JP5740290B2 - Oil passage structure of internal combustion engine - Google Patents

Description

  The present invention relates to an oil passage structure of an internal combustion engine provided with two camshafts and a cam phase variable mechanism, and relates to a technique for realizing improvement in rigidity on a driving end side of the camshaft, optimization of a lubrication route, and the like.

  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 conventional one that switches between a low speed type cam and a high speed type cam. In recent years, however, the cam phase and the valve lift are individually and continuously controlled to further improve the transient characteristics and the throttle. What has become less is becoming mainstream. A valve timing control device (Variable Timing Control Device: hereinafter referred to as VTC) used for variable control of the cam phase is a hydraulic actuator (hereinafter referred to as VTC actuator) installed near the end of the camshaft in the cylinder head. And a hydraulic control valve that controls the supply of hydraulic oil (engine oil) to the VTC actuator.

In an engine equipped with a VTC, both driving of the VTC actuator and lubrication of the camshaft are performed by engine oil supplied from the main gallery. However, in order to stabilize the supplied hydraulic pressure, the hydraulic oil path on the VTC actuator side And a technique for separating the lubricating oil path on the camshaft side are known (see Patent Document 1). On the other hand, the camshaft is supported on the upper part of the cylinder head by a cam holder and a cam cap, and provided with a connecting cam cap in which adjacent cam caps are connected by a connecting portion, and an opening formed in a side surface of the connecting cam cap. A technique for injecting engine oil from a section to a cam lobe is known (see Patent Document 2). In addition, in an engine in which a gas-liquid separation chamber for blow-by gas is formed at the upper part of the head cover, a cam cap adjacent in the axial direction is installed so that engine oil scattered with rotation of the cam shaft does not enter the gas-liquid separation chamber A technique of connecting with a stay that also serves to prevent scattering is known (see Patent Document 3). In addition, in an engine where an oil filler cap is located directly above the VTC actuator, a plate is installed between the VTC actuator and the oil filler cap so that engine oil scattered as the VTC actuator rotates does not adhere to the oil filler cap. The technique to do is publicly known (refer patent document 4).
Japanese Patent No. 3821342 Japanese Utility Model Publication No. 63-108507 JP 2011-64086 A JP 2009-209863 A

  In Patent Document 1, in a DOHC engine in which a VTC actuator is provided at the drive end of an intake camshaft, a lubricating oil pipe is connected to an intake / exhaust center cam cap adjacent to an end cam cap on the drive end side (VTC actuator side). The lubricating oil is supplied from the intake / exhaust center cam caps to the intake camshaft and the camshaft oil passage formed inside the exhaust camshaft. However, in the case of Patent Document 1, since two lubricating oil pipes are used, it is inevitable that the number of parts and the number of assembling steps increase. In addition, the exhaust camshaft of Patent Document 1 has a relatively low rigidity and strength because the oil passage in the camshaft is drilled to the drive end side (cam sprocket side), and is larger than the cam sprocket during engine operation. There was a problem that it was easy to bend when force was applied.

  Moreover, although the connection cam cap of patent document 2 implement | achieves reduction of a number of parts and effective lubrication, it does not have a function as an oil path which supplies lubricating oil from a cylinder head to a cam shaft. In addition, the stay of Patent Document 3 effectively prevents the lubricating oil scattered by the rotation of the camshaft from entering the gas-liquid separation chamber, but this also provides an oil passage for supplying the lubricating oil from the cylinder head to the camshaft. It does not have a function. In addition, since the plate of Patent Document 4 is a separate component from the cam cap, it is inevitable that the number of parts and the number of assembling steps will increase, and as an oil passage for supplying lubricating oil from the cylinder head to the camshaft. It has no function.

  The oil passage structure of the internal combustion engine according to the present invention has been made in view of such a background, and an object thereof is to realize improvement in rigidity on the drive end side of the camshaft, optimization of a lubrication path, and the like.

