Patent Description:
Patent Document <NUM> discloses a technology to suppress the overall height, overall length, and overall width of an engine, thereby to make the engine more compact. Further the engine provided with a turbocharger is also known. In the above engine, a cool system is provided so as to prevent an excessive temperature increase in the turbocharger. For example, Patent Document <NUM> discloses a configuration in which a cool water flow channel is provided in a turbine housing of a turbocharger. Patent Document <NUM> discloses a technology to make the cool system of an engine more compact. In Patent Document <NUM>, a cool water pass unit that integrates a water pump that supplies cool water, a thermo-case that cases a thermostat, a gas-liquid separation chamber that separates air from the cool water, a cool water supply pass that supplies the cool water, which is returned from a radiator, via the thermo-case and the water pump to a water jacket, a cool water discharge pass that discharges the cool water, which passed through the water jacket, to the radiator, and a bypass that causes the cool water, which passed through the water jacket, to bypasses the radiator and to return to the thermo-case is so configured as to be collectively and detachably mounted to an engine body.

The turbocharger-provided engine disclosed in Patent Literature <NUM> is provided with a fresh water cooler that cools fresh water supplied into the engine, and a lubricant oil cooler that cools a lubricant oil. The fresh water cooler is placed on the opposite side of the engine output side in the cylinder head, and the lubricant oil cooler is placed directly below an exhaust manifold so that the longitudinal direction of the lubricant oil cooler is parallel to the longitudinal direction of the exhaust manifold. That is, the lubricant oil cooler is placed on the lateral side of the engine.

The configuration of Patent Document <NUM> is effective when the overall width of the engine is small relative to the overall length of the engine, as in the case of an in-line multi-cylinder engine, for example. However, since the lubricant oil cooler is placed on the lateral side of the engine, there is a concern that the application of the configuration of Patent Document <NUM> may result in an overly large overall width of the engine when the overall width of the engine is large relative to the overall length of the engine, as in the case of a V-type engine, for example. Further, there are concerns that, in a configuration of providing the turbocharger with a cool water flow channel, the configuration of the turbocharger will become more complex, and the manufacturing cost will be higher, for example. It is desirable to create a technology that can suppress an excessive temperature increase of the turbocharger while making it possible to suppress the engine configuration from being complicated. Further, the engine provided with two cylinder rows, such as V-type engine, for example, tends to have more components included in the cool liquid flow channel. Due to this, it is deemed cost effective to configure the cool liquid flow channel with fewer additional engine components.

An object of the present invention is to provide a technology preferable for an engine having an overall width likely to be large relative to an overall length of the engine, to provide a new technology that can prevent a turbocharger, which is provided in the engine, from becoming excessively hot, or to provide a technology that, in the engine provided with two cylinder rows, can configure a cool liquid flow channel while suppressing the number of components from being increased.

<CIT> discloses an engine according to the preamble of claim <NUM>.

An exemplary engine of the present invention includes: a cool liquid cooler that cools a first cool liquid that cools an engine block including a cylinder block and a head block; and a lubricant oil cooler that cools a lubricant oil using the first cool liquid or a second cool liquid. The cool liquid cooler and the lubricant oil cooler are so placed as to be arranged side by side on one end side in a crankshaft direction. The engine includes a gear case placed between the engine block, and the cool liquid cooler and/or the lubricant oil cooler; and the cool liquid cooler and/or the lubricant oil cooler is mounted to the gear case. Further, the exemplary engine is a liquid-cooled engine, including: the engine block including the cylinder block and the head block, an exhaust manifold mounted to the engine block, a turbocharger driven by exhaust gas from the exhaust manifold, an exhaust communication pipe that communicates the exhaust manifold with the turbocharger, and a cool liquid flow channel through which a cool liquid discharged from the engine block flows in an order of the exhaust communication pipe and the exhaust manifold. Further, the exemplary engine includes: two cylinder rows, a first cool liquid flow channel provided for one of the two cylinder rows, and a second cool liquid flow channel provided for another of the two cylinder rows, and a gear case in which a part of the first cool liquid flow channel and/or a part of the second cool liquid flow channel is provided.

The present invention can provide a technology preferable for an engine having an overall width likely to be large relative to an overall length of the engine, can prevent a turbocharger, which is provided in the engine, from becoming excessively hot, or in the engine provided with two cylinder rows, can configure a cool liquid flow channel while suppressing the number of components from being increased.

The following is a detailed description of an exemplary embodiment of the present invention with reference to the drawings. In the drawings, XYZ coordinate system is shown as the 3D Cartesian coordinate system, as appropriate. In the following description, X direction is defined as a front and back direction, Y direction is defined as a right and left direction, and Z direction is defined as an up and down direction. +X side is defined as a front side, and -X side is defined as a back side. +Y side is defined as a right side, and -Y side is defined as a left side. +Z side is defined as an up side, and -Z side is defined as a down side. In detail, the direction in which a center line C of a crankshaft (output shaft) shown in <FIG> extends is defined as the front and back direction, and the side where a flywheel <NUM> is placed relative to a cylinder block <NUM> is defined as the back side. The up and down direction is defined with the side, where an oil pan <NUM> is placed relative to the cylinder block <NUM>, as the down side. The direction orthogonal to the front and back and up and down directions is defined as the right and left direction, with the right side being the right side and the left side being the left side when viewed from the back toward the front. These directions are names merely used for an illustrative purpose, and are not intended to limit the actual positional relation and direction. In the present specification, the crankshaft direction is the same as the front and back direction in which the center line C of the crankshaft extends.

<FIG> is a schematic perspective view showing a configuration of an engine <NUM> according to an embodiment of the present invention. The engine <NUM> is preferable, for example, as a marine engine used for a ship. However, the engine <NUM> is not limited to the marine engine, and may be applied to any other application. The engine <NUM> is a diesel engine.

As shown in <FIG>, the engine <NUM> includes a cylinder block <NUM>, a head block <NUM>, and a head cover <NUM>. The cylinder block <NUM> and the head block <NUM> are included in the engine block (engine body). That is, the engine <NUM> is provided with an engine block. <FIG> is a schematic perspective view showing extracted a portion including the cylinder block <NUM>, the head block <NUM>, and the head cover <NUM> which are provided in the engine <NUM>. <FIG> shows a schematic cross-sectional view of the cylinder block <NUM> portion of the engine <NUM>.

As shown in <FIG> and <FIG>, a crankshaft <NUM>, which extends in the front and back direction, and a piston <NUM> are placed inside the cylinder block <NUM>. The inner portion of the cylinder block <NUM> connects to the inner portion of the oil pan <NUM> which is placed at the down side and stores a lubricant oil. A flywheel <NUM> (see <FIG>) is mounted to the back end of the crankshaft <NUM>. The flywheel <NUM> rotates integrally with the crankshaft <NUM>, and is used to take out power from the engine <NUM>. The piston <NUM>, in detail, is placed in the cylinder <NUM> formed in the cylinder block <NUM>. The piston <NUM> is connected to the crankshaft <NUM> via a connecting rod <NUM>.

In detail, the cylinder block <NUM> has a right cylinder 11R placed on the right side and a left cylinder <NUM> placed on the left side. The right cylinder 11R, when viewed from behind, is of a cylindrical shape which is tilted to the right relative to the up and down direction and extends in an oblique direction. The left cylinder <NUM>, when viewed from behind, is of a cylindrical shape which is tilted to the left relative to the up and down direction and extends in an oblique direction. The right cylinder 11R and the left cylinder <NUM> are placed in a V-shape. The pairwise right cylinder 11R and left cylinder <NUM> which are placed in the V-shape are placed with their cylinder axes slightly offset in the front and back direction. In the present embodiment, the left cylinder <NUM> is placed slightly forward of the right cylinder 11R.

The cylinder block <NUM> has a right cylinder row 111R with the multiple right cylinders 11R arranged in the front and back direction, and a left cylinder row <NUM> with the multiple left cylinders <NUM> arranged in the front and back direction. That is, the engine <NUM> has two cylinder rows 111R and <NUM>. Each of the two cylinder rows 111R and <NUM> extends a row in the direction of the crankshaft. The two cylinder rows 111R and <NUM> are so placed as to be arranged with each other. Further, the two cylinder rows 111R and <NUM> are arranged in the right and left direction in detail. The right cylinder row 111R and the left cylinder row <NUM> form a V-shaped bank. In the present embodiment, the number of right cylinders 11R included in the right cylinder row 111R and the number of left cylinders <NUM> included in the left cylinder row <NUM> are each six, as an example. That is, the engine <NUM> in the present embodiment is a V-type <NUM>-cylinder engine.

