JP2002155712A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently improve the supporting stiffness of a rocker shaft, in an internal combustion engine wherein the rocker shaft rockably bearing a rocker arm following the rotations of a cam shaft is supported in a rocker shaft holder provided with plural shaft supporting portions fastened to plural bearing portions provided on a cylinder head in one or another body so as to rotatably bear the cam shaft, and a coupling portion integrally coupling the shaft supporting portions. SOLUTION: The rocker shaft 37 is supported by each of shaft supporting portions 44a, and supported by a shaft middle supporting portion 44c disposed between the plural shaft supporting portions 44a and provided integrally with the coupling portion 44b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an internal combustion engine,
In particular, a plurality of bearing portions for rotatably supporting the camshaft are provided on the cylinder head, and a plurality of shaft support portions respectively fastened to the bearing portions and a connecting portion for integrally connecting the shaft support portions. The present invention relates to an improvement in an internal combustion engine in which a rocker shaft for swingably supporting a rocker arm driven by rotation of the camshaft is supported by a rocker shaft holder provided.

[0002]

2. Description of the Related Art Conventionally, such an internal combustion engine is already known, for example, from Japanese Patent No. 2688732.

[0003]

In the prior art disclosed in the above publication, the rocker shaft is supported only by the shaft support portion of the rocker shaft holder, and it cannot be said that the rocker shaft has sufficient support rigidity. .

[0004] The present invention has been made in view of such circumstances, and has as its object to provide an internal combustion engine in which the support rigidity of a rocker shaft is sufficiently increased.

[0005]

In order to achieve the above object, according to the present invention, a plurality of bearing portions for rotatably supporting a camshaft are provided integrally or separately on a cylinder head. A rocker arm that is driven by the rotation of the camshaft is swingably supported on a rocker shaft holder that includes a plurality of shaft support portions fastened to the bearing portions and a connecting portion that integrally connects the shaft support portions. In an internal combustion engine in which a rocker shaft is supported, the rocker shaft is supported by each of the shaft support portions, and is provided between the plurality of shaft support portions and provided integrally with the connection portion. It is characterized by being supported by.

According to such a configuration, the shaft support portions of the rocker shaft holder are fastened to a plurality of bearing portions integrally or separately provided on the cylinder head so as to rotatably support the camshaft, respectively. While the rocker shaft is supported by those shaft supports,
Since the rocker shaft is also supported by the shaft intermediate support portion provided integrally with the connecting portion of the rocker shaft holder and disposed between the plurality of shaft support portions, the support rigidity of the rocker shaft can be sufficiently increased.

[0007] The invention according to claim 2 provides the above-described claim 1.
In addition to the configuration of the invention described in the above, the rocker shaft holder supports a rocker shaft supported by the shaft intermediate support portion and another rocker shaft having an axis parallel to the rocker shaft. On the rocker arm swingably supported by the other rocker shaft at a position corresponding to the support portion, a roller that is in rolling contact with a cam provided on the camshaft is opposed to the shaft intermediate support portion. A notch that is pivotally supported and avoids interference with the roller is provided in the shaft intermediate support. According to this configuration, the rocker arm including the roller is provided despite the shaft intermediate support. Place it close enough to the rocker shaft side,
The valve train including the rocker arm and the rocker shaft can be made compact.

According to a third aspect of the present invention, in addition to the structure of the first or second aspect, a rocker arm disposed adjacent to the shaft intermediate support is supported by the shaft intermediate support. The rocker shaft is swingably supported by the rocker shaft. According to such a configuration, the axial intermediate movement of the rocker arm can be restricted by the shaft intermediate support portion, and a dedicated component for restricting the axial movement of the rocker arm is provided. Can be eliminated, and the number of parts can be reduced.

[0009] The invention according to claim 4 is the above-mentioned claims 1-3.
In addition to the configuration of the invention described in any one of the above, the rocker shaft holder is provided integrally with a rib extending in a direction parallel to the axis of the rocker shaft and connecting the shaft support portion and the shaft intermediate support portion. According to this configuration, the rigidity of the rocker shaft holder, particularly the rigidity of the shaft intermediate support portion, can be increased, and the support rigidity of the rocker shaft can be further increased.

