JP3426578B2 - Lubrication structure for internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an internal combustion engine,
In particular, a rocker shaft holder that is fixed to a cylinder head supports a rocker shaft that swingably supports a plurality of rocker arms, and a valve operating characteristic changing mechanism that can change the operating characteristics of an engine valve by changing the hydraulic pressure is used. And a hydraulic control valve for controlling the hydraulic pressure of the hydraulic oil supplied to a hydraulic oil passage formed in the rocker shaft through a valve operating characteristic changing mechanism. Regarding

[0002]

2. Description of the Related Art Conventionally, such an internal combustion engine is already known, for example, from Japanese Utility Model Publication No. 7-7524.

[0003]

In the prior art disclosed in the above publication, a conduit member is fixedly arranged above the valve mechanism to guide the lubricating oil to the sliding portion of the rocker arm. Lubricating oil is made to flow down to the valve mechanism side below, and a pipe line member is required for lubrication, and the number of parts increases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a lubricating structure for an internal combustion engine, which avoids an increase in the number of parts when lubricating at least a part of the rocker arm sliding portion. And

[0005]

In order to achieve the above object, the invention according to claim 1 supports a rocker shaft holder fixed to a cylinder head, on which a rocker shaft for rockably supporting a plurality of rocker arms is supported. The rocker arm is provided with a valve operating characteristic changing mechanism capable of changing the operating characteristic of the engine valve by changing the hydraulic pressure, and the valve operating characteristic changing mechanism is supplied to the hydraulic oil passage formed in the rocker shaft through the valve operating characteristic changing mechanism. In an internal combustion engine in which a hydraulic control valve for controlling the hydraulic pressure of hydraulic oil is attached to a cylinder head, an oil reservoir capable of causing drain oil to flow out from the hydraulic control valve is provided at a sliding portion of at least a part of the rocker arm of the rocker arm. Lubricating oil can be supplied and is formed on the upper surface of the rocker shaft holder.

According to this structure, the drain oil discharged from the hydraulic control valve is supplied to at least a part of the rocker arm sliding portion through the oil reservoir of the rocker shaft holder that supports the rocker shaft. Therefore, a dedicated part for lubricating at least a part of the rocker arm sliding part is not required, and it is possible to lubricate the rocker arm sliding part while avoiding an increase in the number of parts. Since it is formed on the upper surface of, the oil sump can be easily processed.

The invention according to claim 2 is the above-mentioned claim 1.
In addition to the configuration of the invention described above, an upper portion of a passage forming member that is provided between the hydraulic control valve and the rocker shaft holder and has a communication passage that connects the hydraulic control valve and the hydraulic oil passage is The drain oil discharged from the hydraulic control valve is formed so as to be able to be transferred to the oil reservoir. According to such a configuration, the drain oil discharged from the hydraulic control valve is transferred from the passage forming member to the rocker shaft. Since the oil is supplied to the oil sump of the holder, a dedicated part for delivering the drain oil between the oil pressure control valve and the oil sump is unnecessary.

Further, in addition to the structure of the invention according to claim 2, the invention according to claim 3 further includes a recessed portion for receiving drain oil from the hydraulic control valve, in an upper portion of the passage forming member,
A guide part for guiding the drain oil accumulated in the recess to the oil sump side is provided, and the guide part is extended from the passage forming member to a position above the oil sump. The drain oil can be reliably transferred from the passage forming member to the oil sump of the rocker shaft holder, and a sufficient amount of drain oil can be supplied to the oil sump for sufficient lubrication.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on an embodiment of the present invention shown in the accompanying drawings.

1 to 12 show an embodiment of the present invention. FIG. 1 is a front view of a V-type multi-cylinder internal combustion engine to which the present invention is applied, and FIG. 2 is a plan view seen from the direction of the arrow-2, FIG. 3 is a plan view corresponding to FIG. 2 with the rocker shaft holder and a part of the camshaft cut out, and FIG. 4 is a cross section taken along line 4-4 of FIG. 5 is a sectional view taken along line 5-5 of FIG. 2, FIG. 6 is a sectional view taken along line 6-6 of FIG.
7 is an enlarged sectional view taken along line 7-7 of FIG. 6, and FIG. 8 is taken along line 8-8 of FIG.
9 is an enlarged sectional view taken along the line 9-9 of FIG. 8, FIG. 10 is an enlarged sectional view taken along the line 10-10 of FIG. 2, and FIG. 11 is a view of the passage forming member viewed from the direction of arrow 11 in FIG. , FIG. 12 is 1 of FIG.
FIG. 2-12 is an enlarged sectional view taken along line 2-12.

First, referring to FIG. 1, a V-type multi-cylinder internal combustion engine E mounted on a vehicle includes an engine block 15 having first and second cylinder row portions 14A and 14B arranged so as to form a V-shape with each other. , Cylinder heads 16 and 16 respectively coupled to the upper ends of the first and second cylinder row portions 14A and 14B, and those cylinder heads 16 and 1.
6 and head covers 17 and 17 respectively coupled to the first and second cylinder row portions 14A and 14B,
Cylinder bores 18 ... Lined up in the direction perpendicular to the paper surface of FIG.
Pistons 19 provided in each cylinder and slidably fitted in each cylinder bore 18 are commonly connected to a single crankshaft 21 via a connecting rod 20.

