JPS6246857Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is based on a four-valve diesel engine, in which the shaft center of the fuel injection valve is eccentrically mounted approximately in the middle of the bridge axis for the intake and exhaust valves, and high pressure is injected into the fuel injection valve. This relates to an attempt to make the upper surface of the cylinder compact by screwing the tube.

[Conventional technology and its problems]

Conventionally, a thick walled part is formed in the main body of a fuel injection valve, and the end of a high pressure pipe communicating with a fuel injection pump is screwed into the thick walled part, and the high pressure pipe is supported from the outside of the cylinder head. A structure in which it is inserted into a horizontally installed drill hole is known (Utility Model No. 54-82814).
(See Japanese Utility Model Publication No. 55-97168).

However, since the cylinder head originally houses the intake and exhaust valves, intake and exhaust ports, and even fuel injection valves, it has the most complex structure among the engine parts made of cast iron with many partitions. Moreover, it is further complicated because it passes through the push rod and 4 to 8 cylinder head bolts per cylinder. In such a cylinder head,
In particular, when a four-valve intake/exhaust valve is installed, if the above-described high-pressure pipe mounting structure is applied as is, there is a problem in that it is difficult to open the drilled holes.

[Means for solving problems]

Therefore, the present invention was devised to eliminate such inconveniences.The configuration of the present invention will be explained below with reference to an embodiment.
In the plan view of the valve type cylinder head, 1 and 1' are exhaust valves which are pressed by an exhaust bridge 2, which is pressed by an exhaust rocker arm 3. 4 and 4' are intake valves, and intake bridge 5
The intake bridge 5 is pressed by the intake rocker arm 6. The intake/exhaust rocker arms 6, 3 are swingably attached to an intake/exhaust valve arm mount 7, and the intake/exhaust valve arm mount 7 is screwed 9, 9', 9'' onto the upper surface of the cylinder head 8. The ends 10, 11 of the intake/exhaust rocker arms 6, 3 on the opposite side of the valve are subjected to the movement of a push rod (not shown) that is moved up and down by a cam (not shown) from below. , 3 make a rocking motion.

Reference numeral 12 denotes the fuel injection valve main body, point A is the midline of the piston (not shown), that is, the center point of the Hetzelmann combustion chamber, and point B is the axis of the fuel injection valve main body 12, and the main body 12 is eccentric. There is a thick walled portion 13, to which a high pressure pipe 14 passing laterally through the cylinder head 8 is screwed. 15 is a valve holder for attaching the fuel injection valve body 12, 16 is a high pressure pipe joint,
17 indicates the wall of the valve arm chamber.

FIG. 2 is a sectional view of the exhaust valve box 19, and in this embodiment, two valves are used since it is a four-valve type. 2 corresponds to the A to A cross section or the Ro to Ro cross section in FIG. 1. The exhaust valve box 19 of the present embodiment shown in FIG. In addition, it communicates with the water jacket of the cylinder head 8 to allow cooling water to pass therethrough, making it convenient for valve removal. That is, 2
0 is the exhaust valve box body, with flange parts 2 on both sides at the top.
1 extends and is attached to the upper surface of the cylinder head 8 by two mounting bolts 22, 22',
If necessary, remove the mounting bolts 22, 22' and pull up the exhaust valve box body 20 to take it out. Reference numeral 23 denotes an exhaust valve, which is slidably provided within the exhaust valve box main body 20 via a bush 24, and has a valve rotator 24' provided above with a valve spring 21' interposed therebetween. 25 is a cooling water jacket, 26 is a collar,
27 indicates an exhaust passage. In addition, the mounting bolt 22,
The screwing depth of 22' into the cylinder head is the same as that of a normal valve box, and is located above the position of the high pressure pipe 14.

Since the flange portion 21 of the exhaust valve box 19 is arranged in the cross-sectional direction of the upper surface of the cylinder head 8 in FIG. , the fuel injection valve main body 12 is mounted at a position substantially perpendicular to these cross sections and midway between these axes 28 and 29. The thick portion 13 of the fuel injection valve body 12 is aligned with the axes 28 and 29.
It is located along the direction.

Since the present embodiment has the above-described configuration, the following general operations are performed. In other words, the fuel injected from the fuel injection valve burns in a Hesselmann-shaped combustion chamber,
The vertical movement of the bushing rod for the intake and exhaust valves by the cam causes the intake and exhaust rocker arms 6 and 3 to swing around the intake and exhaust valve arm mounting base 7, causing the intake and exhaust bridges 5 and 2 to resist the valve spring 21'. and press intermittently,
Open and close intake/exhaust 1, 1', 4, 4'.

Since the diesel engine of this embodiment employs a long stroke, the opening and closing positions of each valve in the horizontal direction are shifted upwards of the engine, and the valve edge provided on the upper surface of the piston is omitted.

Therefore, the long stroke takes a large amount of intake air, combustion becomes insensitive under both low and high loads, and the lack of valve exhaust improves scavenging of exhaust gas, all of which are mixed together. Contributes to low fuel consumption.

Furthermore, the engine of this embodiment employs an exhaust valve case 19 only for the exhaust valve, and the high pressure pipe 14 for the fuel injection valve is passed through the cylinder head 8 and is structured so as not to straddle the exhaust valve, making it easy to disassemble and assemble the exhaust valve case 19. Also, the use of the exhaust valve case 19, which takes up a relatively large amount of space, makes it difficult to employ a high pressure pipe 14 joint that forms a large outer diameter of the fuel injection valve body. However, since the thick wall portion 13 is provided eccentrically on the body 12, a thread portion for screwing in the high pressure pipe can be provided on the thick wall portion 13, making it possible to make the engine more compact and,
It can be easily screwed on.

The present invention, which requires the above, has the following effects because it employs the configuration described in the claims for utility model registration.

[Effect of idea]

Since the exhaust valve box 19 is adopted, the exhaust valve can be easily maintained and inspected without removing the cylinder head 8, and of course it also allows the use of low-quality fuel.
Although the use of two exhaust valve boxes 19, which occupy a relatively large space, takes up more space, a thick wall portion 13 for screwing the high pressure pipe 14 onto the fuel injection valve main body 12 is provided eccentrically, and the thickness is increased. Since the flesh portion 13 is located in the direction of the axes 28 and 29 of the bridge for intake and exhaust valves, high-pressure pipes can be attached without the need for high-pressure pipe joints, and the whole can be made compact. Therefore, there is no problem in extracting the exhaust valve box 19 upwardly.

[Brief explanation of the drawing]

FIG. 1 is a plan view, and FIG. 2 is a cross-sectional view of FIG. 8...Cylinder head, 12...Fuel injection valve body, 13...Thick wall part, 14...High pressure pipe, 19...
Exhaust valve box, 28, 29... Axis of bridge for intake and exhaust valves.

Claims (1)

[Scope of utility model registration request] In a four-valve diesel engine equipped with an exhaust valve box 19, at least the bridge axis 2 for the intake and exhaust valves is sandwiched between the flange portions of the exhaust valve box 19.
The fuel injection valve main body 12 is mounted at a position sandwiched between the intermediate positions of the fuel injection valve main bodies 8 and 29, and the fuel injection valve main body 12
A cylinder head for a diesel engine, in which a thick wall portion 13 for screwing a high pressure pipe 14 is provided eccentrically, and the thick wall portion 13 is positioned in the direction of the bridge axes 28 and 29 for intake and exhaust valves.