  An oil passage structure of an internal combustion engine according to the present invention includes a plurality of cam holders (11 to 15) disposed along a cylinder row direction on an upper portion of a cylinder head (3), and the intake side and the exhaust side of the cylinder head. A pair of camshafts (23, 26) that respectively extend along the cylinder arrangement direction and are supported by the respective cam holders, and a cam phase variable actuator (31) provided on one end side of one camshaft. And a journal support surface (1) which is formed in a first cam holder (11) closest to the actuator and supports the operation of the actuator and the one camshaft. 11a) a hydraulic oil supply oil passage (52, 53) for supplying hydraulic oil used for lubrication, and the first cam holder, The first lubricating oil supply oil passage (61) into which the lubricating oil from the oil flows in, and the journal that supplies the lubricating oil from the first lubricating oil supply oil passage to the journal support surface (11b) that supports the other camshaft. A supply-side oil passage, a communication oil passage (51) for supplying lubricating oil from the first lubricating oil supply oil passage to the second cam holder (12) adjacent to the other end of the first cam holder, and the second cam holder A second lubricating oil supply oil passage (71) for supplying lubricating oil from the communication oil passage to both journal support surfaces of the second cam holder, and both the camshafts. And a camshaft oil passage (27, 28) for guiding lubricating oil supplied from both cam journal support surfaces formed on the two cam holders to a cam holder located on the other end side of the second cam holder.

  In the second aspect of the present invention, the other camshaft is pivotally supported by a connecting cam cap (25) fastened to the first cam holder and the second cam holder, and the communication oil passage is connected to the connecting cam cap. Formed.

  Moreover, in the 3rd side surface of this invention, the said journal supply side oil path branched from the said 1st lubricating oil supply oil path.

  In the fourth aspect of the present invention, a head cover (4) attached to the upper surface of the cylinder head, an oil supply hole (9) provided in the head cover and closed by an oil filler cap (8), and the head cover A gas-liquid separation chamber (6) provided integrally therewith and separating lubricating oil from blow-by gas generated in the internal combustion engine and having a communication hole (6a) communicating with the valve operating chamber at a lower portion thereof. The connecting cam cap has a shielding portion (43) that covers the camshaft with respect to the oil supply hole and the communication hole.

  In the fifth aspect of the present invention, the shielding portion extends in the axial direction of the camshaft and guides the lubricating oil dropped from the communication hole to the outside of the camshaft (43a). Have

  According to the present invention, lubrication between the journal support surface of the first cam holder and the two camshafts is performed by the hydraulic oil supplied from the hydraulic oil supply oil passage and the lubricating oil supplied from the first lubricating oil supply oil passage, Since the lubrication between the journal support surface of the cam holder excluding the first cam holder and the two camshafts is quickly performed by the lubricating oil supplied from the second lubricating oil supply oil passage or the oil passage in the camshaft, the power transmission of the cam chain and the like Lubricating oil can be supplied quickly to the first cam holder side of both camshafts, which are subjected to a large load because they are close to the mechanism. In addition, the portion between the first cam holder and the second cam holder in both camshafts can be made solid, and even when a large force is applied from the cam sprocket, the camshaft is less likely to be bent. In addition, a connecting cam cap that is fastened to the first cam holder and the second cam holder, and a communication oil passage formed in the connecting cam cap, eliminates the need for a lubricating oil pipe and reduces the number of parts and the number of assembly steps. Is done. Further, in the case where the journal supply side oil passage is branched from the first lubricating oil supply oil passage, sufficient pressure and amount of lubricating oil is supplied to the second lubricating oil supply oil passage through the communication oil passage, Lubrication of the valve mechanism of the cylinder can be performed appropriately. In addition, when the connecting cam cap is formed with a shielding portion that covers the camshaft with respect to the oil supply hole and the communication hole, the lubricant oil scattered by the rotation of the camshaft adheres to the oil filler cap and the oil supply hole and gas-liquid separation Intrusion into the room can be prevented. Further, when the shielding portion has the guide portion, it is possible to prevent the lubricating oil falling from the communication hole from being scattered by the rotating camshaft.

