JPS6337446Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a refueling system for a valve train in a multi-cylinder internal combustion engine.

As for the above-mentioned device, an oil gear lary is formed inside the rocker arm shaft which is inserted and supported by the bearing of the cylinder head and is prevented from coming out by a stopper, and lubricating oil is supplied to the lubricated parts such as the rocker arm swinging support part through the gear lary. This is conventionally known for single-cylinder internal combustion engines, as shown in Japanese Patent Application Laid-Open No. 118511/1982, but the same refueling structure has been applied to multi-cylinder internal combustion engines in which the cylinder head is long in the cylinder arrangement direction. If applied as is, the rocker arm shaft would become extremely long in the direction of cylinder arrangement, making manufacturing and handling troublesome, and when assembling the rocker arm shaft to the cylinder head, the outer end of the head would have to be There are other problems such as a large working space is required and working efficiency is reduced, and furthermore, it is not easy to machine the oil gear into the rocker arm shaft.

The present invention makes it possible to effectively use the rocker arm shaft and its stopper as the main oil gear without causing such problems in a multi-cylinder internal combustion engine. It is possible to quickly and accurately distribute and supply lubricating oil with little air contamination to the bearing surface for the valve drive camshaft, the fitting support surface of each rocker arm shaft to the rocker arm, and the sliding contact area between the rocker arm and the valve drive camshaft. It is an object of the present invention to provide an oil supply device for a valve operating mechanism having a simple oil passage structure as a whole.

In order to achieve this objective, the present invention provides a cylinder head with a plurality of combustion chambers arranged parallel to each other along the crankshaft, and a valve drive camshaft that rotates in conjunction with the crankshaft in parallel with the crankshaft. In a multi-cylinder internal combustion engine, a center bearing is provided at the center of the cylinder head in the parallel direction of the combustion chambers, and first and second end bearings are provided at both ends of the cylinder head in the parallel direction, and are located on the same axis as the center bearing. Each is arranged,
A first rocker arm shaft is connected to one end of the first end bearing and the center bearing from one end of the cylinder head, and a second rocker arm shaft is connected to the other end of the second end bearing and the center bearing from the other end of the cylinder head. The opposing inner ends of the first and second rocker arm shafts are respectively engaged with both end walls of a small diameter hole formed in the center of the bearing hole of the central bearing, and the first and second ends are inserted and supported respectively. First and second stoppers are installed in the opening of the section bearing to close the opening and engage with the outer ends of the first and second rocker arm shafts, respectively;
Each rocker arm shaft has a rocker arm corresponding to each combustion chamber swingably fitted and supported on its outer periphery, and an oil gear lary that communicates with the small diameter hole is formed inside the rocker arm shaft, and the second stopper is provided with a rocker arm. , forming a communication oil passage communicating with the oil gear gallery in the second rocker arm shaft; an oil supply passage bored in the cylinder head so as to communicate with the communication oil passage; and an oil supply passage formed in the cylinder block and communicating with the oil pump. The valve drive cam of the cylinder head is connected to the main oil supply passage through the joint surface of the cylinder head and the cylinder block. forming a first horizontal hole that communicates between a bearing surface for the shaft and each oil gear rally; and a second horizontal hole that communicates between a fitting support surface of each rocker arm shaft for the rocker arm and each oil gear rally;
Each rotsuka arm has a second
The present invention is characterized in that an oil injection hole is drilled through which a part of the oil introduced into the fitting support surface through the horizontal hole is ejected toward the sliding contact portion between the rocker arm and the valve drive camshaft.

Hereinafter, an embodiment in which the present invention is applied to a DOHC, 4-valve, 4-cylinder internal combustion engine will be described with reference to the drawings.

In FIGS. 1 to 6, four combustion chambers 1 are formed in the lower part of the cylinder head H which is polymerized and bonded onto the cylinder block B, and are arranged in parallel with each other along its longitudinal axis, that is, in the direction of the crankshaft. The opening lower surface of the combustion chamber 1 faces the top surface of the piston 3 in the cylinder 2 of the cylinder block B.