Referring to FIGS. 2 to 6 together, the structure of the engine E on the side of the first cylinder row portion 14A will be described. Combustion occurs between the cylinder head 16 and the pistons 19 in the cylinder bores 18. Chambers 22 ... Are formed. The cylinder head 16 has a pair of intake valve openings 23, which can communicate with the combustion chamber 22, and a portion of the cylinder head 16 which is commonly connected to the intake valve openings 23. An intake port 24 that opens, a pair of exhaust valve ports 25 that can communicate with the combustion chamber 22, and an exhaust port 26 that communicates with the exhaust valve ports 25 and opens to the other side surface of the cylinder head 16 are provided. Based on the first and second cylinder row portions 14A and 14B forming a V shape with respect to each other, the cylinder head 16 inclines to the left or right side in the cylinder arrangement direction, that is, the exhaust port 26 intakes air. Port 24
It is arranged so as to be located at a lower position than that.

The stems of the intake valves VI, VI as engine valves, which can individually open and close the intake valve ports 23, are slidably fitted to guide cylinders 28 provided on the cylinder head 16, and the intake valves The intake valves VI, V are provided between the cylinder head 16 and the retainer 29 provided at the upper ends of the VI, VI.
Valve springs 30 are provided for urging I in the valve closing direction. Further, the stems of the exhaust valves VE, VE as engine valves capable of individually opening and closing the exhaust valve ports 25 ... Are slidably fitted to the guide cylinders 31 provided on the cylinder head 16, and the exhaust valves VE ,. A retainer 32 provided at the upper end of the VE,
Between the cylinder head 16 and the cylinder head 16, valve springs 33, which urge the exhaust valves VE, VE in the valve closing direction, are provided.

The intake valves VI, VI ... And the exhaust valves VE, VE ... For each cylinder are driven to open / close by a valve operating device 34A, and the valve operating device 34A extends along the cylinder arrangement direction. Camshaft 35, a pair of rocker shafts 36 and 37 having an axis parallel to the camshaft 35, drive rocker arms 38 and 39 rotatably supported on one rocker shaft 36 for each cylinder, and free. The rocker arm 40 and the drive rocker arm 4 that is rockably supported by the other rocker shaft 37 for each cylinder.
1, 41 and free rocker arms 42, 42.

In the cylinder head 16, each combustion chamber 22 ...
Are sandwiched between each other (four in this embodiment)
Of the bearings 43 of the camshaft 35 are integrally formed so as to project in the cylinder arrangement direction at intervals.
It is rotatably supported by 3. Moreover, the camshaft 35
Are linked and linked to the crankshaft 21 at a reduction ratio of 1/2.

The pair of rocker shafts 36 and 37 are fixedly arranged above the cam shaft 35, and the rocker shaft holder 44 that supports these rocker shafts 36 and 37 has an upper surface of each of the bearing portions 43. It is fastened and fixed to.

Referring also to FIG. 7, the rocker shaft holder 44 has a shaft support portion 44a corresponding to each of the plurality of bearing portions 43, and a connecting portion integrally connecting the shaft support portions 44a. 44b, and each of the shaft support portions 44a ...
5 are fastened to the bearings 43 ... With bolts 45.

The pair of rocker shafts 36 and 37 are supported by the respective shaft support portions 44a of the rocker shaft holder 44 at positions where the cam shaft 35 is arranged below the rocker shafts 36 and 37. , The bolts 45 for fastening the shaft support portions 44a to the bearing portions 43 are engaged with part of the outer surfaces of the rocker shafts 36 and 37, thereby preventing the rocker shafts 36 and 37 from rotating about their axes. The rocker shafts 36 and 37 are fixedly supported by the rocker shaft holder 44.

By the way, each of the bearing portions 43 ... Has flat fastening seats 46, 47 for fastening the rocker shaft holder 44 on both sides of the portion rotatably supporting the cam shaft 35.
However, the bearing portions 43 ... Are formed so as to bulge above the fastening seats 46, 47 between the fastening seats 46, 47.

On the other hand, on the lower surface of each shaft support portion 44a of the rocker shaft holder 44, the bearing portion 43 is formed.
Accommodation recess 48 into which a part of the central raised portion of
Is provided so as to be located between both rocker shafts 36 and 37, and a part of the central ridge portion of the bearing portion 43 is
Avoiding contact with the rocker shaft holder 44, that is, the gap 4 between the housing recess 48 and the bearing 43.
As 9 is formed, it is inserted into the accommodation recess 48.

Further, the connecting portion 44b of the rocker shaft holder 44 for connecting the shaft supporting portions 44a ...
At least the accommodation recess 4 of each shaft support portion 44a.
The parts corresponding to 8 are formed so as to be integrally connected to each other.

The rocker shafts 36, 37 are supported by the respective shaft support portions 44a of the rocker shaft holder 44, but the rocker shaft 37 on the exhaust valve VE, VE side has a space between the shaft support portions 44a. The shaft intermediate support portion 4 arranged and integrally provided to the connecting portion 44b.
Also supported by 4c.