In each of the right and left cylinder rows 111R and <NUM>, the head block <NUM> is placed overlapping each cylinder <NUM>. The head block <NUM> is fastened to the cylinder block <NUM> by using a screw. In detail, the head block <NUM> includes a right head block 4R that overlaps the right cylinder 11R and a left head block <NUM> that overlaps the left cylinder <NUM>. Because one right head block 4R overlaps each right cylinder 11R, there are as many right head blocks 4R as there are right cylinders 11R. Because one left head block <NUM> is overlaps each left cylinder <NUM>, there are as many left head blocks <NUM> as there are left cylinders <NUM>. In the present embodiment, the number of right head blocks 4R and the number of left head blocks <NUM> are each six.

Each of the head blocks <NUM> has an intake port <NUM> to supply gas to a combustion chamber including the cylinder <NUM>, the piston <NUM>, and the head block <NUM>, and an exhaust port (not shown) to exhaust the gas from the combustion chamber. Further, the exhaust port is provided on the opposite face of the face where the intake port <NUM> is provided. In detail, the right head block 4R has the intake port <NUM> on the left lateral face and the exhaust port on the right lateral face. The left head block <NUM> has the intake port <NUM> on the right lateral face and the exhaust port on the left lateral face.

Each head block <NUM> is covered with the head cover <NUM>. The head cover <NUM> is fastened to the head block <NUM> by using a screw. Each head cover <NUM> covers intake and exhaust valves (not shown) placed at the head block <NUM>. An injector <NUM> is mounted on each head cover <NUM>. The injector <NUM>'s one end portion, where an injection port for injecting a fuel is provided, faces the combustion chamber. The injector <NUM>'s another end portion projects outward from the head cover <NUM>.

In detail, the head cover <NUM> includes a right head cover 5R that covers the right head block 4R and a left head cover <NUM> that covers the left head block <NUM>. The right head covers 5R, due to covering the respective right head blocks 4R, are the same in number as the right head blocks 4R. The left head covers <NUM>, due to covering the respective left head blocks <NUM>, are the same in number as the left head blocks <NUM>. In the present embodiment, the number of right head cover 5R and the number of left head cover <NUM> are each six. Also, the number of right injectors 8R placed at the right head cover 5R and the number of left injectors <NUM> placed at the left head cover <NUM> are each six.

On the right side of cylinder block <NUM>, the right cylinder 11R, the right head block 4R and the right head cover 5R, which are included in a right bank RB, extend diagonally upward to the right. On the left side of cylinder block <NUM>, the left cylinder <NUM>, the left head block <NUM>, and the left head cover <NUM>, which are included in a left bank LB, extend diagonally upward to the left. In plan view from the front and back direction, a combination of the right bank RB and the left bank LB is V-shaped, and the engine <NUM> has a V-bank. An intra-bank area <NUM> is formed between the right bank RB and the left bank LB in the right and left direction.

Returning to <FIG>, the engine <NUM> has an upper face cover <NUM> and a lateral face cover <NUM>. The upper face cover <NUM> suppresses water from splashing, due to condensation, for example, onto a controller <NUM> (see <FIG>, etc., below) and the like placed inside. The lateral face cover <NUM> suppresses the fuel from splashing due to a crack, etc. in a component part such as the head block <NUM>, for example. Although <FIG> shows only the lateral face cover <NUM> placed on the right lateral face, a similar lateral face cover <NUM> is also placed on the left lateral face. That is, the engine <NUM> is provided with a pair of right and left lateral face covers <NUM>.

<FIG> is a schematic top view showing the configuration of the engine <NUM> according to the embodiment of the present invention. In <FIG>, the upper face cover <NUM> and the pair of lateral face covers <NUM> are omitted. As shown in <FIG> and <FIG>, the engine <NUM> includes an intake manifold <NUM> and an exhaust manifold <NUM>. The intake manifold <NUM> and the exhaust manifold <NUM> are mounted to the engine block (head block <NUM> in detail).

To each of the cylinders <NUM>, the intake manifold <NUM> distributes intake air which is air or mixture air taken in from the outside. The intake manifold <NUM> is placed at an upper portion of the engine <NUM>, and extends in the front and back direction. In detail, the intake manifold <NUM> includes a right intake manifold 21R for the right cylinder 11R, and a left intake manifold <NUM> for the left cylinder <NUM>. That is, the engine <NUM> has two intake manifolds 21R and <NUM>.

The right intake manifold 21R is placed above the respective intake ports <NUM> (see <FIG>) of the multiple right head blocks 4R which are arranged in the front and back direction. The inner portion of the right intake manifold 21R and the respective right cylinders 11R are connected via the respective intake ports <NUM>. The left intake manifold <NUM> is placed above the respective intake ports <NUM> of the multiple left head blocks <NUM> which are arranged in the front and back direction. The inner portion of the left intake manifold <NUM> and the respective left cylinders <NUM> are connected via the respective intake ports <NUM>.

In detail, an intake valve (not shown) is interposed between each intake port <NUM> and each cylinder <NUM>; when the intake valve is open, the inner portion of intake manifold <NUM> and cylinder <NUM> are communicated.

The exhaust manifold <NUM> collects the exhaust air from the respective cylinders <NUM>. The exhaust manifold <NUM> is placed at the lateral face portion of the engine <NUM>, and extends in the front and back direction. In detail, the exhaust manifold <NUM> includes a right exhaust manifold 22R for the right cylinder 11R, and a left exhaust manifold <NUM> for the left cylinder <NUM>.

The right exhaust manifold 22R is placed on the right side of the multiple right head blocks 4R (see <FIG>) which are arranged in the front and back direction. The inner portion of the right exhaust manifold 22R and the respective right cylinders 11R are connected via exhaust ports (not shown) provided on the right side of the right head blocks 4R. The left exhaust manifold <NUM> is placed on the left side of the multiple left head blocks <NUM> (see <FIG>) which are arranged in the front and back direction. The inner portion of the left exhaust manifold <NUM> and the respective left cylinders <NUM> are connected via the exhaust ports (not shown) provided on the left side of the left head blocks <NUM>.

In detail, an exhaust valve (not shown) is interposed between each exhaust port and each cylinder <NUM>; when the exhaust valve is open, the inner portion of the exhaust manifold <NUM> and the cylinder <NUM> are communicated.

The exhaust gas collected at the right exhaust manifold 22R is exhausted to the outside via the right turbocharger 23R and the right exhaust outlet pipe 24R which are each placed at the right back of the engine <NUM>. The exhaust gas collected at the left exhaust manifold <NUM> is exhausted to the outside via the left turbocharger <NUM> and the left exhaust outlet pipe <NUM> which are each placed at the left back of the engine <NUM>.

The right turbocharger 23R and the left turbocharger <NUM> each have a compressor unit <NUM> and a turbine unit <NUM>. The compressor unit <NUM> pressurizes and compresses intake air such as air supplied from outside the engine <NUM>. The pressurized and compressed intake air is supplied via an intercooler <NUM> to the intake manifold <NUM>. The turbine unit <NUM> is rotated by the exhaust gas supplied from the exhaust manifold <NUM>. The rotary power of the turbine unit <NUM> is transmitted to the compressor unit <NUM>. That is, the right turbocharger 23R and left turbocharger <NUM> in the present embodiment are so-called turbochargers that are driven by an exhaust gas turbine. The engine <NUM> is provided with a turbocharger <NUM> driven by the exhaust gas from the exhaust manifold <NUM>.

The intercooler <NUM>, which is connected with the intake manifold <NUM>, is supplied with cool water by a cool water pump (not shown), thereby to cool the intake air. The intake air supplied from the compressor unit <NUM> is pressurized and compressed, thereby to generate a compression heat and to be increased in temperature. The intercooler <NUM> performs heat exchange between the cool water, which is supplied by the cool water pump, and the pressurized compressed intake air, thereby to cool the intake air. That is, providing the intercooler <NUM> allows the temperature of the intake air, which is supplied to the intake manifold <NUM>, to be adjusted to a desired temperature.

