Patent Description:
<CIT> describes an arrangement structure of a solenoid valve including a first solenoid valve which controls hydraulic oil supplied to an intake valve phase changing means for changing a rotation phase of an intake valve cam shaft and a second solenoid valve which controls hydraulic oil supplied to an exhaust valve phase changing means for changing a rotation phase of an exhaust valve cam shaft. In <CIT>, the first solenoid valve and the second solenoid valve are provided in a timing chain cover disposed at an end portion of an engine. Other examples of engines are provided in <CIT> or <CIT>.

However, in the technique described in Patent Literature <NUM>, since the first solenoid valve and the second solenoid valve are arranged to protrude from an end portion of the timing chain cover to the outside, there is concern that a portion of the first solenoid valve or the second solenoid valve exposed to the outside may be damaged by collision with foreign matter such as flying stones flying from a road surface.

This invention has been made in view of the above-described circumstances and an object of this invention is to provide an internal combustion engine capable of protecting a portion of a hydraulic control valve exposed to the outside from foreign matter such as flying stones flying from below.

According to aspects of this invention, there is provided a vehicle comprising an internal combustion engine according to claim <NUM>.

In this way, according to this invention, it is possible to provide an internal combustion engine capable of protecting a portion of a hydraulic control valve exposed to the outside from foreign matter such as flying stones flying from below.

A vehicle according to embodiments of this invention is a vehicle comprising an internal combustion engine mounted thereon with center lines of a plurality of cylinders inclined with respect to an up to down direction of the vehicle, the internal combustion engine including:a variable valve timing mechanism configured by winding a timing chain thereon, a hydraulic control valve controlling hydraulic oil supplied to the variable valve timing mechanism, and a chain casing fixed to a cylinder head to cover the timing chain and the variable valve timing mechanism, wherein the chain casing includes a bulging portion bulging in a crank shaft direction and covering the variable valve timing mechanism and a cylindrical cylinder portion attaching the hydraulic control valve thereto, wherein the hydraulic control valve includes a small diameter portion inserted from an upper end of the cylinder portion in an axial direction thereof into the cylinder portion, the upper end being open; and a large diameter portion exposed from the upper end of the cylinder portion in the axial direction, wherein the cylinder portion is adjacently formed below the bulging portion, wherein the other end portion of the cylinder portion in the axial direction is located below the upper end of the cylinder portion in the axial direction, wherein the chain casing includes a connection rib to connect the other end portion of the cylinder portion in the axial direction to the bulging portion, and wherein the chain casing includes a reinforcement rib extending in the axial direction of the cylinder portion from the upper end of the cylinder portion in the axial direction to at least a position above the large diameter portion along an end portion on the side opposite to the bulging portion in the cylinder portion.

Accordingly, the internal combustion engine according to an embodiment of this invention can protect a portion exposed to the outside of the hydraulic control valve from foreign matter such as flying stones flying from below.

Hereinafter, an internal combustion engine according to an embodiment of this invention will be described with reference to the drawings. <FIG> are diagrams showing the internal combustion engine according to an embodiment of this invention.

In <FIG>, the display in the up, down, front, rear, right, and left directions shows the up, down, front, rear, right, and left when mounted on the vehicle. Further, the display of the AB direction, the CD direction, and the EF direction is based on the case in which the internal combustion engine separated from the vehicle is upright so that the cylinder head is located right above the crank shaft. The AB direction, the CD direction, and the EF direction are directions orthogonal to each other and the EF direction coincides with the front to rear direction of the vehicle equipped with the internal combustion engine.

First, a configuration will be described. In <FIG>, an internal combustion engine <NUM> mounted on the vehicle includes a cylinder block <NUM>. The cylinder block <NUM> is provided with a crank shaft 2A and the crank shaft 2A extends in the EF direction.

The cylinder block <NUM> is provided with three cylinders (not shown) arranged in the EF direction and the cylinder extends in the AB direction. The internal combustion engine <NUM> of this embodiment is an FR (front engine-rear drive) type vertical engine. Additionally, the internal combustion engine <NUM> is not limited to an in-line engine and may be, for example, a V-type engine. Then, the number of cylinders is not limited to three.

