JPS6315522Y2 - - Google Patents

Description

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

Conventionally, the cylinder head, which forms part of the engine body, has two valve drive camshafts for intake and exhaust, and an end pivot type that is swung by the valve drive cams on these valve drive camshafts. DOHC type multi-cylinder internal combustion engines are known which have two valve operating systems that are equipped with intake and exhaust rocker arms and whose intake and exhaust valves are opened and closed by the rocking of these rocker arms.

By the way, in such an engine, sufficient lubricating oil is supplied to the lubricating surfaces of the multiple bearings of the two valve drive camshafts and the lubricating surfaces of the rocking supports of the multiple rocker arms for intake and exhaust. It is necessary to operate two valve train camshafts and a plurality of rocker arms smoothly and easily, especially in a multi-cylinder engine. It is desirable to supply a predetermined amount of lubricating oil quickly while minimizing the amount of lubricating oil.

However, in conventional multi-cylinder internal combustion engines of this type, oil is distributed from an oil supply source provided at one longitudinal end of the engine body to the lubricated surfaces of two valve drive camshafts and a plurality of rocker arms. There is a large difference in the path of the oil supply path between the lubricating surface closest to the source and the lubricating surface farthest from the source, resulting in a disadvantage that there is a large time lag when distributing oil to each lubricating surface after engine startup.

The present invention was developed in view of the above circumstances, and it is possible to supply the desired amount of lubricating oil to all lubricated surfaces with a minimum time lag, and it is also simple in structure and easy to process, resulting in a significant cost reduction. The main purpose is to provide a lubricating device for the valve train in a DOHC multi-cylinder internal combustion engine.

In order to achieve this object, the present invention provides a cylinder head that is superimposed on a cylinder block, two valve drive camshafts that extend parallel to each other in the longitudinal direction of the cylinder head, and two valve drive camshafts that extend parallel to each other in the longitudinal direction of the cylinder head. Two rocker arms are provided on the intake and exhaust sides that are swing-driven by the cylinders to open and close the intake and exhaust valves, respectively.
In a DOHC multi-cylinder internal combustion engine, which is provided with a valve train and a spark plug interposed between the two valve trains, the cylinder head has a plug socket for inserting the spark plug. a main oil supply passage located in the longitudinal center of the cylinder head and communicating with the oil supply passage on the cylinder block side, and a cylinder head adjacent to the plug insertion hole with the insertion hole sandwiched between them. two linear oil gear larages extending parallel to each other in the longitudinal direction, and extending across the longitudinal center portions of the two oil gear rallies;
A communication oil passage is directly formed in which these oil gear rallies communicate with the main oil supply passage, and the two oil gear larches are connected to the lubricating surface of the bearing portion of the intake and exhaust valve drive camshaft and the lubricating surface of the bearing portion of the intake and exhaust valve drive camshaft, respectively. It is characterized by communicating with the lubricating surface of the swing support.

Hereinafter, an embodiment in which the present invention is applied to a four-cylinder engine will be described with reference to the drawings.

1 to 3, a cylinder head H is polymerized and bonded to a cylinder block B via a gasket, and four combustion chambers 1 are provided on the lower surface of the cylinder head H in correspondence with the cylinders. Each combustion chamber 1 includes a pair of intake valve ports 3 communicating with an intake port 2 and a pair of exhaust valve ports 5 communicating with an exhaust port 4.
The intake and exhaust valve ports 3 and 5 are opened and closed by intake and exhaust valves 6 and 7 which are slidably supported on the cylinder head H as usual.

At the top of the cylinder head H, there is provided a DOHC type valve mechanism equipped with two valve drive camshafts 8, 9 and end pivot type rocker arms 10, 11 that open and close the intake valve 6 and the exhaust valve 7, respectively. It will be done.