It is a perspective view showing the upper part of the engine for cars concerning an embodiment. It is a top view which shows the upper part of the cylinder head which concerns on embodiment. It is a perspective view which shows the oil-path structure of the cylinder head upper part which concerns on embodiment. It is a longitudinal cross-sectional view of the 1st cam holder and cam cap which concern on embodiment. It is a longitudinal cross-sectional view of the 2nd cam holder and cam cap which concern on embodiment. It is a perspective view of the connection cam cap which concerns on embodiment. It is a longitudinal cross-sectional view in the connection cover part of the connection cam cap which concerns on embodiment. It is a perspective view of the connection cam cap installation part which concerns on embodiment.

  Hereinafter, an embodiment of a variable valve opening characteristic internal combustion engine according to the present invention will be described in detail with reference to the drawings.

<< Configuration of Embodiment >>
<Overall configuration>
An engine 1 shown in FIG. 1 is a DOHC 4-valve type four-cycle in-line four-cylinder gasoline engine mounted on an automobile, and an outer shell is formed from a cylinder block 2, a cylinder head 3, a head cover 4, a cam chain cover 5, and the like. . A breather chamber 6 (gas-liquid separation chamber) and a new introduction chamber 7 constituting a PCV (Positive Crankcase Ventilation) system and a new introduction chamber 7 are integrally formed on the upper portion of the head cover 4, and the front end portion of the breather chamber 6 is formed. Is provided with an oil supply hole 9 (shown by a broken line) which is closed by an oil filler cap 8. An exhaust pipe connection flange 10 to which an exhaust pipe (not shown) is connected is formed on the left side surface of the cylinder head 3.

  As shown in FIG. 2, the first cam holder 11 to the fifth cam holder 15 are fastened to the upper surface of the cylinder head 3 from the front to the rear (that is, in the cylinder row direction). As shown in FIGS. 3 to 5, the first and second cam holders 11 and 12 cooperate with the first and second intake-side cam caps 21 and 22 to rotatably support the intake camshaft 23. The exhaust camshaft 26 is rotatably supported in cooperation with the connecting cam cap 25. Note that the intake camshaft 23 and the exhaust camshaft 26 include an intake camshaft internal oil passage 27 and an exhaust camshaft inside the support portion of the second cam holder 12 to the support portion of the fifth cam holder 15 indicated by broken lines in FIG. Each oil passage 28 is formed.

  As shown in FIG. 2, a VTC actuator 31 having an intake cam sprocket 32 formed on the outer periphery is fixed to the front end of the intake camshaft 23. A cam chain 34 is wound around the intake side cam sprocket 32 and an exhaust side cam sprocket 33 attached to the front end of the exhaust cam shaft 26, and the intake cam shaft 23 is driven by a crank sprocket (not shown) via the cam chain 34. And the exhaust camshaft 26 is rotationally driven. Note that the engine 1 of the present embodiment includes a valve lift control mechanism that variably controls the valve lift on the intake side, and an intake rocker shaft 37 that will be described later is provided with a control oil path, but is complicated. The description is omitted to avoid this.

  As shown in FIGS. 3 and 4, the first cam holder 11 supports the intake camshaft 23 (not shown in FIG. 3) together with the journal support surface 21 a formed on the first intake side cam cap 21. A journal support surface 11 a and an exhaust side journal support surface 11 b that supports the exhaust camshaft 26 (not shown in FIG. 3) are provided together with the front journal support surface 25 a of the connecting cam cap 25. The first cam holder 11 is disposed below the exhaust camshaft 26 and an intake rocker shaft support hole 11c that supports an intake rocker shaft 37 (not shown in FIG. 3) disposed below the intake camshaft 23. An exhaust rocker shaft support hole 11d for supporting the exhaust rocker shaft 38 (not shown in FIG. 3) is formed.

  Rocker shaft internal oil passages 37a and 38a for supplying lubricating oil to valve operating parts (see FIG. 7) such as a roller rocker arm 81 and a valve stem 82 are formed at the shaft centers of the intake rocker shaft 37 and the exhaust rocker shaft 38, respectively. ing. Further, an advance side oil passage 23 a and a retard side oil passage 23 b for supplying the advance side hydraulic oil or the retard side hydraulic oil to the VTC actuator 31 are formed in the front portion of the intake camshaft 23.

