JP2013113158A - Head cover structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve gear mechanism including an oil channel structure capable of preventing a cam holder from thickening and enlarging without impairing compactification of an engine due to narrowing of an interval between camshafts.SOLUTION: A valve gear mechanism of an engine 1 includes: an intake camshaft 8 and an exhaust camshaft 9 provided at different height positions in a direction of a cylinder axis 7, both including VTC actuators 17 and 18; an intermediate cam holder 31 for forming a first bearing 28 of the exhaust camshaft 9 in cooperation with a cylinder head 4; and an upper cam holder 32 for forming a first bearing 26 of the intake camshaft 8 in cooperation with the intermediate cam holder 31. An in-holder oil channel 64 formed in the intermediate cam holder 31 and the upper cam holder 32 among exhaust-side spark-advancing oil channels 60 to the lower exhaust-side VTC actuator 18 is structured to incorporate an in-upper-holder oil channel 64B provided in the upper cam holder 32.

Description

  The present invention relates to a valve operating mechanism for an internal combustion engine in which two camshafts are arranged at different positions in the cylinder axis direction, and a cam phase varying mechanism is provided at each end.

  Many 4-cycle engines (hereinafter simply referred to as engines) are equipped with various variable valve mechanisms to improve output and fuel consumption, reduce harmful exhaust gas components, and the like. As a variable valve mechanism, there is a cam switching type valve characteristic variable device (Variable valve Timing and lift Electronic Control: hereinafter referred to as VTEC) that switches between a low-speed cam and a high-speed cam. A valve timing control device (Variable Timing Control Device) with variable phase control and a valve phase control device that achieves further improvement of transient characteristics and throttle-less operation by continuously variable control of phase and valve lift. : Hereinafter referred to as VTC) and the like (see, for example, Patent Document 1).

  The VTC is composed of a hydraulic actuator (hereinafter referred to as a VTC actuator) installed near the end of the camshaft in the cylinder head, a hydraulic control valve that controls the supply of hydraulic oil (engine oil) to the VTC actuator, and the like. ing. There is also a lock pin that locks the cam phase in a predetermined state, and a lock releasing operation by the lock pin is performed by hydraulic pressure (see, for example, Patent Document 2).

  On the other hand, in a DOHC engine having two camshafts, the two camshafts are arranged at different height positions in the cylinder axial direction in order to make the engine compact by narrowing the gap between the camshafts. There is known a valve operating mechanism in which the lower part of the cam holder that pivotally supports the upper camshaft is divided at the axial position of the lower camshaft on the lower side to serve also as the upper camholder (cam cap) of the lower camshaft (for example, Patent Documents 3 and 4).

Japanese Patent No. 3447601 Japanese Patent No. 4160408 Registered Utility Model No. 2553101 German patent invention 4215051 specification

  In an engine equipped with a VTC, the drive of the VTC actuator and the lubrication of the camshaft are both performed by engine oil supplied from the main gallery, and the oil passage of hydraulic oil supplied from the hydraulic control valve is connected from the cylinder head to the cam holder. It is necessary to form more than one. Therefore, the cam holder has to be increased in thickness and size, leading to an increase in size of the internal combustion engine. In particular, when forming an oil passage for other hydraulically driven devices such as VTEC, or when reducing the width of the cylinder head by disposing two camshafts at different heights in the cylinder axis direction. This problem becomes noticeable.

  The present invention has been devised to solve the problems included in the conventional technology, and without taking advantage of the downsizing of the engine due to the narrowing of the camshaft, utilizing the structure in which the cam holder is divided, An object of the present invention is to provide a valve mechanism having an oil passage structure that can suppress an increase in the thickness and size of a cam holder.

  In order to solve such a problem, according to one aspect of the present invention, the internal combustion engine (1) is arranged in parallel to each other at different height positions in the cylinder axis (7) direction, and the cam phase is variable at one end. An upper camshaft (8) and a lower camshaft (9) provided with a mechanism (17, 18), a cylinder head (4) having a bearing lower portion (281) of the lower camshaft, and the bearing of the cylinder head An intermediate cam holder having a bearing upper portion (28u) of the lower cam shaft that forms a lower cam shaft bearing (28) on the one end side (11) in cooperation with a lower portion, and a bearing lower portion (261) of the upper cam shaft. 31) and the upper camshaft forming the upper camshaft bearing (26) on the one end side (11) in cooperation with the lower bearing portion of the intermediate cam holder. And an upper cam holder (32) extending so as to reach the upper part of the lower camshaft. The hydraulic oil supplied from the hydraulic control valve is supplied to the upper oil passage. (50, 55) and a lower side oil passage (60, 65), the valve operating mechanism of the internal combustion engine that feeds to both the cam phase variable mechanisms, wherein the upper side oil passage and the lower side oil passage are In-head oil passages (52, 57, 62, 67) provided in the cylinder head so as to extend in the vertical direction, cam holder oil passages (54, 59, 64, provided in the cam holder to the bearing) 69) and an in-shaft oil passage in the camshaft, and the cam holder oil passage (64) of the lower oil passage is provided at least partially in the upper cam holder.

  According to this configuration, by connecting the cam holders constituting the bearings of both camshafts to each other, it is possible to improve the processing accuracy of the bearing that requires roundness and to reduce the number of parts. In addition, the upper cam holder that does not form the lower cam shaft bearing is configured to reach the upper portion of the lower cam shaft, and a part of the oil path in the cam holder of the lower side oil path is provided in the upper cam holder. The thickness of the intermediate cam holder can be suppressed as compared with the configuration in which the oil passage is formed only in the intermediate cam holder while reducing the weight of the upper cam holder as much as possible. In addition, since the strength of the intermediate cam holder can be ensured by reducing the machining holes of the intermediate cam holder, the fastening rigidity can be increased and the sealing performance can be improved.