According to a fifth aspect of the present invention, in addition to the configuration of the third aspect, an oil reservoir is formed on an upper surface of the rocker shaft holder, and the shaft intermediate support portion and the shaft intermediate support portion are formed. A lubricating oil path for guiding lubricating oil from the oil reservoir is provided in the rocker shaft holder in a sliding portion with the rocker arm adjacent to the rocker arm. According to this configuration, components other than the rocker shaft holder are unnecessary. The lubricating oil can be supplied to the sliding portion between the shaft intermediate support portion and the rocker arm.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on one embodiment of the present invention shown in the attached 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 as seen from the direction of the arrow 2-line, FIG. 3 is a plan view corresponding to FIG. 2 in a state where a part of the rocker shaft holder and the camshaft are cut away, and FIG. 4 is a cross-section taken along line 4-4 in FIG. FIG. 5, 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 the line 7-7 in FIG. 6, and FIG. 8 is an 8-8 in FIG.
9 is an enlarged sectional view taken along line 9-9 of FIG. 8, FIG. 10 is an enlarged sectional view taken along line 10-10 of FIG. 2, and FIG. And FIG.
It is a 2-12 line expanded sectional view.

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 rows 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 the cylinder heads 16 and 1
6 and head covers 17, 17 respectively connected to the first and second cylinder row portions 14A, 14B.
The cylinder bores 18 arranged in a direction perpendicular to the plane of FIG.
Pistons 19 provided for each cylinder and slidably fitted to the respective cylinder bores 18 are commonly connected to a single crankshaft 21 via connecting rods 20.

The structure of the engine E on the side of the first cylinder row portion 14A will be described with reference to FIGS. 2 to 6. The combustion between the cylinder head 16 and the pistons 19 in the cylinder bores 18 will be described. Chambers 22 are formed. At a portion corresponding to each combustion chamber 22, a pair of intake valve ports 23, which can communicate with the combustion chamber 22, and one side of the cylinder head 16 which commonly communicates with the intake valve ports 23, are provided on the cylinder head 16. 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 commonly communicates with the exhaust valve ports 25 and opens on the other side of the cylinder head 16 are provided. Based on the fact that the first and second cylinder row portions 14A and 14B form a V-shape with each other, the cylinder head 16 is inclined to one side to the left and right in the cylinder arrangement direction, that is, the exhaust port 26 Port 24
It is arranged so as to be inclined below.

The stems of the intake valves VI, VI, which can individually open and close the intake valve ports 23, are slidably fitted to guide cylinders 28 provided on the cylinder head 16.
Valve springs 30, which bias the intake valves VI, VI in the valve closing direction, are provided between the cylinder head 16 and retainers 29, which are provided at the upper end portions of the valves I, VI. Exhaust valve port 25
Are individually slidably fitted to guide cylinders 31 provided on the cylinder head 16 and retainers provided at upper end portions of the exhaust valves VE, VE. 32 and the cylinder head 16 are provided with valve springs 33 for urging the exhaust valves VE, VE in the valve closing direction.

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

Each of the combustion chambers 22.
Are interposed between each other (four in this embodiment)
Are integrally protruded at intervals in the cylinder arrangement direction, and the camshaft 35 is mounted on the bearings 4.
It is rotatably supported by 3 ... Moreover, the camshaft 35
Are linked and connected to the crankshaft 21 at a reduction ratio of 1/2.

A pair of rocker shafts 36, 37 are fixedly arranged above the camshaft 35, and a rocker shaft holder 44 for supporting these rocker shafts 36, 37 is mounted on the upper surface of each of the bearings 43. Is fastened and fixed.

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

The pair of rocker shafts 36, 37 are supported by the respective shaft support portions 44a of the rocker shaft holder 44 at a position where the cam shaft 35 is disposed below the rocker shafts 36, 37. The bolts 45 for fastening the shaft support portions 44a to the bearing portions 43 engage with a part of the outer surface of the rocker shafts 36, 37, thereby preventing the rocker shafts 36, 37 from rotating around the axis. The rocker shafts 36 and 37 are fixedly supported by the rocker shaft holder 44.

By the way, flat fastening seats 46, 47 for fastening rocker shaft holders 44 to both sides of a portion for rotatably supporting the cam shaft 35 are provided on each of the bearing portions 43.
Are formed between the two fastening seats 46, 47 so that the bearing portions 43 are formed to protrude above the fastening seats 46, 47.

