JPH07102934A - Vertical overhead cam type multiple cylinder engine - Google Patents

Abstract

PURPOSE:To suppress the amount of oil mist which invades into a breather chamber by flying up oil reserved in the inner bottom part of a valve system chamber by each valve system cam, and arranging a blow-by gas inlet provided with a lead valve on the end part of the breather chamber formed on the ceiling wall of the valve system chamber. CONSTITUTION:A valve system cam shaft 8 provided with a plurality of valve system cams 6, 7 is mounted horizontally inside a valve system chamber 4 formed on the upside of a cylinder head 1. A plurality of valve interlocking arms 10, 11 for outputting input from each valve system cams 6, 7 to each valve shaft input end. are pivotally supported rockably to an arm pivotal shaft 9 which is in parallel with the valve system cam shaft 8. In this case, an oil reserving groove 15 is provided on the inner bottom part of the valve system chamber 4, and oil 16 reserved therein is flied up by the cam top of each valve system cam 6, 7. A breather chamber 42 is formed on the ceiling wall 34 of the valve system chamber 4 between both valve system cams 6 of adjacent cylinders 40, 41. A blow-by gas inlet provided with a lead valve is arranged on the end part of the breather chamber 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical overhead cam type multi-cylinder engine, and more particularly to an engine capable of sufficiently lubricating a cam surface of a valve cam and a valve shaft input end.

[0002]

As a conventional technology of a vertical overhead cam engine,
There is one shown in FIG. Like the present invention, it has the following basic structure. That is, the intake and exhaust valves 102 and 103 are attached to the lower portion of the cylinder head 101, and the valve operating chamber 104 is provided in the upper portion of the cylinder head 101, and the valve operating chamber 104 is connected to the crank chamber via the oil flow passage 105. A valve operating cam shaft 108 having a plurality of valve operating cams 106 and 107 is horizontally installed in a lower portion of the valve operating chamber 104, and an arm pivot shaft 109 parallel to the valve operating cam shaft 108 is provided in an upper portion of the valve operating chamber 104. The arm pivot 109
A plurality of valve interlocking arms 110 and 111 are swingably supported, and the input ends 110a and 111a of the valve interlocking arms 110 and 111 are brought into contact with the cam surfaces of the valve operating cams 106 and 107, respectively. The output ends 110b and 111b of the arms 110 and 111 are in contact with the valve shaft input ends 102b and 103b of the valves 102 and 103, respectively.

By the way, in this prior art, the valve operating chamber 10
The lubrication device for lubricating the inside of the valve 4 introduces the oil pressure feed passages 113 communicating with the oil pump 112 into the valve gear cam shaft 108 and the arm pivot shaft 109, respectively, and these oil pressure feed passages 113 are mounted on the bearing slides of the valve cam shaft 108. The moving portion 114 and the pivotally supporting portions 135 of the valve interlocking arms 110 and 111 are connected to each other. In this lubricating device, oil leaking from the bearing sliding portion 114 of the valve operating cam shaft 108 travels along the inner bottom of the valve operating chamber 104 and immediately flows into the oil flow passage 105.
Flow into. Further, when the oil leaking from the pivotally supporting portion 135 of the valve interlocking arms 110 and 111 flows down along the valve interlocking arms 110 and 111, the oil is splashed around and falls to the inner bottom of the valve operating chamber 104. Then
Immediately after passing through here, the oil flows into the oil flow-down passage 105.

[0004]

In the above prior art, most of the lubricating oil leaked from the bearing sliding portion 114 of the valve cam shaft 108 and the pivotally supporting portion 135 of the valve interlocking arms 110 and 111 is mostly the valve cam 106. Since the oil flows into the oil flow-down passage 105 immediately without reaching the cam surface of 107 or the valve shaft input ends 102b and 103b, the lubrication of these parts is not sufficient, which results in the operation of the valve cams 106 and 107 and the valve interlocking arm 110. This is a factor that shortens the service life of 111 and valves 102 and 103.