  Further, according to one aspect of the present invention, the lower side oil passage includes a lower side advance angle oil passage (60) for driving the cam phase variable mechanism to an advance angle side, and a delay of the cam phase variable mechanism. A lower-side retarded oil passage (65) for driving to the corner side, and the cam holder oil passages (64, 69) of both the lower-side oil passages are cammed on the inner peripheral surface of the lower camshaft bearing. The lower side grooved oil passages (63, 68) arranged in parallel in the axial direction, and the cam holder oil passage of one of the lower side advance angle oil passage and the lower side retard oil passage (65) is the intermediate The cam holder is provided with an intermediate holder oil passage (69) having one end connected to the in-head oil passage (67) and the other end connected to the lower groove-like oil passage (68). The cam holder oil passage of the other (60) of the oil passage and the lower-side retarded oil passage is formed in the intermediate cam holder. One end is connected to the oil passage in the head, and the other end is formed in the intermediate holder oil passage (64A) opened on the upper surface of the intermediate cam holder and the upper cam holder, and one end is formed in the intermediate holder oil passage. It can be set as the structure which has the oil path (64B) in an upper holder connected to the other end of a path, and the other end connected to the said lower side grooved oil path.

  According to this configuration, one of the two lower cam holder oil passages is connected to the lower groove oil passage by the intermediate holder oil passage, and the other is connected to the lower groove oil passage by the upper holder oil passage. Further, both the intermediate cam holder and the upper cam holder can be prevented from becoming thicker and larger. Further, by dividing the lower-side cam holder oil passage into upper and lower parts, the processing can be simplified, and the rigidity of the upper cam holder can be increased by the oil passage in the upper holder while reducing waste. In addition, even when the intermediate holder oil passage is formed on the joint surface with the upper cam holder, it is possible to ensure a joining area sufficient to ensure sealing performance without increasing the thickness. In addition, since it is not necessary to provide an oil passage along the joint surface between the cylinder head and the intermediate cam holder, it is possible to improve the fastening rigidity of the lower camshaft bearing section, and the freedom to design the oil passage used for devices other than the cam phase variable mechanism The degree becomes higher.

  Further, according to one aspect of the present invention, the upper side oil passage includes an upper side advance angle oil passage (50) for driving the cam phase variable mechanism to an advance angle side, and a delay of the cam phase variable mechanism. An upper side retarded oil passage (55) for driving toward the corner side, and the head internal oil passages (52, 57) of the upper side oil passages are arranged in parallel in the camshaft direction. The cam holder oil passage of the upper side oil passage is formed in the upper side groove-like oil passage (53, 58) juxtaposed in the cam shaft direction on the inner peripheral surface of the upper camshaft bearing, and the intermediate cam holder, and the head There are intermediate holder inner oil passages (54, 59) connecting the inner oil passage and the upper groove oil passage, respectively, and both the upper oil passages are respectively the head oil passage and the upper groove oil passage. The passage and the oil passage in the intermediate holder are located on a plane perpendicular to the cam shaft direction It can be formed configuration as.

  According to this configuration, both the upper oil passages are formed in parallel on a plane orthogonal to the cam shaft direction, so that processing is easy and the structure of the intermediate cam holder oil passage can be simplified. Further, the upper cam holder can be set to a minimum size by forming the oil passage concentrated on the intermediate cam holder.

  According to another aspect of the present invention, an upper rocker shaft (41) and a lower rocker shaft (42) supported by the cylinder head and disposed in parallel with the corresponding cam shaft are further provided below the corresponding cam shaft. The head oil passages (52, 57) of the both upper side oil passages (50, 55) and the head oil passages (62, 67) of the both lower side advance oil passages (60, 65). Is located between the upper rocker shaft and the lower rocker shaft, and the upper cam holder and the intermediate cam holder are placed in the cylinder head at a position surrounded by the four oil passages in the head in a top view of the cylinder head. The first fastening bolt (40) to be fastened together can be fastened.

  According to this configuration, the processing is facilitated by arranging and arranging the oil passages in the head. In addition, the first fastening bolt is arranged at a position surrounded by the oil passage, so that the oil passage around the mating surface of the cylinder head and the intermediate cam holder and the mating surface of the intermediate cam holder and the upper cam holder can be provided. Sealability can be improved.

  According to another aspect of the present invention, the upper cam phase varying mechanism (17) includes a hydraulically driven lock pin that locks the cam phase in a predetermined state, and is used for operating or releasing the lock pin. The lock pin oil passage (70) supplied from the hydraulic control valve is further provided, and the lock pin oil passage is formed on the inner circumferential surface of the upper camshaft bearing (26). 58) on the side opposite to the upper oil passages (50, 55) relative to the upper camshaft (8) and the grooved oil passage (73) for the pin formed at a position different from the cam shaft direction. A pin intermediate holder oil passage (74) formed so as to open to the upper surface and the lower surface of the intermediate cam holder (31), and a joint surface between the intermediate cam holder and the upper cam holder (32), Previous The pin intermediate oil passage (74) communicates with the pin intermediate holder oil passage and the pin groove oil passage, the pin intermediate holder oil passage (74) and the pin groove oil. Between the passage (73), there is a second fastening bolt for fastening the upper cam holder and the intermediate cam holder together with the cylinder head on the side opposite to the first fastening bolt with respect to the upper cam shaft. A bolt insertion hole (39) may be formed, and the pin communication oil passage (75) may be formed integrally with the bolt insertion hole (39) of the second bolt.

  According to this configuration, by arranging the oil path in the pin intermediate holder on the side opposite to the upper side oil paths with respect to the upper cam shaft, the area of the mating surface in the vicinity of the upper cam shaft bearing can be secured and the cam holder Can be prevented from increasing in size, and oil leakage from the mating surfaces can be suppressed to prevent a decrease in response of the upper cam phase variable mechanism.

  Further, according to one aspect of the present invention, the intermediate holder oil passage (68) of the one (65) of the lower side advance angle oil passage and the lower side retard oil passage is joined to the upper cam holder. A grooved portion formed on the surface may be included, and a thinning recess (110) may be formed below the grooved portion on the joint surface of the intermediate cam holder with the cylinder head.

  According to this configuration, since the intermediate holder oil passage includes the groove-like oil passage, the processing is facilitated, and the intermediate cam holder can be reduced in weight by forming the lightening recess.