In FIG. 8, the drive rocker arms 38 and 39 and the free rocker arm 40, which are rockably supported by the rocker shaft 36, are arranged such that the free rocker arm 40 is sandwiched between the drive rocker arms 38 and 39, and both drive rocker arms are provided. 38 and 39 are interlocked with and connected to the intake valves VI and VI by abutting tappet screws 54 and 54, which are screwed to the rocker arms 38 and 39 with their advancing and retracting positions adjustable, to the upper ends of the intake valves VI and VI. To be done.

The drive rocker arms 41, 41 and the free rocker arms 42, 42, which are rockably supported by the rocker shaft 37, are arranged so as to be paired with each other at positions spaced apart in the axial direction of the rocker shaft 37. The drive rocker arms 41, 41 are configured such that tappet screws 55, 55 screwed to the rocker arms 41, 41 with their advancing and retracting positions adjustable are brought into contact with the upper ends of the exhaust valves VE, VE. VE and VE are linked and linked.

Moreover, the shaft intermediate support portion 44c of the rocker shaft holder 44 is provided with both drive rocker arms 41, 41.
The drive rocker arms 41 and 4 are arranged between them.
1 is arranged adjacent to both sides of the shaft intermediate support portion 44c in the axial direction of the rocker shaft 37.

Further, a plug insertion cylinder 56 ... Is attached to the cylinder head 16 so as to be arranged between the both drive rocker arms 41, 41, and the plug insertion cylinder 56 ...
Are inserted into the cylinder head 16 so as to face the combustion chambers 22.

Referring to FIG. 9 together, the camshaft 35
Includes a cam 62 for rollingly contacting a roller 58 axially supported by the free rocker arm 40 on the intake valves VI, VI side,
Cams 63 and 63 for rollingly contacting rollers 59 and 59 pivotally supported on the free rocker arms 42 and 42 on the exhaust valves VE and VE, respectively, and cam slippers provided on the drive rocker arms 38 and 39 on the intake valves VI and VI side. 60, 60
And the exhaust valve VE, the drive rocker arm 41 on the VE side,
A pair of cams 64, 64 for slidingly contacting the cam slippers 61, 61 provided on the camshaft 41.
The cam 62 at the central portion along the axial direction of the
The cams 64, 64 are sandwiched between the cams 63, 63 on both sides along the axial direction of 5, respectively.
64, 64 are arranged.

Further, the cams 62 are provided on the cam shaft 35 at positions corresponding to the shaft intermediate support portions 44c of the rocker shaft holder 44, and the intake valve V
The free rocker arm 40 on the I and VI side has a cam 62 ...
The rollers 58 that are in rolling contact with each other are axially supported so as to face the shaft intermediate support portions 44c. On the other hand, the shaft intermediate support portions 44c ... Are provided with notches 53, which avoid interference with the rollers 58, so that each shaft intermediate support portion 44c ... Is formed in a substantially J-shape.

The cam 62 is formed so as to have a cam profile for opening and closing the intake valves VI, VI.
3 is formed so as to have a cam profile for opening and closing the exhaust valves VE, VE. The cams 64, 64 are
The intake valves VI and VI and the exhaust valves VE and VE are formed so as to be substantially closed. Therefore, the intake valve V
I and VI open and close when both drive rocker arms 38 and 39 are connected to the free rocker arm 40, but both drive rocker arms 3 to the free rocker arm 40
When the connections of 8 and 39 are released, the valve closing state is substantially entered. The exhaust valves VE, VE open and close when the drive rocker arms 41, 41 are connected to the free rocker arms 42, 42, but the connection of both drive rocker arms 41, 41 to the free rocker arms 42, 42 is released. In this case, the valve is closed and stopped.

Intake valves VI, VI-side drive rocker arm 3
8 and 39 and the free rocker arm 40 are provided with a valve operating characteristic changing mechanism 65 that hydraulically switches connection and disconnection of the drive rocker arms 38 and 39 to the free rocker arm 40.

The valve operating characteristic changing mechanism 65 has one end facing the first hydraulic chamber 66 formed in the drive rocker arm 38, and the drive rocker arm 38 and the free rocker arm 4 are connected.
A connecting pin 67 slidably fitted to 0, and a connecting pin 68 slidably fitted to the free rocker arm 40 and the drive rocker arm 39 by sliding one end to the other end of the connecting pin 67, A pin 69 having one end slidably contacting the other end of the connecting pin 68 and the other end facing a second hydraulic chamber 70 formed in the drive rocker arm 39, and the drive rocker arm 38 housed in the first hydraulic chamber 66. And a return spring 71 provided between the connecting pins 67.

In this valve actuation characteristic changing mechanism 65, when hydraulic pressure is applied to the first hydraulic chamber 66, as shown in FIG. 8, the connecting pins 67 and 68 and the pin 69 connected to each other move to the second hydraulic chamber. After moving to a position where the volume of 70 is minimized, the connecting pin 67 connects the drive rocker arm 38 and the free rocker arm 40, and the connecting pin 68 connects the free rocker arm 40 and the drive rocker arm 39.
When hydraulic pressure is applied to the second hydraulic chamber 70, the connecting pins 67, 68 and the pin 69 connected to each other move to a position where the volume of the first hydraulic chamber 66 is minimized, and the connecting pins 67, 68 The contact surface is between the drive rocker arm 38 and the free rocker arm 40 to disconnect the drive rocker arm 38 and the free rocker arm 40,
The contact surfaces of the connecting pins 68 and 69 are located between the free rocker arm 40 and the drive rocker arm 39, so that the connection between the free rocker arm 40 and the drive rocker arm 38 is released.

