JPH0663449B2 - Cylinder head cooling structure - Google Patents

Description

The present invention relates to a cylinder head cooling structure for an engine.

[Prior Art] Generally, in an engine, various cooling structures are adopted in order to remove an adverse effect of heat generated in a combustion chamber and ensure an appropriate temperature condition.

These conventional cooling structures are roughly classified into an air cooling type cooling structure and a water cooling type cooling structure.

Among them, the air-cooled type has fins for heat dissipation standing on each surface of the cylinder block and cylinder head of the engine,
The cooling air passing through the surface of the fin is used to cool the engine.

In the water-cooled type, a water jacket is formed in each of a cylinder block and a cylinder head of the engine, and the engine is cooled by cooling water passing through the water jacket.

By the way, the air-cooling type cooling structure is extremely simple because it is sufficient to form the heat dissipation fins on the surfaces of the engine cylinder block and cylinder head, but on the other hand, it is difficult to uniformly cool the entire engine. Therefore, there is a drawback that temperature control is difficult and thermal deformation easily occurs in the cylinder block and the cylinder head, and that engine noise is increased due to resonance of the heat dissipation fins.

The water-cooled cooling structure can cool each part of the engine relatively uniformly, but the number of parts is large because parts such as radiators and fans must be placed, and a water jacket is installed on the cylinder block and cylinder head. Since it had to be formed, the manufacturing process was extremely complicated (manufacturing the core), resulting in an increase in the cost of the engine.

[Object of the Invention]

In view of the above-mentioned circumstances, an object of the present invention is to provide a cylinder head cooling structure having a simple structure and further improving the cooling efficiency around the combustion chamber formed in the cylinder head.

[Structure of Invention]

In order to achieve the above-mentioned object, in the present invention, an oil ejection port for injecting oil for engine lubrication is arranged in opposition to and close to an inner peripheral surface of a cylinder head formed in an upper portion of a combustion chamber, and an ejection port is ejected from the oil ejection port. In a cylinder head cooling structure configured to cool a cylinder head around a combustion chamber by the generated oil, an oil passage for supplying oil to the oil ejection port extends vertically upward from substantially the center of the combustion chamber. The boss for attaching the spark plug is formed.

[Action]

According to the above-described cylinder head cooling structure, since the oil ejection port is arranged close to the cylinder head inner peripheral surface in the upper part of the combustion chamber, the ejected oil vigorously reaches the cylinder head inner peripheral surface which is the cooling surface, and Since the oil passage for supplying the cooling oil to the ejection port is formed in the spark plug attachment boss of the cylinder head extending vertically upward from the substantial center of the combustion chamber, a special oil passage for forming the cooling oil passage is formed. No space is required, and the oil passage for the cooling oil can be easily formed.

〔Example〕

Hereinafter, an embodiment of the cylinder head cooling structure of the present invention will be described in detail.

3 and 4 are a top view and a bottom view of a cylinder head 10 to which the cylinder head cooling structure of the present invention is applied, particularly a parallel four-cylinder four-valve DO mounted on a motorcycle.
It shows a cylinder head of an HC (double overhead camshaft) type engine.

As shown in FIG. 3, on the exhaust port side (arrow A) and the inlet port side (arrow B) of the cylinder head 10, a camshaft (not shown) for driving rocker arms on the exhaust side and the inlet side, respectively. Bearing portions 12 and 14 are formed. Also, each of these bearings 12,14
In the lower portion of the rocker shaft, bearing portions of a rocker shaft (not shown) for supporting the rocker arms on the exhaust side and the inlet side, respectively, are formed.

On the other hand, the cylinder head 10 is provided on the peripheral surfaces of the bearings 12 and 14.
Lubricating oil ejection holes 16 that are pumped through an oil gallery (not shown) formed therein are formed.