A cylinder head <NUM> is provided at the end portion of the cylinder block <NUM> in the A direction. The cylinder head <NUM> includes an intake port (not shown) which takes air, an exhaust port 3B which discharges an exhaust gas, an intake valve, and an exhaust valve (not shown). The exhaust port 3B opens to a side wall of the cylinder head <NUM> in the D direction. The intake port opens to a side wall of the cylinder head <NUM> in the C direction.

A cylinder head cover <NUM> is installed at the end portion of the cylinder head <NUM> in the A direction. An oil pan <NUM> is installed at the end portion of the cylinder block <NUM> in the B direction and the oil pan <NUM> stores lubricating oil of the internal combustion engine <NUM>.

The internal combustion engine <NUM> is installed below a floor panel of a driver seat on the front part of the vehicle (not shown). Thus, the vehicle equipped with the internal combustion engine <NUM> is a so-called cab-over type vehicle in which a driver seat is disposed above the internal combustion engine <NUM>. The internal combustion engine <NUM> is installed in the vehicle so that the center line C of the cylinder is inclined in the left to right direction with respect to the up to down direction of the vehicle.

An undercover 1A is provided below the internal combustion engine <NUM>. The undercover 1A extends in the horizontal direction and covers the internal combustion engine <NUM> from below. A bottom surface 5A of the oil pan <NUM> is located at the bottom portion of the internal combustion engine <NUM> in a vehicle mounted state. This bottom surface 5A is inclined with respect to the left to right direction of the internal combustion engine <NUM> itself to extend in parallel to the undercover 1A in the vehicle mounted state.

In this way, the internal combustion engine <NUM> is mounted on the front part of the vehicle in a largely inclined posture. Therefore, in the vehicle mounted state, the side surface (intake side) of the internal combustion engine <NUM> in the C direction faces the upper side of the vehicle and the side surface (exhaust side) of the internal combustion engine <NUM> in the D direction faces the lower side of the vehicle.

The internal combustion engine <NUM> includes a variable valve timing mechanism <NUM> on which a timing chain <NUM> is wound and the cylinder head cover <NUM> which is connected to the cylinder head <NUM>. Further, the internal combustion engine <NUM> includes an intake hydraulic control valve <NUM> and an exhaust hydraulic control valve <NUM> each having a cylindrical shape and serving as an intake hydraulic control valve controlling hydraulic oil supplied to the variable valve timing mechanism <NUM>.

The internal combustion engine <NUM> includes a chain casing <NUM> and this chain casing <NUM> is fixed to the side surface of the cylinder head <NUM>. The chain casing <NUM> covers the timing chain <NUM> and the variable valve timing mechanism <NUM>. The variable valve timing mechanism <NUM> includes an intake side variable valve timing mechanism <NUM> which is disposed on the side of the intake port and an exhaust side variable valve timing mechanism <NUM> which is disposed on the side of the exhaust port 3B.

The internal combustion engine <NUM> includes an oil pan <NUM> which is provided on the side opposite to the cylinder head <NUM> with respect to the chain casing and is connected to the cylinder head <NUM> through the cylinder block <NUM>, an intake port which is provided in the cylinder head <NUM> and takes air, and an exhaust port 3B which is provided on the side opposite to the intake port with respect to the chain casing and discharges an exhaust gas.

The chain casing <NUM> is provided with a bulging portion <NUM> which covers the variable valve timing mechanism <NUM>. The bulging portion <NUM> bulges in the crank shaft direction. Here the crank shaft direction is the axial direction of the crank shaft 2A. In this embodiment, the bulging portion <NUM> bulges toward the outside of the chain casing <NUM> (the front side in the vehicle mounted state). The bulging portion <NUM> is formed at the end portion on the side of the cylinder head cover <NUM> (the end portion in the A direction) of the chain casing <NUM>. The intake hydraulic control valve <NUM> and the exhaust hydraulic control valve <NUM> are arranged closer to the oil pan <NUM> than the bulging portion <NUM> of the chain casing <NUM>.