In this way, the valve operating characteristic changing mechanism 65
Changes the operating characteristics of the intake valves VI, VI by switching the connection and disconnection of the free rocker arm 40 to and from the drive rocker arm 38, 39 by the action of the alternative hydraulic pressure on the first and second hydraulic chambers 66, 70. The return spring 71 prevents rattling of the pins 67, 68, 69 in a state where the hydraulic pressure does not act on any of the first and second hydraulic chambers 66, 70 when the engine E is stopped. It suffices to exert a sufficient spring force.

A dividing member 72 that divides the rocker shaft 36 into two is fitted in the rocker shaft 36, and the dividing member 72 allows the first member to communicate with the first hydraulic chamber 66 in the rocker shaft 36. The first hydraulic oil passage 73 and the second hydraulic oil passage 74 communicating with the second hydraulic chamber 70 are formed independently of each other.

The free rocker arm 4 is connected to the drive rocker arms 41, 41 and the free rocker arms 42, 42 which are arranged adjacent to each other in pairs on the exhaust valve VE, VE side.
A valve operating characteristic changing mechanism 75, 7 for switching connection and disconnection of the drive rocker arms 41, 41 to and from 2, 42 by hydraulic pressure.
5 are provided.

The valve operating characteristic changing mechanism 75 has a connecting pin 77 slidably fitted to the drive rocker arm 41 and the free rocker arm 42 with one end facing the first hydraulic chamber 76 formed in the drive rocker arm 41. , The connecting pin 77
A pin 78 slidably contacting the other end of the free rocker arm 42 and slidably fitted to the free rocker arm 42 and having the other end facing a second hydraulic chamber 79 formed in the free rocker arm 42;
A return spring 80 is provided which is housed in the first hydraulic chamber 76 and provided between the drive rocker arm 41 and the connecting pin 77.

In this valve operating characteristic changing mechanism 75, when hydraulic pressure is applied to the first hydraulic chamber 76, as shown in FIG. 8, the connecting pin 77 and the pin 78 connected to each other are in the second hydraulic chamber 79. The drive rocker arm 41 and the free rocker arm 42 are connected by the connecting pin 77 after moving to the position where the volume is minimized. When hydraulic pressure is applied to the second hydraulic chamber 79, the connecting pin 77 and the pin 78 connected to each other move to a position where the volume of the first hydraulic chamber 76 is minimized, and the connecting pin 77 and the pin 78 come into contact with each other. The fact that the surface lies between the free rocker arm 42 and the drive rocker arm 41 disconnects the free rocker arm 42 and the drive rocker arm 41.

In this way, the valve operating characteristic changing mechanism 75
Is configured to selectively connect and disconnect the drive rocker arm 41 and the free rocker arm 42 by the action of the alternative hydraulic pressure to the first and second hydraulic chambers 76 and 79 to switch the exhaust valve V.
This is to change the operating characteristics of E and VE, and the return spring 8
0 exhibits a spring force to the extent that each pin 77, 78 can be prevented from rattling in a state where the hydraulic pressure does not act on both the first and second hydraulic chambers 76, 79 when the engine E is stopped. Good.

A dividing member 82 for dividing the inside of the rocker shaft 37 into two is fitted in the rocker shaft 37. The dividing member 82 allows the first hydraulic chamber 76 to communicate with the inside of the rocker shaft 37. The first hydraulic oil passage 83 and the second hydraulic oil passage 84 communicating with the second hydraulic chamber 79 are formed independently of each other.

By the way, a spring force for pressing the free rocker arm 40 against the cam 62 of the cam shaft 35 in a state where the valve actuation characteristic changing mechanism 65 on the intake valve VI, VI side releases the connection of the free rocker arm 40 to the drive rocker arms 38, 39. Lost motion springs 85 that exhibit are provided between the cylinder head 16 and the free rocker arm 40, and a part of the springs 85 is housed in a bottomed hole 86 provided on the upper surface of the cylinder head 16.

Further, the free rocker arms 42, 42 are cammed by the camshaft 35 while the exhaust valve VE, VE side valve operating characteristic changing mechanism 75, 75 disconnects the free rocker arms 42, 42 from the drive rocker arms 41, 41. 63,
The lost motion springs 87, 87, which exert a spring force to press against the 63, are provided between the rocker shaft holder 44 and the free rocker arms 42, 42.
Rocker shaft holder 4 to accommodate a part of
The bottomed cylindrical portions 88, 88 protruding upward from the No. 4 are integrally provided on the connecting portion 44b of the rocker shaft holder 44.

The rocker shaft 37, which supports the drive rocker arms 41, 41, and the free rocker arms 42, 42 so as to be swingable, is supported by the rocker shaft holder 44, and the bottomed cylindrical portions 88, 88. The lost motion springs 87, 87 ... Partly housed do not fall off from the rocker shaft holder 44, and the lost motion spring 87 has an extremely simple structure in which only a part is housed in the bottomed cylindrical portion 88, 88. , 87 ... Can be held on the rocker shaft holder 44.

