JPS6315612Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine, and more particularly to a crankshaft for an internal combustion engine whose piston is cooled with oil.

Figure 1 shows an example of a diesel engine in which the piston is cooled with oil. In the figure, 1 is the piston, 2 is the piston pin, 3 is the connecting rod, 4 is the cooling chamber of the piston, and 5 is the cooling chamber formed inside the piston pin 2. 6 is an oil hole formed in the connecting rod 3, 7 is a crank pin, 8 is a crank web, 9 is a crank pin bearing, 10 is a crank journal, and 11 is attached to an end surface 8a of the crank web 8. 12 is an oil reservoir formed inside the crank journal 10, 13 is a main bearing, 14 is a crank case, 15 is a main gear rally, and 20 is an oil reservoir formed inside the crank pin 7.

In the above engine, the lubricating oil in the main gear rally 15 reaches the main bearing 13 through the oil hole 17, is branched from there, passes through the oil hole 18 in the journal part, enters the oil sump 12 in the journal, and then the oil in the crank web. The oil reaches the crank pin bearing 9 through the hole 19 and the oil reservoir 20 in the crank pin to lubricate it.
A portion of the lubricating oil is branched off at the crank pin bearing 9, passes through an oil hole 6 in the connecting rod and an oil reservoir 5 in the piston pin, and enters the piston cooling chamber 4 to cool the piston 1.

In such an engine, conventionally, in order to drill the oil hole 19 in the crank web 8, the oil hole 19 is first machined from the crank pin 7 side end of the crank web 8, and then the crank pin 7 side opening is blinded. Stopper 23
It was blocked by For this reason, 23 blind plugs had to be machined with screws, resulting in problems such as an increase in the number of processing steps and the number of parts. Furthermore, with such a structure, it becomes difficult to reduce the rotational mass of the crankshaft by thinning out the shoulder 24 of the crank web 8 as shown in FIG. 4, which increases the weight of the crankshaft and reduces engine vibration. It also had the problem that it was not desirable.

In addition, in FIGS. 2 to 4, 22 is a lid of the oil reservoir 11, and 21 is a bolt for tightening the lid 22.

SUMMARY OF THE PRESENT DISCLOSURE The present invention has been made in consideration of the above, and has an object to provide a crankshaft which reduces the number of machining steps, the number of parts, and the weight.

One embodiment of the present invention will be described below with reference to FIGS. 5 and 6. Reference numeral 7 indicates a crank pin, 8 a crank web, and 10 a crank journal. It forms the main part of the shaft. 20 is the crank pin oil reservoir, 11 is the balance weight, 1
2 is a journal oil reservoir, 22 is a lid of the oil reservoir 20, and 21 is a bolt for fixing the lid 22. 31 is an oil hole bored in the crank web 8, 32 is a dowel pin, and 34 is a lid for the oil reservoir 12 of the journal.

The oil hole 31 is drilled from the end surface 8a of the crank web 8 for mounting the balance weight 11, passing through the oil reservoir 12 of the crank journal and opening into the oil reservoir 20 of the crank pin. It is designed to be closed with a dowel pin 32. That is, the dowel pin 33 has the functions of both positioning between the crank web 8 and the balance weight 11 and plugging the opening.

In the above crankshaft, in order to form an oil passage, the oil hole 31 is connected from the balance weight mounting end surface 8a of the crank web 8 to the oil sump 1 of the journal.
2 to open into the oil reservoir 20 of the crank pin, a hole for the dowel pin 32 is drilled, the dowel pin 32 is press-fitted into the hole, and the balance weight 11 is fixed with a mounting bolt 35.
The lubricating oil for cooling the piston 1 is supplied from the main gear rally 15 to the oil hole 1 as shown in FIGS. 1 and 5.
7, 18, journal oil sump 12, oil hole 31,
The piston cooling chamber 4 passes through the crank pin oil sump 20, the connecting rod oil hole 6, and the piston pin oil sump 5.
will be sent to

The present invention is constructed as described above, and according to the present invention, the oil hole in the crank web can be machined from the end face for mounting the balance weight, and the pin for positioning the balance weight can also be used as a plug for the oil hole. This eliminates the need for thread machining as in conventional products, and reduces the number of parts. Furthermore, since the shoulder portion of the crank web can be formed into any desired shape and a hollow portion can be formed in this portion, the rotational mass of the crankshaft is reduced, the weight of the crankshaft is reduced, and engine vibrations are also reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a piston oil-cooled diesel engine. Figures 2 to 4 show an example of a conventional crankshaft, with Figure 2 being a sectional view of the main part, Figure 3 being a cross-sectional view of Figure 2, and Figure 4 corresponding to Figure 2. It is. 5 and 6 show one embodiment of the present invention, FIG. 5 is a view corresponding to FIG. 2, and FIG. 6 is a cross-sectional view taken from the side of FIG. 5. 7...Crank pin, 8...Crank web,
8a... End face for mounting balance weight, 10...
Crank journal, 11... Balance weight, 12... Journal oil reservoir, 20... Crank pin oil reservoir, 31... Oil hole, 32... Dowel pin.

Claims (1)

[Scope of utility model registration request] In a crankshaft configured such that a balance weight is attached to the end face of the crank web opposite to the crank pin, there is a crank pin oil reservoir formed at the axial center of the crank pin, and an end face for attaching the balance weight of the crank web. and an oil hole that passes through the journal oil sump and communicates with the crank pin oil sump, and the opening of the oil hole on the mounting end side is closed by the positioning pin of the balance weight. crankshaft.