As shown in <FIG>, the right intake manifold 21R and the left intake manifold <NUM> are spaced apart and arranged in the right and left direction at the upper portion of the engine <NUM>. As shown in <FIG>, with the upper face cover <NUM> removed, the intra-bank area <NUM> is exposed to the outside via a space between the right intake manifold 21R and the left intake manifold <NUM>. In the intra-bank area <NUM>, there are placed, for example, the controller <NUM> that controls the entire engine <NUM>, and a fuel pump <NUM> that supplies the fuel to the injector <NUM>.

That is, the engine <NUM> includes the controller <NUM> placed in the intra-bank area <NUM> positioned between the right and left cylinder rows 111R and <NUM>. Also, the engine <NUM> includes the fuel pump <NUM> placed in the intra-bank area <NUM>. The intra-bank area <NUM> may be, in a strict sense, a space area between the right and left cylinder rows 111R and <NUM>. In the present embodiment, however, the intra-bank area <NUM> widely includes the space area in the right and left direction between the right bank RB which includes the right cylinder row 111R, and the left bank LB which includes the left cylinder row <NUM>.

Creating the configuration to place the controller <NUM> and the fuel pump <NUM> in the intra-bank area <NUM> can efficiently use the intra-bank area <NUM> for placing the component part. This makes it possible to downsize the engine <NUM>. However, the controller <NUM> and the fuel pump <NUM> may be placed outside of the intra-bank area <NUM>.

Further, the controller <NUM> includes, in detail, a first controller <NUM> and a second controller <NUM>. However, the number of controllers <NUM> may be changed as needed; for example, the controller <NUM> may include only one controller. In the present embodiment, the first controller <NUM> and the second controller <NUM> are arranged in the front and back direction (crankshaft direction). In detail, the first controller <NUM> is placed forward of the second controller <NUM>. Any one of the first controller <NUM> and the second controller <NUM> is a main controller and another thereof is a sub-controller. In the present embodiment, the first controller <NUM> is the main controller, and the second controller <NUM> is the sub-controller.

The first controller <NUM> configured as the main controller executes a calculation necessary to control the engine <NUM>. The calculations required to control the engine <NUM> include, for example, a calculation related to the control of fuel injection and a calculation related to stopping the engine <NUM>. The second controller <NUM> which is configured as the sub-controller is connected with the first controller <NUM> by a communication line (not shown), and is so provided as to be capable of communicating with the first controller <NUM>. The second controller <NUM> executes a control operation according to an instruction from the first controller <NUM>.

The first controller <NUM> controls the right injector 8R placed at the right bank RB. That is, the first controller <NUM> and each right injector 8R are electrically connected. Further, the second controller <NUM> controls the left injector <NUM> placed at the left bank LB. That is, the second controller <NUM> and each left injector <NUM> are electrically connected.

Further, the fuel pump <NUM> discharges the fuel, which is at a high pressure, toward a high pressure fuel pipe (not shown) for the right bank RB and a high pressure fuel pipe (not shown) for the left bank LB. The fuel passing through the high-pressure fuel pipe for the right bank RB is distributed to each of the right injectors 8R placed at the right bank RB. The fuel passing through the high-pressure fuel pipe for the left bank LB is distributed to each of the left injectors <NUM> placed at the left bank LB. Under control by the controller <NUM>, each of the injectors <NUM> injects the fuel to the combustion chamber.

The engine <NUM> in the present embodiment is a liquid-cooled engine. The engine <NUM> is provided with a cool liquid flow channel <NUM> (see <FIG> below) that flows a cool liquid which cools the cylinder block <NUM> included in the engine block and also cools each of the multiple head blocks <NUM> included in the engine block. The cool liquid in the present embodiment is cool water. However, the cool liquid may be a liquid other than water, such as antifreeze, for example. Antifreeze is, for example, a liquid mixture of pure water and ethylene glycol in a given ratio.

<FIG> is a diagram showing the schematic configuration of the cool liquid flow channel <NUM> provided in the engine <NUM> according to the embodiment of the present invention. In the present embodiment, the cool liquid flow channel <NUM> includes a first cool liquid flow channel 50R and a second cool liquid flow channel <NUM>. That is, the engine <NUM> is provided with the first cool liquid flow channel 50R and the second cool liquid flow channel <NUM>. The first cool liquid flow channel 50R is provided for one of the two cylinder rows 111R and <NUM>. The second cool liquid flow channel <NUM> is provided for the other of the two cylinder rows 111R and <NUM>. In detail, the first cool liquid flow channel 50R is a cool liquid flow channel provided for the right cylinder row 111R. The second cool liquid flow channel <NUM> is a cool liquid flow channel provided for the left cylinder row <NUM>.

The first cool liquid flow channel 50R includes a right cylinder row-dedicated cool liquid flow channel 51R and a shared cool liquid flow channel <NUM>. The second cool liquid flow channel <NUM> includes a left cylinder row-dedicated cool liquid flow channel <NUM> and the shared cool liquid flow channel <NUM>. The shared cool liquid flow channel <NUM> is a cool liquid flow channel shared by both the first cool liquid flow channel 50R and the second cool liquid flow channel <NUM>.

As shown in <FIG>, the shared cool liquid flow channel <NUM> includes a cool liquid pump <NUM>, a cool liquid cooler <NUM>, a lubricant oil cooler <NUM>, and a thermostat case <NUM> that cases a thermostat <NUM>. <FIG> is a schematic front view of the configuration of the engine <NUM> according to the embodiment of the present invention. <FIG> shows the engine <NUM> viewed from the front toward the back. As shown in <FIG>, the cool liquid pump <NUM>, the cool liquid cooler <NUM>, the lubricant oil cooler <NUM>, and the thermostat case <NUM> are placed at the front end portion of the engine <NUM>.

The cool liquid pump <NUM> circulates the cool liquid in the cool liquid flow channel <NUM>. The cool liquid pump <NUM> is driven by rotational power sent from the crankshaft <NUM> via a gear (not shown). In the present embodiment, the cool liquid pump <NUM> is a cool water pump.

The cool liquid cooler <NUM> cools the cool liquid circulating in the cool liquid flow channel <NUM>. In the present embodiment, the cool liquid cooler <NUM> is a fresh water cooler. The cool liquid cooler <NUM>, by using heat exchange with seawater pumped by drive of a seawater pump <NUM>, cools the cool liquid circulating in the cool liquid flow channel <NUM>. Further, the seawater pump <NUM> is placed in the front end portion of the engine <NUM>. The seawater pump <NUM> is driven by rotational power sent from the crankshaft <NUM> via the gear (not shown). Further, in the present embodiment, the seawater pumped by the seawater pump <NUM> is sent to the intercooler <NUM> and then to the cool liquid cooler <NUM>, to be discharged to the outside (sea). That is, the seawater pump <NUM> is an example of a cool water pump that supplies the cool water to the above intercooler <NUM>.

The lubricant oil cooler <NUM> cools the lubricant oil. Driving the lubricant oil pump (not shown) supplies the lubricant oil from the oil pan <NUM> to each part of the engine <NUM>, and returns the lubricant oil to the oil pan <NUM>. The lubricant oil cooler <NUM> is included also in the lubricant oil flow channel. Using the cool liquid flowing in the cool liquid flow channel <NUM>, the lubricant oil cooler <NUM> cools the lubricant oil. Further, the lubricant oil pump is driven by rotational power sent from the crankshaft <NUM> via the gear (not shown).

The thermostat case <NUM> covers the thermostat <NUM> placed at the cool liquid cooler <NUM>, and is included in the cool liquid flow channel <NUM>. The thermostat <NUM> has a function to keep the temperature of the cool liquid near a set temperature. The function of the thermostat <NUM> sends the cool liquid, which needs to be cooled, to the cool liquid cooler <NUM>.