Further, the internal combustion engine <NUM> includes an oil pump <NUM> and the oil pump <NUM> pressure-feeds oil stored in the oil pan <NUM> to a lubrication required portion and the variable valve timing mechanism <NUM>. The oil pump <NUM> is provided around the crank shaft 2A.

Here, in this embodiment, the direction of the cylinder head cover <NUM> with respect to the chain casing <NUM> and the direction of the oil pan <NUM> are defined as the AB direction, the direction of the intake port with respect to the chain casing <NUM> and the direction of the exhaust port 3B are defined as the CD direction, and the outward direction of the chain casing <NUM> (the front side in the vehicle mounted state) and the inward direction (the rear side in the vehicle mounted state) are defined as the EF direction.

The intake hydraulic control valve <NUM> is disposed on the side of the intake port in the CD direction. The exhaust hydraulic control valve <NUM> is disposed on the side of the exhaust port 3B in the CD direction.

In <FIG> and <FIG>, the chain casing <NUM> is provided with a cylindrical intake side cylinder portion <NUM> to which the intake hydraulic control valve <NUM> is attached and a cylindrical exhaust side cylinder portion <NUM> to which the exhaust hydraulic control valve <NUM> is attached. The intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> extend in the CD direction. The exhaust side cylinder portion <NUM> constitutes the cylinder portion and the first cylinder portion of this invention. The intake side cylinder portion <NUM> constitutes the second cylinder portion of this invention.

The intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> are adjacently formed below the bulging portion <NUM>. In a state in which the internal combustion engine <NUM> is mounted on the vehicle, the other end portion 23D (the end portion in the D direction. See <FIG>) of the intake side cylinder portion <NUM> in the axial direction is disposed below one end portion 23C of the intake side cylinder portion <NUM> in the axial direction (the end portion in the C direction. See <FIG>). Similarly, the other end portion 24D of the exhaust side cylinder portion <NUM> in the axial direction (the end portion in the D direction. See <FIG>) is disposed below one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction (the end portion in the C direction. See <FIG>).

In <FIG> and <FIG>, the intake hydraulic control valve <NUM> includes a small diameter portion 15B (see <FIG>) which is inserted from one end portion 23C of the intake side cylinder portion <NUM> in the axial direction (see <FIG>) into the intake side cylinder portion <NUM> and a large diameter portion 15A (see <FIG>) which is exposed from one end portion 23C of the intake side cylinder portion <NUM> in the axial direction (see <FIG>). Similarly, the exhaust hydraulic control valve <NUM> includes a small diameter portion 16B (see <FIG>) which is inserted from one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction (see <FIG>) into the exhaust side cylinder portion <NUM> and a large diameter portion 16A (see <FIG>) which is exposed from one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction (see <FIG>).

In <FIG>, the intake side cylinder portion <NUM> is provided with an accommodation hole 23A accommodating the small diameter portion 15B of the intake hydraulic control valve <NUM>. The exhaust side cylinder portion <NUM> is provided with an accommodation hole 24A accommodating the small diameter portion 16B of the exhaust hydraulic control valve <NUM>.

In <FIG>, the chain casing <NUM> is provided with an oil pump accommodation portion <NUM> which accommodates the oil pump <NUM>. The intake side cylinder portion <NUM>, the exhaust side cylinder portion <NUM>, and the oil pump accommodation portion <NUM> are integrally formed with each other.

The oil pump accommodation portion <NUM> is a flat portion which does not bulge in the direction of the crank shaft in the chain casing <NUM>. The oil pump accommodation portion <NUM> is disposed below the bulging portion <NUM> and is continuous to the lower portion of the bulging portion <NUM>.

Since the oil pump accommodation portion <NUM> has a flat shape rather than a bulging shape like the bulging portion <NUM>, the rigidity thereof is inferior to that of the bulging portion <NUM> as it is. Here, in this embodiment, the rigidity of the portion provided with the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> of the oil pump accommodation portion <NUM> is improved. Further, since it is preferable to compactly arrange the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> in the AB direction, the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> are arranged to be offset in the CD direction and the EF direction.

A connector (not shown) for electrically controlling the intake hydraulic control valve <NUM> and the exhaust hydraulic control valve <NUM> is connected to the side of the intake port of the large diameter portions 15A and 16A in the CD direction. A connection port of each connector faces the outside (front side) of the chain casing <NUM> in the EF direction.

