JP2671023B2 - V-type DOHC engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a valve operating valve for directly opening and closing a plurality of intake valves and exhaust valves per cylinder with two camshafts in each bank forming a V-shape. The present invention relates to a V-type DOHC engine having a device.

(Background of the Invention) A four-stroke engine having two camshafts parallel to a crankshaft, and two or more direct-acting heads each of which directly opens and closes a plurality of intake valves and exhaust valves by a quantity camshaft. Camshaft (DOHC) engines are known. This type of engine has two camshafts, so the valve device becomes large. Therefore, when a V-type engine is configured using this engine, there is a problem that the cylinder head protrudes in a direction perpendicular to the crankshaft of the engine, and the engine width in this direction increases.

When the engine is mounted on a passenger car or the like, the engine is often serviced from above with the engine cover opened upward. At this time, it is desirable that the engine be easily serviced from above.

(Object of the Invention) The present invention has been made in view of such circumstances,
When each bank is a two-head camshaft type, the engine width in the direction orthogonal to the crankshaft is reduced to improve the mountability on the vehicle, and the maintainability from above in the engine room is improved. The object is to provide a V-type DOHC engine capable of operating.

(Constitution of the Invention) According to the present invention, an object of the present invention is to provide a V-type DOHC engine having two camshafts for directly opening and closing a plurality of intake valves and exhaust valves in two banks forming a V-type.
One camshaft and an exhaust / intake valve that opens and closes the camshaft are arranged so as to be substantially on a plane that passes through the center of the cylinder and that is parallel to the crankshaft, and the other camshaft and the intake / exhaust valve that opens and closes the camshaft. Deviate more greatly in the valley between both banks than in the plane, hold both cam shafts between the split faces of the cylinder head and head cover, and make these split faces closer to the horizontal side than the split faces of the cylinder and cylinder head. This is achieved by the V-type DOHC engine, which is characterized by

(Embodiment) FIG. 1 is an overall schematic view of a V-type six-cylinder engine according to one embodiment of the present invention, FIG. 2 is a plan view showing a valve operating chamber in a right bank thereof, and FIGS. It is the III-III sectional view taken on the line, and the IV-IV sectional view taken on the line.

In FIG. 1, the engine is a pair of banks 1 forming a substantially V-shape.
Each bank 10 has a cylinder head 14 and a head cover 16 attached to a cylinder block 12 having a substantially pentagonal shape in front view. Cylinders 18, 18 in both banks 10, 10
The pistons 20, 20 of the cylinders in each bank 10, 10, which are paired with each other, are connected by connecting rods 26, 26 to crank pins 24a, 24b having a phase difference of 30 ° of the crankshaft 22, respectively. ing. The crankshaft 22 rotates clockwise in FIG. Each bank 10,10 has both banks 10,10
An intake pipe 28 arranged on the V-shaped valley side formed between them is connected, and the exhaust pipes 30, 30 are connected to the outer surfaces of the banks 10, 10, respectively. 32 is an oil pan.

Next, the cylinder head 14 will be described, but since it is symmetrical to the left and right, the cylinder head 14 of the bank 10 on the right side will be described.

The cylinder head 14 has cylinders 18 for three cylinders.
Are arranged side by side in parallel with the crankshaft 22, and the valve train of each cylinder is displaced to the V-shaped valley side with respect to a plane A including the cylinder center and parallel to the crankshaft 22. That is, two camshafts 3
The centers of 4 and 36 are both located on the V-shaped valley side from the plane A, and the spark plug 38 is also inclined in the same direction. Reference numerals 40 and 40 denote exhaust valves, and the exhaust valve 40 and the cam shaft 34 are arranged so as to be substantially on the plane A. Also intake valves 42, 42 and camshaft
36 is located on a plane that is largely inclined to the V-shaped valley side with respect to the plane A. As shown in FIG. 2, each of these cam shafts 34, 36 is provided with two exhaust cams 34a, 34a and intake cams 36a, 36a, respectively. The valve lifters 44 and 46 of the intake valve 42 are directly pressed to open and close these valves 40 and 42.

The cam shafts 34 and 36 are the cylinder head 14 and the head cover 16
Is held on the split surface B. That is, the head cover 16
Inside, the mating surface of the cap 48 fixed to the cylinder head 14 and the cylinder head 14 is located on the same plane as the split surface B.
Held between. The split surface B is closer to the horizontal side than the split surface C between the cylinder 12 and the cylinder head 14, as shown in FIG.