An object of the present invention is to provide a vertical overhead cam engine that can sufficiently lubricate the cam surface of the valve cam and the input end of the valve shaft.

[0006]

[Means for Solving the Problems]

(First Invention) As shown in FIG. 1 (B), the first invention is that a valve 2 for intake / exhaust is provided in a lower portion of a cylinder head 1.
And a valve operating chamber 4 is provided above the cylinder head 1. The valve operating chamber 4 is communicated with the crank chamber via an oil flow passage 5 as illustrated in FIG. 4, a valve operating cam shaft 8 provided with a plurality of valve operating cams 6 and 7 is horizontally installed in the lower part, and an arm pivot 9 parallel to the valve operating cam shaft 8 is installed horizontally in the upper part in the valve operating chamber 4. A plurality of valve interlocking arms 10 and 11 are pivotally supported on this arm pivot 9 so that they can swing freely.
As illustrated in (B), each valve interlocking arm 10.1
The input end portions 10a and 11a of 1 are brought into contact with the cam surfaces of the valve cams 6 and 7, and the output end portions 1 of the valve interlocking arms 10 and 11 are connected.
0b and 11b are the valve shaft input ends 2b of the respective valves 2 and 3
-The vertical overhead cam engine constructed by abutting on 3b is characterized as follows.

That is, as illustrated in FIGS. 1 (B) and 2 (B), an oil sump groove 15 is provided in the inner bottom of the valve operating chamber 4, and oil 16 accumulated in the oil sump groove 15 is formed. Is configured to be flipped up by the cam tops 6a and 7a of the valve operating cams 6 and 7, and viewed from above, the valve operating chamber ceiling wall is provided between the adjacent valve operating cams 6 and 6 of the adjacent cylinders 40 and 41. 34, a breather chamber 42 is provided, and a blow-by gas inlet 45 having a reed valve 44 is provided at an end portion 43 of the breather chamber opposite to the oil splashing side of the valve operating cams 6 and 7.

(Second Invention) As shown in FIG. 1 (A), the second invention is a vertical overhead cam type multi-cylinder engine of the first invention, in which the adjacent cylinders 40 and 41 are viewed from above. The breather chamber 42 is provided between the adjacent valve interlocking arms 10 and 11.
A peripheral side wall 46 of the valve is vertically provided from the valve operating chamber ceiling wall 34.

[0009]

[Operation and effect of the invention]

(First Invention) The first invention has the following actions and effects, as illustrated in FIG. The oil 16 accumulated in the oil sump groove 15 wets the cam surface immersed in the oil 16 and also causes the cam tops 6a, 7
It is flipped up by a, becomes oil mist, and is supplied to the valve shaft input ends 2b and 3b. Therefore, the valve cam 6
7, the cam surface of 7 and the valve shaft input ends 2b and 3b are sufficiently lubricated, and the valve operating cams 6 and 7 and the valve interlocking arm 10 and 1
1. The service life of valves 2 and 3 can be extended.

Most of the oil mist formed by the jumping up of the cam tops 6a and 7a floats in the valve operating chamber 4 on the oil jumping up side, so that the breather chamber 42 formed on the opposite side of the oil mist. It is difficult to flow into the blow-by gas inlet 45. For this reason, the amount of oil entering the breather chamber 42 can be reduced even though a large amount of oil mist is formed in the valve operating chamber 4.

(Second Invention) In addition to the operation and effect of the first invention, the second invention is as shown in FIG. 1 (B).
It also exerts the following actions and effects. The oil mist that has floated around the breather chamber 42 is blocked by the peripheral side wall 46 of the breather chamber 42, and is prevented from flowing into the lower side wall of the breather chamber 47 having the blow-by gas inlet 45. Therefore, even though a large amount of oil mist is formed in the valve operating chamber 4, the breather chamber 4
The amount of oil that enters 2 can be reduced.