As shown in FIG. 1, on one side of each combustion chamber 1, there are two
Two intake valve ports 4 are opened in parallel in the crankshaft direction, and on the other side, two exhaust valve ports 5 are opened in parallel in the crankshaft direction. An intake port 6 is communicated with each of the two intake valve ports 4, and these intake ports 6 extend along the lateral direction of the cylinder head H, and are collected into one on one side of the cylinder head H (first side). (right side in the figure), and each of the two exhaust valve ports 5 has an exhaust port 7 opened, which extends along the lateral direction of the cylinder head H, and is collected into one to open the cylinder head H.
It is opened on the other side.

Above the intake port 6 group, there is an intake side valve operating cam chamber 8.
However, exhaust side valve camshafts 9 are formed above the exhaust port 7 groups, and these valve cam chambers 8,
9 are communicated with each other via a plurality of communication passages 11 formed in a central block portion 10 that runs longitudinally through the center of the cylinder head H.

The intake side valve operating cam chamber 8 and the exhaust side valve operating cam chamber 9
Each valve mechanism is provided inside, and all of these valve mechanisms have the same structure, so
The configuration of the intake side valve train mechanism will be described in detail below. In the intake-side valve-operating cam chamber 8, a plurality of bearings 12 for supporting the intake-side valve-operating camshaft 16 are arranged at intervals in the longitudinal direction of the intake-side valve-operating cam chamber 8, that is, in the parallel direction of the combustion chambers. The bearing 12 is composed of a bearing half 13 that is integral with the cylinder head H, and a plurality of bearing caps 15 that are each fixed to the bearing half 13 with connecting bolts 14.
, the intake side valve operating camshaft 16 parallel to the crankshaft
is rotatably supported. Further, as shown in FIG. 6, a valve cam chamber 8 is located below the intake side valve camshaft 16.
There are a plurality of bearings in the longitudinal direction of the head H, namely a central bearing 17c located at the longitudinal center of the head H, and first and second end bearings 1 located at both longitudinal ends thereof.
7 ₁ , 17 ₂ and first and second intermediate bearings 17 , 17 located intermediate between the end bearings 17 ₁ , 17 ₂ and the center bearing 17c are coaxially provided. At one end of the first end bearing 17 ₁ , the first intermediate bearing 17 and the center bearing 17c, there is a first rocker arm shaft 18 ₁ on the intake side which is hollow from one end side of the cylinder head H.
Further, at the other ends of the second end bearing 17 ₂ , the second intermediate bearing 17 and the center bearing 17c, there is provided a second rocker arm shaft 18 ₂ on the intake side which is hollow from the other end side of the cylinder head H.
are supported through each other, and the first and second rocker arm shafts 18 ₁ and 18 ₂ are coaxially aligned with each other in tandem. Also, the first and second rocker arm shafts 18 ₁ , 18 ₂
The opposing inner ends of the center bearing 17c are positioned inward in the axial direction by engaging with both end walls e ₁ and e ₂ of a small diameter hole 34 formed at the center of the bearing hole of the central bearing 17c. The outer ends of the first and second rocker arm shafts 18 ₁ and 18 ₂ are connected to first and second stopper plugs 35 that are fitted into the first and second end bearings 17 ₁ and 17 ₂ via O-rings R, respectively. , 36 to restrict the axial position, and the first stopper 35 is used for mounting an auxiliary device, such as a distributor D, which is fixed to one end surface of the cylinder head H (left end surface in FIG. 6). The second stopper 36 is covered and fixed by the plate _D1 , and the second stopper 36 is a mounting plate for an accessory, such as a timing belt cover T, which is fixed to the other end surface of the cylinder head H (right end surface in FIG. 6).
The cover is fixed by T ₁ . Between adjacent bearings, the first and second rocker arm shafts 18 ₁ , 18 ₂
, the rocking support part 1 of the rocker arm 19, respectively.
9a is fitted and supported so as to be swingable, and the upper end of an intake valve Vi supported by the intake valve support portion 20 of the cylinder head H is connected to the tip of each rocker arm 19.