  According to one aspect of the present invention, the upper cam holder (32) extends so as to straddle the lower cam shaft (9), and the intermediate cam holder and the upper cam holder are fastened to the cylinder head. There are four bolt insertion holes (39) for fastening bolts to be connected, including two places for sandwiching the lower camshaft and two places for sandwiching the upper camshaft, and the cylinder head (4) and the intermediate cam holder. (31) and the upper cam holder (32) have oil level gauge insertion holes (101 to 103) extending from the upper surface of the upper cam holder to the lower surface of the cylinder head at a position adjacent to one of the fastening bolts. It can be set as the structure which defines.

  According to this configuration, by forming the oil level gauge insertion hole on the upper surface of the upper cam holder, the oil level gauge mounting hole formed in the head cover fastened to the upper surface of the cylinder head and the oil level gauge insertion hole are separated from each other. The distance can be shortened, and the oil level gauge can be inserted more easily.

  As described above, according to the present invention, an oil passage structure that can suppress the increase in thickness and size of the cam holder by utilizing the structure in which the cam holder portion is divided without hindering the downsizing of the engine due to the narrowing of the cam shaft. The provided valve mechanism can be provided.

The partial top view of the valve mechanism which concerns on embodiment The perspective view which looked at the valve mechanism shown in FIG. 1 from upper direction 1 is an exploded perspective view of the valve mechanism shown in FIG. 1 is an exploded perspective view of the valve mechanism shown in FIG. Schematic configuration diagram of oil passage configuration viewed from the right side Schematic configuration diagram of oil passage configuration viewed from the rear Sectional view of the engine along the line VII-VII in FIG.

  Hereinafter, an embodiment in which a valve operating mechanism according to the present invention is applied to a DOHC 4-valve type 4-cycle in-line four-cylinder gasoline engine (hereinafter simply referred to as engine 1) will be described in detail with reference to the drawings. . In the following description, it is assumed that the engine 1 is mounted on the automobile in the direction indicated by the arrow in FIG.

  First, the overall configuration of the engine 1 will be described with reference to FIG. The engine 1 includes a cylinder block 2, an oil pan 3 fastened to the lower end of the cylinder block 2, a cylinder head 4 fastened to the upper end of the cylinder block 2, a cylinder head cover 5 fastened to the upper end of the cylinder head 4, and the like. Yes. The valve operating chamber 6 defined by the cylinder head 4 and the cylinder head cover 5 has an intake camshaft 8 disposed at a relatively high position (upper side) in the cylinder axis 7 direction and relatively in the cylinder axis 7 direction. Exhaust camshafts 9 arranged at a low position (lower side) are arranged in parallel to each other.

  Next, as shown in FIG. 1, the first to first four cylinders (not shown) are sandwiched on the upper surface of the cylinder head 4 from right to left (that is, in the cylinder row direction). A fifth cam holder (only the first cam holder 11 and the second cam holder 12 are shown in the figure) is formed. The first cam holder 11 is formed integrally with the right end wall 4 </ b> R of the cylinder head 4.

  A cam chain cover 14 that forms a cam chain chamber 13 with the cylinder head 4 is fastened to the right side surface of the cylinder head 4. An intake side VTC actuator 17 and an exhaust side VTC actuator 18 having an intake side cam sprocket 15 and an exhaust side cam sprocket 16 formed on the outer periphery at the right ends of the intake camshaft 8 and the exhaust camshaft 9 that enter the cam chain chamber 13 respectively. Is fixed. A cam chain 19 is wound around the intake side cam sprocket 15 and the exhaust side cam sprocket 16, and the intake cam shaft 8 and the exhaust cam shaft 9 are driven to rotate by a crank sprocket (not shown) via the cam chain 19. . Although a detailed description of the VTC actuator is omitted here, the intake-side VTC actuator 17 is provided with a lock pin that locks the cam phase in a predetermined state. The lock pin is always urged toward the lock side by a compression coil spring, and the lock state is released by driving the lock pin in the release direction by hydraulic pressure.

  The intake camshaft 8 includes two first cam lobes 21 for low valve lift provided at positions corresponding to two intake valves, and one for high valve lift provided between the first cam lobes 21. Two second cam lobes 22 are formed, and two first rocker arms 23 and one second rocker arm 24 provided corresponding to the cam lobes 21 and 22 are connected and separated by a hydraulically driven connecting pin. The VTEC mechanism 20 for changing the valve lift of the intake valve is provided. On the other hand, the exhaust camshaft 9 is formed with one cam lobe 25 for each cylinder.

  As shown in FIGS. 2 and 3, in the first cam holder 11, a bearing lower portion 28 l (lower portion of the journal support surface) of the exhaust camshaft 9 is formed on the upper surface side of the right end wall 4 </ b> R of the cylinder head 4. An intermediate cam holder 31 is fastened to the upper surface of the right end wall 4R of the cylinder head 4. In the intermediate cam holder 31, a bearing upper portion 28 u of the exhaust camshaft 9 that forms the first bearing 28 of the exhaust camshaft 9 in cooperation with the bearing lower portion 28 l formed in the cylinder head 4 is formed on the lower surface side thereof. A bearing lower portion 26l of the camshaft 8 is formed on the upper surface side thereof. An upper cam holder 32 having substantially the same longitudinal dimension as the intermediate cam holder 31 is fastened to the upper surface of the intermediate cam holder 31. In the upper cam holder 32, a bearing upper portion 26u of the intake camshaft 8 that forms the first bearing 26 of the intake camshaft 8 in cooperation with a bearing lower portion 26l formed in the intermediate cam holder 31 is formed on the lower surface side. .

  The upper cam holder 32 and the intermediate cam holder 31 have bolt insertion holes 39 that are continuous with each other at four locations near both sides of the intake camshaft 8 and near both sides of the exhaust camshaft 9, and four fastening bolts. 40 is fastened to the cylinder head 4 together. As shown in FIG. 1, a bolt insertion hole 46 for fastening the cylinder head 4 to the cylinder block 2 is provided in the vicinity of the right end wall 4 </ b> R in the bottom wall of the cylinder head 4, and the intake camshaft 8 of the exhaust camshaft 9. The intermediate cam holder 31 and the upper cam holder 32 are bolt insertion holes when viewed from the direction of the cylinder axis 7 so that the bolts can be inserted and tightened with a tool. The dimension in the left-right direction of the portion is reduced so as not to overlap with 46.