Further, at the center of the surface of the cylinder head 10 shown in FIG. 3, recesses 20, 22, 24, 26, 28, 30 are formed along the longitudinal direction thereof. These recesses 20, 22, 24, 26, 28, 3
0 is formed in a portion located substantially above the combustion chambers 32, 34, 36, 38 shown in FIG. 4, and, as shown in FIG. 5 which is a front partially broken front view of the cylinder head 10, Each combustion chamber 32,3
Range including bore diameter of 4,36,38 (however, for each combustion chamber 32,34,36,
It is formed on a cylindrical spark plug mounting boss 40, 42, 44, 46 which extends vertically upward from substantially the center of 38). Therefore, the peripheral wall portion 20 of each of the recesses 20, ..., 30 described above
a, 22a, 24a, 26a, 28a and 30a are adjacent to the peripheral surfaces of the valve seat 50 supporting the exhaust valve and the valve seat 52 supporting the inlet valve as shown in FIG. 3 and shown in FIG. Thus, it is adjacent to the periphery of the plug seat 54 formed for each combustion chamber 32, 34, 36, 38. When oil for lubrication is jetted from the oil supply passage described later into the recesses 20, 22, 24, 26, 28, 30 formed in this way, the oil is injected into the recesses 20, 22, 24, 26, Since it temporarily stays in the combustion chambers 28,30, the oil that is injected and temporarily stays in the combustion chambers 32,3
The heat generated around 4,36,38 (Fig. 4) and around the valve seat 50 and the plug seat 54 is absorbed, and the cylinder head 10
Will be cooled.

On the other hand, as shown in FIG. 3, each of the above-mentioned recesses 20, 22, 24, 26,
Each of the peripheral portions 20a, 22a, 24a, 26a, 28a, 30a of 28, 30 temporarily discharges the oil supplied into the recess and then sequentially discharges the oil 60, 62, 64, 66, 68, 70,72,74 are formed,
Of these, the recesses 20, 24, 2 formed at the positions facing the left and right ends of the cylinder head 10 with the cam chain chamber 90 therebetween.
The discharge holes 60, 66, 68, 74 of 6, 30 communicate with the insertion holes 90, 92, 94, 96 of the stat bolt through the discharge passages 80, 82, 84, 86.

Therefore, the oil supplied to the recesses 20, 24, 26, 30 passes through the discharge holes 60, 66, 68, 74 and the discharge passages 80, 82, 84, 86, and the stud bolt insertion holes 90, 92, 94, It is discharged to 96 and is returned to the oil pan of the engine through the insertion holes 90, 92, 94 and 96.

On the other hand, the discharge holes 62, 64, 70, 72 of the recesses 22, 28 are the discharge passages.
The main discharge passages 110, 112 formed on the exhaust port side are communicated with each other via 100, 102, 104, 106. The main discharge passages 110, 112 are formed on the surface of the cylinder head 10 between the exhaust ports, as shown in FIG. Further, the discharge passages 100, 102, 104, 106 are formed adjacent to the peripheral surface of the exhaust port formed in the cylinder block. When exhausted to 110 and 112, the heat generated in the exhaust port is sucked and the exhaust port is cooled at the same time.

In addition to the discharge passages 100, 102, 104, 106 communicating with the recesses 22, 28, the main discharge passages 110, 112 have the same structure as shown in FIGS.
As shown in the figure, the cylinder head 10 above the exhaust port is in communication with the respective discharge passages 132, 134, 136, 138, 140, 142 having openings 120, 122, 124, 126, 128, 130, so that the oil flowing above the exhaust port of the cylinder head 10 is passed through the respective discharge passages 132, 134, 136, 138, 140. It is discharged into the main discharge passages 110 and 112. In FIG. 3, reference numerals 150, 152, 154, 156, 158, 160, 162 and 164 are through holes for stud bolts (not shown), and reference numerals 170, 172, 174 and 176 are flange portions formed on the upper portions of the spark plug mounting bosses 40, 42, 44 and 46, respectively.

