JP7144294B2 - Cylinder block - Google Patents

Description

The present invention relates to a cylinder block used in internal combustion engines for automobiles and the like.

In an internal combustion engine, the blow-by gas blown into the crank chamber is returned to the intake system via the PCV passage. is provided. Oil separation chambers are generally classified broadly into those provided in the cylinder block and those provided in the head cover.

When the oil separation chamber is provided in the cylinder block, it is formed on one longitudinal side of the cylinder block so as to open outward, and is closed with a lid to form a hollow structure. Strictly speaking, therefore, the oil separation chamber is composed of a body portion formed in the cylinder block and a lid fixed thereto, and one or both of the inner surface of the body portion and the inner surface of the lid is provided with oil. Ribs are formed to collect the mist.

Patent Document 1 discloses that a cooling water passage is formed in a lid (auxiliary equipment bracket) provided in an oil separation chamber for the purpose of preventing freezing of moisture contained in blow-by gas.

JP-A-2015-86701

Exchanging heat between the blow-by gas and the cooling water is effective in preventing freezing of the moisture contained in the blow-by gas by warming the blow-by gas with the cooling water in cold conditions. During operation in non-cold conditions such as the operation of , by promoting the condensation of the water contained in the blow-by gas, the bonding between water and oil is enhanced, and the oil mist collection effect is improved. Demonstrate.

If the oil separation chamber is placed in the upper part of the cylinder block, the temperature of the upper part of the cylinder block is high, so the temperature of the blow-by gas rises and the tendency of moisture to evaporate increases. It is beneficial to cool the blow-by gas with cooling water, as it is less likely to bond with

In Patent Document 1, it can be said that the ability to collect oil mist can be improved by the cooling effect of blow-by gas in non-cold conditions. It is understood that the effect of suppressing heat transfer from the cylinder block to the oil mist is poor, and the improvement of the oil mist collection effect is limited.

In addition, the piping structure of Patent Document 1 is complicated, and the increase in the number of parts not only greatly increases the cost, but also increases the weight and deteriorates the fuel consumption due to pressure loss in the flow of cooling water.

The present invention is made to improve such a situation.

The present invention relates to a cylinder block provided with an oil separation chamber for separating oil from blow-by gas on one longitudinal side extending in the longitudinal direction of the crank axis.
"A cooling water passage is formed in a part of a portion surrounding the oil separation chamber when viewed in a direction perpendicular to the crank axis and the cylinder axis, and is separated from the oil separation chamber by a partition wall, At least part of the partition wall is inclined with respect to the opening direction of the inlet of the cooling water passage."
It has a basic configuration. The "opening direction of the inlet of the cooling water passage" can be defined as a direction orthogonal to the opening surface of the inlet (perpendicular direction to the opening surface).

And the invention of claim 1, in the above basic configuration ,
"The inlet of the cooling water passage opens toward the cylinder head in the direction of the cylinder axis, while the partition wall is continuous with a long ceiling wall in a direction orthogonal to the cylinder axis and one end of the ceiling wall. and a side wall inclined with respect to the cylinder axis, and the ceiling wall and the side wall intersect at an obtuse angle.
It is configured.

In addition, the invention of claim 2 , in the above basic configuration ,
"The inlet of the cooling water passage opens toward the cylinder head in the direction of the cylinder axis, the outlet of the cooling water passage opens in the direction of the crank axis, and the outlet is for the water pump driven by the crank shaft. It is arranged almost concentrically with the axis of rotation.
It is configured.

In the invention of the present application, since the cooling water passage is built in the cylinder block, piping is unnecessary, which contributes to cost reduction and weight reduction. In addition, by suppressing the heat transfer from the cylinder block to the blow-by gas, it is possible to suppress the evaporation of the moisture contained in the blow-by gas. can improve.

Moreover, since the partition has an inclined portion, it is possible to greatly reduce the pressure loss while increasing the contact of the cooling water with the partition. Therefore, it is possible to improve the ability to collect oil mist by enhancing the cooling performance of blow-by gas while preventing deterioration of fuel consumption due to pressure loss. In addition, when operating in cold conditions, the blow-by gas can be warmed up by the cooling water, which is highly effective in preventing freezing.

As in claim 1 , when the partition is configured to have a ceiling wall and inclined side walls, the length of the partition can be increased as much as possible, and heat can be exchanged with the blow-by gas through the partition, so that the blow-by gas can be cooled. (warming in cold conditions) can be further improved.

Further, since the cooling water passage is formed outside the combustion chamber in the cylinder block, the cooling water filled in the cooling water passage can absorb vibrations. Therefore, it can contribute to engine noise suppression and noise suppression.