The cool liquid discharged from the cool liquid pump <NUM> is sent to the right cylinder row-dedicated cool liquid flow channel 51R and the left cylinder row-dedicated cool liquid flow channel <NUM>, respectively. The cool liquids that respectively pass through the right cylinder row-dedicated cool liquid flow channel 51R and the left cylinder row-dedicated cool liquid flow channel <NUM> are sent to the thermostat case <NUM> which cases the thermostat <NUM>. In the cool liquids sent to the thermostat case <NUM>, there is a cool liquid that is sent to the cool liquid cooler <NUM> by the action of the thermostat <NUM>, and a cool liquid that, without being sent to the cool liquid cooler <NUM>, returns to the cool liquid pump <NUM>. The cool liquid sent to the cool liquid cooler <NUM> is cooled by a heat exchange unit <NUM> (see <FIG>) of the cool liquid cooler <NUM>, and is sent to a cool liquid tank <NUM> (see <FIG>) of the cool liquid cooler <NUM>. The cool liquid tanked in the cool liquid tank <NUM> is sent to the cool liquid pump <NUM> as appropriate. Further, a part of the cool liquid sent to the cool liquid cooler <NUM> returns via the lubricant oil cooler <NUM> to the cool liquid pump <NUM>.

<FIG> is a schematic perspective view of components included in a part of each of the right cylinder row-dedicated cool liquid flow channel 51R and the left cylinder row-dedicated cool liquid flow channel <NUM>. In <FIG>, a white arrow shows the cool liquid flow. As shown in <FIG>, the components included in the right cylinder row-dedicated cool liquid flow channel 51R include the right exhaust manifold 22R, a right cool liquid collection pipe 28R, and a right exhaust communication pipe 29R. The components included in the left cylinder row-dedicated cool liquid flow channel <NUM> include the left exhaust manifold <NUM>, a left cool liquid collection pipe <NUM>, and a left exhaust communication pipe <NUM>.

The right exhaust manifold 22R and the left exhaust manifold <NUM> are each cylindrical in shape, extending in the front and back direction. <FIG> is a schematic cross sectional perspective view of a cross section taken along the line VIII-VIII shown in <FIG>. In <FIG>, a thick arrow shows the cool liquid flow. As shown in <FIG>, the inner portion of each of the right exhaust manifold 22R and the left exhaust manifold <NUM> has an intra-manifold exhaust pipe <NUM> that communicates with an exhaust gas inlet <NUM> provided on the lateral side on the inside. Further, the plural exhaust gas inlets <NUM>, in each of the exhaust manifolds 22R, <NUM>, are so provided as to be arranged side by side in the front and back direction, and each of the plural exhaust gas inlets <NUM> communicates to an exhaust port provided in one of the head blocks <NUM>. In each of the right and left exhaust manifolds 22R and <NUM>, the cool liquid flows through an inner space SP1 of one of the respective exhaust manifolds 22R and <NUM>. In detail, the cool liquid flows around the intra-manifold exhaust pipe <NUM> placed in the inner space SP1.

The right cool liquid collection pipe 28R and the left cool liquid collection pipe <NUM> are each cylindrical, extending in the front and back direction. The right cool liquid collection pipe 28R is placed alongside the right exhaust manifold 22R, and is mounted to the right exhaust manifold 22R. The right cool liquid collection pipe 28R is placed diagonally to the right of the right exhaust manifold 22R. The left cool liquid collection pipe <NUM> is placed alongside the left exhaust manifold <NUM>, and is mounted to the left exhaust manifold <NUM>. The left cool liquid collection pipe <NUM> is placed diagonally to the left of the left exhaust manifold <NUM>.

A plurality of cool liquid holes <NUM> is provided on the lateral side on the inside of each of the right cool liquid collection pipe 28R and the left cool liquid collection pipe <NUM>. In each of the cool liquid collection pipes 28R, <NUM>, the same number of cool liquid holes <NUM> as the number of cylinders (cylinders) included in one of the respective cylinder rows 111R, <NUM> are so placed as to be spaced apart in the front and back direction. In the present embodiment, the number of cool liquid holes <NUM> in each of the cool liquid collection pipes 28R, <NUM> is six.

A cool liquid pipe (not shown) connects each of the cool liquid holes <NUM> to a cool liquid flow channel provided in each of the head blocks <NUM>. The cool liquid discharged from the cool liquid pipe that connects to the cool liquid flow channel of each of the head blocks <NUM> included in the right bank RB flows via one of the cool liquid holes <NUM> into an inner space SP2 of the right cool liquid collection pipe 28R. The cool liquid discharged from the cool liquid pipe that connects to the cool liquid flow channel of each of the head blocks <NUM> included in the left bank LB flows via one of the cool liquid holes <NUM> into the inner space SP2 of the left cool liquid collection pipe <NUM>.

As shown in <FIG>, the right exhaust communication pipe 29R is connected to the back end of the right exhaust manifold 22R. The left exhaust communication pipe <NUM> is connected to the back end of the left exhaust manifold <NUM>. As shown in <FIG>, the right exhaust communication pipe 29R is connected to the turbine unit <NUM> of the right turbocharger 23R. The left exhaust communication pipe <NUM> is connected to the turbine unit <NUM> of the left turbocharger <NUM>. In other words, the right exhaust communication pipe 29R connects the right exhaust manifold 22R with the right turbocharger 23R. The left exhaust communication pipe <NUM> connects the left exhaust manifold <NUM> with the left turbocharger <NUM>. That is, the engine <NUM> is provided with an exhaust communication pipe <NUM> that connects the exhaust manifold <NUM> with the turbocharger <NUM>.

<FIG> is a schematic perspective view of a configuration of the right exhaust communication pipe 29R provided in the engine <NUM> according to the embodiment of the present invention. In <FIG>, a thick arrow shows the cool liquid flow. Further, the left exhaust communication pipe <NUM> is the same in main configuration as the right exhaust communication pipe 29R. Due to this, the configuration of the exhaust communication pipe <NUM> is to be described with the right exhaust communication pipe 29R as a typical example.

As shown in <FIG>, the inner portion of the right exhaust communication pipe 29R has a space SP3. In this inner space SP3, an intra-communication pipe exhaust pipe <NUM> through which the exhaust gas passes is placed. On the front face of the right exhaust communication pipe 29R, an exhaust inlet <NUM> that connects to one end of the intra-communication pipe exhaust pipe <NUM> is provided. In a state of the right exhaust communication pipe 29R being connected to the right exhaust manifold 22R, the intra-communication pipe exhaust pipe <NUM> and the intra-manifold exhaust pipe <NUM> communicate with each other.

Further, the right exhaust communication pipe 29R is provided with an exhaust outlet <NUM> that connects to the other end of the intra-communication pipe exhaust pipe <NUM>. In a state of the right exhaust communication pipe 29R being connected to the turbine unit <NUM> of the right turbocharger 23R, the intra-communication pipe exhaust pipe <NUM> and the inner portion of the turbine unit <NUM> communicate with each other. That is, the exhaust gas from each combustion chamber of the right bank RB is sent to the turbine unit <NUM> of the right turbocharger 23R through the intra-manifold exhaust pipe <NUM> of the right exhaust manifold 22R and the intra-communication pipe exhaust pipe <NUM> of the right exhaust communication pipe 29R. Similarly, the exhaust gas from each combustion chamber of the left bank LB is sent to the turbine unit <NUM> of the left turbocharger <NUM> through the intra-manifold exhaust pipe <NUM> of the left exhaust manifold <NUM> and the intra-communication pipe exhaust pipe <NUM> of the left exhaust communication pipe <NUM>.

As shown in <FIG>, the right exhaust communication pipe 29R is provided with a cool liquid inlet <NUM> which is an inlet for the cool liquid. In detail, the cool liquid inlet <NUM> is placed on the right side of the right exhaust communication pipe 29R. However, the place where the cool liquid inlet <NUM> is provided may be changed as needed. As shown in <FIG>, the cool liquid inlet <NUM> communicates via a cool liquid communication pipe <NUM> with the inner space SP2 of the right cool liquid collection pipe 28R. Further, on the front face of the right exhaust communication pipe 29R, a cool liquid outlet <NUM> which is the outlet for the liquid water is provided. In a state of the right exhaust communication pipe 29R being connected to the right exhaust manifold 22R, the cool liquid outlet <NUM> communicates with the inner space SP1 of the right exhaust manifold 22R.