Here, since the internal combustion engine <NUM> of this embodiment is mounted on the vehicle in a largely inclined posture, the uppermost portions of the intake hydraulic control valve <NUM> and the exhaust hydraulic control valve <NUM> in the up to down direction of the vehicle are located below the uppermost portion of the cylinder head cover <NUM> in the up to down direction of the vehicle in the vehicle mounted state. Further, a connector (not shown) of the end portion on the side of the intake port of the large diameter portion 16A of the exhaust hydraulic control valve <NUM> in the CD direction is disposed at a position which is on the lower side in the up to down direction of the vehicle and on the side of the cylinder head cover <NUM> with respect to a connector (not shown) of the end portion on the side of the intake port of the large diameter portion 15A of the intake hydraulic control valve <NUM> in the CD direction.

Accordingly, the connector of the large diameter portion 16A of the exhaust hydraulic control valve <NUM> is disposed between the connector of the large diameter portion 15A of the intake hydraulic control valve <NUM> and the cylinder head cover <NUM> and below the uppermost portions of both the intake hydraulic control valve <NUM> and the cylinder head cover <NUM> in the up to down direction of the vehicle. Therefore, it is possible to suppress foreign matter such as dust from settling and accumulating on the connector of the large diameter portion 16A of the exhaust hydraulic control valve <NUM> without disposing the exhaust hydraulic control valve <NUM> inside the cylinder head cover <NUM>.

The intake hydraulic control valve <NUM> and the exhaust hydraulic control valve <NUM> are respectively inserted in the D direction from the end portions of the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> in the C direction (the upper side in the vehicle mounted state). Therefore, since the insertion directions of the intake hydraulic control valve <NUM> and the exhaust hydraulic control valve <NUM> are the same as each other, the insertion work can be facilitated.

Further, since the intake hydraulic control valve <NUM> is disposed above the intake side cylinder portion <NUM> and the exhaust hydraulic control valve <NUM> is disposed above the exhaust side cylinder portion <NUM> in the vehicle mounted state, it is possible to prevent a foreign mater from entering the intake hydraulic control valve <NUM> and the exhaust hydraulic control valve <NUM> even when the foreign matter or the like mixed with the hydraulic oil precipitates.

In <FIG>, the edge portion of the chain casing <NUM> is provided with a plurality of cylinder head fastening portions <NUM> and <NUM> and the cylinder head fastening portions <NUM> and <NUM> respectively include fastening holes 41A and 42A for fastening the oil pump accommodation portion <NUM> to the cylinder head <NUM>. The cylinder head fastening portions <NUM> and <NUM> are adjacent to each other in the AB direction. The portion provided with the cylinder head fastening portions <NUM> and <NUM> of the chain casing <NUM> is a portion having a large wall thickness and high strength.

In <FIG> and <FIG>, the accommodation hole 23A of the intake side cylinder portion <NUM> and the accommodation hole 24A of the exhaust side cylinder portion <NUM> are arranged on either the side of the intake port or the side of the exhaust port 3B in the CD direction and open to either the side of the intake port or the side of the exhaust port 3B. That is, the accommodation hole 23A of the intake side cylinder portion <NUM> and the accommodation hole 24A of the exhaust side cylinder portion <NUM> are arranged in the same direction in the CD direction and open in the same direction. In this embodiment, the accommodation hole 23A of the intake side cylinder portion <NUM> and the accommodation hole 24A of the exhaust side cylinder portion <NUM> are arranged on the side of the intake port and open to the side of the intake port.

In <FIG>, an axis 23R of the accommodation hole 23A of the intake side cylinder portion <NUM> and an axis 24R of the accommodation hole 24A of the exhaust side cylinder portion <NUM> are arranged at different positions in the EF direction.

Specifically, the axis 23R is disposed on the inside of the chain casing <NUM> in relation to the axis 24R in the EF direction. The axis 23R and the axis 24R are parallel to each other. Accordingly, since the casting pins forming the accommodation holes 23A and 24A can be extracted in the same direction, it is possible to manufacture the chain casing <NUM> from a simple mold structure and to further shorten the distance between the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> in the CD direction (the direction of the axes 23R and 24R).