Similarly to the intake side valve cam chamber 8, the exhaust side valve cam chamber 9 also includes a plurality of bearing halves 23 and connecting bolts 24 for rotatably supporting the exhaust side valve cam shaft 21. Bearing cap 2 fixed with
A bearing 22 consisting of 5 is provided. Below the exhaust side valve drive camshaft 21, there are a plurality of bearings 27 ₁ , 27 ,
27c, 27, 27 ₂ are provided, and the first and second rocker arm shafts 26 ₁ on the exhaust side are connected by these bearings.
The support structure for 26 ₂ is the above-mentioned first intake side,
Since it is completely similar to that of the second rocker arm shafts 18 ₁ and 18 ₂ , its explanation will be omitted. Therefore, the outer ends of the first and second rocker arm shafts 26 ₁ and 26 ₂ are
First and second stoppers 40 are fitted to the first and second end bearings 27 ₁ and 27 ₂ via O-rings R, respectively;
41 to restrict the axial position, the first stopper 40 is held by an auxiliary device, for example, the mounting plate _S1 of the TDC sensor S, and the second stopper 41 is held by the mounting plate of the timing belt cover T. The cover is fixed by T ₁ . Between adjacent bearings, the first,
The rocking support portion 28a of the exhaust side rocker arm 28 is fitted and supported on the second rocker arm shafts 26 ₁ and 26 ₂ so as to be able to swing freely, and at the tip of each rocker arm 28,
The upper end of the exhaust valve Vo, which is slidably supported by the exhaust valve support part 29 of the cylinder head H, is connected.

Above the center of each combustion chamber 1, the central block portion 10 extends longitudinally above the combustion chamber group 1 so as to partition the intake and exhaust valve cam chambers 8, 9, as shown in FIG. As shown in the figure, a hollow cylindrical plug mounting tube 30 is provided to protrude straight upward. This plug mounting cylinder 30 is formed with a plug insertion hole 31 whose top surface is open.
1 has a screw hole 3 formed in the upper wall of the combustion chamber 1.
It communicates with the combustion chamber 1 via 2.

The cylinder head H includes lubricating surfaces of the bearings 12, 22 of the intake and exhaust valve camshafts 16, 21, the swing bearings 19a, 28a of the intake and exhaust rocker arms 19, 28, and the lubricating surfaces of the intake and exhaust side rocker arms 19, 28. Side valve cams 16a, 21a and rocker arm 1
An oil supply device is provided for distributing and supplying lubricating oil to the sliding surfaces of the slippers 9 and 28. The structure of the oil supply device will be explained below.

In FIG. 6, the first and second rocker arm shafts 18 ₁ and 18 ₂ on the intake side are formed with oil gear rallies _{33 1} and 33 ₂ that are open at both ends _, respectively. The ends communicate with each other via a small diameter hole 34 (FIG. 3) formed at the center of the bearing surface of the central bearing 17c. The open outer end of the oil gear gallery 33 ₁ (left end in FIG. 6) is sealed by a first stopper 35, and the open outer end of the other oil gear gallery 33 ₂ (right end in FIG. 6) is sealed by a first stopper 35.
It communicates with a communication oil passage 36a formed in the second stopper 36. On the other hand, the first and second rocker arm shafts 26 ₁ and 26 ₂ on the exhaust side are also formed with oil gear rallies 38 ₁ and 38 ₂ that are open at both ends thereof, and the inner ends of these oil gear rallies 38 ₁ and 38 ₂ are located at the center. Small diameter hole 39 formed in the center of the bearing surface of the bearing 27c
(Fig. 3). The open outer end (left end in FIG. 6) of the oil gear rally 38 ₁ of the first rocker arm shaft 26 ₁ on the exhaust side is sealed by a first stopper 40 , and the second rocker arm shaft 26 ₂ on the exhaust side is sealed with a first stopper 40 .
Opening outer end of oil gear lary 38 ₂ (right end in Figure 6)
is communicated with a communication oil passage 41a formed in the second stopper 41.