In the right exhaust communication pipe 29R, the cool liquid entering the inner space SP3 from the cool liquid inlet <NUM> flows around the intra-communication pipe exhaust pipe <NUM>, to be discharged from the cool liquid outlet <NUM>. Similarly, in the left exhaust communication pipe <NUM>, the cool liquid entering the inner space SP3 from the cool liquid inlet <NUM> flows around the intra-communication pipe exhaust pipe <NUM>, to be discharged from the cool liquid outlet <NUM>.

The cool liquid discharged from the cool liquid pump <NUM> and flowing in the right cylinder row-dedicated cool liquid flow channel 51R is sent to the cool liquid flow channel for the right cylinder row 111R provided in the cylinder block <NUM> and in each of the head blocks <NUM> included in the right bank RB. As shown by the white arrow in <FIG>, the cool liquid discharged from each of the head blocks <NUM> included in the right bank RB flows through in the order of the right exhaust communication pipe 29R and the right exhaust manifold 22R.

Further, the cool liquid discharged from the cool liquid pump <NUM> and flowing in the left cylinder row-dedicated cool liquid flow channel <NUM> is sent to the cool liquid flow channel for the left cylinder row <NUM> provided in the cylinder block <NUM> and in each of the head blocks <NUM> included in the left bank LB. As shown by the white arrow in <FIG>, the cool liquid discharged from each of the head blocks <NUM> included in the left bank LB flows through in the order of the left exhaust communication pipe <NUM> and the left exhaust manifold <NUM>.

That is, in the present embodiment, the engine <NUM> is provided with the cool liquid flow channel <NUM> through which the cool liquid discharged from the engine block flows through in the order of the exhaust communication pipe <NUM> and the exhaust manifold <NUM>. Creating the above configuration makes it possible to cause the cool liquid to cool the engine block (cylinder block <NUM> and head block <NUM>) which is an essential portion of the engine <NUM>. Then, sending the relatively low-temperature cool liquid, which is discharged from the engine block, first to the exhaust communication pipe <NUM>, not the exhaust manifold <NUM>, makes it possible to preferentially cool the front portion of the turbocharger <NUM> which is, in the engine <NUM>, particularly likely to have a high temperature. This makes it possible to properly suppress the temperature increase in the exhaust inlet portion of the turbocharger <NUM>, making it possible to suppress the turbocharger <NUM> from being excessively increased in temperature.

In detail, the cool liquid discharged from each of the head blocks <NUM> included in the right bank RB flows through in the order of the right cool liquid collection pipe 28R, the right exhaust communication pipe 29R, and the right exhaust manifold 22R. Further, the cool liquid discharged from each of the head blocks <NUM> included in the left bank LB flows through in the order of the left cool liquid collection pipe <NUM>, the left exhaust communication pipe <NUM>, and the left exhaust manifold <NUM>. That is, the cool liquid flow channel <NUM> includes a cool liquid collection pipe <NUM> which collects the cool liquid discharged from several portions of the engine block and discharges the cool liquid to the exhaust communication pipe <NUM>.

In the present embodiment, the exhaust manifold <NUM> and the cool liquid collection pipe <NUM> are placed parallel to the crankshaft <NUM>. In other words, the exhaust manifold <NUM> and the cool liquid collection pipe <NUM> are placed alongside the crankshaft <NUM>. In detail, the exhaust manifold <NUM> and the cool liquid collection pipe <NUM> are placed alongside the crankshaft <NUM> in the right and left direction. More in detail, the right exhaust manifold 22R and the right cool liquid collection pipe 28R are so placed as to be arranged on the right side of the crankshaft <NUM>. The left exhaust manifold <NUM> and the left cool liquid collection pipe <NUM> are so placed as to be arranged side by side on the left side of the crankshaft <NUM>.

At least a part of the turbocharger <NUM> is placed more on one side in the crankshaft direction than the exhaust manifold <NUM>. In this example, one side in the crankshaft direction refers to the back side. In detail, at least a part of the right turbocharger 23R is placed behind the right exhaust manifold 22R and the right cool liquid collection pipe 28R. At least a part of the left turbocharger <NUM> is placed behind the left exhaust manifold <NUM> and the left cool liquid collection pipe <NUM>. Creating the above placement allows the configuration connecting the exhaust communication pipe <NUM>, which is placed near the turbocharger <NUM>, with both the cool liquid collection pipe <NUM> and the exhaust manifold <NUM>, to be made without complicated geometry. That is, a compact and simple configuration can be formed for the cool liquid flow channel in which the cool liquid flows through in the order of the cool liquid collection pipe <NUM>, the exhaust communication pipe <NUM>, and the exhaust manifold <NUM>.

At an end portion on the other side of the engine <NUM> in the crankshaft direction, there is placed a cool liquid flow channel component to which the cool liquid flowing through the exhaust manifold <NUM> is sent. In this example, the other side in the crankshaft direction refers to the front side. As shown by the white arrow in <FIG>, the cool liquid flowing through the right exhaust manifold 22R and the left exhaust manifold <NUM> flows from back to front. Due to this, placing the cool liquid flow channel component in the end portion on the back side of the engine <NUM> can be efficiently place the component included in the engine <NUM>.

The cool liquid flow channel component may include a wide range of components included in the cool liquid flow channel. The cool liquid flow channel component may include, for example, a cool pipe through which the cool liquid flows. The cool liquid flow channel component is preferably a component related to cooling of the cool liquid. In detail, the cool liquid flow channel component preferably includes at least one of the thermostat case <NUM> which cases the thermostat <NUM>, and the cool liquid cooler <NUM>. The cool liquid discharged from the exhaust manifold <NUM> is higher in temperature than when being discharged from the cool liquid pump <NUM> while taking heat from the exhaust gas and the like. Due to this, creating the configuration in which the cool liquid cooler <NUM> and thermostat <NUM>, which is used as a set with the cool liquid cooler <NUM>, are placed near where the cool liquid is discharged from the exhaust manifold <NUM> can effectively cool the cool liquid for keeping a cooling performance.

Further, in the present embodiment, the cool liquid cooler <NUM> is a fresh water cooler as described above, but may be other than the fresh water cooler, for example, a radiator. That is, the category of the cool liquid coolers may include the fresh water cooler and the radiator.

The first cool liquid flow channel 50R includes a right cool liquid collection pipe (first cool liquid collection pipe) 28R that collects the cool liquid having cooled one of the two cylinder rows 111R and <NUM>. The first cool liquid flow channel 50R further includes a water-cooled right exhaust communication pipe 29R that is connected to the right cool liquid collection pipe 28R, and a water-cooled right exhaust manifold 22R that is connected to the right exhaust communication pipe 29R. In detail, the right cool liquid collection pipe 28R, the water-cooled right exhaust communication pipe 29R, and the water-cooled right exhaust manifold 22R constitute the right cylinder row-dedicated cool liquid flow channel 51R.

The second cool liquid flow channel <NUM> includes a left cool liquid collection pipe (second cool liquid collection pipe) <NUM> that collects the cool liquid having cooled the other of the two cylinder rows 111R and <NUM>. The second cool liquid flow channel <NUM> further includes a water-cooled left exhaust communication pipe <NUM> that is connected to the left cool liquid collection pipe <NUM>, and a water-cooled left exhaust manifold <NUM> that is connected to the left exhaust communication pipe <NUM>. In detail, the left cool liquid collection pipe <NUM>, the water-cooled left exhaust communication pipe <NUM>, and the water-cooled left exhaust manifold <NUM> constitute the left cylinder row-dedicated cool liquid flow channel <NUM>.

In the present embodiment, as shown in <FIG>, the cool liquid discharged from the right exhaust manifold 22R flows via a cool pipe <NUM> into the cool liquid flow channel provided in the gear case <NUM>. The cool liquid discharged from the left exhaust manifold <NUM> flows via the cool pipe <NUM> into the cool liquid flow channel provided in the gear case <NUM>. That is, the engine <NUM> has the gear case <NUM> in which a part of the first cool liquid flow channel 50R and a part of the second cool liquid flow channel <NUM> are provided. However, this is an exemplification; it may be so configured that the gear case <NUM> is provided with a part of the first cool liquid flow channel 50R and/or a part of the second cool liquid flow channel <NUM>.