The oil mist that has floated up around the breather chamber 42 is blocked by the peripheral side wall 46 of the breather chamber 42, and the oil mist is blocked by the peripheral portion of the breather chamber 42 of the upper lid ceiling wall 34 and the surface of the peripheral side wall 46 of the breather chamber 42. Since the oil is condensed and drops on the arm pivot 9 and the valve interlocking arm 10 located below and enters the pivotal support portion 35 of the valve interlocking arm 10, the lubrication of each part is enhanced.

(Third Invention) In addition to the operation and effect of the first invention or the operation and effect of the second invention, the third invention has the following operation and effect as illustrated in FIG. Also plays. A part of the oil splashed up from the oil sump groove 15 toward the valve operating chamber lateral side wall 36 by the cam tops 7a of the valve operating cams 7 and 7a is bulged toward the valve operating cams 7 and 7. Since it collides with the exposed portions 37 and 37 at a high speed and disperses around them, the formation of oil mist is promoted and the lubrication of each portion is promoted.

Since the spark plugs 39, 39 or the fuel injection nozzles are housed in the recesses 38, 38 in the lateral wall 36 of the valve operating chamber, they do not project and the engine is made compact.

[0015]

Embodiments of the present invention will be described with reference to the drawings.
1 to 3 are diagrams illustrating an engine according to an embodiment of the present invention. The engine of this embodiment is a vertical overhead cam type water-cooled two-cylinder gasoline engine.

As shown in FIG. 1B, a cylinder head 1 of this engine is provided with a pair of valves 2.3 for intake and exhaust for each cylinder at the lower part thereof. The left side is the intake valve 2 and the right side is the exhaust valve 3. The pair of valves 2 and 3 are arranged so as to be distributed to the left and right, and are inclined so that the valve heads 2a and 3a face the center of the cylinder.

A valve operating chamber 4 is provided above the cylinder head 1. The valve operating chamber 4 is covered from the upper side by a bowl-shaped upper lid 18 assembled on the upper portion of the cylinder head 1. Then, as shown in FIG. 1A, the valve operating chamber 4 communicates with a crank chamber (not shown) via an oil flow passage 5. As shown in FIG. 2A, the oil flow-down passages 5 are provided at the four corners of the inner bottom of the valve operating chamber 4.

As shown in FIG. 1 (A), a valve operating cam shaft 8 having two pairs of valve operating cams 6 and 7 is horizontally installed in the lower portion of the valve operating chamber 4. This valve camshaft 8 is used for the front and rear journals 1
9 and 20 and a central journal portion 21, which are fitted in the front and rear bearing bosses 22 and 23 and the central bearing boss 24 provided in the valve operating chamber 4 to support the valve operating cam shaft 8. An arm pivot 9 that is parallel to the valve cam shaft 8 is laterally provided above the valve operating chamber 4. This arm pivot 9
Is the front and rear bearing bosses 22 and 23 and the central bearing boss 24.
It is fixed by bolting it above. Two pairs of valve interlocking arms 10 and 11 are swingably supported on the arm pivot 9.

As shown in FIG. 1B, the input end portions 10a and 11a of the valve interlocking arms 10 and 11 are connected to the valve cam 6 respectively.
・ Abutting against the cam surface of 7, each valve interlocking arm 10.1
The output ends 10b and 11b of 1 are brought into contact with the valve shaft input ends 2b and 3b of the valves 2 and 3, respectively.

In this embodiment, in order to sufficiently lubricate the cam surfaces of the valve operating cams 6 and 7 and the valve shaft input ends 2b and 3b, the following structure is adopted. That is, as shown in FIG. 1 (A), the oil pressure passage 13 communicating with the oil pump 12 is connected to the bearing sliding portions 14 of the valve camshaft 8.
Connected to. The oil pressure passage 13 has an oil discharge passage 26 led out from the discharge port 25 of the oil pump 12.
And a shaft passage 2 that is internally provided in series at the center of the valve camshaft 8.
7 and 7.

