JP3271446B2 - Internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine having a balance weight for adjusting the natural frequency of the shaft system of the engine.
About the location.

[0002]

2. Description of the Related Art In an internal combustion engine, a connecting lock is used.
Relative to the rotating weight of the crankshaft.
Balance weight to the crankshaft
To remove the above weight
The art is known. Conventionally, shaft screws of internal combustion engines
When adjusting the natural frequency
Of the torsional vibration of the shaft system on the anti-flywheel side of the motor
They had to adjust the weights.

[0003]

However, in such a conventional technique, a coupling is required at the tip of the crankshaft, and an oil drain is required for the cylinder block. In the present invention, the prior art is improved, and a torsional vibration natural frequency adjusting weight 2a of a shaft system is attached to a portion above the bearing center line 27 integrally with the balance weight 2 of the crankshaft 5. The weights for adjusting the natural frequency of the torsional vibration of the shaft system provided on the side opposite to the flywheel of the crankshaft 5 are dispersedly arranged for each cylinder.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. In the balance weight 2 attached to the crankshaft of the internal combustion engine, the natural weight for adjusting the natural frequency of the torsional vibration of the engine shaft system integrally above the bearing center line 27 inside the rotation space 1 of the cylinder block 2. A frequency adjusting weight 2a was provided.

[0005]

Next, the operation will be described. Unlike the related art, it is not necessary to support the torsional vibration natural frequency adjusting weight 2a of the shaft system outside the cylinder block 17, and the weight 2a can be attached to the balance weight 2 in a state of being dispersed for each cylinder. Also, since the torsional vibration natural frequency adjusting weight 2a of the shaft system is mounted using the rotating space 1 of the balance weight 2 in the cylinder block 17, no coupling or oil drain is required, and the total length of the internal combustion engine is reduced. Can be shortened.

[0006]

Next, an embodiment will be described. FIG. 1 shows a balance weight 2 and a torsional vibration natural frequency adjustment weight 2 of a shaft system.
a is a front view of a portion of a crankshaft 5 and a connecting rod 3 showing a configuration provided with a, FIG. 2 is a side sectional view showing a direct connection structure between an internal combustion engine and a generator, and FIG. 4 is a side sectional view of the oil pan 10, FIG. 5 is a front view showing a part of the end face reinforcing plate 8, FIG. 6 is a front sectional view of the oil pan 10, and FIG. 7 is a flywheel. FIG. 8 is a side cross-sectional view showing the housing 7 and the spigot fitting portion 16, and FIG.
6 is a front view showing the special shape of FIG. 6, FIG. 9 is a side sectional view showing a structure in which the shaft of the internal combustion engine and the generator are directly connected without using a flange, a coupling, a bolt, etc., and FIG. 5 is a side cross-sectional view showing a connection structure between a generator and a rotor shaft, and FIG. 11 is also a side cross-sectional view showing a conventional direct connection structure between a crankshaft 5 and a rotor shaft.

Referring to FIG. 1, a description will be given of an invention in which the balance weight 2 is provided with a torsional vibration natural frequency adjusting weight 2a of the shaft system. Conventionally, connecting rod 3
It is well known that the balance weight 2 corresponding to the rotational weight of the crankshaft 5 and the rotational weight of the crankshaft 5 are attached to the opposite side of the connecting rod 3 of the crankshaft 5 to cancel the weight.

In the shaft system of the engine, there is a natural frequency, and this natural frequency coincides with the unique torsional vibration resonance frequency of the internal combustion engine, so that the torsional vibration of the shaft system does not generate large resonance. It is also known to provide a vibration-specific frequency adjusting weight to avoid a resonance frequency.

However, in the prior art, the torsional vibration natural frequency adjustment weight of the shaft system is attached to the end of the crankshaft opposite to the side on which the flywheel is supported by the shaft system torsional vibration natural frequency adjustment. Only one weight was attached. As described above, in the case where the weight for adjusting the natural frequency of the torsional vibration of the shaft system is provided on the side opposite to the flywheel, it is a portion protruding from the cylinder block. This was necessary, and the cylinder block 17 needed oil drainage. In the present invention, the natural frequency adjustment weight 2a is divided for each cylinder,
The balance weight 2 conventionally provided is extended at a position corresponding to a position above the bearing center line 27.