The gear case <NUM> cases a gear (not shown) that transmits the rotational power of the crankshaft <NUM>, for example, to the rotary shafts of the cool liquid pump <NUM>, the seawater pump <NUM>, an alternator (not shown), etc. That is, the configuration according to the present embodiment uses the gear case <NUM>, which is an accessory part originally provided in the engine <NUM>, thereby to form the cool liquid flow channel <NUM> of the two cylinder rows 111R and <NUM>. Thus, in the engine <NUM> provided with the two cylinder rows 111R and <NUM>, the cool liquid flow channel <NUM> can be configured while suppressing the number of components from being increased. Because the number of components can be reduced, the engine <NUM> can be made more compact by reducing the space in which the cool liquid flow channel <NUM> is placed.

Further, in the present embodiment, the cool liquid pump <NUM> and the seawater pump <NUM> are mounted to the gear case <NUM>. Further, the gear case <NUM> is placed forward of the two cylinder rows 111R and <NUM>. The gear case <NUM> is placed forward of the engine block.

<FIG> is a schematic perspective view of a configuration of the gear case <NUM> provided in the engine <NUM> according to the embodiment of the present invention. <FIG> is a schematic perspective view of the gear case <NUM> when viewed from a direction different from that in <FIG> shows the gear case <NUM> viewed from the right diagonally forward. <FIG> shows the gear case <NUM> viewed from the right diagonally backward. <FIG> is a schematic right side view of the configuration of the gear case <NUM> provided in the engine <NUM>. <FIG> is a schematic cross sectional perspective view of a cross section taken along the line XIII-XIII shown in <FIG>. <FIG> is a schematic cross sectional perspective view of a cross section taken along the line XIV-XIV shown in <FIG>. In <FIG>, <FIG>, <FIG>, and <FIG>, the thick arrow shows the cool liquid flow.

As shown in <FIG>, the gear case <NUM> is plate-shaped, thick in the front and back direction, and spread out in a direction orthogonal to the front and back direction. In plan view from the front and back direction, the gear case <NUM>, to the lower in the center, has a crankshaft hole <NUM> which passes through in the front and back direction. The front end portion of the crankshaft <NUM> is inserted into the crankshaft hole <NUM>. Further, the gear case <NUM> has a bearing receiving recess portion <NUM> forward of the crankshaft hole <NUM>. The bearing receiving recess portion <NUM> is recessed from frontward to backward, and receives a bearing <NUM> (see <FIG>) by which the crankshaft <NUM> is rotatably supported. Further, the gear case <NUM>, on the back side, has a gear receiving recess portion <NUM> that is recessed toward the front. The gear receiving recess portion <NUM> receives a plurality of gears (not shown) that transmit the rotational power of the crankshaft <NUM>. The plurality of gears includes, for example, a gear that transmits the rotational power to the cool liquid pump <NUM>, and a gear that transmits the rotational power to the seawater pump <NUM>. The gear case <NUM>, on the front right side, has a cool liquid pump mounting opening <NUM> for mounting the cool liquid pump <NUM>. Further, the gear case <NUM>, on the front left side, has a seawater pump mounting opening <NUM> for mounting the seawater pump <NUM>.

The gear case <NUM>, in the upper portion on the right side face, has a right side cool liquid inlet 406R for receiving the cool liquid from the right cool liquid collection pipe 28R. The right side cool liquid inlet 406R connects to a right cylinder row-dedicated first intra-case flow channel 407R (see <FIG>) which is provided inside the gear case <NUM>. The right cylinder row-dedicated first intra-case flow channel 407R is provided in the upper portion of the gear case <NUM>, and extends in the right and left direction. Further, the right cylinder row-dedicated first intra-case flow channel 407R is included in the first cool liquid flow channel 50R, and, in detail, included in the right cylinder row-dedicated cool liquid flow channel 51R.

Further, the gear case <NUM>, in the upper portion on the left side face, has a left side cool liquid inlet <NUM> for receiving the cool liquid from the left cool liquid collection pipe <NUM>. The left side cool liquid inlet <NUM> connects to a left cylinder row-dedicated first intra-case flow channel <NUM> (see <FIG>) which is provided inside the gear case <NUM>. The left cylinder row-dedicated first intra-case flow channel <NUM> is provided in the upper portion of the gear case <NUM>, and is placed to the left of the right cylinder row-dedicated first intra-case flow channel 407R. Further, the left cylinder row-dedicated first intra-case flow channel <NUM> is included in the second cool liquid flow channel <NUM>, and, in detail, included in the left cylinder row-dedicated cool liquid flow channel <NUM>.

The right cylinder row-dedicated first intra-case flow channel 407R and the left cylinder row-dedicated first intra-case flow channel <NUM>, in the gear case <NUM>, are partitioned by a bulkhead <NUM> extending in the up and down direction. That is, the gear case <NUM> has the bulkhead <NUM> that partitions the first cool liquid flow channel 50R from the second cool liquid flow channel <NUM>. A difference in water pressure may be caused between the cool liquid entering the gear case <NUM> from the right side cool liquid inlet 406R and the cool liquid entering the gear case <NUM> from the left side cool liquid inlet <NUM>. In the above case, without the bulkhead <NUM>, backflow due to the pressure difference may be caused. Providing the bulkhead <NUM> can prevent the backflow due to the above pressure difference. It may be so configured that; when the cool liquid entering the gear case <NUM> from the right side cool liquid inlet 406R and the cool liquid entering the gear case <NUM> from the left side cool liquid inlet <NUM> each have a sufficient pressure, and flow downstream without causing the backflow due to the pressure difference, without providing the bulkhead <NUM>, the cool liquid entering the gear case <NUM> from the right side cool liquid inlet 406R and the cool liquid entering the gear case <NUM> from the left side cool liquid inlet <NUM> merge in the gear case <NUM>.

On the upper face of the gear case <NUM>, there are provided a right upper face cool liquid outlet 409R and a left upper face cool liquid outlet <NUM>. To the left end on the upper face of the gear case <NUM>, the right upper face cool liquid outlet 409R and the left upper face cool liquid outlet <NUM> are so placed as to be arranged on right and left. The right upper face cool liquid outlet 409R is placed to the right of the left upper face cool liquid outlet <NUM>. The right upper face cool liquid outlet 409R connects to the right cylinder row-dedicated first intra-case flow channel 407R. The left upper face cool liquid outlet <NUM> connects to the left cylinder row-dedicated first intra-case flow channel <NUM>.

The cool liquid entering the right cylinder row-dedicated first intra-case flow channel 407R from the right side face cool liquid inlet 406R is discharged out of the gear case <NUM> from the right upper face cool liquid outlet 409R and sent to the thermostat case <NUM>. The cool liquid entering the left cylinder row-dedicated first intra-case flow channel <NUM> from the left side cool liquid inlet <NUM> is discharged out of the gear case <NUM> from the left upper face cool liquid outlet <NUM> and sent to the thermostat case <NUM>. That is, the cool liquids entering the gear case <NUM> from the right cool liquid collection pipe (first cool liquid collection pipe) 28R and the left cool liquid collection pipe (second cool liquid collection pipe) <NUM> are discharged to the thermostat case <NUM> which cases the thermostat <NUM>. However, this is an exemplification; it may be so configured that the cool liquid entering the gear case <NUM> from the right cool liquid collection pipe 28R and/or the left cool liquid collection pipe <NUM> is discharged to the thermostat case <NUM> which cases the thermostat <NUM>.

As shown in <FIG> and <FIG>, the gear case <NUM>, to the right in the upper portion on the front face, has a first front cool liquid inlet <NUM> that leads the cool liquid, which is discharged from the lubricant oil cooler <NUM>, to the inner portion of the gear case <NUM>. The inner portion of the gear case <NUM> has a shared intra-case flow channel <NUM> that connects to the first front cool liquid inlet <NUM>. The shared intra-case flow channel <NUM> is included in the shared cool liquid flow channel <NUM>. The gear case <NUM>, in the right end portion of the front face, has a front cool liquid outlet <NUM> that connects to the shared intra-case flow channel <NUM>. The front cool liquid outlet <NUM> is placed to the right and lower than the first front cool liquid inlet <NUM>. The cool liquid entering the shared intra-case flow channel <NUM> from the first front cool liquid inlet <NUM> is discharged out of the gear case <NUM> from the front cool liquid outlet <NUM> and sent to the cool liquid pump <NUM>.