  On the other hand, as shown in FIGS. 3 and 5, the second cam holder 12 includes an intake side journal support surface 12 a that supports the intake camshaft 23 together with a journal support surface 22 a formed on the second intake side cam cap 22, and An exhaust-side journal support surface 12 b that supports the exhaust camshaft 26 is provided together with the rear journal support surface 25 b of the connecting cam cap 25. The second cam holder 12 also supports an intake rocker shaft support hole 12c that supports an intake rocker shaft 37 disposed below the intake camshaft 23, and an exhaust rocker shaft 38 disposed below the exhaust camshaft 26. An exhaust rocker shaft support hole 12d is formed. As shown in FIG. 5, the intake camshaft 23 is provided with a lubricating oil introduction hole 39 that communicates the outer periphery of the intake camshaft 23 with the oil passage 27 in the intake camshaft. A lubricating oil introduction hole 40 communicating with the intake camshaft internal oil passage 27 is formed.

<Linked cam cap>
As shown in FIG. 6, the connecting cam cap 25 includes a front cam cap portion 41 that supports the exhaust cam shaft 26 together with the first cam holder 11, and a rear cam cap portion 42 that supports the exhaust cam shaft 26 together with the second cam holder 12. And a connecting cover portion 43 that connects the upper rear surface of the front cam cap portion 41 and the upper front surface of the rear cam cap portion 42.

  As shown in FIGS. 7 and 8, the connection cover portion 43 has a guide portion 43a having an arcuate cross section that covers the upper portion of the cam lobe 26a of the exhaust camshaft 26, and a pair of portions at a position separated from the front and rear from the cam lobe 26a. Reduction holes 44 and 45 are provided. A blow-by gas introduction hole 6a drilled in the lower surface of the breather chamber 6 (only the bottom wall is shown in FIG. 7) and the bottom wall of the breather chamber 6 are formed integrally with the upper portion of the connecting cover portion 43. A number of foreign matter mixing prevention holes 16a formed in the foreign matter fall prevention plate 16 and an oil supply hole 9 into which the oil filler cap 8 is screwed are located. The mixing prevention hole 16 a and the oil supply hole 9 are shielded from the cam lobe 26 a of the exhaust camshaft 26.

  On the other hand, on the right end side of the connecting cam cap 25, a communication oil passage 51 that constitutes a part of an oil passage described later is formed. The communication oil passage 51 is continuous to the introduction portion 51a extending upward at the right end of the front cam cap portion 41, the horizontal portion 51b extending continuously from the introduction portion 51a to the rear at the right end of the connection cover portion 43, and the horizontal portion 51b. The rear cam cap portion 42 has a lead-out portion 51c that extends downward at the right end. The introduction portion 51a and the lead-out portion 51c are opened on the lower surfaces of the front cam cap portion 41 and the rear cam cap portion 42, respectively.

<Oil channel configuration>
As shown in FIGS. 3 and 4, the first cam holder 11 receives advance side hydraulic oil and retard side hydraulic oil (both engine oil) from the upper surface of the cylinder head 3 from an oil control valve (not shown). An inflow advance oil passage 52 and a retard oil passage 53 are formed. The intake oil is introduced into the intake side journal support surface 11 a of the first cam holder 11 and the journal support surface 21 a of the first intake side cam cap 21 from the advance oil passage 52 or the retard oil passage 53. Arc-shaped grooves 54 to 57 that lead to the advance side oil passage 23a and the retard side oil passage 23b (see FIG. 4) of the shaft 23 are formed.

  Further, the first cam holder 11 is formed with a first lubricating oil supply oil passage 61 through which lubricating oil (engine oil) from an oil main gallery (not shown) flows from the upper surface of the cylinder head 3. The first lubricating oil supply oil passage 61 includes a horizontal portion 61a that extends horizontally to the left, and a raised portion 61b that extends upward from the horizontal portion 61a on the right end side of the connecting cam cap 25. A journal supply-side oil passage 61c for supplying lubricating oil to the arc-shaped groove 62 formed on the exhaust-side journal support surface 11b branches off. 3 and 4, a member denoted by reference numeral 65 is a plug that closes an opening generated when the horizontal portion 61a is formed (during drilling).