A lateral oil passage 42 is bored in one end wall of the cylinder head H (the right end wall in FIG. 6), and both ends of this lateral oil passage 42 are connected to connecting oil passages formed in the second stoppers 36 and 41. 36a and 41a. Further, the cylinder head H has the oil gear rallies 33 ₁ , 3 extending from the center thereof toward the horizontal oil passage 42 .
3 ₂ , and an oil feed path 43 approximately parallel to 38 ₁ and 38 ₂
is formed, and the outer end of this oil feed passage 43 is communicated with the middle of the horizontal oil passage 42 . Furthermore, the oil supply path 4
The inner end of 3 is connected to the cylinder head H as shown in Figure 3.
It communicates with the upper end of a vertical oil supply passage 44 extending vertically in the central block portion 10 of
The lower end of the main oil supply passage 45 formed in the cylinder block B (FIG. 1) and connected to the oil pump P communicate with each other through the joint surface of the cylinder head H and the block B. Thus, the vertical oil supply passage 44, the oil supply passage 43, and the horizontal oil passage 42 cooperate with each other to constitute the oil supply passage h of the present invention.

The oil gears 33 1 , 33 ₂ of the intake side locker arm shafts 18 ₁ , 18 2 have first oil gears 33 ₁ , 33 ₂ formed on their peripheral walls.
The oil gears 33 1 and 33 2 are connected to a bearing oil passage 48 formed in the intake side bearing half 13 of the cylinder head H through a horizontal hole 46 and annular groove 47 (FIG. 5) or the communication oil passage 34 (FIG. 3). Further, the oil gears 33 ₁ and 33 ₂ are connected to a second horizontal hole 50 and annular groove 51 formed in their peripheral walls as shown in FIG.
The swing support portion 1 of the intake side locker arm 19 is connected via the
The oil passage 48 for the bearing has a downstream end that opens into the bearing surface of the intake side bearing half 13, and the oil injection hole 52 is directed to a sliding contact portion between the slipper surface of the intake side locker arm 19 and the valve cam 16a of the intake side valve camshaft 16. Similarly, the exhaust side locker arm shaft ₂₆₁ ,
The oil gears 38 ₁ , 38 ₂ of the exhaust side lock arm 26 ₂ are also connected to a bearing oil passage 56 formed in the exhaust side bearing half 23 via a first horizontal hole 54 and annular groove 55 (FIG. 5) or the communication oil passage 39 (FIG. 3). Furthermore, the oil gears 38 ₁ , 38 ₂ are connected to the swing support portion 28 a of the exhaust side lock arm 28 via a second horizontal hole 58 and annular groove 59 as shown in FIG.
The downstream end of the bearing oil passage 56 is open to the bearing surface of the exhaust side bearing half 23, and the oil injection hole 60 is connected to the slipper surface of the exhaust side locker arm 28 and the exhaust side valve camshaft 2.
The valve cam 21a is urged toward the valve cam 21a.

Next, the operation of the above embodiment will be explained.

When the intake and exhaust side valve drive camshafts 16 and 21 are rotated by engine operation, the intake and exhaust side rocker arms 19 and 28 swing up and down around the rocker arm shafts 18 ₁ and 18 ₂ and 26 ₁ and 26 ₂ , respectively. The intake and exhaust valves Vi and Vo open and close at predetermined timing.