In <FIG>, at least a part of the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> overlaps in the AB direction.

In <FIG>, the chain casing <NUM> includes a wall-shaped connection portion <NUM>. The connection portion <NUM> extends in the EF direction and connects the end portion on the side of the exhaust port 3B (the other end portion 23D shown in <FIG>) of the intake side cylinder portion <NUM> in the CD direction to the end portion on the side of the intake port (one end portion 24C shown in <FIG>) of the exhaust side cylinder portion <NUM> in the CD direction. Additionally, the connection portion <NUM> also extends in the AB direction. Thus, the connection portion <NUM> connects the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> in the EF direction and the AB direction.

In <FIG>, the chain casing <NUM> includes a cylindrical oil gallery portion <NUM> and an oil passage (not shown) through which hydraulic oil flows is formed inside the oil gallery portion <NUM>.

The oil gallery portion <NUM> extends in the CD direction. The chain casing <NUM> includes a wall portion 21A extending in the EF direction and continuous to the oil pump accommodation portion <NUM> and this wall portion 21A is provided at the end portion on the side of the oil pan <NUM> in the bulging portion <NUM> in the AB direction. The intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> are arranged between the oil gallery portion <NUM> and the wall portion 21A in the AB direction.

Additionally, in order to suppress the vibration of an intake manifold (not shown) connected to the intake port of the cylinder head <NUM> from being transmitted to the chain casing <NUM>, it is preferable to improve the rigidity of the portion in the vicinity of the intake manifold in the chain casing <NUM>. Here, the intake port and the intake manifold connected to the intake port are arranged between the cylinder head fastening portion <NUM> and the cylinder head fastening portion <NUM> in the AB direction. Accordingly, since it is possible to set the distance between the cylinder head fastening portion <NUM> and the cylinder head fastening portion <NUM> to a minimum distance, it is possible to improve the rigidity of the portion in the vicinity of the cylinder head fastening portions <NUM> and <NUM> in the chain casing <NUM>. Further, it is possible to suppress the vibration of the portion in the vicinity of the cylinder head fastening portions <NUM> and <NUM> in the chain casing <NUM>.

The chain casing <NUM> includes an intake side fastening boss portion <NUM> and an exhaust side fastening boss portion <NUM> for attaching the chain casing <NUM> to the cylinder head <NUM>. The intake side fastening boss portion <NUM> and the exhaust side fastening boss portion <NUM> are arranged in the vicinity of the bulging portion <NUM> in the B direction.

The end portion of the bulging portion <NUM> in the B direction is connected to the end portions of the intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> in the A direction. The end portion of the intake side fastening boss portion <NUM> in the A direction is connected to the end portion of the intake side cylinder portion <NUM> in the B direction. The end portion of the exhaust side fastening boss portion <NUM> in the A direction is connected to the end portion of the exhaust side cylinder portion <NUM> in the B direction. The end surface of the cylinder head <NUM> in the A direction forms a planar joint surface extending in the CD direction and the EF direction and is joined to the cylinder head cover <NUM>.

The intake hydraulic control valve <NUM>, the exhaust hydraulic control valve <NUM>, the intake side cylinder portion <NUM>, and the exhaust side cylinder portion <NUM> extend in the CD direction. Further, the intake hydraulic control valve <NUM> and the intake side cylinder portion <NUM> are arranged side by side in the EF direction with respect to the exhaust hydraulic control valve <NUM> and the exhaust side cylinder portion <NUM>.

The intake side fastening boss portion <NUM> and the exhaust side fastening boss portion <NUM> are arranged side by side in the CD direction. The intake side fastening boss portion <NUM> and the exhaust side fastening boss portion <NUM> are formed to protrude in the E direction (forward in the vehicle mounted state) in relation to the intake side cylinder portion <NUM>.

The intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> are arranged side by side at different positions in the crank shaft direction. The intake side cylinder portion <NUM> and the exhaust side cylinder portion <NUM> are arranged in parallel in the crank shaft direction so that a part thereof overlaps in the crank shaft direction. In this embodiment, the exhaust side cylinder portion <NUM> is disposed adjacent to the front side of the intake side cylinder portion <NUM>.