Further, the bottomed cylindrical portions 88, 88 ... Are integrally provided on the rocker shaft holder 44 so as to be continuous with the shaft support portions 44a. ... by each shaft support 4
4a ... and eventually the rigidity of the rocker shaft holder 44 as a whole can be increased.

Referring also to FIG. 10, in the cylinder head 16 at one end side along the cylinder arrangement direction, the first hydraulic oil passages 73, 83 and the second hydraulic oil passages formed in the rocker shafts 36, 37 are formed. A hydraulic control valve 90 for controlling the hydraulic pressure of the hydraulic oil supplied to 74, 84 is attached.

The hydraulic control valve 90 comprises, for example, a spool valve 91 mounted on the cylinder head 16 and an electromagnetic valve 92 mounted on the spool valve 91 so as to control the switching operation of the spool valve 90. On the cylinder head 16 between the spool valve 91 and the rocker shaft holder 44, a passage forming member 93 for fitting one end of the rocker shafts 36, 37 is attached.

Referring also to FIG. 11, the passage forming member 9
3 includes the first hydraulic oil passage 7 of the rocker shafts 36 and 37.
First communication oil passage 9 connecting between 3, 83 and the spool valve 91
4 and the second hydraulic oil passage 7 of the rocker shafts 36, 37
Second connecting oil passage 9 connecting between 4, 84 and spool valve 91
5 is provided, the spool valve 91 is connected to the first communication oil passage 94, that is, the first operation oil passages 73 and 83 in a first state in which the hydraulic oil from a hydraulic source (not shown) is connected to the spool valve 91. It is possible to switch between the second state in which the hydraulic oil is communicated with the second communication oil passage 95, that is, the second hydraulic oil passages 74 and 84.

Moreover, the spool valve 91 includes the first and second spool valves.
The drain oil is discharged when the state is switched, and a drain oil passage 96 for guiding the drain oil is provided above the passage forming member 93.

On the other hand, on the upper surface of the rocker shaft holder 44, an oil sump 97 for accumulating the oil scattered in the valve operating chamber between the cylinder head 16 and the head cover 17 is formed.

The oil sump 97 is arranged between the groove 98 extending along the cylinder arrangement direction and the pair of bottomed cylindrical portions 88, 88 at a position corresponding to the center of each combustion chamber 22. A substantially T-shaped branch groove portion 99 which is respectively connected to the groove portion 98 is provided, and oil in the groove portion 98 is branched into the branch groove portion 99.
Each of the branch groove portions 99 ...
Since the cylinder head 16 is arranged so as to be positioned below the intake port 23, the groove 9
8 exhaust valves VE, VE are formed so as to be continuous with the side portion.

Referring also to FIG. 12, on the upper surface of the rocker shaft holder 44, there is provided a rib 101 which is located below the groove portion 98 and has a side surface which is flush with the end peripheral wall of each branch groove portion 99. , Are provided so as to extend along the cylinder arrangement direction. The rib 101 has a branch groove portion 99.
Of the bottomed cylindrical portions 88, 88 arranged on both sides of the ..., the bottomed cylindrical portions 88, 88 are connected to the portions located on the lower side in the inclination direction as the cylinder head 16 is inclined. 88 and the rib 101 form the oil sump 97.
The rib 101 serves as a wall defining the lowermost portion of the oil sump 97, and constitutes a part of the oil reservoir 97.

A pair of oil pools 97 are formed at the ends of the respective branch groove portions 99, which are portions closer to the rib 101, that is, in the oil pool 97 in the area surrounded by the bottomed cylindrical portions 88, 88 and the rib 101. Are connected to the upper ends of the ribs 101, 100 ...
The rocker shaft holder 44 is provided so as to vertically penetrate the connecting portion 44b along the side surface on the seventh side.

The pair of lubricating oil passages 100, 100 are provided in the shaft intermediate support portion 44 of the rocker shaft holder 44.
The rocker arms 38 to 40, 41, and 42 are arranged at positions sandwiching c between them, and the shaft intermediate support portion 44 of the rocker arms 38 to 40, 41, and 42.
c, the sliding portion between the drive rocker arms 41, 41 and the shaft intermediate support portion 44c, the sliding portion between the drive rocker arms 41, 41 and the rocker shaft 37, and the free rocker arm adjacent to the drive rocker arms 41, 41. Lubricating oil for lubricating the sliding portions between 42, 42 and the rocker shaft 37 is supplied from the lubricating oil passages 100, 100.

On the upper surface of the rocker shaft holder 44, a rib 102 for sandwiching the oil sump 97 with the rib 101 is formed.
Are projected so as to extend along the cylinder arrangement direction. Moreover, the ribs 101 and 102 are provided over the entire length in the longitudinal direction of the rocker shaft holder 44, and each of the shaft support portions 44 of the rocker shaft holder 44 is provided.
A and the shaft intermediate support portions 44c are connected by the ribs 101 and 102.

By the way, the drain oil discharged from the hydraulic control valve 90 is also guided to the oil sump 97, and the upper portion of the passage forming member 93 provided between the hydraulic control valve 90 and the rocker shaft holder 44 has a hydraulic pressure. The drain oil discharged from the control valve 90 can be transferred to the oil sump 97.

