and 64 that have been set are assembled to the mold 90. Assembling the first and second pipe members 61 and 62 in the set state to the mold 90 is performed by using the baseboards 91 and 92 as the front-end mold 95, the rear-end mold 96, and the width formed in the oil chamber core 97. The baseboards 98 and 99 are assembled from the upper side by fitting the baseboards 98 and 99, and the baseboards 91 and 92 are set to the front-end type 95 and the rear-end type 96.

  Similarly, the third and fourth pipe members 63 and 64 in the set state are assembled so that the baseboards 93 and 94 are fitted to the baseboard receivers formed in the front end type 95 and the back end type 96. Then, the baseboards 100 and 101 are assembled from above to set the baseboards 93 and 94 to the front-end type 95 and the back-end type 96.

  Thereafter, an upper die (not shown) or the like is assembled to complete the mold 90, and then a molten aluminum alloy is poured by a casting process to complete the material of the cylinder head 31. The first to fourth pipe members 61 to 64 are cast with a molten aluminum alloy of the same material, so that the first to fourth pipe members 61 to 64 and the base material portion of the cylinder head 31 can be joined well. Can be cast while securing.

  The material of the cylinder head 31 in which the first to fourth pipe members 61 to 64 are cast is attached with cover structures 70 and 80 on the rear end side of the cylinder head 31 as a cover process after being machined. It is done. The rear end openings of the first and second pipe members 61 and 62 are covered with the cover structure 70 and communicated with each other through a slit portion 721 a formed in the seal member 72. Similarly, the rear end openings of the third and fourth pipe members 63 and 64 are covered by the flange portion 82 of the fuel pump 81 and communicated by a slit portion 831 a formed in the seal member 83.

Next, oil supply by the oil supply system 1 according to the present embodiment will be described. As shown in FIG. 1, when the engine 30 is started, the oil in the oil pan 33 protrudes by the oil pump 35 and is supplied to the distribution oil passage 2 of the oil supply system 1. In the distribution oil passage 2, the flow is divided into the intake side first oil passage 4, the exhaust side first oil passage 14, and the OCV supply oil passage 3. Oil supplied to the intake side first oil passage 4 is supplied to each HLA arranged holes ₃₈ 1 to 38 _4, the valve clearance adjusting mechanism 36a of the valve stop mechanism with HLA36 and HLA37, 37a is operated, the intake and exhaust valves 42 , 43 and the intake / exhaust side swing arms 47, 48 are adjusted to substantially zero. In this case, all cylinders operation in the first to fourth cylinders ₃₀ 1 to 30 ₄ has been performed.

Next, the intake side OCV 9 and the exhaust side OCV 19 are energized by a control device (not shown) according to the operating state, and the intake side second oil passage is passed from the OCV supply oil passage 3 through the intake side OCV supply oil passage 7. 5 is supplied with oil. Similarly, oil is supplied from the OCV supply oil passage 3 to the exhaust side second oil passage 15 via the exhaust side OCV supply oil passage 17. Thus, first, oil is supplied to the fourth cylinder ₃₀ 1, 30 ₄ of HLA arrangement hole ₃₈ 1, 38 of the valve stop mechanism with HLA36 attached to ₄ the valve stop mechanism 36b, the valve stop mechanism 36b is operated . As a result, first, the intake and exhaust valves 42, 43 of the fourth cylinder ₃₀ 1, 30 ₄ stops the opening motion, the second, so that the reduced-cylinder operation of only the third cylinder ₃₀ 2, 30 ₃ is performed.

  Since the intake-side second oil passage 5 communicates with the intake-side first oil passage 4 via the intake-side orifice 10, a certain amount of oil has already been supplied to the intake-side first oil before the intake-side OCV 9 is energized. 2 exists in the oil passage 5. For this reason, as compared with the case where the intake-side orifice 10 is not provided, the oil filling into the intake-side second oil passage 5 by supplying the oil from the intake-side OCV supply oil passage 7 is performed in a short time. The oil pressure increase in the road will be accelerated. As a result, the operation time of the valve stop mechanism 36b can be shortened. Similarly, by providing the exhaust-side orifice 20, the hydraulic pressure in the exhaust-side second oil passage 15 is increased, and the operation time of the valve stop mechanism 36b can be shortened.

  In addition, by allowing the intake side first oil passage 4 and the intake side second oil passage 5 to communicate with each other via the intake side orifice 10, oil outflow from one oil passage to the other oil passage can be suppressed. The increase in hydraulic pressure in the intake side first and second oil passages 4 and 5 can be accelerated. Similarly, by providing the exhaust-side orifice 20, it is possible to accelerate the increase in hydraulic pressure in the exhaust-side first and second oil passages 14 and 15.