  In the second cam holder 12 to the fifth cam holder (only the second cam holder 12 is shown in FIGS. 2 and 3 as a whole), the intake side cam holder and the exhaust side cam holder are separated from each other and protrude from the bottom wall of the cylinder head 4. It is installed. The lower cam holder 36 integrally formed with the cylinder head 4 of the second exhaust side cam holder 12B has an upper surface flush with the upper surface of the cylinder head 4, and a bearing lower portion 29l of the exhaust cam shaft 9 is formed on the upper surface side. ing. On the upper surface of the lower cam holder 36 of the second exhaust side cam holder 12B, an upper holder 37 having a bearing upper portion 29u of the exhaust cam shaft 9 formed on the lower surface side thereof is fastened by two fastening bolts 40.

  The upper surface of the lower cam holder 33 of the second intake side cam holder 12 </ b> A is flush with the upper surface of the cylinder head 4 as in the exhaust side. An intermediate cam holder 34 having a bearing lower portion 27l of the intake camshaft 8 formed on the upper surface side thereof is fastened to the upper surface of the lower cam holder 33 of the second intake side cam holder 12A. An upper cam holder 35 having an upper portion 27u formed on the lower surface side thereof is fastened. The upper cam holder 35 and the intermediate cam holder 34 of the second intake side cam holder 12 </ b> A are fastened together with the lower cam holder 33 by two fastening bolts 40. The third cam holder to the fifth cam holder are configured similarly.

  The first cam holder 11 to the fifth cam holder are disposed below the exhaust camshaft 9 and an intake rocker shaft support hole 43 that supports an intake rocker shaft 41 (see FIG. 7) disposed below the intake camshaft 8. An exhaust rocker shaft support hole 44 for supporting the exhaust rocker shaft 42 (see FIG. 7) is formed.

  On the right side surface of the cylinder head 4, an intake side advance oil passage 50 for driving the intake side VTC actuator 17 to the advance side, and an intake side retard oil for driving the intake side VTC actuator 17 to the retard side. Passage 55, lock pin oil passage 70 for driving the lock pin of intake side VTC actuator 17 to the release side, exhaust side advance oil passage 60 for driving exhaust side VTC actuator 18 to the advance side, exhaust side An exhaust side retarded oil passage 65 for driving the VTC actuator 18 to the retarded angle side, an intake VTEC-ON oil passage 80 for driving the connecting pin of the VTEC mechanism 20 provided on the intake side to the connected side, and a VTEC mechanism An intake VTEC-OFF oil passage 85 for driving the 20 connecting pins to the separation side is opened. Hydraulic oil (engine oil) is supplied to these oil passages from an oil control valve (not shown).

  Further, although not provided in the engine 1 of the present embodiment, the cylinder head 4 drives the connection pin of the exhaust side VTEC mechanism to the connection side so that the cylinder head 4 can be applied to an engine provided with both the exhaust side and the VTEC mechanism. The exhaust VTEC-ON oil passage 90 for the exhaust gas and the exhaust VTEC-OFF oil passage 95 for driving the connecting pin of the exhaust side VTEC mechanism to the separation side can be formed. An oil return hole 45 for returning engine oil from the valve operating chamber 6 to the oil pan 3 is opened toward the cam chain chamber 13 on the right side surface of the cylinder head 4.

  Of these oil passages, the intake side advance oil passage 50, the intake side retard oil passage 55, the exhaust side advance oil passage 60, the exhaust side retard oil passage 65, the intake VTEC-OFF oil passage 85, and The six oil passages of the exhaust VTEC-ON oil passage 90 are open to one joint surface formed between the intake rocker shaft 41 and the exhaust rocker shaft 42. In this embodiment, since oil is supplied to these oil passages from the oil control valve via the cam chain chamber 13, the oil passages are consolidated, so that the sealing performance on the hydraulic oil delivery surface is improved. .

  Next, the configuration of the oil passage formed in the first cam holder 11 will be described with reference to FIGS. In the present embodiment, since no VTEC mechanism is provided on the exhaust side, there is no need to form oil passages provided to the exhaust side VTEC mechanism. However, these oil passages are also described here, and FIG. These oil passages are also shown in FIG. 6, (A) is an outline of the oil passage configuration of portion A in FIG. 5, (B) is an outline of the oil passage configuration of portion B in FIG. 5, and (C) is a portion C of FIG. The outline of the oil passage configuration is schematically shown in a state viewed from the rear.

  The intake side advance oil passage 50 and the intake side retard oil passage 55 are respectively arranged in cylinder row direction oil passages 51, 56 extending leftward (cylinder row direction) from the opening end of the right side surface of the cylinder head 4, and the cylinder head 4. In the head, and the cam shafts on the inner peripheral surface of the first bearing 27 of the intake camshaft 8. Intake side annular groove oil passages 53, 58 arranged in parallel to each other, and an intermediate holder internal oil passage formed in the intermediate cam holder 31 and connecting the head internal oil passages 52, 57 and the intake side annular groove oil passages 53, 58. 54, 59.

  The intermediate holder inner oil passages 54 and 59 of the both intake side oil passages 50 and 55 are arranged on the front side of the intake camshaft 8 (with the exhaust camshaft 9 and the upper surface of the intermediate cam holder 31 along the cylinder axis 7 direction from the lower surface of the intermediate cam holder 31). ) To the intake-side annular groove oil passages 53, 58 through a groove-like portion formed rearward along the upper surface of the intermediate cam holder 31. Both intake-side oil passages 50 and 55 are located on a plane in which the head inner oil passages 52 and 57, the intake-side annular groove oil passages 53 and 58, and the intermediate holder inner oil passages 54 and 59 are orthogonal to the cam shaft direction. In addition, the portions corresponding to each other are formed so as to be aligned in the cylinder row direction. The hydraulic oil supplied to both the intake-side annular groove oil passages 53, 58 passes through the oil introduction holes formed at different positions in the axial direction of the outer peripheral surface of the intake camshaft 8. Are introduced into the oil passage in the intake shaft (not shown) formed in step S1 and supplied to the advance chamber and the retard chamber of the intake side VTC actuator 17, respectively.