  As shown in FIGS. 3 and 5, the second cam holder 12 is formed with a second lubricating oil supply oil passage 71 into which the lubricating oil from the lead-out portion 51 c of the communication oil passage 51 flows. The second lubricating oil supply oil passage 71 is a journal supply side oil that supplies lubricating oil to a rising portion 71a extending downward on the right end side of the connecting cam cap 25 and an arcuate groove 72 formed in the exhaust side journal support surface 12b. A path 71b, a horizontal portion 71c extending horizontally to the lower end of the standing portion 71a, a rising portion 71d rising from the right end of the horizontal portion 71c along the left end of the second cam holder 12, and an intake side from the upper end of the rising portion 71d It comprises a journal supply side oil passage 71e for supplying lubricating oil to an arc-shaped groove 73 formed in the journal support surface 12a. Further, the second cam holder 12 is supplied with lubricating oil from the horizontal portion 71c to the exhaust rocker shaft support hole 12d and to the exhaust rocker shaft side supply oil passage 75, and from the arc-shaped groove 73 to the intake rocker shaft support hole 12c. An intake rocker shaft-side supply oil passage 76 to be supplied is formed. As shown in FIG. 5, the intake rocker shaft 37 is provided with a lubricating oil introduction hole 37b communicating the outer peripheral side with the rocker shaft internal oil passage 37a, and the exhaust rocker shaft 38 also has an outer peripheral side and a rocker. A lubricating oil introduction hole 38b communicating with the in-shaft oil passage 38a is formed.

<< Operation of Embodiment >>
When the driver starts the engine 1, engine oil is discharged from the oil pump driven by the crankshaft with a predetermined discharge pressure, and this engine oil passes through the oil main gallery and the journal support surface of the cylinder head 3 and the crankshaft. Etc. A part of the engine oil supplied to the cylinder head 3 is supplied as an operating oil to an oil control valve and a valve lift control valve for the VTC actuator 31, and the other is supplied as a first lubricating oil supply oil for the first cam holder 11 as a lubricating oil. It flows into the path 61.

  When the oil control valve is actuated by a drive command from an engine ECU (not shown), the hydraulic oil supplied to the oil control valve is advanced oil path 52 or retarded angle formed in first cam holder 11 or first intake side cam cap 21. The oil flows into the oil passage 53 and the arc-shaped grooves 54 to 57 and is supplied to the VTC actuator 31 via the advance side oil passage 23a and the retard side oil passage 23b in the intake camshaft 23. As a result, the VTC actuator 31 operates toward the advance side or the retard side, and the cam phase of the intake camshaft 23 changes. At this time, the hydraulic oil leaks from the arc-shaped grooves 54 to 57 to the intake side journal support surface 11a of the first cam holder 11 and the journal support surface 21a of the first intake side cam cap 21, and these journal support surfaces 11a, 21a It functions as a lubricating oil that lubricates the intake camshaft 23.

  A part of the lubricating oil flowing into the first lubricating oil supply oil passage 61 is supplied from the journal supply side oil passage 61c to the arc-shaped groove 62 of the exhaust side journal support surface 11b after passing through the horizontal portion 61a and the upright portion 61b. The journal support surfaces 11b and 25a and the exhaust camshaft 26 are lubricated. Further, most of the lubricating oil flowing into the first lubricating oil supply oil passage 61 flows into the introduction portion 51a of the communication oil passage 51 formed in the connecting cam cap 25 from the upright portion 61b, and the horizontal portion 51b and the outlet portion. It flows into the 2nd lubricating oil supply oil path 71 of the 2nd cam holder 12 through 51c. In this embodiment, since the journal supply side oil passage 61c branches off from the first lubricant supply oil passage 61, sufficient lubricant is quickly supplied to the second lubricant supply oil passage via the communication oil passage 51. .