Further, when the chain casing <NUM> is viewed along the crank shaft direction (see <FIG>), the exhaust side cylinder portion <NUM> is disposed to be offset to the exhaust side (the D direction) in relation to the intake side cylinder portion <NUM>. In this embodiment, the exhaust side cylinder portion <NUM> is disposed adjacently to the side of the D direction of the intake side cylinder portion <NUM>. Thus, the exhaust side cylinder portion <NUM> is adjacently disposed in the E direction and the D direction of the intake side cylinder portion <NUM>.

Thus, the intake side cylinder portion <NUM> is adjacently formed above the exhaust side cylinder portion <NUM> to be parallel to the axial direction of the exhaust side cylinder portion <NUM> and to be located at a position different from the exhaust side cylinder portion <NUM> in the axial direction.

In <FIG> and <FIG>, the oil gallery portion <NUM> extends in a direction orthogonal to the crank shaft direction through the end portion of the intake side fastening boss portion <NUM> in the B direction and the end portion of the exhaust side fastening boss portion <NUM> in the B direction. The oil gallery portion <NUM> is connected to the end portion of the intake side fastening boss portion <NUM> in the B direction and the end portion of the exhaust side fastening boss portion <NUM> in the B direction.

The chain casing <NUM> includes a reinforcement rib <NUM> formed below the intake side cylinder portion <NUM>. The reinforcement rib <NUM> extends in the axial direction of the intake side cylinder portion <NUM>. The reinforcement rib <NUM> connects the intake side cylinder portion <NUM>, the exhaust side cylinder portion <NUM>, and the intake side fastening boss portion <NUM>.

Specifically, the reinforcement rib <NUM> extends in the axial direction of the exhaust side cylinder portion <NUM> from one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction to at least a position above the large diameter portion along the end portion on the side opposite to the bulging portion <NUM> (the end portion in the B direction) in the exhaust side cylinder portion <NUM>. The reinforcement rib <NUM> connects one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction to one end portion 23C of the intake side cylinder portion <NUM> in the axial direction. Specifically, the reinforcement rib <NUM> extends to one end portion 23C of the intake side cylinder portion <NUM> in the axial direction and connects one end portion 24C of the exhaust side cylinder portion <NUM> to a boss portion <NUM> formed at one end portion 23C of the intake side cylinder portion <NUM>.

The chain casing <NUM> includes the boss portion <NUM> formed at the end portion of the intake side cylinder portion <NUM> in the C direction and the B direction. The boss portion <NUM> is provided in the B direction of the bulging portion <NUM>. A leg portion 15C of the intake hydraulic control valve <NUM> is fastened to the boss portion <NUM>. The leg portion 15C extends in the E direction and the B direction at the end portion of the large diameter portion 15A of the intake hydraulic control valve <NUM> in the D direction.

The chain casing <NUM> includes a boss portion <NUM> on the side of the A direction of the end portion of the exhaust side cylinder portion <NUM> in the C direction. The boss portion <NUM> is provided in the bulging portion <NUM>. A leg portion 16C of the exhaust hydraulic control valve <NUM> is fastened to the boss portion <NUM>. The leg portion 16C extends in the E direction and the A direction at the end portion of the large diameter portion 16A of the exhaust hydraulic control valve <NUM> in the D direction.

An extension rib <NUM>, a connection rib <NUM>, and an upper rib <NUM> are formed on the surface of the chain casing <NUM>. The extension rib <NUM>, the connection rib <NUM>, and the upper rib <NUM> protrude in the E direction.

A boss portion <NUM> which extends in the E direction is formed in the vicinity of the end portion of the bulging portion <NUM> of the chain casing <NUM> in the D direction. A boss portion <NUM> which extends in the E direction is formed at the end portion of the chain casing <NUM> in the A direction.