  The lock pin oil passage 70 includes a cylinder row direction oil passage 71 extending leftward from a right side opening end of the cylinder head 4 on a plane orthogonal to the cylinder axis 7, and the cylinder row direction oil passage 71 extending from the intake camshaft 8. On the rear side (the side opposite to both intake-side oil passages 50 and 55 with respect to the intake camshaft 8), an in-head oil passage 72 extending upward along the direction of the cylinder axis 7, and the first intake camshaft 8 first An annular groove oil passage 73 for pins formed on the right side (a position different in the cam shaft direction) of both intake side annular groove oil passages 53 and 58 on the inner peripheral surface of the bearing 27, and extends upward from the lower surface of the intermediate cam holder 31. The pin intermediate holder oil passage 74 opened on the upper surface of the intermediate cam holder 31 and the pin intermediate hole oil passage 74 formed on the upper surface of the intermediate cam holder 31 and communicating with the pin annular groove oil passage 73. Communicating And a Mizoyuro 75.

  The head inner oil passage 72 and the pin intermediate holder inner oil passage 74 are provided behind the fastening bolt 40 disposed in the vicinity of the rear side of the intake camshaft 8. That is, the intermediate cam holder 31 is formed with a bolt insertion hole 39 through which the fastening bolt 40 is inserted between the pin intermediate holder oil passage 74 and the pin annular groove oil passage 73. In order to minimize the right and left thickness of the right end wall 4R of the cylinder head 4 and the intermediate cam holder 31, the pin communication groove oil passage 75 is integrated with the bolt insertion hole 39 so as to surround the fastening bolt 40. Is formed.

  The hydraulic oil supplied to the pin annular groove oil passage 73 is a suction air (not shown) through an oil introduction hole formed in the outer peripheral surface of the intake camshaft 8 in the same manner as the two intake-side oil passages 50 and 55. It is introduced into the oil passage in the shaft and supplied to one end of the lock pin of the intake side VTC actuator 17.

  The exhaust side advance oil passage 60 extends in the cylinder row direction oil passage 61 leftward from the opening end of the right side surface of the cylinder head 4 and extends upward from the cylinder row direction oil passage 61 along the cylinder axis 7 direction. Over the head internal oil passage 62 provided in the head 4, the exhaust side annular groove oil passage 63 formed in the inner peripheral surface of the first bearing 28 of the exhaust camshaft 9, the intermediate cam holder 31 and the upper cam holder 32. And a holder internal oil passage 64 having one end connected to the head internal oil passage 62 and the other end connected to the exhaust-side annular groove oil passage 63.

  The holder internal oil passage 64 of the exhaust-side advance oil passage 60 includes an intermediate holder oil passage 64 </ b> A formed in the intermediate cam holder 31 and an upper holder oil passage 64 </ b> B formed in the upper cam holder 32. The intermediate holder oil passage 64 </ b> A extends in the direction of the cylinder axis 7 and opens on the upper surface and the lower surface of the intermediate cam holder 31. On the other hand, the oil path 64B in the upper holder extends upward from the lower surface of the upper cam holder 32 along the cylinder axis 7 direction, a forward part extending forward from the upward part, and downward from the forward part. The exhaust side annular groove oil passage 63 is led through the downward portion. The forward portion is perforated (drilled) from the front surface of the upper cam holder 32, but the opening at the front end is closed by a plug. The exhaust side advance oil passage 60 is formed so that the head inner oil passage 62, the holder inner oil passage 64, and the exhaust side annular groove oil passage 63 are located on a plane orthogonal to the cam shaft direction.

  The exhaust side retarded oil passage 65 extends in the cylinder row direction oil passage 66 extending leftward from the opening end of the right side surface of the cylinder head 4, and extends upward from the cylinder row direction oil passage 66 along the cylinder axis 7 direction. A head internal oil passage 67 provided on the left side of the head internal oil passage 62 of the exhaust side advance oil passage 60 in the head 4 and an exhaust side formed on the inner peripheral surface of the first bearing 28 of the exhaust camshaft 9. It has an annular groove oil passage 68 and an intermediate holder oil passage 69 formed in the intermediate cam holder 31, one end connected to the in-head oil passage 67 and the other end connected to the exhaust side annular groove oil passage 68.

  The intermediate holder oil passage 69 of the exhaust-side retarded oil passage 65 is located behind the exhaust camshaft 9 (between the intake camshaft 8) on the upper surface of the intermediate cam holder 31 along the cylinder axis 7 direction from the lower surface of the intermediate cam holder 31. An exhaust-side annular groove oil passage through an upward portion extending to the upper side of the intermediate cam holder 31, a groove-like portion extending forward and to the right along the upper surface of the intermediate cam holder 31, and a downward portion extending downward from the tip of the groove-like portion 68. The exhaust-side retarded oil passage 65 is located on a plane in which the head inner oil passage 67 and the exhaust-side annular groove oil passage 68 are orthogonal to the cam shaft direction, and the head inner oil passage 67 and the exhaust-side annular groove oil passage 68. Are aligned with the corresponding portion of the exhaust side advance oil passage 60 in the cylinder row direction.

  The in-head oil passages 52 and 57 of both the intake-side oil passages 50 and 55 and the in-head oil passages 62 and 67 of both the exhaust-side oil passages 60 and 65 are provided between the intake rocker shaft 41 and the exhaust rocker shaft 42 and The fastening bolts 40 are provided in the vicinity of the fastening bolts 40 arranged in the vicinity of the front side of the camshaft 8, and the fastening bolts 40 are arranged at positions surrounded by these four head internal oil passages 52, 57, 62, 67. The intermediate cam holder 31 and the upper cam holder 42 are fastened to the cylinder head 4.

  The hydraulic oil supplied to both exhaust side annular groove oil passages 63 and 68 passes through the oil introduction hole formed at a different position in the axial direction of the outer peripheral surface of the exhaust camshaft 9 to the inside of the exhaust camshaft 9. Are introduced into the oil passage in the exhaust shaft (not shown) formed in the above, and are respectively supplied to the advance angle chamber and the retard angle chamber of the exhaust side VTC actuator 18.