Each of the flange portions 170, 172, 174, 176 is formed with a hole 180 which is a part of an oil supply passage described later for supplying oil into the recesses 20, 22, 24, 26, 28, 30. Further, in FIG. 4, reference numerals 190, 192, 194, 196 are holes formed below the exhaust ports 50, 52, 54, 56, respectively, and these holes 190, 192, 194, 196 correspond to the spark plug mounting bosses 40, 42, 44, 46 shown in FIG. It communicates with the inside. Also, the fifth
In FIG. 3 and FIG. 3, reference numerals 210, 212, 214, 216, 218, 220 respectively denote bosses that are erected in the recesses 20, 22, 24, 26, 28, 30. 214a, 216a, 218a, 220a (3rd
Figure) has been formed. This female thread 210a, 212a, 214a, 2
Reference numerals 16a, 218a, 220a denote female threads for mounting the plate-like lid 230 shown in the enlarged plan view of FIG. 6, and the outer shape of the lid 230 is approximately equal to that shown in FIG. The recesses 20, 22, 24 and the recesses 26, 28, which are formed symmetrically with respect to 90, are formed symmetrically.
30 and 30 are formed so as to cover them independently. It should be noted that this lid 230 is formed in a U-shaped cross section to increase its mechanical strength. In addition, a hole 232 for fitting a mounting bolt and a fitting hole 234 for a pipe forming an oil supply passage described later are formed in the lid 230. Therefore, when the cover 230 is mounted in the cylinder head 10 shown in FIG. 3, the recesses 20, 22, 24, 26, 28 are formed by the cover 230 as shown in the enlarged plan view of the main part of FIG. , 30
Will be blocked.

In this way, by covering the recess for storing oil with the lid 230, it is possible to prevent the injected oil from splashing out of the recess 20, 22, 24, 26, 28, 30 into the cylinder head 10. It will be. In FIG. 7, reference numeral 240 is a mounting bolt for the lid 230.

On the other hand, in the cylinder head 10 of the embodiment to which the present invention is applied, in order to prevent excess oil from adhering to the exhaust valve and the valve spring of this valve, the enlarged plan view of FIG. 8 and the side view of FIG. A plate-shaped valve spring seat 250 is used as shown in FIG. The valve spring seat 250 is formed with a plurality of holes 252 into which the valve guides are inserted, and the cross section thereof is formed in an L shape to increase the mechanical strength.

FIG. 10 is a plan view showing a state in which the valve spring seat 250 is mounted in the cylinder head 10, and the same parts as those in FIGS. 3 and 7 are designated by the same reference numerals. Note that this valve spring seat 250 is fixed to the valve seat by a valve spring (not shown), and since one plate is fitted into a plurality of valve guides at the same time, it is different from an ordinary disc-shaped valve spring seat. That is, the turning around is prevented.

Next, the recesses 20 formed in the cylinder head 10,
…, About the oil supply passage that supplies oil into 30
Detailed description.

11 and 12 are a top view and a bottom view of a cylinder head cover 260 that covers the cylinder head 10 shown in FIG. 3, respectively.

The cylinder head cover 260 is formed so as to cover the entire surface of the cylinder head 10 shown in FIG. 3, and a hole 262 for taking out blow-by gas is formed in the center thereof. Further, in the central longitudinal direction, insertion holes 270, 272, 274, 276 for the spark plug and the spark plug attaching / detaching tool are formed. In addition, on the peripheral surface of each of the insertion holes 270, 272, 274, 276, there is a guide groove 270a, 272a, 274a, 2 for the spark plug and a tool for attaching and detaching the spark plug.
76a are formed respectively.

On the other hand, on the bottom surface of the head cover 260, as shown in FIG. 12, oil supply passages 280 and 282 for guiding the oil pressure-fed from an oil supply device (not shown) to the central portion of the cylinder head cover 260 are formed. One end of each of the oil supply passages 280, 282 is a supply hole 290, 2 formed in the cylinder head cover 260 on the inlet port side.
The flange portion 270 formed in the insertion holes 270, 272, 274, 276 for attaching the spark plug is connected to each other.
b, 272b, 274b, 276b.