When the configuration of claim 2 is adopted, the cooling water discharged from the cooling water passage is directly sucked into the pump chamber of the water pump without changing the flow direction, thereby further reducing pressure loss and contributing to improved fuel efficiency. can.

It is the perspective view which looked at the cylinder block which concerns on embodiment from the front part. It is a top view of a cylinder block. It is a side view of a principal part. FIG. 3 is a vertical cross-sectional side view taken along line IV-IV of FIG. 2; FIG. 4 is a cutaway perspective view of a main part;

(1). Basic Structure Next, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the terms front and rear are used to specify the direction, and the front and rear direction is the direction of the crankshaft, and the side on which the timing chain is arranged is defined as the front. Just to make sure, the directions are clearly shown in FIGS. The vertical direction is the direction of the cylinder axis.

As shown in FIGS. 1 and 2, the cylinder block of this embodiment has three cylinders, and three bores 1 are formed side by side in the crank axial direction. When it is necessary to specify the individual bores 1, they are numbered 1, 2, and 3 from front to back. A group of bores 1 is surrounded by a loop-shaped water jacket 2 .

On the upper surface of the cylinder block, on the intake side and outside the water jacket 2, there is a longitudinal cooling water inlet 3 into which cooling water flows through the cylinder head, and a water pump 4 (see FIG. 2). ) and a water supply port 5 for sending the cooling water pressure-fed to the water jacket 2 are opened upward. The water supply port 5 is located in the front part of the water jacket 2, and the cooling water inlet 3 is formed at a position overlapping the two bores 1 of No. 1 and No. 2 in side view.

As shown in FIG. 2, a front cover 6 is fixed to the front surface of the cylinder block, and a housing of the water pump 4 is provided integrally with the front cover 6 . Therefore, the housing formed on the front cover 6 is in close contact with the pump mounting seat 7 (see FIG. 1) formed on the cylinder block.

The water pump 4 is of a centrifugal type in which cooling water flows into the pump chamber from the axial direction and is carried out in the outer peripheral direction. As shown in FIG. A concentric cooling water suction port 8 and a cooling water discharge port 9 located thereon are formed, and the cooling water discharge port 9 communicates with the water supply port 5 .

In the plan view of FIG. 2, the cooling water inlet 3 and the water supply port 5 are arranged in a straight line, but as shown in FIG. , the cooling water inlet 3 and the water supply port 5 can be aligned in a straight line in a plan view, and there is an advantage that the space can be effectively used.

The cooling water that has flowed into the water jacket 2 from the water supply port 5 splits into two, flows through the water jacket 2 in the circumferential direction, and flows upward into the communication hole 10 provided in the cylinder head at the rear of the water jacket 2. go. A gasket (not shown) is arranged between the cylinder head and the cylinder block, and the communication hole 10 is also formed in the gasket.

(2).Oil separation chamber and cooling water passage As shown in Fig. 1, an oil separator that removes oil mist from blow-by gas blown into the crankcase is installed on the intake side of the cylinder block (one longitudinal side). A chamber 11 is formed. The oil separation chamber 11 is formed so as to overlap the entire second bore 1 and about the rear half of the first bore 1 in side view, and as shown in FIGS. It overlaps with the cooling water inlet 3.

As shown in FIGS. 3 to 5, an upper end of a PCV lower passage 13 communicating with the crankcase opens in the lower portion of the oil separation chamber 11 . Further, as shown in FIG. 2, a lid 14 is fixed to the oil separation chamber 11 with bolts. A rib 15 is formed for this purpose.

As shown in FIG. 2, a PCV upper passage 16 is connected to the lid 14, and blow-by gas from which the oil mist is separated is sent to an intake system (for example, an intake manifold) via the PCV upper passage 16. Although not shown, a PCV valve is arranged in a portion of the PCV passage downstream of the oil separation chamber 11 . Note that the PCV valve may be provided in the oil separation chamber 11 .

The oil separation chamber 11 has a generally trapezoidal shape when viewed from the side, the vertical interval of which narrows upward, and includes a substantially horizontal ceiling wall 17 and a front side wall 18 and a rear side wall 19 that are continuous with the ceiling wall 17 . and the front and rear side walls 18, 19 are angled with respect to the bore axis. Therefore, the ceiling wall 17 and the front wall 18 are connected in a posture forming an obtuse angle when viewed from the side. As indicated by reference numeral 3a in FIG. 4, the opening direction of the cooling water inlet 3 is a direction orthogonal to the opening surface of the cooling water inlet 3. is consistent with

A cooling water return passage 20 for returning the cooling water from the cooling water inlet 3 to the water pump 4 is formed outside the ceiling wall 17 and the front wall 18 of the thick portion on the intake side of the cylinder block. It is formed so as to be separated from the front wall 18 . Therefore, the upper end of the cooling water return passage 20 serves as the cooling water inlet 3 , and the lower end of the cooling water return passage 20 serves as the cooling water outlet 21 communicating with the cooling water suction passage 8 of the water pump 4 . Roughly speaking, the cooling water return passage 20 is formed on the front side of the oil separation chamber 11 .