  The intake VTEC-ON oil passage 80 opens to the right side surface of the cylinder head 4 behind the intake rocker shaft 41 with respect to the cylinder axis 7 direction, and a cylinder row direction oil passage 81 extending leftward from the opening. , Provided inside the cylinder head 4, extending upward from the cylinder row direction oil passage 81 in the direction of the cylinder axis 7, and reaching the upper surface of the cylinder head 4, and along the upper surface of the cylinder head 4. A groove-like oil passage 83 that is formed and extends forward from the upper end of the head oil passage 82 to the rear portion of the intake rocker shaft support hole 43 is provided.

  The intake VTEC-OFF oil passage 85 is opened in front of the intake rocker shaft 41 with respect to the direction of the cylinder axis 7 and above the cylinder row direction oil passages 51 and 56 of both intake-side oil passages 50 and 55. A cylinder row direction oil passage 86 extending in the left direction (cylinder row direction) from the opening and provided in the cylinder head 4 and extending upward from the cylinder row direction oil passage 86 along the cylinder axis 7 direction. 4 and a groove-like oil passage formed along the upper surface of the cylinder head 4 and extending rearward from the upper end of the head oil passage 87 to the front side portion of the intake rocker shaft support hole 43. 88.

  The exhaust VTEC-ON oil passage 90 opens on the right side surface of the cylinder head 4 behind the exhaust rocker shaft 42 with respect to the direction of the cylinder axis 7, and a cylinder row direction oil passage 91 extending leftward from the opening. The head inward oil passage 92 is provided in the cylinder head 4 and extends upwardly from the cylinder row direction oil passage 91 with respect to the cylinder axis 7 direction, and forward from the head inward oil passage 92. An in-head forward oil passage 93 extending to the rear portion of the exhaust rocker shaft support hole 44 is provided. The head upward oil passage 92 is formed by drilling from the upper surface of the cylinder head 4, but the opening at the upper end is closed by a plug.

  The exhaust VTEC-OFF oil passage 95 opens to the right side surface of the cylinder head 4 in front of the exhaust rocker shaft 42 with respect to the direction of the cylinder axis 7, and a cylinder row direction oil passage 96 extending leftward from this opening. The head internal oil passage 97 provided in the cylinder head 4 and extending upward from the cylinder row direction oil passage 96 along the cylinder axis 7 direction, and the exhaust rocker extending rearward from the head internal oil passage 97. A head internal rear oil passage 98 that reaches the front portion of the shaft support hole 44 is provided. The head internal oil passage 97 and the head internal oil passage 98 are formed by drilling from the upper surface and the front surface of the cylinder head 4, respectively, but the opening at the upper end and the opening at the front end are respectively closed by plugs. It is.

  Although not shown, the intake rocker shaft 41 is formed therein with an ON oil passage in the rocker shaft and an OFF oil passage in the rocker shaft, and an intake VTEC-ON oil passage 80 and an intake VTEC-OFF on the outer peripheral surface thereof. An oil introduction hole is formed to connect the portion to which the oil passage 85 is connected and the oil passage in each rocker shaft.

  As shown in FIG. 3, the intermediate cam holder 31 is formed with an intermediate holder oil passage 69 of the exhaust side retarded oil passage 65 on the upper surface thereof, while the intermediate holder oil passage 69 is formed on the lower surface thereof as shown in FIG. 4. Is formed, and the intermediate cam holder 31 is reduced in weight.

  As shown in FIGS. 1, 3, and 7, the cylinder head 4, the intermediate cam holder 31, and the upper cam holder 32 include a cylinder in a bolt insertion hole 39 of a fastening bolt 40 disposed in the vicinity of the rear side of the exhaust camshaft 9. Oil level gauge insertion holes 101 to 103 formed from the upper surface of the upper cam holder 32 to the lower surface of the cylinder head 4 so as to guide the oil level gauge 100 are positioned adjacent to the inner side (right side) of the head 4. Each is formed.

  According to the valve mechanism of the engine 1 configured as described above, when the driver starts the engine 1, the engine oil is discharged from the oil pump driven by the crankshaft with a predetermined discharge pressure. It is supplied to the cylinder head 4 and the journal support surface of the crankshaft through the oil main gallery. A part of the engine oil supplied to the cylinder head 4 is supplied as hydraulic oil to the oil control valves for the VTC actuators 17 and 18 and the oil control valve for the VTEC mechanism 20.

  The hydraulic oil supplied to each oil control valve is operated when an oil control valve is actuated by a drive command from an engine ECU (not shown). An intake side advance oil passage 50, an intake side retard oil passage 55, a lock pin oil passage 70, It flows into the exhaust side advance oil passage 60, the exhaust side retard oil passage 65, the intake VTEC-ON oil passage 80, and the intake VTEC-OFF oil passage 85, and is supplied to both the VTC actuators 17 and 18 and the VTEC mechanism 20. . As a result, both VTC actuators 17 and 18 are operated to advance or retard to change the cam phase of the intake camshaft 8 or the exhaust camshaft 9, or change the lift amount of the intake valve by the intake camshaft 8. I will let you.

  Further, by using the intermediate cam holder 31 in which the cam holders constituting the first bearings 26 and 28 of the camshafts 8 and 9 are connected to each other, the processing accuracy of the first bearings 26 and 28 that require roundness is improved. In addition, the number of parts is reduced. Further, the upper cam holder 32 that does not form the first bearing 28 of the exhaust camshaft 9 extends so as to reach the upper side of the exhaust camshaft 9, and the oil passages 64 and 69 in the holders of both exhaust side oil passages 60 and 65 are provided. Compared to the configuration in which the oil path is formed only in the intermediate cam holder 31 while at least partially reducing the weight of the upper cam holder 32 as much as possible by providing the upper cam holder 32 with the oil path 64B in the upper holder. Thickening of the intermediate cam holder 31 in the left-right direction is suppressed. Furthermore, since the machining holes of the intermediate cam holder 31 are reduced, the strength of the intermediate cam holder 31 can be secured, the fastening rigidity is increased, and the sealing performance of the intermediate holder oil passage 69 is improved.

