JPS633411Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection pump cooling device for a diesel engine.

Conventional fuel injection pump cooling devices, for example as in Utility Model Publication No. 50-30491, cool the lubricating oil collected in the pump case with cooling water.
This indirectly prevents the fuel injection pump from heating up. However, the indirect cooling structure as in the prior art described above has a small cooling effect.

The purpose of this invention is to forcibly cool the fuel injection pump by injecting the lubricating oil by using lubricating oil that lubricates various parts in the crankcase such as the crankshaft, and to reduce the injection amount of the fuel injection pump. The goal is to keep the characteristics stable at all times. The present invention will be explained below based on the drawings.

In FIG. 1a, which is a side view of a diesel engine, 1 is a crankcase, 1a is a cylinder head, 1b is a head cover, and an oil pan 2 is fixed to the lower end of the crankcase 1. A gear case 5 is fixed to one longitudinal end of the crankshaft 3 of the crankcase 1 via a front plate 4 made of iron plate. A pump case 6 for mounting a fuel injection pump and an oil filter 7 are fixed to the projecting front plate 4 portion. The number of fuel injection pumps 8 is the same as the number of cylinders, but each injection pump 8 is installed in one support stand 9, and as one unit, the pump case 6 is inserted from the top opening of the pump case 6.
It is inserted into the pump case 6 and fixed to the pump case 6 with bolts or the like. 20 is a governor case integrally formed with the pump case 6. Reference numeral 10 denotes an oil pump (for example, a trochoid pump) formed within the gear case 5.

FIG. 1b is a front view of FIG. 1a in the direction of arrows, and in this FIG. 1b, a lubricant suction passage 11 is formed in the oil pump 10, and a main lubricant oil passage 12 on the discharge side communicates with the oil pump 10. The main lubricating oil passage 12 includes an oil filter 7, a relief valve 22, and an auxiliary oil passage 1.
5 is formed, and their relationship is shown in the lubricating oil system diagram in FIG.

That is, in FIG. 2, the inlet of the oil pump 10 and the oil pan 2 are connected via the oil passage 11, and the outlet of the oil pump 10 and the inside of the crankcase 1 are connected via the main lubricating oil passage 12, so that the main lubricating oil Road 12
An oil filter 7 is placed in the middle.
That is, the lubricating oil sucked up from inside the oil pan 2 by the oil pump 10 is filtered by the oil filter 7, and then sent into the crankcase 1 via the main lubricating oil passage 12, where it lubricates the crankshaft 3, etc., and is then reused. Return to oil pan 2 (the return oil path is shown by a broken line).

The main lubricating oil passage 12 is connected to the gear case 5 (2 in Fig. 2).
A relief valve 22 is provided on the outlet side of the filter 7 to keep the oil pressure of the main lubricating oil path constant at all times. In other words, it is a pressure regulating valve that opens the valve when the pressure exceeds a certain level and releases the lubricating oil in the main lubricating oil passage into the gear case 5, and closes the valve when the pressure falls below a certain level. Further, a sub-oil passage 15 is formed in the main lubricating oil passage 12 within the wall of the gear case 5, and the sub-oil passage 15 branches between the oil filter 7 and the crankcase 1, and this sub-oil passage 15 extends to the pump case 6. The lower end of the pump case 6 is a return oil passage 21
It communicates with the gear case 5 via.

That is, as shown in FIG. 3, which is an enlarged partial cross-sectional view of FIG. 16, and the nozzle portion 16 opens toward the injection pump 8 (support stand 9) inside the pump case 6.

The lubricating oil that has been pressure-fed through the auxiliary oil passage 1 and has reached the nozzle portion 16 is sprayed at high pressure onto the injection pump 8 (support stand 9) to forcibly and efficiently cool the injection pump 8. For example, the diameter of the pores in the nozzle part 16 is 1.4
mm, the oil pump 10 has a sufficient discharge amount, and the pressure is regulated by the relief valve 22, so that lubricating oil is always injected into the pump 8 at a high pressure of 4 kg/cm ² .
can be sprayed on.