Due to such a relationship between the cooling water return passage 20 and the oil separation chamber 11, as indicated by the arrow in FIG. , changes direction in the horizontal direction and is sucked into the water pump 4 . A part of the cooling water that has flowed down to the cooling water inlet 3 hits the ceiling wall 17 forming the upper surface of the oil separation chamber 11, changes direction, and flows downward along the front wall 18. As shown in FIG. Also, part of the cooling water directly hits the front wall 18 and flows downward.

Part of the cooling water hits the ceiling wall 17, but the area of the ceiling wall 17 is small compared to the opening area of the cooling water inlet 3, and the ceiling wall 17 and the front wall 18 are connected at an obtuse angle. Therefore, the cooling water that has collided with the ceiling wall 17 is smoothly redirected downward by the front wall 18 . Further, since the front wall 18 and the cooling water suction passage 8 also intersect at an obtuse angle, the direction change from the cooling water return passage 20 to the cooling water suction passage 8 is also performed smoothly.

In this manner, the cooling water smoothly changes direction and flows from the cooling water inlet 3 to the cooling water suction passage 8, and cools the blow-by gas through the ceiling wall 17 and the front wall 18. - 特許庁Therefore, the ability to collect oil mist can be improved with almost no pressure loss due to the flow resistance of the cooling water.

Further, in the present embodiment, since the cooling water outlet 21 is positioned on the rotation axis of the water pump 4, the cooling water flowing into the cooling water outlet 21 flows straight toward the pump chamber of the water pump 4. . As a result, it is possible to further prevent pressure loss and contribute to an improvement in fuel efficiency.

As shown in FIG. 4, the circulation passage of the cylinder head is elongated in the crank axial direction. Flow into 20. Since the front wall 18 is inclined forward, the cooling water smoothly changes direction and passes through the cooling water return passage 20 . This is also an advantage of the sloped front wall 18 .

The present invention can be embodied in various forms other than the illustrated form. For example, when cooling water enters the cooling water passage from above as in the embodiment, a mode in which the ceiling wall 17 is not provided can also be adopted. Also, in the illustrated example, the cooling water passage is a passage through which the cooling water returns from the cylinder head to the water pump. Further, the cooling water passage may be configured such that the cooling water flows in the direction of the crank axis.

The present invention can be embodied in a cylinder block of an internal combustion engine. Therefore, it can be used industrially.

REFERENCE SIGNS LIST 1 bore 2 water jacket 3 cooling water inlet to cooling water return passage 4 water pump 5 water supply port to water jacket 6 front cover 7 pump mounting seat 8 cooling water suction passage for water pump 9 cooling water discharge port for water pump 11 Oil Separation Chamber 13 PCV Lower Passage 14 Lid 15 Rib 16 PCV Upper Passage 17 Ceiling Wall 18 Inclined Front Side Wall 20 Coolant Return Passage 21 Coolant Outlet of Coolant Return Passage

Claims (2)

A cylinder block provided with an oil separation chamber for separating oil from blow-by gas on one longitudinal side extending in the longitudinal direction of the crank axis,
A cooling water passage is formed in a part of a portion surrounding the oil separation chamber when viewed in a direction orthogonal to the crank axis and the cylinder axis so as to be separated from the oil separation chamber by a partition wall. In a configuration in which at least part of the partition wall is inclined with respect to the opening direction of the inlet of the cooling water passage,
The inlet of the cooling water passage opens toward the cylinder head in the direction of the cylinder axis,
The partition wall is composed of a ceiling wall elongated in a direction perpendicular to the cylinder axis and a side wall continuous with one end of the ceiling wall and inclined with respect to the cylinder axis. intersect at an obtuse angle,
Cylinder block. A cylinder block provided with an oil separation chamber for separating oil from blow-by gas on one longitudinal side extending in the longitudinal direction of the crank axis,
A cooling water passage is formed in a part of a portion surrounding the oil separation chamber when viewed in a direction orthogonal to the crank axis and the cylinder axis so as to be separated from the oil separation chamber by a partition wall. In a configuration in which at least part of the partition wall is inclined with respect to the opening direction of the inlet of the cooling water passage,
The cooling water passage has an inlet opening toward the cylinder head in the cylinder axis direction, and an outlet of the cooling water passage opening in the crank axis direction. It is arranged almost concentrically with the axis,
cylinder block.

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