The two valve drive camshafts 8 and 9 on the intake and exhaust sides are arranged parallel to each other on the cylinder head H in its longitudinal direction, that is, along the crankshaft direction,
As shown in FIGS. 1 and 2, these valve drive camshafts 8 and 9 are provided with a plurality of semicircular bearing halves 12a and 13a formed in the cylinder head H, and a semicircular bearing half 12a and 13a, which are superimposed and fixed on the upper part of the bearing halves 12a and 13a. semicircular bearing cap 12
It is rotatably supported by bearing parts 12 and 13 consisting of b and 13b, respectively.

Between the two valve drive camshafts 8 and 9, a central block 14 is integrally provided above the plurality of combustion chambers 1 along the longitudinal direction thereof, and each of the central blocks 14 At the upper center of the combustion chamber 1, as shown in FIG. 2, a hollow cylindrical plug insertion tube 15 is provided that projects straight upward. This plug insertion tube 15 is provided with a plug insertion hole 16 whose top surface is open, and the bottom surface of this plug insertion hole 16 is inserted into the combustion chamber 1 through a threaded hole 17 formed in the upper wall of the combustion chamber 1. 1. The spark plug P (FIG. 2) inserted into the plug insertion hole 16 is fixed to the cylinder head H by screwing its threaded portion into the screw hole 17.

As shown in FIGS. 1 and 2, on both sides of each plug insertion cylinder 15, there are two intake valve side rocker arm mounting portions 18 corresponding to the two intake valves 6 and two exhaust valves corresponding to the two exhaust valves 7. Valve side rocker arm 1
The first mounting portion 19 is formed to bulge in the lateral direction. The upper surfaces of the mounting portions 18 and 19 are flat inclined seat surfaces 18a and 1 which are inclined downwardly toward the outside.
9a. The rocker arm attachment part 18
and 19 have screw holes 20 and 21, respectively.
are drilled, and rocker arm support screws 22 and 23 are screwed into these screw holes 20 and 21. A hemispherical swing support portion 22a is formed on the upper surface of the intake side rocker arm support screw 22, and a spherical surface at the lower end of the adjustment screw 24 screwed onto the base end of the end pivot type rocker arm 10 is formed on the swing support portion 22a. The convex portion 24a is rotatably supported. The tip of each intake-side rocker arm 10 is brought into contact with the upper end of the stem portion of the intake valve 6. Similarly, a hemispherical swing support portion 23a is formed on the upper surface of the exhaust side rocker arm support screw 23, and a spherical convex portion at the lower end of the adjustment screw 25 screwed onto the base end of the end pivot type rocker arm 11 is formed on the support portion 23a. The portions 25a are each rotatably supported. Exhaust side rocker arm 11
The tip of the exhaust valve 7 is brought into contact with the upper end of the stem portion of the exhaust valve 7.

a plurality of rocker arms 10 on the intake and exhaust sides;
11 have slipper surfaces 10a and 11, respectively.
a is formed, and their slipper surfaces 10a, 11
Valve drive cams 8a and 9a on two valve drive camshafts 8 and 9 on the intake and exhaust sides are brought into contact with a, respectively.

Valve springs 30 and 31 are provided between the spring seats 26 and 27 formed on the cylinder head H and the spring seats 28 and 29 that are secured to the upper ends of the stems of the intake and exhaust valves 6 and 7, respectively. are interposed, and these valve springs 30 and 31 bias the intake and exhaust valves 6 and 7, respectively, in the valve closing direction.

As clearly shown in Figure 6, the cylinder head H
In the longitudinal direction of the central block 14, that is, in the direction of the crankshaft, a pair of linear oil gear rallies 32 and 33 are arranged vertically parallel to each other in the vicinity of the plug insertion hole 16 and sandwich the plug insertion hole 16 between them. The oil gears 32 and 33 are communicated with each other by a communication oil passage 34 that traverses their central portions and communicates with them. The communication oil passage 34 extends outward from one of the oil gear 32, and as shown in FIG.
The upper part of the is connected. The lower part of the main oil supply passage 35 is an oil supply passage 3 bored vertically in the cylinder block B.
6, and this oil feed passage 36 communicates with an oil pump (not shown) below the cylinder block B.