Pressurized lubricating oil from the oil pump P (Fig. 3), which rotates in conjunction with engine operation, passes from the main oil supply passage 45 through the vertical oil supply passage 44, oil supply passage 43, and horizontal oil passage 42, and further The oil flows through the communication oil passages 36a, 41a formed in the stopcocks 36, 41 to the intake and exhaust oil gears 33 ₁ , 33 ₂ ; 38 ₁ , 38 ₂ . The lubricating oil passing through the oil gear larries 33 ₁ and 33 ₂ on the intake side flows through the horizontal holes 46 as shown in Figures 3, 5 and 6.
The bearing surface of the bearing 12 of the intake valve camshaft 16 is lubricated through the annular groove 47 or the oil passage 48 formed in the intake side bearing half 13 from the communication oil passage 34, and further as shown in FIG. through the horizontal hole 50 and the annular groove 51 to the intake side rocker arm shaft 18 ₁ ,
Lubricate the fitting bearing surface of 18 ₂ for the rocker arm 19. Further, a part of the lubricating oil is jetted from an oil injection hole 52 formed in the intake side rocker arm 19 toward the sliding surface between the intake side valve operating cam 16a and the slipper surface of the rocker arm 19. Lubricate.

Similarly, the exhaust side oil gear rally 38 ₁ , 3
The lubricating oil passing through 8 ₂ flows through the horizontal hole 54 and the annular groove 55 or the communicating oil passage 39 as shown in FIGS. 3, 5, and 6.
The bearing surface of the bearing 22 of the exhaust valve camshaft 21 is lubricated through the oil passage 56 formed in the exhaust side bearing half 23, and the horizontal hole 58 and the annular groove 59 are further lubricated as shown in FIG. Pass through the exhaust side rocker arm shaft 2
Lubricate the fitting bearing surfaces of 6 ₁ and 26 ₂ for the rocker arm 28. In addition, part of the lubricating oil is supplied to oil injection holes 60 drilled in the exhaust side rocker arm shafts 26 ₁ and 26 _2.
The liquid is ejected from the air toward the sliding surface between the exhaust side valve operating cam 21a and the slipper surface of the rocker arm 28, thereby lubricating the sliding surface.

As described above, according to the present invention, a cylinder head having a plurality of combustion chambers arranged in parallel with each other along the crankshaft is provided with a valve drive camshaft that rotates in conjunction with the crankshaft in parallel with the crankshaft. In a multi-cylinder internal combustion engine, a center bearing is provided at the center of the cylinder head in the parallel direction of the combustion chambers, and first and second end bearings located on the same axis as the center bearing are provided at both ends of the cylinder head in the parallel direction. A first rocker arm shaft is provided at one end of the first end bearing and the center bearing from one end of the cylinder head, and a first rocker arm shaft is provided from the other end of the cylinder head at the other end of the second end bearing and the center bearing. The two rocker arm shafts are respectively inserted and supported, and the opposing inner ends of the first and second rocker arm shafts are respectively engaged with both end walls of a small diameter hole formed at the center of the bearing hole of the central bearing. , the opening of the second end bearing is fitted with first and second stoppers that close the opening and engage with the outer ends of the first and second rocker arm shafts, respectively. rocker arm corresponding to each combustion chamber is swingably fitted and supported on its outer periphery, and an oil gear gallery communicating with the small diameter hole is formed inside thereof, and a second rocker arm is attached to the second stopper. Since we have formed a communication oil passage that communicates with the oil gear rally in the shaft, even if a large number of rocker arms are arranged in parallel along the combustion chamber parallel direction due to multiple cylinders, the first and second
Due to the coaxial arrangement of the rocker arm shafts, it is possible to accommodate the rocker arm shafts without making them particularly long, and therefore each rocker arm shaft is easy to manufacture and handle, as well as to form an oil gear rally inside the shaft. Furthermore, when assembling the shaft to the cylinder head, a large work space is not required around the head, which can contribute to improving work efficiency. In particular, since both end walls of the small diameter hole formed at the center of the bearing hole of the central bearing can be used as they are as positioning locking parts for the inner ends of each rocker arm shaft, the stopper structure for the rocker arm shaft can be simplified. Furthermore, since the small diameter hole can be used as it is as a communication path between the oil gear larlies in both rocker arm shafts, the oil gear larries in the first and second rocker arm shafts, which are independent from each other, can be communicated without any trouble at the same time as these shafts are assembled. This can contribute to improving the assembly workability and simplifying the communication structure. Furthermore, a second stopcock is attached to the second stopcock.
By forming a communication oil passage that communicates with the oil gear rally in the rocker arm shaft, both the rocker arm shaft and the stopper for fixing the shaft can be used as part of the oil supply system of the valve mechanism. By using the stopper, the oil supply path can be closed at the same time as the rocker arm shaft is fixed, and the efficiency of engine assembly work can be improved.