On the other hand, on the lower surface of each shaft support portion 44a in the rocker shaft holder 44, the bearing portion 43 is provided.
Receiving recesses 48 for projecting a part of the central raised portion in
Is provided so as to be located between both rocker shafts 36 and 37, and a part of the central raised portion in the bearing portion 43 is
In order to avoid contact with the rocker shaft holder 44, that is, the gap 4 between the accommodation recess 48 and the bearing portion 43.
As shown in FIG. 9, the protrusion 9 protrudes into the accommodation recess 48.

Further, the connecting portion 44b for connecting the shaft support portions 44a of the rocker shaft holder 44 is
At least the accommodation recess 4 of each shaft support portion 44a.
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. The rocker shaft 37 on the exhaust valves VE, VE side is located between the shaft support portions 44a. Shaft intermediate support portion 4 arranged and provided integrally with connecting portion 44b
4c ... is also supported.

In FIG. 8, the drive rocker arms 38, 39 and the free rocker arm 40, which are swingably supported on the rocker shaft 36, are arranged so that the free rocker arm 40 is sandwiched between the drive rocker arms 38, 39. 38, 39 are interlocked with and connected to the intake valves VI, VI by abutting tappet screws 54, 54, which are screwed to the rocker arms 38, 39 so that the advance / retreat positions can be adjusted, to the upper ends of the intake valves VI, VI. Is done.

The drive rocker arms 41, 41 and the free rocker arms 42, 42, which are swingably supported by the rocker shaft 37, are arranged so as to form a pair at positions spaced apart in the axial direction of the rocker shaft 37. The drive rocker arms 41, 41 are provided with tappet screws 55, 55 which are screwed to the rocker arms 41, 41 so that the advance / retreat positions can be adjusted, and contact the upper ends of the exhaust valves VE, VE. Linked with VE, VE.

Further, the shaft intermediate support portion 44c of the rocker shaft holder 44 is provided with two drive rocker arms 41, 41.
Drive rocker arms 41, 4
1 are disposed adjacent to both sides of the shaft intermediate support portion 44c in the axial direction of the rocker shaft 37.

A plug insertion tube 56 is attached to the cylinder head 16 so as to be disposed between the two drive rocker arms 41, 41.
Are screwed into the cylinder head 16 so as to face the respective combustion chambers 22.

Referring also to FIG. 9, the camshaft 35
A cam 62 for rollingly contact a roller 58 supported by the free rocker arm 40 on the side of the intake valves VI, VI;
Cams 63, 63 for rollingly contact rollers 59, 59 supported by free rocker arms 42, 42 on the exhaust valves VE, VE, and cam slippers provided on drive rocker arms 38, 39 on the intake valves VI, VI. 60,60
And the drive rocker arm 41 on the exhaust valve VE, VE side,
A pair of cams 64, 64 for slidingly contacting the cam slippers 61, 61 provided on the camshaft 35 are provided.
A cam 62 along the axis of the cam shaft 3
5 so as to sandwich the cams 64, 64 between the cams 63, 63 on both sides along the axial direction of the cam 5.
64, 64 are arranged.

The cams 62 are provided on the camshaft 35 at positions corresponding to the shaft intermediate supports 44c of the rocker shaft holder 44.
The free rocker arms 40 on the I and VI sides have cams 62.
Rollers 58 that are in rolling contact with each other are axially supported so as to face the shaft intermediate supports 44c. On the other hand, the shaft intermediate support portions 44c are provided with notches 53 for avoiding interference with the rollers 58, so that the shaft intermediate support portions 44c are 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 to have a cam profile for opening and closing the exhaust valves VE, VE.
The intake valves VI, VI and the exhaust valves VE, VE are formed so as to be substantially closed and stopped. 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. However, both drive rocker arms 3 to the free rocker arm 40 are operated.
When the connection between the switches 8 and 39 is released, the valve-closing stop state is substantially achieved. The exhaust valves VE, VE open and close when the drive rocker arms 41, 41 are connected to the free rocker arms 42, 42. However, the connection between the drive rocker arms 41, 41 to the free rocker arms 42, 42 is released. When this happens, the valve is substantially in a valve-closing rest state.

Drive rocker arm 3 on intake valves VI, VI
Each of the free rocker arms 8 and 39 is provided with a valve operating characteristic changing mechanism 65 for hydraulically switching connection and disconnection of the drive rocker arms 38 and 39 to and from the free rocker arm 40.