That is, in the upper part of the passage forming member 93,
A recess 103 communicating with a drain oil passage 96 for guiding the drain oil from the hydraulic control valve 90 and a substantially U-shaped guide opened upward so as to guide the drain oil accumulated in the recess 103 to the oil sump 97 side The guide portion 104 is extended from the passage forming member 93 to a position above one end of the groove portion 98 in the oil sump 97.

The structure on the second cylinder row portion 14B side is basically the same as the structure on the first cylinder row portion 14A side described above, but the cylinder head 1 on the second cylinder row portion 14B side is the same.
The valve operating device 34B for driving the intake valves VI ... And the exhaust valves VE ... provided in 6 is different from the valve operating device 34A on the side of the first cylinder row portion 14A, and the intake valve VI ... Also, the exhaust valves VE ... Are never closed.

Next, the operation of this embodiment will be described. The bearing portion 43 that rotatably supports the camshaft 35.
, Are protruded from the cylinder head 16 so as to sandwich the combustion chambers 22 with each other in the cylinder arrangement direction. On the other hand, the rocker shafts 36, 37 arranged above the cam shaft 35 by rockably supporting the rocker arms 38, 39, 40; 41, 42 that follow the rotation of the cam shaft 35 are fastened to the bearing portions 43 .... The rocker shaft holder 44 is fixedly supported by the rocker shaft holder 44, and the support rigidity of the rocker shafts 36 and 37 can be increased.

The rocker shaft holder 44 has shaft support portions 44a ... Which are respectively fastened to the bearing portions 43.
, And a connecting portion 44b for integrally connecting the shaft supporting portions 44a ... With the shaft supporting portions 44a.
On the lower surface of the housing, accommodating recesses 48, into which a part of the bearing portions 43 are projected, are provided. As a result, the fastening structure of the bearing portion 43 ... And the rocker shaft holder 44 is fixed to the cylinder bore 18.
The size of the engine E can be prevented from becoming large by making it compact in the direction along the axis. Moreover, the connecting portion 4
Since 4b integrally connects at least the parts corresponding to the housing recesses 48 of the plurality of shaft support portions 44a to each other, the housing recesses 48 ... Are provided in the respective shaft support portions 44a. Regardless, it is possible to avoid a decrease in the rigidity of the rocker shaft holder 44.

Further, since a part of the bearing portions 43 ... Is projected into the accommodating recess 48 while avoiding contact with the rocker shaft holder 44, the vibration of the camshaft 35 is transmitted through the rocker shaft holder 44. It is possible to suppress the transmission to 36 and 37 as much as possible.

Further, a pair of rocker shafts 36 and 37 which are parallel to each other are supported by the rocker shaft holder 44, and the accommodating recesses 48 are provided in the rocker shaft holder 44 between the rocker shafts 36 and 37.
By making it possible to set the distance between the rocker shafts 36, 37 and the cam shaft 35 shorter, the fastening structure of the bearing portions 43 ... And the rocker shaft holder 44 can be made more compact in the direction along the axis of the cylinder bore 18. it can.

Connecting part 4 of the rocker shaft holder 44
4b is integrally provided with a shaft intermediate support portion 44c, which is arranged between a plurality of shaft support portions 44a, and the rocker shaft 37 of both rocker shafts 36, 37 is formed by each shaft support portion 44a. It is supported and also supported by the shaft intermediate support portion 44c. As a result, the support rigidity of the rocker shaft 37 can be sufficiently increased.

Further, the shaft intermediate support portions 44c are provided with notches 53 which are pivotally supported by the free rocker arms 40 on the intake valves VI, VI side and which avoid interference with the rollers 58 facing the shaft intermediate support portions 44c. Despite each being provided with a shaft intermediate support 44c ...
Valve mechanism 34A, 34B, which is arranged sufficiently close to the 7 side and includes a free rocker arm 40 and a rocker shaft 37.
Can be made compact.

Moreover, since the drive rocker arms 41, 41 on the side of the exhaust valves VE, VE are arranged adjacent to the shaft intermediate support portions 44c ... In the axial direction of the rocker shaft 37, the shaft intermediate support portions 44c. Axial movement can be restricted, and the drive rocker arm 41
The number of parts can be reduced by eliminating the need for a dedicated part for restricting the axial movement of the.

An oil sump 97 is formed on the upper surface of the rocker shaft holder 44, and the lubricating oil passages 100, 100 ... Communicating with the oil sump 97 are connected to the rocker arms 38-4.
Drive rocker arm 4 which is a part of 0, 41, 42
1 and the free rocker arm 42 are provided on the rocker shaft holder 44 so that the lubricating oil can be supplied to the sliding parts between the rocker shaft 37 and the shaft intermediate support parts 44c ... The oil stored in the oil sump 97 is supplied from the oil sump 97 via the lubricating oil passages 100, 100 ... to the rocker shaft 37 of the drive rocker arm 41 and the free rocker arm 42.
It is possible to surely supply the sliding parts with and the sliding parts between the shaft intermediate support parts 44c ... And the drive rocker arm 41, and to positively lubricate those sliding parts. Therefore, a dedicated part for lubricating the sliding parts of the drive rocker arm 41 and the free rocker arm 42, and the sliding part between the shaft intermediate support part 44c ... and the drive rocker arm 41 is unnecessary, and the increase in the number of parts is avoided while avoiding an increase in the number of parts. Each sliding part can be lubricated. Moreover, since the oil sump 97 is formed on the upper surface of the rocker shaft holder 44, the oil sump 97 can be easily processed.