  A part of the lubricating oil that has flowed into the second lubricating oil supply oil passage 71 is supplied from the journal supply side oil passage 71b to the arc-shaped groove 72 of the exhaust side journal support surface 12b, and exhausted from both the journal support surfaces 12b and 25b. Lubricating with the camshaft 26 is performed, and flows into the exhaust camshaft oil passage 28 from the arc-shaped groove 72 through the lubricant introduction hole 40. The lubricating oil that has flowed into the exhaust camshaft oil passage 28 is supplied to the exhaust side of the third cam holder 13 to the fifth cam holder 15 to lubricate the journal support surface (not shown) and the exhaust camshaft 26. The remaining portion of the lubricating oil that has flowed into the second lubricating oil supply oil passage 71 flows into the horizontal portion 71c via the vertical portion 71a, and then a part thereof passes through the exhaust rocker shaft-side supply oil passage 75 to the exhaust rocker shaft support hole 12d. And is supplied to the rocker shaft oil passage 38a from the lubricating oil introduction hole 38b.

  Most of the lubricating oil flowing into the horizontal portion 71c of the second lubricating oil supply oil passage 71 is supplied to the arc-shaped groove 73 via the upright portion 71d and the journal supply side oil passage 71e, and both journal support surfaces 12a, 22a While lubricating with the intake camshaft 23, it flows into the intake camshaft internal oil path 27 from the circular-arc-shaped groove 73 via the lubricating oil introduction hole 39. FIG. Supplied to the intake side of the third cam holder 13 to the fifth cam holder 15 to lubricate the journal support surface (not shown) and the intake camshaft 23, and in the intake camshaft from the arcuate groove 73 through the lubricating oil introduction hole 39. It flows into the oil passage 27. The lubricating oil that has flowed into the intake camshaft oil passage 27 is supplied to the intake side of the third cam holder 13 to the fifth cam holder 15 to lubricate the journal support surface (not shown) and the intake camshaft 23. Part of the lubricating oil flowing into the arc-shaped groove 73 further flows into the intake rocker shaft support hole 12c via the intake rocker shaft side supply oil passage 76, and is supplied to the rocker shaft inner oil passage 37a from the lubricating oil introduction hole 37b. Is done.

<Operation of connecting cover>
As shown in FIG. 7, when the exhaust camshaft 26 rotates with the operation of the engine 1, the lubricating oil adhering to the cam lobe 26a is scattered around by centrifugal force. However, in the present embodiment, the upper portion of the cam lobe 26a is covered between the first cam holder 11 and the second cam holder 12 because the upper portion of the cam lobe 26a is covered by the arc-shaped cross-section connecting cover portion 43 that constitutes the connecting cam cap 25. The lubricating oil falls to the left after colliding with the lower surface of the connecting cover portion 43. This makes it difficult for the lubricating oil to adhere to the oil filler cap 8, the blow-by gas introduction hole 6 a, and the foreign matter mixing prevention hole 16 a located above the cam lobe 26 a, so that the operator can remove the lubricating oil when removing the oil filler cap 8. And when the oil filler cap 8 is forgotten to be attached, the lubricating oil is prevented from splashing into the engine room, and the scattered lubricating oil is also prevented from entering the breather chamber 6. The On the other hand, the lubricating oil separated in the breather chamber 6 falls from the blow-by gas introduction hole 6a. However, the lubricating oil is not dropped on the cam lobe 26a by being blocked by the connecting cover portion 43, and the guide portion 43a. , The oil falls to the left side, so that scattering of the lubricating oil and oil mist formation by the cam lobe 26a can be suppressed.

  In the case of the present embodiment, the intake camshaft 23 and the exhaust camshaft 26 are solid from the support portion of the first cam holder 11 to the support portion of the second cam holder 12, so that the VTC actuator 31, the intake side, and the exhaust side Even if a large force is input from the cam sprockets 32, 33, it becomes difficult to bend, and the valve operating mechanism can be driven with high accuracy. Further, since the connection cover portion 43 having the communication oil passage 51 is formed in the connection cam cap 25, an oil pipe or the like used in the conventional apparatus becomes unnecessary, and the number of components and assembly man-hours can be reduced.

