JPH0113792Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for arranging various drive devices near the cylinder head of a diesel engine, which can reduce the overall height of an overhead cam type engine.

Conventionally, commonly used overhead cam type engines have a camshaft for driving intake and exhaust valves in the cylinder head, so the height of the timing belt pulley that drives the camshaft is higher than the valve arm chamber provided on the top surface of the cylinder head. The drawback was that the overall height of the engine was correspondingly higher.

Also, if the exhaust port or intake port provided on the cylinder head is formed on the camshaft side, the camshaft must be installed above the intake and exhaust ports, so the camshaft If the supporting bearing retaining member must be installed at a high position on the cylinder head and the top surface of the cylinder head needs to be lowered to a certain degree, another camshaft bearing retaining member must be provided on the top surface of the cylinder head. However, the number of parts increases and the mechanism becomes complicated.

Therefore, the present invention aims to reduce the overall height of the engine by lowering the height of the cylinder head part, even though it is an overhead cam type and a unit injector type. It was done with the purpose of

That is, the present invention provides an overhead cam type diesel engine with an intake port and an exhaust port located on the same side of the cylinder head with respect to the cylinder center line, and a unit injector inserted into the combustion chamber from the opposite side of the intake port and exhaust port. The cylinder head is inserted at an angle, an overhang is formed on the side opposite to the side where the intake port and the exhaust port are provided, and the camshaft is disposed in the overhang, so that the camshaft is tilted. The unit injector, the intake valve, and the exhaust valve are each driven separately by each valve arm that engages with each cam separately provided on the camshaft. It consists of the arrangement structure of various drive devices near the cylinder head of a diesel engine.

Embodiments of the present invention will be described below with reference to the drawings.

First, in the diesel engine according to the embodiment of the present invention shown in FIG.
The center of the tip of the unit injector 3, which integrates an injection pump and an injection valve, which is a fuel injection device installed inside the combustion chamber 4, is slightly eccentric from the center of the cylinder and tilted by an angle θ. The injection valves are installed facing each other.

In addition, an intake valve 5 and a third valve shown in FIG.
An exhaust valve 6 shown in the figure is provided, and the intake valve arm 7 of the intake valve 5 and the exhaust valve arm 8 of the exhaust valve 6 are supported by an intake and exhaust valve arm shaft 9, and are connected to the intake port of the cylinder head 1 and the exhaust valve arm 8 of the exhaust valve 6. The intake cam 11 and the exhaust cam 12 are respectively provided on a single camshaft 10 disposed on a projecting portion 22 formed on the side opposite to the side where the port is provided. 23 indicates the upper surface of the cylinder head 1.

A valve arm support 13 that supports the intake and exhaust valve arm shafts 9 of the intake valve arm 7 and the exhaust valve arm 8 is provided at an intermediate portion between the cylinders of this diesel engine.

Next, the valve arm 14 of the unit injector 3 shown in FIG. 1 is supported by a valve arm shaft 15 and is oscillated by a fuel cam 16 provided coaxially with the camshaft 10.

Therefore, the intake port 17 provided with the above-mentioned intake valve 5
An exhaust port 18 provided with an exhaust valve 6 and an exhaust valve 6 are formed in the cylinder head 1, but both are provided on the opposite side of the cylinder center line from the unit injector 3 inserted at an angle. The camshaft 10 is provided at a lower position on the side opposite to the cylinder center line of the intake port 17 and the exhaust port 18, that is, on the unit injector 3 side and below the side of the unit injector 3.

In the cylinder head 1 of the diesel engine of the present invention having the above-mentioned configuration, a camshaft 10 is provided at a low position on the side of the unit injector 3 which is provided at an angle. The provided intake cam 11, exhaust cam 12, and fuel cam 16 swing the intake valve arm 7, the exhaust valve arm 8, and the valve arm 14 for fuel injection of the unit injector 3, respectively. At the same time as the lift is performed, fuel is injected from the unit injector 3.

Further, since the camshaft 10 is disposed on the overhanging portion 22 formed on the opposite side of the cylinder center line of the intake port 17 and exhaust port 18 of the cylinder head 1, the camshaft 10 and its driving device are The position of the camshaft drive pulley 20 can also be provided at a position lower than the upper end of the valve arm chamber 2, as shown in FIG.

Furthermore, the bearing 21 that supports the camshaft 10 can be easily mounted at a low position on the cylinder head 1 itself, and the structure of the drive and support device for the camshaft 10 is also simplified.

Therefore, in a diesel engine employing the cylinder head of the present invention, the height of the cylinder head can be lowered even though it is an overhead cam type and a unit injector type, so the overall height of the engine can be lowered and its It is also possible to reduce the weight of the engine.

In addition, the camshaft bearing can be easily attached to the cylinder head itself, and its structure is simple, allowing for a reduction in the number of parts compared to the case where the camshaft bearing support member is provided above the cylinder head. .

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of the main part of the unit injector portion of the cylinder head in an embodiment of the present invention;
Figure 2 is a front sectional view of the main part of the intake port part in Figure 1, Figure 3 is a front sectional view of the main part of the exhaust port part in Figure 1, and Figure 4 is a side sectional view of the main part of Figure 1. be. 1... Cylinder head, 3... Unit injector, 4... Combustion chamber, 10... Camshaft, 17...
...Intake port, 18...Exhaust port.

Claims (1)

[Scope of Claim for Utility Model Registration] In an overhead cam type diesel engine, an intake port and an exhaust port are provided on the same side of the cylinder head with respect to the cylinder center line, and a unit injector is installed from the opposite side of the intake port and exhaust port. The camshaft is inserted into the combustion chamber at an angle, an overhang is formed on the side opposite to the side where the intake port and exhaust port are provided, and the camshaft is placed in the overhang. The unit injector, the intake valve, and the exhaust valve are located at a low point on the lower side of the inclined unit injector, and the unit injector, the intake valve, and the exhaust valve are each connected to each other by each valve arm that engages with each cam separately provided on the camshaft. Arrangement structure of various drive devices near the cylinder head of a diesel engine that is driven separately.