The oil discharge passage 26 is provided in the central journal portion 2.
It is connected to the bearing sliding portion 14 of the central bearing boss 24 so as to communicate with the ring groove 28 formed around the first bearing 1. And
An oil hole 29 is provided from the inner bottom of the ring groove 28 along the radial direction of the central journal portion 21, and the oil discharge passage 26 and the shaft passage 27 communicate with each other through the oil hole 29. Front and rear journals 19.2 are provided at both ends of the shaft passage 27.
An oil outlet hole 30 is provided along the radial direction of 0, and is connected to each bearing sliding portion 14 of the front and rear bearing bosses 22 and 23. Oil suction port 31 of the oil pump 12
Is immersed in the oil in the oil pan 32.

Further, as shown in FIG. 1 (A), an oil reservoir groove 15 is provided in the inner bottom of the valve operating chamber 4 between the adjacent bearing sliding portions 14, 14, and the oil reservoir groove 15 is formed. Part of the valve operating cams 6 and 7 is soaked in the oil 16 that has accumulated inside, and as shown in FIG. 1B, the cam surface is wetted by the oil 16 by the rotation 17 of the valve operating cam shaft 8. In addition, the oil 16 is splashed up by the cam tops 6a and 7a.

According to this structure, as shown in FIG. 1A, the oil in the oil pan 32 is transferred to the oil pump 1.
It is supplied to the ring groove 28 of the central journal portion 21 through the oil discharge passage 26 by the pressure feeding force of 2, and a part of it is supplied to the bearing sliding portion 14 of the central bearing boss 24 to lubricate it, and the rest is oil. The oil flows from the hole 29 into the shaft passage 27, is supplied from the oil outlet hole 30 to the bearing sliding portions 14 of the front and rear bearing bosses 22 and 23, and lubricates the bearing sliding portions 14. The oil leaked from each bearing sliding portion 14 is stored in the oil reservoir groove 15
1B, the cam tops 6a, 7
It is flipped up by a, becomes oil mist, and is supplied to the valve shaft input ends 2b and 3b. Therefore, the valve cam 6
7, the cam surface of 7 and the valve shaft input ends 2b and 3b are sufficiently lubricated, and the valve operating cams 6 and 7 and the valve interlocking arm 10 and 1
1. The service life of valves 2 and 3 can be extended.

Further, as shown in FIG. 1B, in this embodiment, the upper lid lateral side wall 33 located on the oil splashing side of the valve operating cams 6 and 7 stands in an inclined shape toward the arm pivot 9 side. The upper lid side wall 33 is lifted up and is continuous with the upper lid ceiling wall 34 above the arm pivot 9.

According to such a structure, the cam top 6a
Most of the oil mist formed by the splashing of 7a floats in the valve operating chamber 4 on the splashing side of the oil, and is guided from the side wall 33 of the upper lid to the ceiling wall 34 of the upper lid. For this reason, a large amount of oil mist drifts around the arm pivot 9, and oil droplets condensed on the surface of the upper lid ceiling wall 34 fall on the arm pivot 9 and the valve interlocking arms 10 and 11,
Since the oil penetrates into the pivotal support portion 35 of the valve interlocking arms 10 and 11, the pivotal support portion 35 of the valve interlocking arms 10 and 11 can be lubricated without providing an oil pressure passage on the arm pivot shaft 9. The structure of can be simplified.

Further, as shown in FIG. 1 (B), in this embodiment, the inner bottom surface of the oil sump groove 15 is formed by the valve cams 6 and 7.
The cam tops 6a and 7a are formed in an arc surface shape along the rotation locus. Therefore, the oil 16 accumulated in the oil sump groove 15 is splashed upward by the guide of the inner bottom surface of the arcuate surface, so that the oil mist is efficiently formed,
Lubrication of each part is promoted.