The oil sump 97 has groove portions 98 extending in the cylinder arrangement direction and branch groove portions 99 connected to the groove portions 98 ...
Is provided on the upper surface of the rocker shaft holder 44 and has a side surface that is flush with the end peripheral wall of each branch groove 99 ... Of the peripheral wall of the oil sump 97.
1 is projectingly provided on the rocker shaft holder 44 so as to extend along the cylinder arrangement direction. In addition, the lubricating oil passage 10
Nos. 0 and 100 have their upper ends communicated with the portion of the oil sump 97 close to the rib 101 (the end of the branch groove 99 ... In this embodiment), and along the side face of the rib 101 on the oil sump 97 side, the rocker shaft holder 44. Is provided on the rocker shaft holder 44 so as to pass through. Therefore, the rib 10 reduces the rigidity of the rocker shaft holder 44 due to the provision of the lubricating oil passages 100, 100 ... While allowing the oil in the oil sump 97 to be supplied to each cylinder.
It can be compensated by 1.

The cylinder head 16 is arranged so as to be inclined with the exhaust port 26 positioned below the intake port 24, and the rib 101 is projected from the upper surface of the rocker shaft holder 44 below the groove 98. Therefore, the rib 101 that enhances the rigidity of the rocker shaft holder 44 functions as a wall that defines the lower portion of the oil sump 97, and more oil can be positively stored on the upper surface of the rocker shaft holder 44.

On the upper surface of the rocker shaft holder 44, there is a bottomed cylindrical portion 88 for accommodating a lost motion spring 87, which urges the free rocker arms 42 on the exhaust valves VE, VE side toward the cam 63 side of the cam shaft 35. And the bottomed cylindrical portions 88 on the lower side of the cylinder head 16 in the inclination direction.
The rib 101 that connects the two is integrally provided, and the oil sump 9
A part of 7 is formed by each bottomed cylindrical portion 88 ... And the rib 101. Therefore, the bottomed cylindrical portion 88 ... And the rib 1
With 01, the rigidity of the rocker shaft holder 44 can be increased, and a part of the oil sump 97 can be formed on the upper surface of the rocker shaft holder 44. Particularly, as in this embodiment, the rigidity of the rocker shaft holder 44 can be further increased by connecting the bottomed cylindrical portions 88, 88 and the rib 101 to each other so as to form a substantially U shape.

The lubricating oil passages 100, 100 are arranged in such a manner that the upper ends of the lubricating oil passages 100, 100 communicate with the oil sump 97 in a region surrounded by the bottomed cylindrical portion 88 ... And the rib 101. 44, and the upper ends of the lubricating oil passages 100, 100 are communicated with the portion where the rigidity is increased.
It is possible to avoid a decrease in the rigidity of the rocker shaft holder 44 due to the formation of the.

On the upper surface of the rocker shaft holder 44, a rib 102 for sandwiching the oil sump 97 with the rib 101 is formed.
Are provided so as to extend along the cylinder arrangement direction, and the ribs 102 also cause the rocker shaft holder 4 to extend.
Therefore, the rigidity of the rocker shafts 36 and 37 can be increased.

Further, since the ribs 101 and 102 also connect the shaft support portions 44a ... And the shaft intermediate support portion 44c ... Of the rocker shaft holder 44, the rocker shaft holder 4 is formed by the ribs 101 and 102.
It is possible to increase the rigidity of No. 4, particularly the rigidity of the shaft intermediate support portions 44c, ..., It is possible to further increase the support rigidity of the rocker shaft 37.

By the way, in the cylinder head 16, a valve operating characteristic changing mechanism 65 provided in each of the intake valve VI, VI side rocker arms 38 to 40 and a valve operating characteristic change provided in the exhaust valve VE, VE side rocker arms 41, 42. A hydraulic control valve 90 capable of controlling the hydraulic pressure of the hydraulic oil supplied to the mechanism 75 is attached, and drain oil discharged from the hydraulic control valve 90 is guided to the oil sump 97. Therefore, the drain oil discharged from the hydraulic control valve 90 can also be guided to the sliding portions of the rocker arms 41 and 42 on the exhaust valves VE and VE and used for lubrication, and another special lubricating oil passage can be provided. It becomes unnecessary. Moreover, the hydraulic control valve 90 discharges the drain oil only when the valve operation characteristic changing mechanisms 65 and 75 are switched, and the operation is supplied to the valve operation characteristic changing mechanisms 65 and 75 by using the drain oil for lubrication. The oil pressure of the oil does not decrease, and the responsiveness of the oil pressure control valve 90 does not decrease.

Further, the hydraulic control valve 90 and the rocker shaft 3
6, first hydraulic oil passages 73 formed in 37,
83 for connecting between 83 and the second hydraulic oil passages 74, 84
And a passage forming member 9 having second communication passages 94, 95
3 is a hydraulic control valve 90 and a rocker shaft holder 44.
The passage forming member 93 is interposed between the drain forming member 93 and the drain forming member 93. The drain oil can be transferred to the oil sump 97. Therefore, a dedicated part for delivering the drain oil between the hydraulic control valve 90 and the oil sump 97 is unnecessary.