  One of the exhaust side oil passages 60 and 65 is connected to the exhaust side annular groove oil passage 68 by the intermediate holder oil passage 69, and the other is connected to the exhaust side annular groove oil passage 63 by the upper holder oil passage 64B. For this reason, both the intermediate cam holder 31 and the upper cam holder 32 are prevented from being thickened and enlarged. Further, the exhaust side oil passages 60, 65 are vertically divided into the intermediate holder oil passage 69 and the upper holder oil passage 64B, so that the processing is simplified and the upper cam holder 32 reduces the waste. Further, the rigidity is enhanced by the oil path 64B in the upper holder. In addition, even if the intermediate holder oil passage 69 (groove-shaped portion) is formed on the joint surface with the upper cam holder 32, a joint area sufficient to ensure the sealing performance is ensured without increasing the thickness. Further, since there is no need to provide an oil passage along the joint surface between the cylinder head 4 and the intermediate cam holder 31, the fastening rigidity of the first bearing 11 portion of the exhaust camshaft 9 is improved, and a VTEC mechanism is provided on the exhaust side. Even when the present invention is applied to an engine, the exhaust VTEC-ON oil passage 90 and the exhaust VTEC-OFF oil passage 95 can be easily formed.

  In this embodiment, both the intake side oil passages 50 and 55 are arranged in parallel in the cam shaft direction, and the head internal oil passages 52 and 57, the intake side annular groove oil passages 53 and 58, and the intermediate holder internal oil passages 54 and 59, respectively. Are positioned on a plane orthogonal to the cam shaft direction. Therefore, processing of each oil passage is easy, and the structure of the oil passages 54 and 59 in the intermediate holder is simplified. In addition, the upper cam holder 32 can be set to a minimum size by forming an oil passage concentrated on the intermediate cam holder 31.

  Further, in the present embodiment, the in-head oil passages 52 and 57 of both the intake side oil passages 50 and 55 and the in-head oil passages 62 and 67 of both the exhaust side oil passages 60 and 65 are combined with the intake rocker shaft 41 and the exhaust rocker shaft. These processes are facilitated by the arrangement, that is, the aggregation between the two. Further, when the fastening bolt 40 is fastened at a position surrounded by the four head internal oil passages 52, 57, 62, 67, the cylinder head 4 and the intermediate cam holder of the head internal oil passages 52, 57, 62, 67 are provided. The sealing properties of the mating surface with 31 and the mating surface between the intermediate cam holder 31 and the upper cam holder 32 are high.

  In the present embodiment, the intake-side VTC actuator 17 has a lock pin that locks the cam phase in a predetermined state, but the pin intermediate holder oil passage 74 has both intake-side oil passages with respect to the intake camshaft 8. 50 and 55 are arranged opposite to each other, so that the area of the mating surface in the vicinity of the first bearing 26 of the intake camshaft 8 is secured, so that the intermediate cam holder 31 and the upper cam holder 32 are prevented from being enlarged. At the same time, oil leakage from the mating surfaces is suppressed, and a decrease in response of the intake side VTC actuator 17 is prevented.

  Further, the intermediate holder oil passage 69 of the exhaust-side retarded oil passage 65 is configured to include a groove-shaped portion, so that processing is easy. In addition, since the lightening recess 110 is formed on the lower surface opposite to the upper surface where the groove-shaped portion of the intermediate cam holder 31 is formed, the intermediate cam holder 31 is reduced in weight while maintaining rigidity.

  In the present embodiment, the upper cam holder 32 extends so as to straddle the exhaust camshaft 9, and the upper cam holder 32 and the intermediate cam holder 31 have two locations that sandwich the exhaust lower camshaft and two locations that sandwich the intake camshaft 8. Oil level gauge insertion holes 101 to 103 extending from the upper surface of the upper cam holder 32 to the lower surface of the cylinder head 4 at positions adjacent to one of them by a fastening bolt 40 at a total of four locations. Is defined. Therefore, the distance between the oil level gauge mounting hole formed in the cylinder head cover 5 fastened to the upper surface of the cylinder head 4 and the oil level gauge insertion hole 103 is shortened, and the oil level gauge insertion property is improved.

  In addition, oil level gauge insertion holes 101 to 103 are formed at positions adjacent to a relatively long fastening bolt 40 that fastens the upper cam holder 32 and the intermediate cam holder 31 together with the cylinder head 4. Since the gauge holes 101 to 103 can be formed in a substantially linear shape, the insertion performance of the oil level gauge is improved.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above embodiment, the valve operating mechanism of the present invention is applied to an in-line four-cylinder gasoline engine, but it can also be applied to other internal combustion engines. Moreover, in the said embodiment, although the VTEC mechanism 20 is provided in the intake camshaft 8, it can also be set as the structure which provides the VTEC mechanism 20 also in the exhaust camshaft 9 side, or neither. In addition, the specific configuration, arrangement, and quantity of each device and member can be changed as appropriate without departing from the spirit of the present invention. On the other hand, all the components of the valve operating mechanism according to the present invention shown in the above-described embodiment are not necessarily essential, and can be appropriately selected as long as they do not depart from the gist of the present invention.

1 Engine 4 Cylinder head 4R Right end wall 7 Cylinder axis 8 Intake camshaft (upper camshaft)
9 Exhaust camshaft (lower camshaft)
11 First cam holder 17 Intake side VTC actuator 18 Exhaust side VTC actuator 26 First bearing (upper camshaft bearing), 26l Bearing lower part, 26u Bearing upper part 28 First bearing (lower camshaft bearing), 28l Bearing lower part, 28u Bearing upper part 31 Intermediate cam holder 32 Upper cam holder 39 Bolt insertion hole 40 Fastening bolt 41 Intake rocker shaft (upper rocker shaft)
42 Exhaust rocker shaft (loar rocker shaft)
50 Intake side advance oil passage (Upper side advance oil passage)
55 Inlet side retarded oil passage (Upper side retarded oil path)
60 Exhaust-side advance oil passage (lower-side advance oil passage)
65 Exhaust-side retarded oil passage (lower-side retarded oil passage)
52, 57, 62, 67 In-head oil passage 53, 58 Intake-side annular groove oil passage 63, 68 Exhaust-side annular groove oil passage 54, 59 Intermediate holder oil passage 64 Holder oil passage 64A Intermediate holder oil passage 64B Upper holder Inner oil passage 69 Intermediate holder oil passage 70 Lock pin oil passage 74 Pin intermediate holder inner oil passage 75 Pin communication groove oil passages 101 to 103 Oil level gauge insertion hole 110 Thickening recess