Further, in this embodiment, as shown in FIG.
As shown in (B), of the lateral wall 36 of the valve chamber located on the oil splashing side of the valve cams 6 and 7, the portions 37 and 37 facing the valve cams 7 and 7 partially move. Valve cam 7 ・ 7
Is formed in a bulge-like shape toward
The spark plugs 39, 39 are housed in the recesses 38, 38 formed in the lateral wall 36 of the valve chamber formed in FIG. Therefore, a part of the oil splashed up from the oil sump groove 15 toward the valve operating chamber side wall 36 by the cam tops 7a of the valve operating cams 7 is directed to the valve operating cams 7 7. The swollen portions 37, 37 collide with each other at a high speed and are dispersed around the swollen portions 37, so that the formation of oil mist is promoted and the lubrication of each part is promoted. Further, the spark plugs 39, 39 are attached to the side wall 3 of the valve operating chamber.
Since they are housed in the recesses 38, 38 of 6, the overhang of these is eliminated and the engine is made compact.

Further, in this embodiment, as shown in FIGS. 1 (A) and 2 (A), adjacent cylinders 40.
41 between the adjacent valve operating cams 6, 6, the valve operating chamber ceiling wall 34
1 is provided with a breather chamber 42, and as shown in FIG. 1B, a blow-by gas inlet 45 equipped with a reed valve 44 is provided at the breather chamber end 43 on the side opposite to the oil splashing side of the valve operating cams 6 and 7. 2 is provided, and a blow-by gas outlet 48 is provided on the oil splashing side, as shown in FIG. 2 (A). As shown in FIG. 3, the breather chamber 42 is formed by being surrounded by a peripheral side wall 46 vertically extending from the upper lid ceiling wall 34 of the upper lid 18 and a lower side wall 47 of the breather chamber attached below the peripheral side wall 46. Blow-by gas inlet 45 with reed valve 44
Is provided on the lower side wall 47 of the breather chamber. In the breather chamber 42, a plurality of detour guide walls 49 which are vertically provided from the upper lid ceiling wall 34 are provided.

With such a configuration, as shown in FIG. 1B, most of the oil mist formed by the flip-up of the cam tops 6a and 7a moves inside the valve operating chamber 4 on the oil flip-up side. Since it floats, it hardly flows into the blow-by gas inlet 45 of the breather chamber 42 formed on the opposite side. For this reason, the amount of oil entering the breather chamber 42 can be reduced even though a large amount of oil mist is formed in the valve operating chamber 4. The blow-by gas containing the oil mist flows in from the blow-by gas inlet 45,
Oil is separated by the reed valve 44. And FIG.
As shown in (A), the blow-by gas containing the unseparated oil mist is guided by the bypass guide wall 49.
It passes through the inside while meandering, and the detour guide wall 49 and the peripheral side wall 46
The oil mist that has not separated is condensed and removed from the blow-by gas.

In this embodiment, as shown in FIGS. 1 (A) and 2 (A), adjacent cylinders 40.
Between the valve interlocking arms 10 and 11 adjacent to each other 41, a peripheral side wall 46 of the breather chamber 42 is vertically provided from an upper lid ceiling wall 34 which constitutes a valve operating chamber ceiling wall. With such a configuration, the oil mist that has floated around the breather chamber 42 is blocked by the peripheral side wall 46 of the breather chamber 42 and flows into the lower side of the lower side wall of the breather chamber 47 having the blow-by gas inlet 45. Is hindered.

Therefore, although a large amount of oil mist is formed in the valve operating chamber 4, the amount of oil entering the breather chamber 42 can be reduced. Further, the oil mist that has floated around the breather chamber 42 is blocked by the peripheral side wall 46 of the breather chamber 42, and the breather chamber 4 of the upper lid ceiling wall 34 is blocked.
2 condenses on the peripheral portion and the surface of the peripheral side wall 46 of the breather chamber 42, and the oil droplets hang down on the arm pivot 9 and the valve interlocking arm 10 below and enter the pivotal support 35 of the valve interlocking arm 10. Lubrication of this portion is promoted.