As clearly shown in FIG.
is formed using one of a plurality of bolt insertion holes 37 for tightly connecting the cylinder head H to the cylinder block B. The attached bolt 38 is inserted and screwed onto the cylinder block B. And bolt insertion hole 37 and tightening bolt 38
Lubricating oil flows through the annular gap between the two. The two oil gear rallies 32 and 33 and the communicating oil passage 34
The opening end to the outer end surface of the cylinder head H is a blind plug 4.
0, 41 and 42, respectively.

As shown in Fig. 2, two oil gear 3
A plurality of branch oil passages 43 and 44 (Fig. 2) are branched from 2 and 33, and one branch oil passage 43 is opened to the lubricating surface of the intake side bearing portion 12, and the other branch The oil passages 44 are each opened to the lubricated surface of the exhaust side bearing portion 13.

Further, as shown in FIG. 3, the two oil gear rallies 32 and 33 have oil reservoirs 45 and 46 formed at the bottom of the plurality of intake side and exhaust side threaded holes 20 and 21.
(Fig. 3), and those oil reservoirs 45 and 46 are connected to the rocker arm support screws 22 and 2.
The intake side and exhaust side rocker arms 10, 11 are connected to the intake side and exhaust side rocker arms 10, 11 through oil passages 22b, 23b drilled in the
The lubricating surfaces of the swing bearings 22a and 23a are communicated with each other.

As shown in FIG. 3A, oil passages 22b, 23b
are adjustment screws 24, 25 and rocker arm 1.
It communicates with the jet oil passages a and a drilled at 0 and 11,
The oil ejected from the ejected oil passage is the valve operating cam 8a, 9a.
and the slipper surfaces 10a, 11a.

Next, the operation of the embodiment of the present invention will be explained.

When the intake and exhaust side valve drive camshafts 8 and 9 are rotated by engine operation, the intake and exhaust side The rocker arms 10 and 11 swing up and down around swing bearings 22a and 23a, respectively, and open and close the intake and exhaust valves 6 and 7 at predetermined timings.

In addition, pressurized lubricating oil from an oil pump that rotates in conjunction with the operation of the engine is supplied to the oil supply path 36 and the main oil supply path 3.
5 to the two oil gear rallies 32, 33.
At the same time, oil is supplied to the lubricating surfaces of the bearing parts 12, 13 of the valve drive camshafts 8, 9 for intake and exhaust through the branch oil passages 43, 44, and at the same time, the oil reservoirs 45, 46 and the oil passage 22 are supplied with oil.
b, through 23b, intake and exhaust rocker arm 1
It is possible to supply oil to the swing bearing parts 22a and 23a of 0 and 11. By the way, in the lubricating oil supply system as described above, the lubricating oil from the communication oil passage 34 is
Since the flow is branched from the axial center of the oil gear 32, 33 toward both ends, after the engine is started, the flow from the oil gear 32, 33 to the 2
A plurality of bearing parts 12, 1 of the valve train camshafts 8, 9
3 and the rocker arms 10, 11 for suction and exhaust, all the lubricated surfaces of the rocking support portions 22a, 23a can be rapidly supplied with oil with minimal time lag.