In FIG. 1, connecting rod 3
Is supported on the crankshaft 5 by a connecting rod large end 3a and a connecting rod large end cap 6 . Assuming that fastening bolts 31 are used to fasten the connecting rod large end 3a and the connecting rod large end cap 6, the balance weight 2 is attached to the balance weight fixing seat 5a of the crankshaft 5 opposite to the connecting rod 3. Fixed.

The balance weight 2 of the present invention is formed in a semi-arc shape. However, since the balance weight 2 balances the rotating weight of the crankshaft 5 and the rotating weight of the connecting rod 3, if the weight is added above the bearing center line 27, the weight does not play a role of canceling the weight. In the present invention, the bearing center line 27
The torsional vibration natural frequency adjusting weight 2a of the shaft system is provided in conformity with the rotating space 1 of the balance weight 2 above.

Since the torsional vibration natural frequency adjusting weight 2a of the shaft system is provided in addition to the balance weight 2 for each cylinder, the torsional vibration natural frequency adjusting weight 2a of all shaft systems is added. The weight thus obtained serves as a weight for adjusting the natural frequency of the torsional vibration of the shaft system of the internal combustion engine.

Next, with reference to FIGS. 2 to 6, a description will be given of a reinforcing structure in a case where the internal combustion engine and the generator are directly connected. Conventionally, flywheel housing 7 and cylinder block 1
7 was directly connected. However, in this case, in the case of a four-point support structure directly connected to the fuselage of the internal combustion engine and the generator,
It is weak in strength. In this configuration , the point of insufficient strength is reinforced by providing the end face reinforcing plate 8 on the oil pan 10 and fastening the end face reinforcing plate 8 and the flywheel housing 7 with the fastening bolt 9.

As shown in FIGS. 3, 4, 5, and 6, the oil pan 10 itself is often made of a thin iron plate or the like. In this configuration , the flywheel housing 7 of the oil pan 10 is used. Is made of a thick iron plate as the end face reinforcing plate 8. And the end face reinforcing plate 8
Bolt holes 7 provided on the flywheel housing 7 side.
a is fixed so as to be sewn with the fastening bolt 9. In this configuration, the bolt holes 7a and the bolt holes 8a provided in the end face reinforcing plate 8 are respectively formed in three rows vertically and can be fastened by a large number of fastening bolts 9.

Next, referring to FIGS. 7 and 8, a description will be given of a configuration in which a deflection journal 15 is provided on the side of the flywheel housing 7 in a body directly connected to an internal combustion engine and a generator. In this configuration, the flywheel housing 7 and the deflection journal 15 are integrally formed. The cylinder block 17 has an insertion opening 17a through which the crankshaft 5 can be assembled from below.
It is opened as shown in FIG. Therefore, the spigot fitting portion 16 for positioning between the flywheel housing 7 and the cylinder block 17 cannot be formed in a full circle over the entire circumference. Therefore, the angle θ missing for the crankshaft insertion opening 17a is set to an angle of 180 degrees or less so as to enable positioning between circles.

As described above, a large notch is formed on the cylinder block 17 side of the outer diameter spigot fitting portion 16 due to the crankshaft insertion opening 17a, and the angle θ of the notch is set to 180 degrees or less. By doing so, positioning can be performed between the inner diameter spigot fitting portion on the side of the flywheel housing 7 having the entire circumference.

This configuration can solve the problem that the centering of the deflection journal 15 becomes difficult by this positioning. Next, a connection structure between the crankshaft 5 and the generator rotor shaft 26 will be described with reference to FIGS. When the internal combustion engine and the generator are directly connected, the connection configuration between the crankshaft 5 and the generator rotor shaft 26 is as shown in FIG.
And the prior art shown in FIG.

That is, in FIG. 10, a flange portion 30 is formed on this end face, and the spigot fitting portion 30a formed on the flange portion 30 is inserted into the spigot fitting hole 25a of the flywheel 25 to perform positioning. I was Also, the generator rotor shaft 26 side also constitutes a flange portion 31, and the spigot fitting portion 31a of the flange portion 31 is inserted into the spigot fitting hole 25b of the flywheel 25 to make the shaft center out.
Then, the flange portion 30, the flywheel 25, and the flange portion 31 are fastened by bolts 39 so as to be integrated with each other.