  This is the end of the description of the embodiment. However, aspects of the present invention are not limited to these. For example, in the above embodiment, the present invention is applied to an engine provided with a VTC actuator only on the intake side, but a VTC actuator may also be provided on the exhaust side. In the above embodiment, the connecting cam cap having the communication oil passage is adopted. However, the communication oil passage may be formed in the cylinder head or the like, or a normal cam cap may be used instead of the connection cam cap. It may be. In addition, the specific shapes of the cam holders and cam caps, the specific configuration of the oil passage, and the like can be changed as appropriate without departing from the spirit of the present invention.

1 Engine 3 Cylinder head 4 Head cover 6 Breather chamber (gas-liquid separation chamber)
6a Blow-by gas introduction hole 8 Oil filler cap 9 Oil supply hole 11 First cam holder 11a Intake side journal support surface 11b Exhaust side journal support surface 12 Second cam holder 12a Intake side journal support surface 12b Exhaust side journal support surface 16 Foreign matter fall prevention plate 16a Foreign matter mixing prevention hole 21 First intake side cam cap 21a Journal support surface 22 Second intake side cam cap 22a Journal support surface 23 Intake camshaft 23a Advance side oil passage 23b Delay angle side oil passage 24 Exhaust camshaft 25 Connecting cam cap 25a Front journal support surface 25b Rear journal support surface 26 Exhaust cam shaft 26a Cam lobe 27 Intake camshaft oil passage 28 Exhaust camshaft oil passage 31 VTC actuator 41 Front cam cap portion 42 Rear cam Cap portion 43 connecting the cover portion 43a guide portion 51 communication oil passage 52 advance fluid passage (hydraulic oil supply path)
53 Retardation oil passage (hydraulic oil supply oil passage)
61 First lubricating oil supply oil passage 71 Second lubricating oil supply oil passage

Claims (4)

A plurality of cam holders arranged along the cylinder row direction at the upper part of the cylinder head, and extended along the cylinder arrangement direction on the intake side and the exhaust side of the cylinder head, respectively, and supported by the respective cam holders An oil passage structure for an internal combustion engine comprising a pair of camshafts and an actuator for varying a cam phase provided on one end side of one camshaft,
A hydraulic oil supply oil passage that is formed in the first cam holder closest to the actuator and supplies hydraulic oil used to actuate the actuator and lubricate a journal support surface that supports the one camshaft;
A first lubricating oil supply oil passage formed in the first cam holder and into which lubricating oil from the cylinder head flows;
A journal supply side oil passage that supplies the lubricant from the first lubricant supply oil passage to a journal support surface that supports the other camshaft;
A communication oil path for supplying lubricating oil from the first lubricating oil supply oil path to a second cam holder adjacent to the other end of the first cam holder;
A second lubricating oil supply oil passage that is formed in the second cam holder and supplies the lubricating oil from the communication oil passage to both journal support surfaces of the second cam holder;
Wherein provided on both camshafts, and a the cam shaft oil passage leading to the cam holder for positioning the lubricating oil supplied to the other end of the second cam holder from both cam journal bearing surface formed on the second cam holder ,
An oil passage for an internal combustion engine, wherein the other camshaft is pivotally supported by a connecting cam cap fastened to the first cam holder and the second cam holder, and the communication oil passage is formed in the connecting cam cap. Construction. 2. The oil passage structure of an internal combustion engine according to claim 1, wherein the journal supply side oil passage is branched from the first lubricating oil supply oil passage. A head cover attached to the upper surface of the cylinder head;
An oil supply hole provided in the head cover and closed by an oil filler cap;
A gas-liquid separation chamber which is provided integrally with the head cover, separates lubricating oil from blow-by gas generated in the internal combustion engine, and has a communication hole formed in its lower portion and communicating with the valve operating chamber;
3. The oil passage of the internal combustion engine according to claim 1, wherein the connecting cam cap is formed with a shielding portion that covers the camshaft with respect to the oil supply hole and the communication hole. Construction. Said shielding portion is configured to extend in the axial direction of the camshaft, and having a guide portion for guiding the lubricating oil dropped from the communication hole to the outside of the cam shaft, according to claim 3 The oil passage structure of the internal combustion engine.

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