Claims (7)

An upper camshaft and a lower camshaft, which are arranged in parallel to each other at different height positions in the cylinder axial direction of the internal combustion engine and each provided with a cam phase variable mechanism at one end;
A cylinder head having a lower bearing portion of the lower camshaft;
An intermediate cam holder having a bearing upper portion of the lower cam shaft that forms the lower cam shaft bearing on one end side in cooperation with the bearing lower portion of the cylinder head, and a bearing lower portion of the upper cam shaft;
An upper cam holder that has a bearing upper portion of the upper cam shaft that forms the upper cam shaft bearing on one end side in cooperation with the bearing lower portion of the intermediate cam holder, and extends to above the lower cam shaft. And
A valve operating mechanism for an internal combustion engine that supplies hydraulic oil supplied from a hydraulic control valve to the both cam phase variable mechanisms via an upper oil passage and a lower oil passage;
The upper side oil passage and the lower side oil passage are respectively a head internal oil passage provided in the cylinder head, a cam holder oil passage provided in the cam holder and reaching the bearing, and a shaft internal oil passage in the cam shaft. Including
A valve operating mechanism for an internal combustion engine, wherein the cam holder oil passage of the lower oil passage is at least partially provided in the upper cam holder. The lower-side oil passage includes a lower-side advance oil passage for driving the cam phase variable mechanism to an advance side, and a lower-side retard oil passage for driving the cam phase variable mechanism to a retard side. Have
The cam holder oil passages of the lower oil passages have lower groove-like oil passages juxtaposed in the cam shaft direction on the inner peripheral surface of the lower camshaft bearing,
One cam holder oil passage of the lower side advance oil passage and the lower side retard oil passage is formed in the intermediate cam holder, and one end is connected to the head internal oil passage, and the other end is the lower groove oil. Having an intermediate holder oil passage connecting to the passage,
The other cam holder oil passage of the lower side advance oil passage and the lower side retard oil passage is formed in the intermediate cam holder, one end is connected to the head internal oil passage, and the other end is the upper surface of the intermediate cam holder. An oil passage in the intermediate holder that opens to the upper cam holder, and an oil passage in the upper holder that is formed in the upper cam holder, and has one end connected to the other end of the oil passage in the intermediate holder and the other end connected to the lower groove-like oil passage. The valve operating mechanism for an internal combustion engine according to claim 1, comprising: The upper-side oil passage includes an upper-side advance oil passage for driving the cam phase variable mechanism to the advance side, and an upper-side retard oil passage for driving the cam phase variable mechanism to the retard side. Have
The oil passages in the heads of both the upper oil passages are arranged in parallel in the camshaft direction,
The cam holder oil passages of the both upper oil passages are formed in an upper groove oil passage juxtaposed in the cam shaft direction on the inner peripheral surface of the upper camshaft bearing, and in the intermediate cam holder, and the head oil passage And an intermediate holder oil passage that connects the upper groove-like oil passage,
The upper oil passages, the upper oil passage, the upper groove oil passage, and the intermediate holder oil passage are respectively formed on a plane perpendicular to the cam shaft direction. The valve operating mechanism for an internal combustion engine according to claim 2. An upper rocker shaft and a lower rocker shaft, which are supported by the cylinder heads and are arranged below the corresponding cam shafts in parallel with the cam shafts;
The oil passages in the heads of the upper oil passages and the oil passages in the heads of the lower oil passages are located between the upper rocker shaft and the lower rocker shaft;
The first fastening bolt that fastens the upper cam holder and the intermediate cam holder together with the cylinder head is fastened at a position surrounded by the four oil passages in the head in a top view of the cylinder head. 3. A valve operating mechanism for an internal combustion engine according to 3. The upper cam phase variable mechanism includes a hydraulically driven lock pin that locks the cam phase in a predetermined state,
A lock pin oil passage supplied from the hydraulic control valve for actuating or releasing the lock pin;
The lock pin oil passage is formed on the inner circumferential surface of the upper camshaft bearing with respect to the upper camshaft and the pin groove oil passage formed at a position different from the both upper side groove oil passages in the cam shaft direction. A pin intermediate holder oil passage formed to open to the upper and lower surfaces of the intermediate cam holder on the side opposite to the upper oil passages, and a joint surface between the intermediate cam holder and the upper cam holder. A pin communicating oil passage that is formed and communicates with the pin intermediate holder oil passage and the pin groove oil passage;
Between the oil passage in the intermediate holder for pins and the groove-like oil passage for pins, the upper cam holder and the intermediate cam holder are disposed on the side opposite to the first fastening bolt with respect to the upper cam shaft. A bolt insertion hole of a second fastening bolt that is fastened to the cylinder head is formed,
The valve operating mechanism for an internal combustion engine according to claim 4, wherein the pin communication oil passage is formed integrally with a bolt insertion hole of the second bolt. The one intermediate holder oil passage of the lower side advance angle oil passage and the lower side retard angle oil passage includes a groove-shaped portion formed on a joint surface with the upper cam holder,
6. The valve operating mechanism for an internal combustion engine according to claim 5, wherein a thinned recess is formed below the groove-like portion on a joint surface of the intermediate cam holder with the cylinder head. The upper cam holder extends so as to straddle the lower cam shaft,
The intermediate cam holder and the upper cam holder have fastening holes for fastening bolts that are fastened to the cylinder head at a total of four locations, two locations that sandwich the lower cam shaft and two locations that sandwich the upper cam shaft. And
The cylinder head, the intermediate cam holder, and the upper cam holder define an oil level gauge insertion hole extending from the upper surface of the upper cam holder to the lower surface of the cylinder head at a position adjacent to one of the fastening bolts. The valve operating mechanism for an internal combustion engine according to any one of claims 1 to 6, wherein:

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