The flange portions 270b, 272b, 274b, 276b have insertion holes 310, 312, 314, 316, 318 for inserting bolts (described later) for fixing the cylinder head cover 260 to the cylinder head 10 (FIG. 3).
320, 322, 324 are formed respectively, and the other ends of the oil supply passages 280, 282 that branch off are the insertion holes 310, 31.
It communicates with 2,314,316,318,320,322,324. Therefore, as shown by the arrow, the oil supplied from the supply holes 290, 292 is guided to the insertion holes 310, 312, 314, 316, 318, 320, 322, 324 via the oil supply passages 280, 282, respectively. These insertion holes 310, 312, 314, 316, 318, 32
0, 322, 324 are formed at positions facing the holes 180 formed in the flange portions 170, 172, 174, 176 of the mounting bosses 40, 42, 44, 46 shown in FIG. 3, respectively. Note that FIG. 11 and FIG.
In FIG. 12, reference numeral 330 is an insertion hole for a fixing bolt for fixing the cylinder head cover 260 to the cylinder head 10 (FIG. 3).

On the other hand, the insertion holes 310, 312, 3 of the cylinder head cover 260
The oil guided to 14,316,318,320,322,324 is the cylinder head tightening bolt as shown in FIG. 13 which is an enlarged cross-sectional view of a main part of FIG. 1 showing a state where the cylinder head cover 260 is mounted on the cylinder head 10 and its DD cross-sectional view. An oil passage 342 formed in 340 and spark plug mounting bosses 40, 42, 4
Holes 180 formed in 4,46 flanges 170,172,174,176
Then, through the pipe 344 fitted in the hole 180, the fuel is injected into the recesses 20, 22, 24, 26, 28, 30 formed in the cylinder head 10.

That is, according to the above-mentioned configuration, the oil ejection ports 344a are the recesses 20, 22, 24, 26, 28, 30 which are the inner peripheral surfaces of the cylinder head.
Since the oil is jetted from the close position to the inner circumferential surface of the cylinder head, which is the cooling surface, the jetted oil vigorously reaches the cooling surface (bottom surface 400), The injected oil destroys the heat retaining layer of the oil staying on the bottom surface 400, and the injected oil is directly applied to the cylinder head inner peripheral surface 400 which is the cooling surface, so that the cylinder head is efficiently cooled. .

Further, according to the above-described configuration, the oil passage for supplying the oil to the oil ejection port 344a is provided with the flange portions 170, 172, 174, 176 of the spark plug mounting bosses 40, 42, 44, 46 extending vertically upward from substantially the center of the combustion chamber. Since it is formed as described above, it is not necessary to provide a special place for forming the oil passage for the cooling oil, and the oil passage for the cooling oil can be easily formed.

In the embodiment shown in FIG. 1, the flange portions 170, 172, 17
The oil supplied to the holes 180 of 4,176 is guided into the recesses 20, 22, 24, 26, 28, 30 through the pipe 344, but of course the same as in FIG. As shown in FIG. 2 in which parts are designated by the same reference numerals, spark plug mounting bosses 40, 42,
Replace the flanges 170, 172, 174, 176 of the 44, 46 with the recesses 20, 22, 2
The holes 500, which are oil passages, may be formed so as to extend so as to extend into the insides of the flanges 4,26,28,30.

The tightening bolt 340 of FIGS. 1 and 2 has a T-shaped oil passage 342 therein as shown in an enlarged partial sectional perspective view of the tightening bolt 340 shown in FIG. The oil that enters from the peripheral surface 340a of the bolt 340 is guided to the lower end of the bolt 340 as indicated by the arrow. In FIGS. 1 and 13, the same parts as those in FIGS. 3, 5, 7, 10 and 12 are designated by the same reference numerals.

On the other hand, the oil supplied into the recesses 20, 22, 24, 26, 28, 30 of the cylinder head 10 is, as described above, the recesses 20, 22, 2, 2.
Discharge holes, 60, 62, 64, 66, 68, 70, 72, 74 (Fig. 3) formed in the peripheral wall portions 20a, 22a, 24a, 26a, 28a, 30a of 4,26, 28, 30 , 96, or the main discharge passages 110, 112 through the stud bolt insertion holes, and then returned into the oil pan of the engine through an oil return passage (not shown).