In FIG. 11, the flywheel 25 is fixed to the end flange portion 35 of the crankshaft 5 by bolts 50 and fastened to the coupling 51 shrink-fitted to the generator rotor shaft 26 by bolts 52. The flange 33 was fastened and connected to the flywheel 25 by bolts 40. As shown in FIGS. 10 and 11, when the flange and the coupling portion are formed between the crankshaft 5 and the generator rotor shaft 26, the end of the crankshaft 5 and the stator 29 and the rotor of the generator are connected. The distance to 28 becomes longer like L1 and L2.

On the other hand, in this configuration, as shown in FIG. 9, no bolt, coupling or flange is used. That is, the hydraulic fitting 34 is fixed to the end of the crankshaft 5, and the front end of the generator rotor shaft 26 is inserted into the hydraulic fitting 34 and hydraulically fitted.
In fixing the crankshaft 5 and the flywheel 25, the bolt 24 is used. However, this is a conventional structure and a bolt, and is not related to the present configuration. With this configuration, the distance L3 between the rear end of the internal combustion engine and the front end of the generator can be reduced.

[0021]

As described above, the present invention has the following advantages. In a balance weight 2 attached to a crankshaft of an internal combustion engine, a shaft for adjusting the natural frequency of the torsional vibration of the engine shaft system integrally above the bearing center line 27 inside the rotation space 1 of the balance weight 2. Since the torsional vibration natural frequency adjusting weight 2a of the system is provided, it is not necessary to support the torsional vibration natural frequency adjusting weight 2a of the shaft system outside the cylinder block 17 as in the related art. Thus, the balance weight 2 can be attached. Further, since the torsional vibration natural frequency adjusting weight 2a of the shaft system is mounted using the rotating space 1 of the balance weight 2 in the cylinder block 17, no coupling or oil drain is required, and the total length of the internal combustion engine is reduced. Can be shortened.

[Brief description of the drawings]

FIG. 1 is a front view of a portion of a crankshaft 5 and a connecting rod 3 showing a configuration in which a torsional natural frequency adjusting weight 2a of a shaft system is attached to a balance weight 2;

FIG. 2 is a side sectional view showing a direct connection structure between an internal combustion engine and a generator.

FIG. 3 is a front view showing a fixed portion between the flywheel housing 7 and the end face reinforcing plate 8;

4 is a front side view of the oil pan 10. FIG.

FIG. 5 is a front view showing a part of an end face reinforcing plate 8;

FIG. 6 is a front sectional view of the oil pan 10.

FIG. 7: Flywheel housing 7 and spigot fitting part 1
FIG.

FIG. 8 is a front view showing a special shape of the spigot fitting portion 16;

FIG. 9 is a side sectional view showing a structure in which the shaft of the internal combustion engine and the generator is directly connected without using a flange, a coupling, a bolt, or the like.

FIG. 10 is a side sectional view showing a connection structure between a conventional crankshaft 5 and a rotor shaft of a generator.

FIG. 11 is a side sectional view showing a conventional direct connection structure between a crankshaft 5 and a rotor shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation space of balance weight 2 Balance weight 2a Torsion vibration natural frequency adjustment weight of shaft system 3 Connecting rod 4 Piston 6 Connecting rod large end side cap 7 Flywheel housing 7a Bolt hole 8 End face reinforcing plate 9 Fastening bolt 10 Oil pan 15 Deflection journal 16 Inlay fitting 17 Cylinder block 17a Crankshaft insertion opening

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02B 77/00 F02B 63/04 F16F 15/10 F16F 15/24 F16F 15/315 F02F 7/00

Claims (1)

(57) [Claims] 1. A balance weight 2 attached to a crankshaft of an internal combustion engine, wherein the natural frequency of the shaft system of the engine is integrally formed above a bearing center line 27 inside the rotation space 1 of the balance weight 2. An internal combustion engine provided with a natural frequency adjusting weight 2a to be adjusted.