A spark plug attachment / detachment hole 50 is formed in the cap 48. That is, the spark plug mounting / dismounting hole 50 is orthogonal to the split surface B, penetrates between the camshafts 34 and 36, and is continuous with the spark plug mounting / dismounting hole 52 on the cylinder head 14 side. A circular opening is formed in the head cover 16 on the extension line of the spark plug attachment / detachment holes 50, 52, and a rubber seal 54 attached to the opening edge of the spark plug attachment / detachment hole 50 on the cap 48 side is formed inside the opening edge on the head cover 16 side. It is sealed by elastic contact. The plug cap 56 has a spark plug attachment / detachment hole
Plugged in 50, 52, the plug cord is connected to the spark plug 38. The cap 48 is located on a plane passing through the center of each cylinder and orthogonal to the crankshaft 22, and is fixed to the cylinder head 14 by four bolts 58 located on both sides of each of the camshafts 34 and 36.

The cylinder head 14 is fixed to the cylinder block 12 by eight head bolts 60 (see FIG. 3). That is, the four head bolts on one side of the plane A are located between the cam shafts 34 and 36 in the valve operating chamber that accommodates the valve operating device. The four bolts 60 on the other side with respect to the plane A are
It is screwed to the cylinder block 12 by penetrating a flange portion 14a protruding outward on the exhaust valve 40 side. In FIG. 2, 60a is a bolt hole into which these bolts 60 are inserted. These bolts 60 are hexagonal bolts.

Therefore, in FIG. 5 in which valve operating devices such as camshafts 34, 36, exhaust / intake holes 40, 42, and a cap 48 are preliminarily assembled on the cylinder head 14, FIG.
What is necessary is just to fix with the head bolt 60.

In FIGS. 1 and 3, reference numeral 62 denotes a magnetic fuel injection valve which injects gasoline fuel in the vicinity of a branch portion to each of the intake valves 42, 42 in an intake passage 64 connected to the intake valve 42. In FIG.
66 is an intermediate sprocket located above the crankshaft 22, and the rotation of the crankshaft 22 is once decelerated by passing through the intermediate sprocket 66, and then the timing chain 68 further causes the camshaft 34 of each bank 10, 10 to rotate. It is conveyed to 36. Although the timing chain 68 of only the left bank 10 is shown in FIG. 1, the same applies to the right bank.

(Effects of the Invention) As described above, the present invention arranges one camshaft and an exhaust valve (or intake valve) that opens and closes directly so that the camshaft rides substantially on a plane passing through the center of the cylinder and parallel to the crankshaft. Since the other camshaft and the intake valve (or exhaust valve) that opens and closes directly are greatly displaced toward the V-shaped valley with respect to the plane, the valve train is displaced toward the V-shaped valley. As a result, the engine width in the direction orthogonal to the crankshaft can be reduced. Since the split surface between the cylinder head that holds the camshaft and the head cover is closer to the horizontal side than the split surface between the cylinder and the cylinder head, when installing this engine in the engine room of a passenger car, etc. It becomes easy to remove the valve and check and maintain the valve train.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic view of a V-type six-cylinder engine according to an embodiment of the present invention, FIG. 2 is a plan view showing a valve operating chamber in a right bank thereof, and FIGS. Is a sectional view taken along the line III-III in FIG.
FIG. 4 is a sectional view taken along line IV. 10 ... Bank, 12 ... Cylinder block, 14 ... Cylinder head, 16 ... Head cover, 22 ... Crank shaft, 34, 36 ... Cam shaft, 40 ... Exhaust valve, 42 ... Intake valve, A ... ... plane, B, C ... ... split surface.

Claims (1)

(57) [Claims] 1. A V-DOHC engine having two camshafts for directly opening and closing a plurality of intake valves and exhaust valves in two banks forming a V-shape, wherein one camshaft and an exhaust / The intake valve and the intake / exhaust valve, which are arranged so as to pass through the center of the cylinder and which are substantially parallel to the crankshaft and which are parallel to the crankshaft, and the other camshaft and the intake / exhaust valve which opens and closes the camshaft, are located on the valley side between the banks. The V-shape is characterized in that the cam shafts are largely displaced, and both cam shafts are held between the split surfaces of the cylinder head and the head cover, and the split surfaces are closer to the horizontal side than the split surfaces of the cylinder and the cylinder head. DOHC engine.