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

In the valve operating characteristic changing mechanism 65, when hydraulic pressure is applied to the first hydraulic chamber 66, as shown in FIG. 8, the connecting pins 67, 68 and the pin 69 connected to each other are connected to the second hydraulic chamber. The drive rocker arm 38 and the free rocker arm 40 are connected by the connecting pin 67, and the free rocker arm 40 and the drive rocker arm 39 are connected by the connecting pin 68.
When hydraulic pressure is applied to the second hydraulic chamber 70, the connecting pins 67 and 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 and 68 Since the contact surface is between the drive rocker arm 38 and the free rocker arm 40, the connection between the drive rocker arm 38 and the free rocker arm 40 is released,
The connection between the free rocker arm 40 and the drive rocker arm 38 is released by the contact surface of the connecting pin 68 and the pin 69 between the free rocker arm 40 and the drive rocker arm 39.

In this manner, the valve operating characteristic changing mechanism 65
Switches the connection and disconnection of the free rocker arm 40 to and from the drive rocker arms 38 and 39 by the action of alternate hydraulic pressure on the first and second hydraulic chambers 66 and 70 to change the operating characteristics of the intake valves VI and VI. The return spring 71 prevents the pins 67, 68, and 69 from rattling in a state where the hydraulic pressure does not act on any of the first and second hydraulic chambers 66 and 70 in response to the stop of the operation of the engine E. What is necessary is just to exert the spring force of the degree which can be performed.

A dividing member 72 for dividing the inside of the rocker shaft 36 into two is fitted in the rocker shaft 36, and the dividing member 72 allows the first hydraulic chamber 66 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 drive rocker arms 41, 41 and the free rocker arms 42, 42 which are arranged adjacently in pairs on the exhaust valves VE, VE side respectively have a free rocker arm 4
Valve operating characteristic changing mechanisms 75, 7 for switching the connection and disconnection of the drive rocker arms 41, 41 to and from the drive rocker arms 41, 42 by hydraulic pressure.
5 are provided.

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

In the valve operating characteristic changing mechanism 75, when a hydraulic pressure is applied to the first hydraulic chamber 76, the connecting pin 77 and the pin 78 connected to each other are connected to the second hydraulic chamber 79, as shown in FIG. The drive rocker arm 41 and the free rocker arm 42 are connected to the position where the volume is minimized, and the connecting pin 77 is connected. When hydraulic pressure is applied to the second hydraulic chamber 79, the mutually connected connecting pin 77 and pin 78 move to a position where the volume of the first hydraulic chamber 76 is minimized. Since the surface is between the free rocker arm 42 and the drive rocker arm 41, the connection between the free rocker arm 42 and the drive rocker arm 41 is released.

In this manner, the valve operating characteristic changing mechanism 75
Switches the connection and disconnection of 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 exhaust valve V
The operation characteristics of E and VE are changed.
0 indicates a spring force that can prevent the pins 77, 78 from rattling in a state where no hydraulic pressure acts on either of the first and second hydraulic chambers 76, 79 in response to the stop of the operation of the engine E. I just need.

A dividing member 82 for dividing the inside of the rocker shaft 37 into two is fitted into the rocker shaft 37, and the dividing member 82 allows the first hydraulic chamber 76 to communicate with the first hydraulic chamber 76 in 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, the spring force which presses the free rocker arm 40 against the cam 62 of the camshaft 35 with the free rocker arm 40 disconnected from the drive rocker arms 38 and 39 is released by the valve operating characteristic changing mechanism 65 on the intake valves VI and VI side. A lost motion spring 85 is provided between the cylinder head 16 and the free rocker arm 40. A part of the spring 85 is accommodated in a bottomed hole 86 provided on the upper surface of the cylinder head 16.

The free rocker arms 42, 42 are connected to the camshaft 35 with the free rocker arms 42, 42 disconnected from the drive rocker arms 41, 41 by the valve operating characteristic changing mechanisms 75, 75 on the exhaust valves VE, VE. 63,
Are provided between the rocker shaft holder 44 and the free rocker arms 42, 42. The lost motion springs 87, 87,.
Rocker shaft holder 4 so as to accommodate a part of
Are provided integrally with the connecting part 44b of the rocker shaft holder 44.