Further, a concave portion 103 for receiving drain oil from the hydraulic control valve 90 and a guide portion 104 for guiding the drain oil accumulated in the concave portion 103 to the oil sump 97 are provided above the passage forming member 93. The cage 104 is
The passage forming member 93 extends to above the one end of the groove 98 in the oil sump 97, so that the drain oil can be reliably transferred from the passage forming member 93 to the oil sump 97 of the rocker shaft holder 44, and a sufficient amount. It is possible to supply sufficient drain oil to the oil sump 97 to achieve sufficient lubrication.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.

For example, in the above embodiment, the bearing portions 43 ... Are integrally provided on the cylinder head 16, but the bearing portion separate from the cylinder head 16 is provided in the cylinder head 16.
The present invention can also be applied to an internal combustion engine provided in the. In the above embodiment, the passage forming member 93, which is a separate body from the hydraulic control valve 90, is arranged between the hydraulic control valve 90 and the rocker shaft holder 44.
The passage forming member may be provided integrally with the hydraulic control valve, which can reduce the number of parts.

[0076]

As described above, according to the first aspect of the invention, the drain oil discharged from the hydraulic control valve passes through the oil reservoir of the rocker shaft holder that supports the rocker shaft, and at least a part of the rocker arm slides. Since it is supplied to the parts, the sliding part of the rocker arm can be lubricated while avoiding an increase in the number of parts, and the oil sump can be easily processed.

According to the second aspect of the invention, since the drain oil discharged from the hydraulic control valve is supplied from the passage forming member to the oil sump of the rocker shaft holder, the drain oil between the hydraulic control valve and the oil sump is drained. There is no need for special parts for delivery.

Further, according to the third aspect of the invention, the drain oil can be reliably transferred from the passage forming member to the oil sump of the rocker shaft holder, and a sufficient amount of drain oil can be supplied to the oil sump sufficiently. You can achieve the perfect lubrication.

[Brief description of drawings]

FIG. 1 is a front view of a V-type multi-cylinder internal combustion engine to which the present invention is applied.

FIG. 2 is a plan view seen from the direction of arrow 2-2 in FIG. 1 with a head cover removed.

FIG. 3 is a plan view corresponding to FIG. 2 in a state where a rocker shaft holder and a cam shaft are partially cut away.

4 is a sectional view taken along line 4-4 of FIG.

5 is a sectional view taken along line 5-5 of FIG.

6 is a sectional view taken along line 6-6 of FIG.

7 is an enlarged sectional view taken along line 7-7 of FIG.

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG.

9 is a sectional view taken along line 9-9 of FIG.

10 is an enlarged cross-sectional view taken along line 10-10 of FIG.

11 is a view of the passage forming member as viewed in the direction of arrow 11 in FIG.

12 is an enlarged sectional view taken along line 12-12 of FIG.

[Explanation of symbols]

16: Cylinder head 36, 37 ... Rocker shaft 38, 39, 40, 41, 42 ... Rocker arm 44: Rocker shaft holder 65, 75 ... Valve operating characteristic changing mechanism 73, 74, 83, 84 ... Hydraulic oil passage 90 ... Hydraulic control valve 93 ... Passage forming member 94, 95 ... Communication passage 97 ... oil sump 103 ... recess 104 ... Guide part E ... Internal combustion engine VI ... Intake valve as an engine valve VE ... Exhaust valve as an engine valve

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Claims (3)

(57) [Claims] 1. A rocker shaft (36, 37) for rockably supporting a plurality of rocker arms (38, 39, 40; 41, 42) on a rocker shaft holder (44) fixed to a cylinder head (16). The rocker arm (38-40; 41, 42) is provided with a valve operating characteristic changing mechanism (65, 75) capable of changing the operating characteristic of the engine valve (VI, VE) by changing the hydraulic pressure. A hydraulic oil passage (73, 8) formed in the rocker shaft (36, 37) through the characteristic changing mechanism (65, 75).
3; 74, 84) in an internal combustion engine in which a hydraulic control valve (90) for controlling the hydraulic pressure of hydraulic oil supplied to the cylinder head (16) causes drain oil to flow out from the hydraulic control valve (90). The obtained oil sump (97) enables supply of lubricating oil to the sliding portions of at least a part of the rocker arms (41, 42) of the rocker arms (38-40; 41, 42), and the rocker shaft holder A lubricating structure for an internal combustion engine, wherein the lubricating structure is formed on the upper surface of (44). 2. The hydraulic control valve (90) and the rocker having communication passages (94, 95) connecting the hydraulic control valve (90) and the hydraulic oil passages (73, 83; 74, 84). The upper portion of the passage forming member (93) interposed between the shaft holders (44) is formed so as to be able to transfer the drain oil discharged from the hydraulic control valve (90) to the oil sump (97). The lubrication structure for an internal combustion engine according to claim 1, wherein: 3. The upper portion of the passage forming member (93) includes:
A recess (103) for receiving the drain oil from the hydraulic control valve (90) and a guide (104) for guiding the drain oil accumulated in the recess (103) to the oil sump (97) are provided. The lubricating structure for an internal combustion engine according to claim 2, wherein the guide portion (104) extends from the passage forming member (93) to a position above the oil sump (97).