Further, an oil supply passage bored in the cylinder head to communicate with the communication oil passage and a main oil supply passage formed in the cylinder block and connected to the oil pump are communicated with each other through the joint surface of the cylinder head and cylinder block. The peripheral wall of each rocker arm shaft is provided with a first lateral hole that communicates between the bearing surface of the cylinder head for the valve drive camshaft and each oil gear rally in cooperation with the bearing oil passage bored in the cylinder head. , a second horizontal hole that communicates between a fitting support surface of each rocker arm shaft for the rocker arm and each oil gear rally is formed, and each rocker arm has a fitting support surface that connects the rocker arm to the fitting support surface through the second horizontal hole from each oil gear rally. Since an oil injection hole is drilled through which a portion of the introduced oil is squirted toward the sliding contact area between the rocker arm and the valve drive camshaft, the oil gears in the first and second rocker arm shafts are flushed into the bearing hole of the central bearing. It works together with the main gear lary to form a long non-rotating main gear that runs vertically through the cylinder head, and from there the lubricating parts of the valve mechanism, such as the bearing surface of the cylinder head for the valve camshaft and each rocker arm shaft. It is possible to quickly and accurately distribute and supply lubricating oil with less air contamination to the fitting support surface for the rocker arm and the sliding contact area between the rocker arm and the valve drive camshaft. Moreover, the main gear and the main oil supply passage on the cylinder block side can be easily connected through the oil supply passage in the cylinder head at the same time as the cylinder head is installed on the cylinder block. , the connection piping work between them can be greatly simplified, and there is no need to take strict measures against oil leakage. Furthermore, since there is no need to provide a special oil gear in the valve camshaft to lubricate the bearing surface, it is not necessary to provide a special oil gear for lubricating the bearing surface. There is no inconvenience caused when the rise of the lubricating oil pressure is delayed due to the relatively large capacity oil gear, and in order to avoid such inconvenience, the hollow hole of the valve camshaft is reduced in diameter. The same disadvantages as those caused by an increase in inertial mass do not occur.

Incidentally, if the stopcock is fixed by an auxiliary device such as a distributor attached to the cylinder head as in the above embodiment, there is no need to separately provide means for fixing the stopcock.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view taken along the line of FIG. 2, and FIG.
Figure 1 is a cross-sectional plan view along the line, Figure 3 is a vertical cross-sectional view through the line in Figure 2, Figure 4 is a vertical cross-sectional view through the line in Figure 2, and Figure 5 is a vertical cross-sectional view through the line in Figure 2. , 6th
The figure is a cross-sectional view taken along the line of FIG. B...Cylinder block, H...Cylinder head,
e ₁ , e ₂ ; e' ₁ , e' ₂ ... end wall, h... oil supply passage, 1... combustion chamber, 16, 21... valve drive camshaft, 17 ₁ , 17 ₂ ...
Intake side first and second end bearings, 17c... Intake side center bearing, 18 ₁ , 18 ₂ ... Intake side first and second rocker arm shafts, 19, 28... Rocker arm, 26 ₁ , 2
6 ₂ ... Exhaust side first and second rocker arm shafts, 27 ₁ ,
27 ₂ ...Exhaust side first and second end bearings, 27c...Exhaust side central bearing, 34, 39...Small diameter hole, 33 ₁ ,
33 ₂ ...Oil gear rally, 36...Stopcock, 36a...
Connecting oil passage, 38 ₁ , 38 ₂ ...Oil gear rally, 41
... Stopcock, 41a... Communication oil passage, 46, 54... First lateral hole, 50, 58... Second lateral hole, 52, 60... Oil injection hole.