With the rocker shaft 37 for swingably supporting the drive rocker arms 41, 41 ... and the free rocker arms 42, 42 ... supported by the rocker shaft holder 44, the rocker shaft 37 is attached to the bottomed cylindrical portions 88, 88 .... The lost motion springs 87 with a partly accommodated portion do not fall off the rocker shaft holder 44, and have a very simple structure that only partially accommodates the bottomed cylindrical portions 88, 88. , 87... Can be held in the rocker shaft holder 44.

Further, the bottomed cylindrical portions 88, 88... Are integrally formed with the rocker shaft holder 44 so as to be continuous with the shaft support portions 44a. …, Each shaft support 4
4a... And the rigidity of the entire rocker shaft holder 44 can be increased.

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

The hydraulic control valve 90 comprises, for example, a spool valve 91 attached to the cylinder head 16 and an electromagnetic valve 92 attached to the spool valve 91 so as to control the switching operation of the spool valve 90. 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 mounted on the cylinder head 16.

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

In addition, the spool valve 91 has the first and second spool valves.
When the state is switched, the drain oil is discharged, 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 which can accumulate oil scattered in the valve operating chamber between the cylinder head 16 and the head cover 17 is formed.

The oil reservoir 97 is arranged between a pair of bottomed cylindrical portions 88, 88 at a position corresponding to the center of each of the combustion chambers 22 and a groove 98 extending along the cylinder arrangement direction. A substantially T-shaped branch groove 99 is connected to the groove 98, and the oil in the groove 98 is supplied to the branch groove 99.
, Each branch groove 99.
Is located below the intake port 23 and the cylinder head 16 is inclined.
8 are formed so as to be connected to the side of the exhaust valves VE, VE.

Referring also to FIG. 12, on the upper surface of the rocker shaft holder 44, a rib 101 which is located below the groove 98 and has a side surface which is continuous with the peripheral wall at the end of each of the branch grooves 99. , Protrudingly extending along the cylinder arrangement direction. The rib 101 has a branch groove 99.
Are connected to portions of the bottomed cylindrical portions 88, 88 located on both sides of the cylinder head 16 that are located on the lower side in the direction of inclination as the cylinder head 16 is inclined. The oil sump 97 and the rib 101
Are arranged in a substantially U-shape, and the rib 101 serves as a wall defining the lowermost portion of the oil sump 97.

Further, a pair of oil pools 97 is provided at the ends of the branch grooves 99... Which are portions of the oil pool 97 near the rib 101, that is, in the oil pool 97 in a region surrounded by the bottomed cylindrical portions 88 and 88 and the rib 101. Each of the lubricating oil passages 100, 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 is provided at the shaft intermediate support portion 44 of the rocker shaft holder 44.
c of the rocker arms 38 to 40, 41, 42.
c, a sliding portion between the drive rocker arms 41, 41 and the shaft intermediate support portion 44c, a sliding portion between the drive rocker arms 41, 41 and the rocker shaft 37, and a free rocker arm adjacent to the drive rocker arms 41, 41. Lubricating oil for lubricating the sliding portion between the rockers 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 sandwiching the oil reservoir 97 between the rock 101 and the rib 101.
Are protruded so as to extend along the cylinder arrangement direction. Moreover, the ribs 101 and 102 are provided over the entire length of the rocker shaft holder 44 in the longitudinal direction.
a and the shaft intermediate support portions 44c are connected by the ribs 101 and 102.

The drain oil discharged from the hydraulic control valve 90 is also guided to the oil reservoir 97. The upper part of the passage forming member 93 interposed between the hydraulic control valve 90 and the rocker shaft holder 44 has a hydraulic pressure. It is formed so that the drain oil discharged from the control valve 90 can be delivered to the oil sump 97.

That is, on the upper part of the passage forming member 93,
A concave portion 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 to guide the drain oil accumulated in the concave portion 103 to the oil reservoir 97 side. A portion 104 is provided, and the guide portion 104 extends from the passage forming member 93 to one end above the groove 98 in the oil reservoir 97.

The configuration of the second cylinder row portion 14B is basically the same as that of the first cylinder row portion 14A described above.
6 and the valve train 34B for driving the exhaust valves VE... Are different from the valve train 34A on the side of the first cylinder row portion 14A, while the intake valves VI. And the exhaust valves VE are not closed and stopped.