The extension rib <NUM> extends upward from the boss portion <NUM> formed at one end portion 23C of the intake side cylinder portion <NUM> in the axial direction. The reinforcement rib <NUM> is connected to the extension rib <NUM>. The extension rib <NUM> extends from the boss portion <NUM> to the vicinity of the cylinder head fastening portion <NUM> of the end portion of the chain casing <NUM> in the C direction. The extension rib <NUM> reinforces the boss portion <NUM> by distributing the load acting on the boss portion <NUM> to the end portion of the chain casing <NUM> in the C direction.

The connection rib <NUM> is provided at a position on the side of the other end portion 24D of the exhaust side cylinder portion <NUM> in the axial direction in the chain casing <NUM> and in the vicinity of the end portion of the bulging portion <NUM> in the D direction. The connection rib <NUM> extends from the end portion of the exhaust side cylinder portion <NUM> in the D direction to the boss portion <NUM> in the A direction and the D direction. The connection rib <NUM> connects the other end portion 24D of the exhaust side cylinder portion <NUM> in the axial direction to the bulging portion <NUM>. Specifically, the connection rib <NUM> connects the other end portion 24D of the exhaust side cylinder portion <NUM> to the boss portion <NUM> formed in the bulging portion <NUM>.

Thus, the exhaust side cylinder portion <NUM> and the boss portion <NUM> are connected by the connection rib <NUM>. Accordingly, a load acting on the exhaust side cylinder portion <NUM> is distributed to the chain casing <NUM> through the boss portion <NUM>.

The upper rib <NUM> is provided in the vicinity of the end portion of the chain casing <NUM> in the A direction. The upper rib <NUM> extends from the boss portion <NUM> to the boss portion <NUM> in the A direction and the C direction. The upper rib <NUM> is connected to the boss portion <NUM> and the boss portion <NUM>. Thus, the boss portion <NUM> and the boss portion <NUM> are connected by the upper rib <NUM>. Accordingly, the load acting on the boss portion <NUM> is distributed to the boss portion <NUM> through the upper rib <NUM>. Further, the reinforcement rib <NUM> is connected to the boss portion <NUM> and the reinforcement rib <NUM> extends from the boss portion <NUM> in the D direction. The load acting on the boss portion <NUM> is also distributed to the portion in the vicinity of the boss portion <NUM> of the bulging portion <NUM> in the D direction by the reinforcement rib <NUM>.

As described above, in this embodiment, the exhaust side cylinder portion <NUM> is adjacently formed below the bulging portion <NUM>. Further, the other end portion 24D of the exhaust side cylinder portion <NUM> in the axial direction is disposed below one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction. Then, the chain casing <NUM> includes the connection rib <NUM> which is formed on the side of the other end portion 24D of the exhaust side cylinder portion <NUM> in the axial direction to connect the other end portion 24D of the exhaust side cylinder portion <NUM> in the axial direction to the bulging portion <NUM>.

Accordingly, when foreign matter such as flying stones flows from the road surface below the vehicle toward the exhaust hydraulic control valve <NUM> along the arrow A (see <FIG>), foreign matter collides with the wall portion 21A of the bulging portion <NUM> or the connection rib <NUM> and falls without colliding with the exhaust hydraulic control valve <NUM>. Thus, it is possible to protect the large diameter portion 16A which is a portion of the exhaust hydraulic control valve <NUM> exposed to the outside from foreign matter such as flying stones flying from below.

Further, in this embodiment, the chain casing <NUM> includes the reinforcement rib <NUM> which extends in the axial direction of the exhaust side cylinder portion <NUM> from one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction to at least a position above the large diameter portion along the end portion on the side opposite to the bulging portion <NUM> in the exhaust side cylinder portion <NUM>.

Accordingly, the large diameter portion 16A of the exhaust hydraulic control valve <NUM> exposed from the exhaust side cylinder portion <NUM> to the outside can be surrounded from below by the reinforcement rib <NUM>, the exhaust side cylinder portion <NUM>, and the bulging portion <NUM>. Therefore, when foreign matter such as flying stones flies from the road surface below the vehicle toward the exhaust hydraulic control valve <NUM> along the arrow B (see <FIG>), foreign matter collides with the bulging portion <NUM> or the connection rib <NUM> and falls without colliding with the exhaust hydraulic control valve <NUM>. Thus, it is possible to more effectively protect the large diameter portion 16A of the exhaust hydraulic control valve <NUM> exposed from the exhaust side cylinder portion <NUM> to the outside from foreign matter such as flying stones. Additionally, the intake side fastening boss portion <NUM> is connected to the lower surface of the reinforcement rib <NUM> and the intake side fastening boss portion <NUM> has a dimension (height) larger than that of the reinforcement rib <NUM> in the E direction. Therefore, it is also possible to more effectively protect the large diameter portion 16A from foreign matter such as flying stones by the intake side fastening boss portion <NUM>.