  Further, when the engine 30 is stopped, the first pipe member 61 that defines the intake-side first oil passage 4 is sealed at the front end by the ball 65 and is located above the base 61a on the rear side. Since it is configured to have the offset portion 61d, the oil is prevented from flowing out from the oil passage 4 between the ball 65 and the offset portion 61d in the intake side first oil passage 4 and remains. Can be made. As a result, the increase of the hydraulic pressure in the intake side first oil passage 4 at the time of engine start can be accelerated, and the operation time of the valve clearance adjustment mechanisms 36a and 37a can be shortened.

  According to the embodiment described above, the following effects can be exhibited.

(1) The intake side first and second oil passages 4 and 5 and the exhaust side first and second oil passages 14 and 15 are formed as inner diameter portions of the first to fourth pipe members 61 to 64 having bent portions. Thus, an oil passage having a bent portion can be easily formed in the cylinder head 31 without providing a horizontal hole or an oblique hole. That is, the oil path is not limited to a straight line in the cylinder head 31 and can be laid out freely, so that the degree of freedom in designing the oil path can be improved. Further, as a result of improving the degree of freedom in designing the oil passage, the degree of freedom in layout of the intake side and exhaust side OCVs 9 and 19 connected to the oil passage can also be improved.

(2) Since it is not necessary to form a horizontal hole or a slanted hole by processing, and a plugging process to the horizontal hole or the slanted hole is also unnecessary, the intake side first and second oil passages 4 having bent portions are provided. 5 and the processing costs of the exhaust side first and second oil passages 14 and 15 can be reduced.

(3) Since the cylinder head 31 and the first to fourth pipe members 61 to 64 are both made of an aluminum alloy, the first to fourth pipe members 61 to 64 are integrally cast into the material of the cylinder head 31. Furthermore, the adhesiveness of the 1st-4th pipe members 61-64 to a cylinder head raw material can be improved.

(4) Since the linear expansion coefficient is substantially the same by configuring the cylinder head 31 and the first to fourth pipe members 61 to 64 with similar materials, when the cylinder head 31 is at a high temperature during operation of the engine 30 In addition, the difference in thermal expansion between the cylinder head 31 and the first to fourth pipe members 61 to 64 is eliminated, and as a result, generation of thermal stress due to the difference in thermal expansion can be suppressed. Thereby, durability of the cylinder head 31 is securable.

(5) When the engine 30 is stopped, the oil in the intake-side and exhaust-side first oil passages 4, 14 is blocked by the bent portions 61b, 61c, 63b, 63c, so that the intake-side and exhaust-side first oil passages 4 and 14 can leave oil. Thereby, when the engine 30 is started, the oil filling time in the intake side and exhaust side first oil passages 4 and 14 can be shortened, and the oil pressure increase in the oil passages 4 and 14 can be accelerated. As a result, the valve clearance adjusting mechanisms 36a and 37a can be operated in a short time.

(6) Since the front end opening of the intake side second oil passage 5 can be arranged offset with respect to the base 62a in a front view, the intake side OCV 9 is provided at the front end opening of the intake side second oil passage 5. The connection can be made while avoiding interference with the intake side cam sprocket 54. Further, since the front end opening of the exhaust side second oil passage 15 can be arranged offset with respect to the base portion 64a in a front view, the exhaust side OCV 19 is provided at the front end opening of the exhaust side second oil passage 15, Connection is possible while avoiding interference with the endless chain 56.

  That is, by disposing the front end openings of the intake-side and exhaust-side second oil passages 5 and 15 so as to be offset, it is possible to improve the degree of freedom of the layout of components connected to these front-end openings.

(7) By covering the rear end openings of the intake side first and second oil passages 4 and 5 with the cover structure 70, the intake side first oil passage 4 and the intake side second oil passage 5 can be easily communicated with each other. . Moreover, by providing the cover structure 70 with an orifice, the intake-side orifice 10 can be easily formed. Similarly, the exhaust side first oil passage 14 and the exhaust side second oil passage 15 can be easily communicated by covering the rear end openings of the exhaust side first and second oil passages 14 and 15 with the cover structure 80. In addition, the exhaust-side orifice 20 can be easily formed.

(8) Even when the valve stop mechanism 36b is not operating, oil can be supplied from the intake-side first oil passage 4 to the intake-side second oil passage 5 via the intake-side orifice 10, and similarly, the exhaust-side first Oil can be supplied from the oil passage 14 to the exhaust-side second oil passage 15 via the exhaust-side orifice 20. As a result, when the OCVs 9 and 19 are energized, the oil pressure increase time in the intake side and exhaust side second oil passages 5 and 15 can be shortened, and the valve stop mechanism 36b can be operated in a short time. As a result, the operating state of the engine 30 can be quickly switched to the reduced cylinder state, so that the control responsiveness of the engine 30 can be improved.

  That is, according to the cylinder head structure of an engine and the manufacturing method thereof according to the present invention, it is possible to facilitate the formation of the oil passage and improve the cost while improving the degree of freedom in designing the oil passage.