Claims (1)

[Scope of utility model registration request] A multi-cylinder internal combustion engine comprising a cylinder head H having a plurality of combustion chambers 1 arranged in parallel with each other along the crankshaft, and valve drive camshafts 16 and 21 which rotate in conjunction with the crankshaft, provided in parallel with the crankshaft. In the cylinder head H, central bearings 17c, 27c are located at the center in the parallel direction of the combustion chambers 1, and first and second end portions located on the same axis as the central bearings 17c, 27c are located at both ends of the cylinder head H in the parallel direction. Bearing 17 ₁ , 17
₂ ; 27 ₁ and 27 ₂ are respectively disposed, and the first end bearings 17 ₁ and 27 ₁ and the central bearings 17c and 27c
At one end, the first rocker arm shafts 18 ₁ and 26 ₁ are attached from one end side of the cylinder head H, and the second end bearing 1
7 ₂ , 27 ₂ and the other ends of the central bearings 17c, 27c respectively insert and support second rocker arm shafts 18 ₂ , 26 ₂ from the other end side of the cylinder head H, and also support the first and second rocker arm shafts 18 ₁ . ,1
8 ₂ ; opposite inner ends of 26 ₁ and 26 ₂ are formed at the center of the bearing hole of the central bearings 17c and 27c. Both end walls e ₁ , e ₂ ; e′ ₁ , e′ ₂ of the small diameter hole portions 34 and 39; the first and second end bearings 17 ₁ , 1 respectively.
7 ₂ ; The openings of 27 ₁ and 27 ₂ are closed and the first and second rocker arm shafts 18 ₁ and 18 ₂ are connected;
26 ₁ , 26 ₂ are fitted with first and second stoppers 35 , 36 ; 40 , 41 that engage with the respective outer ends of the rocker arm shafts 18 ₁ , 18 ₂ ; 26 ₁ , 26 _{2 .} , a rocker arm 1 corresponding to each combustion chamber 1
9 and 28 are pivotally fitted and supported, and oil gear larries 33 ₁ , 33 ₂ ; 38 ₁ , 38 ₂ communicating with the small diameter holes 34 and 39 are formed therein, and the second stopper 36 , 41 include the oil gear 33 ₂ , in the second rocker arm shaft 18 ₂ , 26 ₂ ,
An oil supply passage _h formed in the cylinder head H to communicate with the communication oil passages 36a and 41a, which communicate with the oil supply passages 36a and 41a.
and a main oil supply path 45 formed in the cylinder block B and connected to the oil pump P are communicated with each other through the joint surface of the cylinder head H and the cylinder block B, and each rocker arm shaft 18 ₁ , 18 ₂ ;
The peripheral walls of the cylinder heads 6 ₁ and 26 ₂ cooperate with the bearing oil passages 48 and 56 drilled in the cylinder head H to provide bearing surfaces for the valve drive camshafts 16 and 21 of the cylinder head H, and the respective oil gear 33 ₁ ,33 ₂ ;38
₁ , 38 ₂ first horizontal holes 46 , 54 communicating with each other
and each rocker arm shaft 18 ₁ , 18 ₂ ; 26 ₁ , 2
6 ₂ fitting support surface for the rocker arms 19, 28 and each oil gear rally 33 ₁ , 33 ₂ ; 38 ₁ ,
_{A second} horizontal hole 50, 58 is formed in each rocker arm 19, 28 to provide communication between the oil gear 33 ₁ , 33 ₂ ; 38 ₁ , 38 ₂ .
an oil injection hole 52 for ejecting a part of the oil introduced into the fitting support surface through the horizontal holes 50, 58 toward the sliding contact portion between the rocker arms 19, 28 and the valve drive camshafts 16, 21; , 60 are perforated. Oil supply system for the valve train in a multi-cylinder internal combustion engine.