As can be seen from the above, the gear case <NUM> has the shared cool liquid flow channel <NUM> that is shared by both the first cool liquid flow channel 50R and the second cool liquid flow channel <NUM>. In detail, the gear case <NUM> has a part of the shared cool liquid flow channel <NUM>. The shared cool liquid flow channel <NUM> provided in the gear case <NUM> includes a flow channel that leads the cool liquid, which is discharged from the lubricant oil cooler <NUM> that cools the lubricant oil, to the cool liquid pump <NUM>.

Further, as shown in <FIG> and <FIG>, the gear case <NUM>, in the center portion of the front face, has a second front cool liquid inlet <NUM> that leads the cool liquid, which is discharged from the cool liquid pump <NUM>, to inner portion of the gear case <NUM>. The inner portion of the gear case <NUM> has a branch unit <NUM> that connects to the second front cool liquid inlet <NUM> and that divides the cool liquid into the first cool liquid flow channel 50R and the second cool liquid flow channel <NUM>. The branch unit <NUM> is included in the shared cool liquid flow channel <NUM>.

As shown in <FIG>, the inner portion of the gear case <NUM> has a right cylinder row-dedicated second intra-case flow channel 415R which connects to the branch unit <NUM>, and extends diagonally downward to the right. The right cylinder row-dedicated second intra-case flow channel 415R is included in the first cool liquid flow channel 50R, and, in detail, included in the right cylinder row-dedicated cool liquid flow channel 51R. Further, the inner portion of the gear case <NUM> has a left cylinder row-dedicated second intra-case flow channel <NUM> which connects to the branch unit <NUM>, and extends diagonally downward to the left. The left cylinder row-dedicated second intra-case flow channel <NUM> is included in the second cool liquid flow channel <NUM>, and, in detail, included in the left cylinder row-dedicated cool liquid flow channel <NUM>.

As shown in <FIG>, the gear case <NUM>, at the right end in the lower portion on the back face, has a right back face cool liquid outlet 416R that connects to the right cylinder row-dedicated second intra-case flow channel 415R. Further, the gear case <NUM>, at the left end in the lower portion on the back face, has a left back face cool liquid outlet <NUM> that connects to the left cylinder row-dedicated second intra-case flow channel <NUM>.

The cool liquid discharged from the cool liquid pump <NUM> is divided, at the branch unit <NUM>, into the cool liquid flowing in the right cylinder row-dedicated second intra-case flow channel 415R, and the cool liquid flowing in the left cylinder row-dedicated second intra-case flow channel <NUM>. The cool liquid flowing in the right cylinder row-dedicated second intra-case flow channel 415R is discharged out of the gear case <NUM> from the right back face cool liquid outlet 416R, and is sent to the right cylinder row-dedicated cool flow channel provided in the cylinder block <NUM>. The cool liquid flowing in the left cylinder row-dedicated second intra-case flow channel <NUM> is discharged out of the gear case <NUM> from the left back face cool liquid outlet <NUM>, and is sent to the left cylinder row-dedicated cool flow channel provided in the cylinder block <NUM>.

As can be seen from the above, a part of the first cool liquid flow channel 50R provided in the gear case <NUM> includes a flow channel that leads the cool liquid, which is supplied from the cool liquid pump <NUM>, to one of the two cylinder rows 111R and <NUM>. Also, a part of the second cool liquid flow channel <NUM> provided in the gear case <NUM> includes a flow channel that leads the cool liquid, which is supplied from the cool liquid pump <NUM>, to the other of the two cylinder rows 111R and <NUM>. In this example, one of the two cylinder rows 111R and <NUM> is the right cylinder row 111R. The other of the two cylinder rows 111R and <NUM> is the left cylinder row <NUM>.

In the present embodiment, the inner portion of the gear case <NUM> is provided with the multiple types of flow channels that flow the cool liquids, making it possible to efficiently form the cool liquid flow channel <NUM>.

As described above, the engine <NUM> is provided with the cool liquid cooler <NUM> and the lubricant oil cooler <NUM>. The cool liquid cooler <NUM> cools the cool liquid that cools the engine block (engine body). The lubricant oil cooler <NUM> cools the lubricant oil using the cool liquid that cools the engine block. Further, in the present embodiment, the lubricant oil cooler <NUM> cools the lubricant oil using the cool liquid cooled by the cool liquid cooler <NUM>, which is an exemplification. The lubricant oil cooler <NUM> may be cooled by a cool liquid different from that cooled by cool liquid cooler <NUM>. That is, the lubricant oil cooler <NUM> may be so configured as to cool the lubricant oil using a first cool liquid that cools the engine block or a second cool liquid that is different from the first cool liquid. For example, the first cool liquid may be fresh water, and the second cool liquid may be seawater.

As shown in <FIG>, the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are so placed as to be arranged side by side on one end side in the crankshaft direction in the engine <NUM>. In this example, one end side in the crankshaft direction is the front end side. The cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are so placed as to be arranged side by side at the front of the engine <NUM>.

So placing the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> as to be arranged side by side on one end side of the engine <NUM> in the crankshaft direction makes it possible to suppress the engine <NUM>'s length in the crankshaft direction from being increased, compared to when the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are arranged separately on one end side and the other end side in the crankshaft direction. Further, so placing the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> as to be arranged side by side on one end side of the engine <NUM> in the crankshaft direction makes it possible to suppress the engine <NUM>'s length in the width direction from being increased, compared to when at least one of the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> is placed on the side of the engine <NUM>.

When the engine <NUM> is a V-type engine provided with the two cylinder rows 111R and <NUM> as in the present embodiment, the area of the end face of the engine <NUM> in the crankshaft direction is large. Due to this, the engine <NUM> in the present embodiment makes it easy to so place the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> to be arranged on one end face in the crankshaft direction. Further, according to the engine <NUM> of the present embodiment, the up and down and right and left sizes of each of the cool liquid oil cooler <NUM> and the lubricant oil cooler <NUM> can be increased even when the cool liquid oil cooler <NUM> and the lubricant oil cooler <NUM> are so placed as to be arranged on one end face in the crankshaft direction.

In the present embodiment, the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are so placed as to be arranged in the right and left direction. However, the direction in which the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are arranged is not limited to the right and left direction, but can be, for example, the up and down direction.

The gear case <NUM> provided in the engine <NUM> may be placed between the engine block (such as cylinder block <NUM>) and the cool liquid cooler <NUM> and/or the lubricant oil cooler <NUM>. The cool liquid cooler <NUM> and/or the lubricant oil cooler <NUM> may be mounted to the gear case <NUM>. In the present embodiment, the gear case <NUM> is placed between the engine block and the cool liquid cooler <NUM> and lubricant oil cooler <NUM>. In detail, the gear case <NUM> is placed between the engine block and the cool liquid cooler <NUM> in the crankshaft direction. The cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are mounted to the gear case <NUM>.

Creating the configuration where each of the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> is mounted to the gear case <NUM>, which is originally provided in the engine <NUM>, prevents the number of components of the engine <NUM> from being increased. This accomplishes compactness of the engine <NUM>. Further, the gear case <NUM> is fixed directly to the cylinder block <NUM>, making it difficult to sway. Due to this, creating the configuration where the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> are mounted to the gear case <NUM> can suppress a vibration of each of the coolers <NUM> and <NUM>.

<FIG> is a schematic perspective view of the configuration of mounting the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> which are provided in the engine <NUM> according to the embodiment of the present invention. The lower portion of the cool liquid cooler <NUM> is directly mounted to the gear case <NUM> using a screw or other fixture. Then, the upper portion of the cool liquid cooler <NUM> is mounted to a cool liquid cooler support member <NUM> (see <FIG>) using a screw or other fixture. The cool liquid cooler support member <NUM> is an L-shaped sheet metal member, and is mounted to the upper face of the gear case <NUM>. That is, the upper portion of the cool liquid cooler <NUM> is indirectly mounted to the gear case <NUM> using the cool liquid cooler support member <NUM>.

Also, in the present embodiment, the number of cool liquid cooler support members <NUM> is two, and the two cool liquid cooler support members <NUM> are arranged right and left in the center portion of the upper face of the gear case <NUM>. However, the number of cool liquid cooler support members <NUM> may be changed as needed. Further, other than the cool liquid cooler support member <NUM>, a pipe <NUM> through which the cool liquid flows is mounted to the upper face of the gear case <NUM>. The above pipe <NUM> is also mounted to the cool liquid cooler <NUM>. The upper portion of the cool liquid cooler <NUM> can be said to be supported by the cool liquid cooler support member <NUM> and the pipe <NUM>.

