Internal Combustion Engine

This application claims priority to Japanese Patent Application No. 2024-095879 filed on Jun. 13, 2024, incorporated herein by reference in its entirety.

The present disclosure relates to internal combustion engines.

As disclosed in Japanese Unexamined Patent Application Publication No. 2010-265861 (JP 2010-265861 A), an oil pan for storing oil is provided in a lower part of an internal combustion engine.

In order to increase the amount of oil that circulates in the internal combustion engine, it is necessary to increase the capacity of the oil pan. Increasing the capacity of the oil pan increases the size of an opening of the oil pan. As a result, the rigidity of the oil pan is reduced.

An internal combustion engine that solves the above issue includes:

The above internal combustion engine is advantageous in that the rigidity of the first oil pan can be increased.

Hereinafter, an embodiment of an internal combustion engine will be described with reference to.

As shown in, the internal combustion engineincludes a cylinder block, a cylinder head, and an oil pan. A plurality of cylindersis formed in the cylinder block. A piston is accommodated in the plurality of cylinders. A direction in which the plurality of cylindersis arranged is referred to as a “cylinder arrangement direction”. A direction in which the piston reciprocates in the cylinderis referred to as a “up-down direction X”. The up-down direction X is substantially perpendicular to the cylinder arrangement direction. In the up-down direction X, a moving direction in which the piston approaches the cylinder headis referred to as an “upward direction X”, and a direction opposite to the upward direction Xis referred to as a “downward direction X”.

The cylinder headis mounted on an upper part of the cylinder block. The oil panis mounted on a lower part of the cylinder block. That is, the cylinder head, the cylinder block, and the oil panare arranged in the up-down direction X.

As shown in, oil circulating in the internal combustion engineis stored in the oil pan. The oil panincludes an annular first oil panmounted on the cylinder block, and a second oil panmounted on a lower part of the first oil pan. The opening of the first oil panin the upward direction Xis closed by the cylinder block. The second oil panis mounted on the first oil panso as to close the opening in the downward direction Xof the first oil pan. The second oil panincludes a cylindrical portionand a bottom wallthat closes an opening in the downward direction Xof the cylindrical portion.

A crankshaft, which is an output shaft of the internal combustion engine, is provided in the first oil pan. For example, in the first oil pan, the crankshaftis disposed in the upward direction Xwith respect to the intermediate position in the up-down direction X. That is, the first oil panalso functions as a crankcase.

The internal combustion enginefurther includes a coolant pump, an oil cooler, and a coolant channel. The coolant pumpdischarges coolant circulating in the internal combustion engine. The coolant pumpis mounted on the cylinder block. A direction substantially perpendicular to the cylinder arrangement direction and the up-down direction X is referred to as a “reference direction Y”. At this time, the coolant pumpis mounted on one side in the reference direction Y of the cylinder block.

The oil cooleris installed on the opposite side of the cylinder blockfrom the coolant pump. That is, the oil panis positioned between the oil coolerand the coolant pump. The oil coolercools the oil by using the coolant discharged from the coolant pump.

The coolant channelis a channel for supplying the coolant discharged from the coolant pumpto the oil cooler. The coolant channelis configured to pass through the oil pan. Specifically, as shown in, the coolant channelincludes a coolant pipelocated closer to the second oil panthan the middle in the up-down direction X of the first oil pan. A long dashed double-short dashed line FG inis an imaginary line indicating the middle in the up-down direction X of the first oil pan. The coolant pipeextends in a prescribed direction crossing the up-down direction X. In the examples shown in, the prescribed direction coincides with the reference direction Y.

One of both ends of the coolant pipeis the first end, and the other end is the second end. Both the first endand the second endare fixed to the side wallof the first oil pan. For example, the coolant pipeis integral with the first oil pan.

is a schematic diagram illustrating a sectional shape of the oil panwhen the oil panis cut in an imaginary plane PH perpendicular to the cylinder arrangement direction. Oil flows into the oil panalong at least one flow path. The coolant pipeis set in a flow path. Therefore, the oil flowing along the flow pathcomes into contact with the coolant pipe.

(1) In the internal combustion engine, the coolant channelpasses through the first oil panin the reference direction Y. The coolant pipeconstituting the coolant channelextends in the reference direction Y, and the coolant pipeis disposed in the first oil pan. Both the first endand the second endof the coolant pipeare fixed to the side wallof the first oil pan. This increases the rigidity of the first oil pan.

Specifically, an upper part of the first oil panis mounted to the cylinder block. The cylinder blockis a rigid component. Therefore, by mounting the upper part of the first oil panto the cylinder block, the rigidity of the upper portion of the first oil pancan be secured.

On the other hand, a lower part of the first oil panis mounted to the second oil panhaving a lower rigidity than the cylinder block. Therefore, the rigidity of the lower part of the first oil pantends to be lower than the rigidity of the upper part of the first oil pan.

In this regard, in the internal combustion engine, the coolant pipeis located closer to the second oil panthan the middle in the up-down direction X of the first oil pan. Therefore, since the coolant pipeis disposed at such a position, the rigidity of the lower portion of the first oil panis increased.

Therefore, the internal combustion enginecan increase the rigidity of the first oil pan.

(2) The coolant pipeis installed in a flow pathof oil flowing into the oil pan. Thus, the coolant pipecan reduce the temperature of the oil flowing into the oil pan.

The above embodiment can be modified as follows. The above embodiment and the following modifications can be implemented in combination with each other as long as they are not technically contradictory.

Further, as shown in, the coolant pipemay be installed in a middle region in the cylinder arrangement direction Z of the first oil pan. For example, the middle region may be the middle portion in the case where the first oil panis equally divided into three in the cylinder arrangement direction. In the example illustrated in, the cylinder arrangement direction Z corresponds to a width direction perpendicular to both theup-down direction X and the reference direction Y. This increases the rigidity of the first oil pan.

It should be noted that the expression “at least one” as used herein means “one or more” of the desired options. As an example, the expression “at least one” as used herein means “only one option” or “both of two options” if the number of options is two. As another example, the expression “at least one” as used herein means “only one option” or “any combination of two or more options” if the number of options is three or more.