Next, the operation of this embodiment will be described. A bearing 43 for rotatably supporting the camshaft 35 is described.
Are projected from the cylinder head 16 at intervals in the cylinder arrangement direction so as to sandwich the combustion chambers 22 therebetween. On the other hand, rocker arms 38, 39, 40; 41, 42, which follow the rotation of the camshaft 35, are rockably supported, and rocker shafts 36, 37 disposed above the camshaft 35 are fastened to bearings 43. The rocker shafts 44 and 37 are fixedly supported by the rocker shaft holders 44, and the support rigidity of the rocker shafts 36 and 37 can be increased.

The rocker shaft holders 44 have shaft support portions 44a fastened to the bearings 43, respectively.
And a connecting portion 44b for integrally connecting the shaft supporting portions 44a to each other.
Are provided on the lower surface thereof with recesses 48 into which a part of the bearings 43 project. Thereby, the fastening structure of the bearing portions 43 and the rocker shaft holder 44 is changed to the cylinder bore 18.
The engine E can be made compact by configuring the engine E compactly in the direction along the axis. Moreover, the connecting portion 4
4b integrally connects at least portions of the plurality of shaft support portions 44a corresponding to the accommodation recesses 48 with each other, so that the accommodation recesses 48 are respectively provided in the shaft support portions 44a. Regardless, a decrease in the rigidity of the rocker shaft holder 44 can be avoided.

Since a part of the bearings 43 project into the receiving recesses 48 while avoiding contact with the rocker shaft holder 44, the vibration of the camshaft 35 is transmitted through the rocker shaft holder 44 through the rocker shaft holder 44. 36, 37 can be suppressed as much as possible.

A pair of rocker shafts 36 and 37 which are parallel to each other are supported by the rocker shaft holder 44, and the accommodation recesses 48 are provided in the rocker shaft holder 44 between the rocker shafts 36 and 37.
By setting the distance between the rocker shafts 36 and 37 and the cam shaft 35 to be 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.

The connecting part 4 of the rocker shaft holder 44
4b is provided integrally with a shaft intermediate support portion 44c arranged between the plurality of shaft support portions 44a. The rocker shaft 37 of the two rocker shafts 36, 37 is connected to each of the shaft support portions 44a. Supported by the shaft intermediate support portions 44c. Thereby, the support rigidity of the rocker shaft 37 can be sufficiently increased.

The shaft intermediate support portions 44c are provided with notches 53 which are supported by the free rocker arms 40 on the intake valves VI and VI side to avoid interference with the rollers 58 opposed to the shaft intermediate support portions 44c. The free rocker arm 40 provided with the roller 58 is provided with the rocker shaft 3 despite the shaft intermediate support portions 44c.
7 and the valve trains 34A, 34B including the free rocker arm 40 and the rocker shaft 37.
Can be configured compactly.

Further, since the drive rocker arms 41, 41 on the exhaust valves VE, VE side are arranged adjacent to the shaft intermediate support portions 44c in the axial direction of the rocker shaft 37, the drive rocker arms 41 are formed by the shaft intermediate support portions 44c. The axial movement can be restricted, and the drive rocker arm 41 can be controlled.
Therefore, the number of components can be reduced by eliminating the need for a dedicated component for restricting the axial movement of the component.

An oil sump 97 is formed on the upper surface of the rocker shaft holder 44, and lubricating oil passages 100, 100 ... communicating with the oil sump 97 are formed on the rocker arms 38-4.
Drive rocker arm 4 which is part of 0, 41, 42
1 and the free rocker arm 42 are provided on the rocker shaft holder 44 so that lubricating oil can be supplied to the sliding portion of the free rocker arm 42 with the rocker shaft 37 and the sliding portion between the shaft intermediate support portions 44c. The oil stored in the oil sump 97 is transferred from the oil sump 97 to the rocker shaft 37 of the drive rocker arm 41 and the free rocker arm 42 via the lubricating oil passages 100, 100.
And the sliding portion between the shaft intermediate support portions 44c... And the drive rocker arm 41, and these sliding portions can be positively lubricated. Therefore, a special 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 parts 44c... 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 processing of the oil sump 97 is easy.