Since the engine mounted on the motorcycle is mounted so as to be inclined forward in the normal traveling direction in order to reduce the height of the vehicle body as much as possible, as shown by the horizontal line EE in FIG. Is inclined so that the exhaust port side becomes lower, so that the oil discharged into the cylinder block after lubricating other sliding parts such as the camshaft, as well as the oil temporarily stored in the recess, Third
It flows to the discharge holes 120, 122, 124, 126, 128, 130 side shown in the figure, and is discharged into the main discharge passages 110, 112 through the discharge holes.

In the above embodiment, as shown in FIG.
The bottom surface 400 of the 2, 24, 26, 28, 30 is designed to be flat along the circumferential surface of the combustion chamber.
In order to increase the contact surface between the oil injected into 20,22,24,26,28,30 and temporarily stored and the bottom surface 400 to enhance the cooling effect by the oil, the same parts as in FIG. 3 are the same. As shown in the enlarged cross-sectional view of the main part of FIG.
May be finished into an uneven shape, and further, as shown in FIG. 16 which is a plan view of relevant parts of FIG. 15, the uneven shape may be given a specific directionality. When the direction is given to the oil, the oil supplied into the concave portion is smoothly guided to the discharge hole.

〔The invention's effect〕

As described above, according to the present invention, the oil ejection port for injecting the oil used for lubricating the engine is disposed close to the inner peripheral surface of the cylinder head which is the cooling surface of the upper portion of the combustion chamber so as to face the oil ejection port. Lubricating oil is sprayed from the outlet toward the inner peripheral surface of the cylinder head, so that the sprayed oil vigorously reaches the cooling surface, which enables efficient cooling of the cylinder head and supply of oil to the oil outlet. Since the oil passage to be installed is formed in the spark plug mounting boss of the cylinder head extending vertically upward from substantially the center of the combustion chamber, no special place for forming the cooling oil passage is required, so The structure of the oil passage for use is extremely simple, the manufacturing is easy, and the cooling oil passage can be provided at low cost, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a fragmentary sectional view of a cylinder head showing a cylinder head cooling structure of the present invention, FIG. 2 is a fragmentary sectional view of a cylinder head showing another embodiment, and FIG. A top view of the cylinder head, FIG. 4 is a bottom view of FIG. 3,
FIG. 5 is a partially cutaway front view of FIG. 3, FIG. 6 is an enlarged plan view of a lid, and FIG. 7 is an enlarged top view of a main part of a cylinder head with the lid attached, FIGS. 8 and 9. Is an enlarged top view of the valve spring seat and its side view, FIG. 10 is an enlarged top view of the main part of the cylinder head equipped with the valve spring seat, and FIGS. 11 and 12 are a top view of the cylinder head cover and its bottom surface. Fig. 13 is a sectional view taken along the line DD in Fig. 1, Fig. 14 is an enlarged partial sectional perspective view of a cylinder head tightening bolt, and Fig. 15 is a main part of a cylinder head showing another embodiment of a recess. FIG. 16 is a cross-sectional view, and FIG. 16 is a top view of a main part of FIG. 10 …… Cylinder head, 32, 34, 36, 38 …… Combustion chamber, 4
0, 42, 44, 46 ... Spark plug mounting boss, 344a ... Oil jet, 400 ... Cylinder head inner peripheral surface.

Claims (1)

[Claims] 1. An oil ejection port for injecting oil for engine lubrication is arranged to face and closely face an inner peripheral surface of a cylinder head formed in the upper portion of the combustion chamber, and the combustion chamber is surrounded by the oil ejected from the oil ejection port. In the cylinder head cooling structure for cooling the cylinder head, the oil passage for supplying oil to the oil ejection port is provided on a spark plug mounting boss of the cylinder head extending vertically upward from substantially the center of the combustion chamber. A cylinder head cooling structure characterized by being formed.