Further, in this embodiment, the chain casing <NUM> includes the intake side cylinder portion <NUM> adjacently formed above the exhaust side cylinder portion <NUM> to be parallel to the axial direction of the exhaust side cylinder portion <NUM> and to be located at a position different from the exhaust side cylinder portion <NUM> in the axial direction. Then, the reinforcement rib <NUM> connects one end portion 24C of the exhaust side cylinder portion <NUM> in the axial direction to one end portion 23C of the intake side cylinder portion <NUM> in the axial direction.

Accordingly, since foreign matter such as flying stones flying from the lower side of the vehicle collides with the reinforcement rib <NUM>, it is possible to effectively protect the large diameter portion 15A of the intake hydraulic control valve <NUM> exposed from the intake side cylinder portion <NUM> to the outside.

Further, since the exhaust side cylinder portion <NUM> and the intake side cylinder portion <NUM> are connected by the reinforcement rib <NUM>, it is possible to reinforce the exhaust side cylinder portion <NUM> and the intake side cylinder portion <NUM> by more firmly connecting them and to suppress the vibration or deformation of the exhaust side cylinder portion <NUM> and the intake side cylinder portion <NUM>.

Further, in this embodiment, the reinforcement rib <NUM> extends to one end portion 23C of the intake side cylinder portion <NUM> in the axial direction. Then, the chain casing <NUM> includes the extension rib <NUM> which is connected to the reinforcement rib <NUM> and extends upward from one end portion 23C of the intake side cylinder portion <NUM> in the axial direction.

Accordingly, the large diameter portion 15A of the intake hydraulic control valve <NUM> inserted into the intake side cylinder portion <NUM> is surrounded from below by the bulging portion <NUM>, the reinforcement rib <NUM>, and the extension rib <NUM>. Therefore, it is possible to more effectively protect the large diameter portion 15A of the intake hydraulic control valve <NUM> exposed from the intake side cylinder portion <NUM> to the outside from foreign matter such as flying stones.

Claim 1:
A vehicle comprising an internal combustion engine (<NUM>) mounted thereon with center lines of a plurality of cylinders inclined with respect to an up to down direction of the vehicle, the internal combustion engine including:
a variable valve timing mechanism (<NUM>) configured by winding a timing chain thereon;
a hydraulic control valve (<NUM>) controlling hydraulic oil supplied to the variable valve timing mechanism; and
a chain casing (<NUM>) fixed to a cylinder head (<NUM>) to cover the timing chain and the variable valve timing mechanism,
wherein the chain casing includes:
a bulging portion (<NUM>) bulging in a crank shaft direction and covering the variable valve timing mechanism; and
a cylindrical cylinder portion (<NUM>) attaching the hydraulic control valve thereto,
wherein the hydraulic control valve includes:
a small diameter portion (16B) inserted from an upper end (24C) of the cylinder portion in an axial direction thereof into the cylinder portion, the upper end being open; and
a large diameter portion (16A) exposed from the upper end of the cylinder portion in the axial direction,
wherein the cylinder portion is adjacently formed below the bulging portion,
wherein the other end portion (24D) of the cylinder portion in the axial direction is located below the upper end of the cylinder portion in the axial direction,
wherein the chain casing includes a connection rib (<NUM>) to connect the other end portion of the cylinder portion in the axial direction to the bulging portion, and
wherein the chain casing includes a reinforcement rib (<NUM>) extending in the axial direction of the cylinder portion from the upper end of the cylinder portion in the axial direction to at least a position above the large diameter portion along an end portion on the side opposite to the bulging portion in the cylinder portion.