The oil sump 97 has a groove 98 extending in the cylinder arrangement direction and a branch groove 99 connected to the groove 98.
And a rib 10 formed on the upper surface of the rocker shaft holder 44 and having a side surface that is flush with the end peripheral wall of each of the branch grooves 99.
1 protrudes from the rocker shaft holder 44 so as to extend along the cylinder arrangement direction. The lubricating oil passage 10
Reference numerals 0 and 100 designate an upper end communicating with a portion of the oil reservoir 97 near the rib 101 (an end of the branch groove 99 in this embodiment), and a rocker shaft holder 44 along the side surface of the rib 101 on the oil reservoir 97 side. Is provided on the rocker shaft holder 44 so as to penetrate through. Therefore, the rigidity of the rocker shaft holder 44 due to the provision of the lubricating oil passages 100 is reduced while the oil in the oil sump 97 can be supplied to each cylinder.
One can make up for it.

The cylinder head 16 is disposed so as to be inclined with the exhaust port 26 located below the intake port 24, and the rib 101 protrudes from the upper surface of the rocker shaft holder 44 below the groove 98. Therefore, the ribs 101 that increase the rigidity of the rocker shaft holder 44 function as walls that define the lower part of the oil reservoir 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, a bottomed cylindrical portion 88 for accommodating a lost motion spring 87 for urging the free rocker arms 42 on the exhaust valves VE, VE side toward the cam 63 of the cam shaft 35. And their bottomed cylindrical portions 88 on the lower side in the inclination direction of the cylinder head 16.
… The ribs 101 connecting them are provided integrally, and the oil pool 9 is formed.
7 are formed by the bottomed cylindrical portions 88... And the ribs 101. Therefore, the bottomed cylindrical portion 88 and the rib 1
01 makes it possible to increase the rigidity of the rocker shaft holder 44 and allows a part of the oil reservoir 97 to 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 so as to form a substantially U-shape.

The lubricating oil passages 100, 100 are provided with rocker shaft holders such that the upper ends of the lubricating oil passages 100, 100 communicate with an oil reservoir 97 in a region surrounded by the bottomed cylindrical portion 88 and the rib 101. 44, the upper ends of the lubricating oil passages 100, 100 communicate with the rigidity increasing portions.
Can be prevented from lowering the rigidity of the rocker shaft holder 44.

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

Further, since the ribs 101 and 102 also connect between the shaft support portions 44a and the shaft intermediate support portions 44c of the rocker shaft holder 44, the ribs 101 and 102 provide the rocker shaft holder 4 with the ribs 101 and 102.
4, in particular, the rigidity of the shaft intermediate support portions 44c..., And the support rigidity of the rocker shaft 37 can be further increased.

The cylinder head 16 has valve operating characteristic changing mechanisms 65 provided on the rocker arms 38 to 40 on the intake valves VI and VI, and valve operating characteristics provided on the rocker arms 41 and 42 on the exhaust valves VE and VE. A hydraulic control valve 90 capable of controlling the hydraulic pressure of the hydraulic oil supplied to the mechanism 75 is provided. 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 supplied to the valve operation characteristic changing mechanisms 65 and 75 by using the drain oil for lubrication. The oil pressure does not decrease, and the responsiveness of the hydraulic control valve 90 does not decrease.

The hydraulic control valve 90 and the rocker shaft 3
6 and 37, respectively.
The first and second hydraulic oil passages 74 and 84 are connected to each other.
And a passage forming member 9 having second communication passages 94 and 95
3 is the hydraulic control valve 90 and the rocker shaft holder 44
The upper portion of the passage forming member 93 is formed so as to be able to transfer the drain oil to the oil sump 97. Therefore, there is no need for a dedicated component for delivering the drain oil between the hydraulic control valve 90 and the oil reservoir 97.

Further, a concave portion 103 for receiving the 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 reservoir 97 are provided above the passage forming member 93. And the guide unit 104
It extends from the passage forming member 93 to one end of the groove 98 in the oil sump 97, and 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 Can be supplied to the oil reservoir 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 appended claims. It is possible.

For example, in the above-described embodiment, the bearings 43 are provided integrally with the cylinder head 16, but a bearing separate from the cylinder head 16 is provided.
The present invention can also be applied to an internal combustion engine that is provided in a vehicle. In the above embodiment, the passage forming member 93 separate from the hydraulic control valve 90 is provided 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, so that the number of parts can be reduced.

[0078]

As described above, according to the first aspect of the present invention, the support rigidity of the rocker shaft can be sufficiently increased.