As described above, the return oil passage 21 that leads into the gear case 5 is formed at the lower end of the pump case 6, and after the lubricating oil used for cooling is used to lubricate the camshaft 17, etc., the return oil passage 21 and gear case 5
Although the oil is returned to the oil pan 2 through the pump case 6, an amount of oil is always maintained in the pump case 6 to the extent that the camshaft 17 can be lubricated while the camshaft 17 is immersed in the oil. That is, the lubricating oil in the pump case 6 is circulated (replaced with clean lubricating oil spouted from the nozzle part 16) while maintaining a constant oil level height L in the pump case 6. Therefore, the bearing part 18 of the camshaft 17, the space between the cam 17a and the tappet 19, and the operating parts in the governor case 20 that communicate with the inside of the pump case 6 can always be well lubricated with clean lubricating oil. It is.

As explained above, according to the present invention: (1) Lubricating oil is constantly sprayed at high pressure from the nozzle part 16 to the fuel injection pump 8.
Since the fuel is forcibly cooled, the cooling efficiency is extremely high, and therefore, the injection amount characteristics of the fuel injection pump 8 are stabilized, and the performance of the engine is improved.

To explain in more detail, the nozzle part 16 connected to the lubricating oil pump 10 is arranged to face the fuel injection pump 8 at a distance, and the cooling lubricating oil is directly sprayed at high pressure onto the fuel injection pump 8 itself. Therefore, the cooling effect of the fuel injection pump 8 is extremely good due to the forced cooling effect of the lubricating oil injected at high pressure and the flow of surrounding air accompanying the lubricating oil injection, and the injection amount characteristics of the fuel injection pump 8 are always stable. do.

(2) Since the fuel injection pump 8 is cooled using lubricating oil and the oil pump 10 for lubricating each operating part in the crankcase 1, it is necessary to provide a special cooling device for cooling the fuel injection pump. The production and material costs are low.

(3) Since the fuel injection pump 8 inside the pump case 6 is cooled with lubricating oil, the lubricating oil used for cooling can of course be used to lubricate the camshaft 17, etc. inside the pump case 6, as well as the governor. It can be used to lubricate the operating parts inside the case, and the lubricating oil inside the pump case 6 can be circulated (replaced with clean lubricating oil), so the lubrication performance is extremely good.

To explain in more detail, since the cooling lubricant is sprayed onto the fuel injection pump 8 above the camshaft 17 and tappet 19, the lubricant after spraying will naturally flow onto the camshaft 17 and tappet 19.
It flows down to the parts and lubricates the camshaft 17 and tappet 19.

In other words, the lubricating oil after cooling the fuel injection pump is automatically transferred to the camshaft 17 without providing a special lubricating oil passage.
It can also be used to lubricate the tappet 19, making it extremely practical.

The illustrated pump case 6 is the crank case 1.
Although they are separate parts, the present invention can also be applied to engines in which the crankcase and pump case are integrally cast. Further, the nozzle portion 16 is not limited to one location, but may be formed at multiple locations. Further, the nozzle part 16 shown in the drawing (FIG. 3) is formed by directly making a pore in the wall of the pump case 6, but a nozzle body separate from the pump case 6 is screwed onto the pump case 6, for example. You may.

[Brief explanation of the drawing]

FIG. 1a is a side view of a diesel engine to which the present invention is applied, FIG. 1b is a front view of FIG. 1a, FIG. 2 is a lubricating oil system diagram, and FIG. 3 is an enlarged longitudinal section of the upper right portion of FIG. 1. 1 ... crankcase, 6 ... pump case,
8... fuel injection pump, 10... oil pump,
12: Main lubricating oil passage, 15: Auxiliary oil passage, 16:
Nozzle part.

Claims (1)

[Scope of utility model registration request] A nozzle that has an auxiliary oil passage branching from the main lubrication oil passage leading from the oil pump into the crankcase, extends the auxiliary oil passage to the pump case for mounting the fuel injection pump, and can inject lubricating oil to the outlet of the auxiliary oil passage. The nozzle part is arranged to face the fuel injection pump above the camshaft and the tappet at a distance, and the nozzle part sprays cooling lubricating oil to the fuel injection pump. 1. A fuel injection pump cooling device for a diesel engine, characterized in that a lower camshaft and tappet are lubricated by lubricating oil flowing down from the camshaft.