As described above, according to the present invention, the cylinder head superimposed on the cylinder block is provided with two valve drive camshafts extending parallel to each other in the longitudinal direction of the cylinder head, and these valve drive camshafts. The DOHC is equipped with two valve train systems each having intake and exhaust side rocker arms that are swing-driven to open and close the intake and exhaust valves, and a spark plug interposed between the two valve systems. In a multi-cylinder internal combustion engine,
The cylinder head includes a plug insertion hole into which the spark plug is inserted, a main oil supply passage that is arranged in the longitudinal center of the cylinder head and communicates with the oil supply passage on the cylinder block side, and a main oil supply passage that communicates with the oil supply passage on the cylinder block side. two linear oil gear larries extending parallel to each other in the longitudinal direction of the cylinder head so as to be close to the hole and sandwiching the insertion hole between them; An oil gear lary is directly formed with a communicating oil passage communicating with the main oil supply passage, and the two oil gear rallies are connected to the lubricating surface of the bearing portion of the suction/exhaust valve drive camshaft and the swinging of the suction/exhaust rocker arm. Since it communicates with the lubricating surface of the support part, the oil supplied from the main oil supply path at the longitudinal center of the cylinder head to the center of each oil gear rally through the communicating oil path can be efficiently supplied to each of the plurality of lubricating surfaces. Moreover, since there is no large difference in the route of the oil supply path from the main oil supply path to each lubricating surface, there is no risk of a large time lag occurring in the distribution of oil to each lubricating surface even immediately after the engine starts. In particular, the two oil gear rallies extending in the longitudinal direction of the cylinder head are linear and are formed directly on the cylinder head, so they can be processed extremely easily by drilling etc. from the end face of the head, and each valve camshaft The lubricating surface of the bearing part of the rocker arm and the lubricating surface of the swinging support part of the rocker arm can be easily communicated with each oil gear lary by simply forming a relatively short branch path on each lubricating surface side from the fixed oil gear lary. Therefore, there is no need to form a complicated oil gear on each valve camshaft itself, which simplifies the structure of each valve camshaft, and significantly simplifies the lubrication structure of the valve mechanism as a whole. As well as being able to
The manufacturing process becomes easy, and it is possible to significantly reduce costs. Furthermore, the two oil gears extending in the longitudinal direction of the cylinder head with the plug insertion hole in between can effectively cool the peripheral wall of the plug insertion hole with a large amount of lubricating oil constantly flowing through them. This can contribute to preventing overheating of the spark plug in the insertion hole and the cord connected to it.

[Brief explanation of drawings]

The drawings show one embodiment of the device of the present invention, and FIG. 1 is a plan view thereof, FIG. 2 is a sectional view taken along the line of FIG. 1, FIG. 3 is a sectional view taken along the line of FIG. , a partially broken enlarged view of FIG. 3, FIG. 4 is a sectional view taken along the line of FIG. 1, and FIG. 5 is a sectional view taken along the line of FIG.
FIG. 6 is a sectional view taken along the line of FIG. 4. B...Cylinder block, H...Cylinder head, 6...Intake valve, 7...Exhaust valve, 8, 9...Valve drive camshaft, 12, 13...Bearing portion, 16...Plug insertion hole, P...Spark plug, 22a, 23a...
... Swing bearing part, 32, 33 ... Oil gear rally,
34...Communication oil passage, 35...Main oil supply passage, 36...
Oil route.

Claims (1)

[Scope of utility model registration request] The cylinder head H, which is superimposed and bonded on the cylinder block B, is provided with two valve drive camshafts 8 and 9 extending parallel to each other in the longitudinal direction of the cylinder head H, and these valve drive camshafts 8 and 9. Suction and exhaust valves 6 and 7 are operated to open and close by being oscillated, respectively.
In a DOHC multi-cylinder internal combustion engine, which is equipped with two valve train systems equipped with exhaust-side rocker arms 10 and 11, and a spark plug P interposed between the two valve train systems, the cylinder head H is , a plug insertion hole 16 for inserting the spark plug P, a main oil supply passage 35 arranged in the longitudinal center of the cylinder head H and communicating with an oil supply passage 36 on the cylinder block B side, and the plug difference. The cylinder head H is placed close to the insertion hole 16 with the insertion hole 16 in between.
Two linear oil gear larries 32, 33 extend parallel to each other in the longitudinal direction, and a linear oil gear largery 32, 33 extends across the longitudinal center of the two oil gear rallies 32, 33, and connects these oil gear rallies 32, 33 to the main oil supply path 35. A communicating oil passage 34 is directly formed in communication with the two oil gear larries 32 and 33, respectively, and the bearing portions 1 of the intake and exhaust valve drive camshafts 8 and 9 are formed directly.
1. A lubrication device for a valve mechanism in a DOHC multi-cylinder internal combustion engine, characterized in that the lubrication surfaces are connected to the lubrication surfaces of 2 and 13 and the lubrication surfaces of the rocking support portions 22a and 23a of the intake and exhaust rocker arms 10 and 11.