According to the second aspect of the present invention, the rocker arm provided with the roller is disposed sufficiently close to the rocker shaft side despite the presence of the shaft intermediate support portion, and the valve gear including the rocker arm and the rocker shaft is provided. Can be configured compactly.

According to the third aspect of the invention, the axial movement of the rocker arm can be restricted by the shaft intermediate support portion, and the number of parts is reduced by eliminating the need for a dedicated component for restricting the axial movement of the rocker arm. be able to.

According to the fourth aspect of the present invention, the rigidity of the rocker shaft holder, particularly the rigidity of the shaft intermediate support portion, can be increased, and the support rigidity of the rocker shaft can be further increased.

According to the fifth aspect of the present invention, lubricating oil can be supplied to the sliding portion between the shaft intermediate support portion and the rocker arm without using any components other than the rocker shaft holder.

[Brief description of the 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 showing a head cover removed and viewed from the direction of arrows 2-2 in FIG. 1;

FIG. 3 is a plan view corresponding to FIG. 2 in a state where a part of a rocker shaft holder and a camshaft is cut away.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 2;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 2;

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 4;

FIG. 9 is a sectional view taken along line 9-9 of FIG. 8;

FIG. 10 is an enlarged sectional view taken along line 10-10 of FIG. 2;

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

FIG. 12 is an enlarged sectional view taken along line 12-12 of FIG. 2;

[Explanation of symbols]

 16: Cylinder head 35: Cam shaft 36, 37 ... Rocker shaft 40, 41, 42 ... Rocker arm 43: Bearing 44: Rocker shaft holder 44a: Shaft support 44b ... Connecting part 44c ... Shaft intermediate support part 53 ... Notch 58 ... Roller 62 ... Cam 97 ... Oil pool 100 ... Lubricating oil path 101,102 ... Rib E ... Internal combustion engines

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F02F 1/24 F02F 1/24 F F term (Reference) 3G013 AA06 AA09 BA03 BC22 BD00 BD48 CA14 3G016 AA07 AA10 BA18 BB11 BB16 BB17 BB18 BB22 BB25 BB26 CA02 CA04 CA06 CA18 CA22 CA35 CA36 CA41 CA57 GA02 3G024 AA18 DA06 DA09 DA17 DA19 FA01

Claims (5)

[Claims] A plurality of bearings (43) for rotatably supporting a cam shaft (35) are provided integrally or separately on a cylinder head (16), and are respectively fastened to the bearings (43). Rocker shaft holder (44) including a shaft support portion (44a) and a connecting portion (44b) that integrally connects the shaft support portions (44a).
In the internal combustion engine, a rocker shaft (37) for swingably supporting a rocker arm (41, 42) driven by the rotation of the camshaft (35) is supported. Support (44
a), and is disposed between the plurality of shaft support portions (44a) to form the connection portions (44).
shaft intermediate support part (44c) provided integrally with b)
An internal combustion engine characterized by being supported by: 2. The rocker shaft holder (44) has a rocker shaft (37) supported by the shaft intermediate support portion (44c) and another rocker shaft having an axis parallel to the rocker shaft (37). The rocker arm (40) swingably supported by the other rocker shaft (36) at a position corresponding to the shaft intermediate support portion (44c). The roller (58) that comes into rolling contact with the cam (62) provided on the shaft intermediate support portion (44c)
The internal combustion engine according to claim 1, characterized in that a notch (53) that is axially supported so as to face the roller and that avoids interference with the roller (58) is provided in the shaft intermediate support portion (44c). . 3. A rocker arm (41) disposed adjacent to the shaft intermediate support (44c) is swingably supported by a rocker shaft (37) supported by the shaft intermediate support (44c). 3. The internal combustion engine according to claim 1, wherein: 4. The rocker shaft holder (44)
A rib (101, 10) extending in a direction parallel to the axis of the rocker shaft (37) and connecting the shaft support (44a) and the shaft intermediate support (44c).
4. The method according to claim 1, wherein the step (2) is provided integrally.
The internal combustion engine according to any one of the above. 5. An oil reservoir (97) is formed on the upper surface of the rocker shaft holder (44), and the shaft intermediate support (44c) and the rocker arm (41) adjacent to the shaft intermediate support (44c). A lubricating oil passage (100) for guiding lubricating oil from the oil sump (97) to a sliding portion with
4. The internal combustion engine according to claim 3, wherein the rocker shaft holder is provided on the rocker shaft holder.