Although the contents of the embodiment of the present invention are as described above, the contents of the present invention are not limited to the contents of the above embodiment. For example, the above embodiment has been described with respect to the vertical overhead cam type water-cooled two-cylinder gasoline engine, but the present invention can be applied to any vertical overhead cam type multi-cylinder engine. Therefore, oil-cooled and other liquid-cooled engines, air-cooled engines, multi-cylinder engines with three or more cylinders, gas engines,
It can also be applied to various types of engines such as diesel engines.

[Brief description of drawings]

1 is a diagram illustrating a valve operating chamber according to an embodiment of the present invention, and FIG.
FIG. 1A is a vertical cross-sectional side view of a cylinder head and a valve operating chamber upper lid, and FIG. 1B is a cross-sectional view taken along the line BB of FIG. 1A.

2 is a diagram illustrating a valve operating chamber according to an embodiment of the present invention, and FIG.
2A is a plan view of the cylinder head, and FIG.
It is a BB line sectional view of (A).

FIG. 3 is a diagram illustrating a breather chamber according to an embodiment of the present invention,
3 (A) is a bottom view of the valve operating chamber upper lid, FIG. 3 (B) is a bottom view of the breather chamber lower side wall, and FIG. 3 (C) is CC of FIG. 3 (B).
It is a line sectional view.

FIG. 4 is a view corresponding to FIG. 1 (B) of the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 2.3 ... Valve, 2b / 3b ... Valve shaft input end part, 4 ... Valve chamber, 5 ... Oil flow-down passage, 6
7 ... valve cam, 6a / 7a ... cam top, 8 ... valve cam shaft, 9 ... arm pivot, 10/11 ... valve interlocking arm, 10a / 11a ... input end, 10b / 11b ... output end, 15 ... Oil reservoir groove, 16 ... Oil, 34 ... Valve operating chamber ceiling wall, 40/41 ... Cylinder, 42 ... Breather chamber, 43
... Breather chamber end wall, 44 ... Reed valve, 45 ... Blow-by gas inlet, 46 ... Peripheral side wall.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location F02F 1/24 Q 8109-3G 7/00 P (72) Inventor Naoki Inoue Ishizukitamachi, Sakai City, Osaka Prefecture 64 Kubota Sakai Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A valve (2), (3) for intake and exhaust is attached to a lower portion of a cylinder head (1), and a valve operating chamber (4) is provided above the cylinder head (1). 4) communicating with the crank chamber through the oil flow passage (5), and a valve cam shaft having a plurality of valve cams (6) and (7) in the lower part of the valve chamber (4)
(8) is laid horizontally, and an arm pivot (9) parallel to the valve camshaft (8) is laid above the valve chamber (4), and a plurality of valve interlocking arms are attached to the arm pivot (9). The (10) and (11) pivotally support the input end of each valve interlocking arm (10) and (11).
(10a) and (11a) are brought into contact with the cam surfaces of the valve cams (6) and (7), and the output ends of the valve interlocking arms (10) and (11)
A vertical overhead cam type multi-cylinder engine configured by abutting (10b) and (11b) on the valve shaft input ends (2b) and (3b) of the valves (2) and (3). An oil sump groove (15) is provided on the inner bottom of the chamber (4), and the oil (16) accumulated in the oil sump groove (15) is transferred to the cam tops (6a) of the valve cams (6) and (7). ) ・ (7a) is configured to bounce up, and when viewed from above, adjacent cylinders (40) ・ (41)
Between the valve cams (6) and (6) adjacent to each other, the valve chamber ceiling wall (3
The breather chamber (42) is provided in 4), and the breather chamber end (43) on the side opposite to the oil splashing side of the valve cams (6) and (7) is
A vertical overhead cam type multi-cylinder engine having a blow-by gas inlet (45) equipped with a reed valve (44). 2. The vertical overhead cam type multi-cylinder engine according to claim 1, wherein adjacent cylinders (40) when viewed from above.
Between the valve interlocking arms (10) and (11) adjacent to each other (41), the peripheral side wall (46) of the breather chamber (42) is connected to the valve operating chamber ceiling wall.
A vertical overhead cam multi-cylinder engine characterized by being installed vertically from (34).