  In the embodiment described above, the case where aluminum alloy pipes are used as the first to fourth pipe members 61 to 64 has been described. However, the temperature of the cylinder head 31 during operation of the engine 30 is low and the influence of thermal stress is exerted. In the case of a small size, another pipe member such as iron may be used instead. This also makes it possible to easily form the intake-side and exhaust-side first and second oil passages 4, 5, 14, and 15, and to further reduce the cost.

  Further, the case where the slit portions 721a and 831a are formed in the gasket layers 721 and 831 of the seal members 72 and 83 as the intake-side and exhaust-side orifices 10 and 20 has been described. May be formed. Also by this, an orifice can be formed easily.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made without departing from the spirit and scope of the present invention described in the claims.

  As described above, according to the present invention, it is possible to facilitate the formation of the oil passage while improving the degree of freedom in designing the oil passage, and to reduce the cost. Therefore, the oil passage may be suitably used in this type of manufacturing technology field. There is.

DESCRIPTION OF SYMBOLS 1 Oil supply system 2 Distribution oil path 3 OCV supply oil path 4 Intake side 1st oil path 5 Intake side 2nd oil path 7 Intake side OCV supply oil path 9 Intake side OCV
10 Exhaust-side orifice 14 Exhaust-side first oil passage 15 Exhaust-side second oil passage 17 Exhaust-side OCV supply oil passage 19 Exhaust-side OCV
20 Exhaust-side orifice 30 Engine 31 Cylinder head 33 Oil pan 34 Chain case 35 Oil pump 36 HLA with valve stop mechanism
36a Valve clearance adjustment mechanism 36b Valve stop mechanism 37 HLA
37a Valve clearance adjustment mechanism 38 HLA arrangement hole 54 Intake side cam sprocket 56 Endless chain 61 First pipe member 61a Base 61b Bending part 61c Bending part 61d Offset part 62-63 Second to third pipe members 70 Cover structure 71 Cover member 72 Seal member 721 Gasket layer 721a Slit portion 80 Cover structure 81 Fuel pump 82 Flange portion 83 Seal member 831 Gasket layer 821a Slit portion 90 Mold 91-94 Baseboard

Claims (7)

An engine cylinder head structure in which an oil passage for supplying oil to a hydraulic actuator is formed in a cylinder row direction,
The oil passage is formed as an internal space of a pipe member at least an end portion of which is offset from a base portion by a bent portion,
A cylinder head structure for an engine, wherein the pipe member is integrally cast in a cylinder head material so as to extend in a cylinder row direction from one end portion to the other end portion of the cylinder head. The cylinder head is an aluminum alloy casting,
The pipe member is an aluminum alloy pipe,
The cylinder head structure of the engine according to claim 1. The hydraulic actuator is a hydraulic lash adjuster provided with a valve clearance adjustment mechanism and a valve stop mechanism,
The oil passage is a first oil passage for operating the valve clearance adjustment mechanism and a second oil passage for operating a valve stop mechanism,
Oil is supplied to the first oil passage from above the one end side,
The first pipe member forming the first oil passage has an end on the one end side sealed, and the end on the other end is offset upward with respect to the base,
The second pipe member that forms the second oil passage is the same member as the first pipe member, and is disposed so that the end on the one end side is offset with respect to the base.
The cylinder head structure of the engine according to claim 1 or 2. The first pipe member is disposed above the second pipe member;
The other end of the first pipe member and the other end of the second pipe member are covered with a cover structure,
In the cover structure, an orifice that communicates the first oil passage and the second oil passage is formed,
The engine cylinder head structure according to claim 3. A method of manufacturing a cylinder head of an engine, wherein a plurality of oil passages for supplying oil to a hydraulic actuator are formed in a cylinder row direction,
A pipe preparation step for preparing a plurality of pipe members, the pipe member forming the oil passage, wherein at least an end portion is offset from a base portion by a bent portion;
A pipe setting step for positioning the plurality of pipe members to be in a set state that can be integrally assembled to a mold; and
A mold assembling step for assembling the plurality of pipe members in the set state to a mold of a cylinder head;
A method of manufacturing a cylinder head for an engine, comprising: a casting step of casting the plurality of pipe members set in the set state together with a material of a cylinder head by the mold. The hydraulic actuator is a hydraulic lash adjuster provided with a valve clearance adjustment mechanism and a valve stop mechanism,
The oil passage is a first oil passage for operating the valve clearance adjustment mechanism and a second oil passage for operating a valve stop mechanism,
The pipe preparation step includes a step of preparing a first pipe member that forms the first oil passage and a second pipe member that forms the second oil passage,
The pipe setting step includes a step of bringing the first pipe member into a set state positioned above the second pipe member,
A method for manufacturing a cylinder head for an engine according to claim 5. The method further comprises a cover step of covering one end of the first pipe member and the second pipe member with a cover member.
A method for manufacturing a cylinder head for an engine according to claim 6.

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