The lower portion of the lubricant oil cooler <NUM> is directly mounted to the gear case <NUM> using a screw or other fixture. Then, the upper portion of the lubricant oil cooler <NUM> is mounted to the lubricant oil cooler support member <NUM> (see <FIG>) using a screw or other fixture. The lubricant oil cooler support member <NUM> is mounted to the upper face of the gear case <NUM>. That is, the upper portion of the lubricant oil cooler <NUM> is indirectly mounted to the gear case <NUM> using the lubricant oil cooler support member <NUM>. That is, in the present embodiment, the inner portion of the lubricant oil cooler support member <NUM> has a flow channel for the cool liquid and lubricant oil.

As described above, the inner portion of the gear case <NUM> has the flow channel through which the cool liquid passes. That is, the gear case <NUM> has an intra-case cool liquid flow channel through which the cool liquid passes. The intra-case cool liquid flow channel includes a first flow channel placed upstream of the cool liquid cooler <NUM>, and a second flow channel placed downstream of the cool liquid cooler <NUM>. In the present embodiment, the second flow channel is placed downstream of the lubricant oil cooler <NUM>. Further, in the present embodiment, upstream and downstream are expressions used for the section where the cool liquid which, from the cool liquid pump <NUM> (as a start point) that discharges the cool liquid, flows out, and returns to the cool liquid pump <NUM>. At a certain point in the cool liquid flow channel, the upstream side is the side for progressing in the direction opposite to the direction in which the cool liquid flows, and the downstream side is the side for progressing in the direction same as the direction in which the cool liquid flows.

In detail, the first flow channel is included in the flow channel seen before the cool liquid that has exchanged heat with the exhaust gas enters the cool liquid cooler <NUM>. That is, the first flow channel is included in the flow channel between the exhaust manifold <NUM> and the cool liquid cooler <NUM>. The first flow channel includes the right cylinder row-dedicated first intra-case flow channel 407R and the left cylinder row-dedicated first intra-case flow channel <NUM> (see, for example, <FIG>) described above. Further, the second flow channel is included in the flow channel between the lubricant oil cooler <NUM> and the cool liquid pump <NUM>. The second flow channel includes the shared intra-case flow channel <NUM> (see <FIG>) described above. Using the inner portion of the gear case <NUM> as the flow channel through which the cool liquid passes can efficiently place the cool flow channel. Further, using the inner portion of the gear case <NUM> as a flow channel through which the cool liquid passes can reduce the number of components.

The gear case <NUM> also includes a third flow channel placed downstream of the cool liquid pump <NUM>. The third flow channel, in detail, is included in the intra-case flow channel through which the cool liquid discharged from the cool liquid pump <NUM> passes before entering the cool liquid flow channel provided in the engine block. The third flow channel includes the right cylinder row-dedicated second intra-case flow channel 415R and the left cylinder row-dedicated second intra-case flow channel <NUM> described above.

<FIG> is a schematic perspective view of the heat exchange unit <NUM> provided in the cool liquid cooler <NUM>. In <FIG>, the white arrow P1 shows the flow of the cool liquid that cools the engine block. In detail, the white arrow P1 shows the flow of fresh water. The thick black arrow P2 shows the flow of the seawater for cooling the fresh water.

As shown in <FIG>, the back face of the heat exchange unit <NUM> of the cool liquid cooler <NUM> has a fresh water inlet <NUM> and a fresh water outlet <NUM>. Further, the back face of the heat exchange unit <NUM> has a seawater inlet <NUM>. The front face of the heat exchange unit <NUM> has a seawater outlet <NUM> (see <FIG> below). The seawater outlet <NUM> is provided with a seawater outlet pipe <NUM> that directs downward the flow of the seawater discharged from the seawater outlet <NUM>.

<FIG> shows a schematic view for illustration of the configuration of the heat exchange unit <NUM> of the cool liquid cooler <NUM>. In <FIG>, the heat exchange unit <NUM> is partially disassembled. In <FIG>, as in <FIG>, the white arrow P1 shows the flow of fresh water, and the thick black arrow P2 shows the flow of the seawater. As shown in <FIG>, the heat exchange unit <NUM> has a front frame <NUM> and a back frame <NUM>. Further, the heat exchange unit <NUM> has a plurality of plates <NUM> between the front frame <NUM> and the back frame <NUM> in the front and back direction. A plurality of plates <NUM> is stacked in the front and back direction, and sandwiched between the front frame <NUM> and the back frame <NUM>.

In the heat exchange unit <NUM> of the cool liquid cooler <NUM>, fresh or sea water flows between each of the <NUM> plates. In detail, the type of liquid flowing between the two plates <NUM> is alternated. For example, the type of liquid flowing between the two plates <NUM> alternates from back to front: fresh water, sea water, fresh water, sea water. Creating the above configuration allows efficient heat exchange between fresh water and seawater. The heat exchange unit <NUM> is a so-called multi-plate heat exchange unit. That is, the cool liquid cooler <NUM> includes a multi-plate heat exchange unit <NUM>.

<FIG> is a schematic perspective view of the heat exchange unit <NUM> provided in the lubricant oil cooler <NUM>. In <FIG>, a solid arrow P3 shows the flow of the cool liquid that cools the engine block, and a dashed arrow P4 shows the flow of the lubricant oil. As shown in <FIG>, the back face of the heat exchange unit <NUM> of the lubricant oil cooler <NUM> has a lubricant oil cooler cool liquid inlet <NUM> which is the cool liquid (fresh water) inlet, and a lubricant oil cooler cool liquid outlet <NUM> which is the cool liquid outlet. Further, the back face of the heat exchange unit <NUM> has a lubricant inlet <NUM> and a lubricant outlet <NUM>.

The heat exchange unit <NUM> of the lubricant oil cooler <NUM>, like the cool liquid cooler <NUM>, is also a so-called multi-plate heat exchange unit. That is, the lubricant oil cooler <NUM> includes a multi-plate heat exchange unit <NUM>. The heat exchange unit <NUM> has a plurality of plates that are stacked in the front and back direction. The type of liquid flowing between each of the plates alternates. For example, the type of liquid flowing between the two plates alternates from back to front: cool liquid (fresh water), lubricant oil, cool liquid, lubricant oil. Creating the above configuration allows efficient heat exchange between the cool water and the lubricant oil.

In the present embodiment, the cool liquid for the lubricant oil cooler <NUM> is fresh water, but if fresh water is used as the first cool liquid, the cool liquid for the lubricant oil cooler <NUM> may be a second cool liquid, such as seawater, which is different from the first cool liquid.

The multi-plate heat exchange units <NUM> and <NUM>, depending on the required cooling capacity, can adjust the size of a single plate vertically and horizontally, or the number of plates. Due to this, creating the configurations of the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> each provided with the multi-plate heat exchange unit makes it easy to so place the cool liquid cooler <NUM> and the lubricant oil cooler <NUM> as to be arranged on the same face. Further, the heat exchange units <NUM> and <NUM> each may have a configuration other than the multi-plate type, such as a multi-pipe type, for example. Further, the heat exchange unit <NUM> of the cool liquid cooler <NUM> and the heat exchange unit <NUM> of the lubricant oil cooler <NUM> may be configured by methods different from each other.

Claim 1:
An engine (<NUM>) comprising:
a cool liquid cooler (<NUM>) that cools a first cool liquid that cools an engine block including a cylinder block (<NUM>) and a head block (<NUM>); and
a lubricant oil cooler (<NUM>) that cools a lubricant oil using the first cool liquid or a second cool liquid,
wherein
the cool liquid cooler (<NUM>) and the lubricant oil cooler (<NUM>) are so placed as to be arranged side by side on one end side in a crankshaft direction, characterized in that
the engine (<NUM>) further includes
a gear case (<NUM>) placed between the engine block and the cool liquid cooler (<NUM>), and/or between the engine block and the lubricant oil cooler (<NUM>),
wherein
the cool liquid cooler (<NUM>) and/or the lubricant oil cooler (<NUM>) is mounted to the gear case (<NUM>).