JPH0416019Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology belongs to the technical field of the structure of a crankshaft mounted on a 60° V6 type engine of a small, medium, or large vehicle.

Therefore, this idea is based on the structure of a crankshaft mounted on a 60° V6 engine installed in a small, medium, or large vehicle, between the first journal at the front end and the fourth journal at the end. The first to third and fourth to sixth pins for the plurality of connecting rods and the second and third journals for the main bearing are adjacently integrated with each other through the arms on the front and rear sides of the central fifth arm provided. This invention relates to a 60° V6 engine crankshaft structure in which the arms are connected to each other, and a counterweight is integrally provided on the arm to maintain balance as a whole.
At least one of the plurality of arms on the front side and the rear side of the fifth arm is arranged such that an arm is not provided with a counterweight symmetrically with respect to the fifth arm in the length direction of the crankshaft. Separate balance masses are provided on the counterweights at the frontmost and final ends, which are made of a material with a higher specific gravity than the counterweights, and are protruded toward the axial side at the radial tips. This invention relates to a 60° V6 engine crankshaft structure that ensures a balance between the primary couple and the inertial force.

<Prior art> As is well known, automobiles are equipped with engines, such as 60° V6 engines in small, medium-sized, and large-sized cars.
There is an embodiment in which a so-called 60° V6 type engine with six cylinders in a type arrangement is provided, and its crankshaft 1 is formed as shown in FIG.

That is, from the left side to the right side in the figure, the first to fourth journals 21 and 2 are connected to the bearing.
2, 23, and 24 are provided, and the first
to the ninth arm 31, 32, 33, 34,
The first to sixth pins 41, 42, 43, 44, 45, 4 are connected to connecting rods of pistons (not shown) via 35, 36, 37, 38, 39, respectively.
6 is integrally formed.

Incidentally, a mounting surface 6 for a flywheel 5 (FIG. 2) is integrally formed at the rear of the fourth journal 24 at the end.

Therefore, if we schematically show the so-called 9-balance mode having nine counterweights, the longitudinal direction is schematically shown in Fig. 2, and the axial direction is shown in Fig. 3. It is shown as shown.

As shown in both schematic diagrams, the first and ninth
The counterweights 61 and 69 are arranged in opposite directions and have equal weights, and the second, fifth, and eighth counterweights 62, 65, and 68 are arranged at 120° intervals and have equal weights, and these counterweights cancel each other out. , and third, sixth, fourth, and seventh counterweights 63, 6
Since the weights 7, 64, and 66 are arranged plane-symmetrically and equally weighted in the direction of the arm 35, they also cancel each other out, so that the balance of the rotational moment as a whole is reliably maintained.

<Problems to be solved by the invention> However, the above-mentioned conventional crankshaft structure maintains balance, has sufficient metal surface pressure, and has the advantage of having a large margin against bending moment. However, since each arm is provided with a counterweight to maintain overall balance, the weight becomes extremely large, and the torsional natural frequency of the crankshaft 1 cannot be made large enough, resulting in the engine crankshaft torsion. It has the drawback that the amplitude exceeds the permissible range in the high rotational speed region, and also has the drawback that the acceleration and deceleration performance is unfavorable due to the large moment of inertia.It also has the disadvantage that it prevents a decrease in fuel efficiency due to increased engine weight.

Therefore, the crankshaft 1 has two movements: the so-called "misosuri motion" in which the front and rear sides of the crankshaft swing around its center, and the other in which external masses such as pulleys and flywheels swing around the journals 21 and 24 at the front and rear ends as fulcrums. However, if a pulley or fly-eel is provided to correct the balance of the former, there is a problem in that the above-mentioned run-out problem occurs.

The purpose of this invention is to solve the technical problem of excessive weight and runout due to the counterweight of the crankshaft of a 60° V6 engine of an automobile based on the above-mentioned conventional technology, and to improve the effectiveness of metal surface pressure and bending moment. By making full use of the free space available in the crankshaft, it is possible to reduce the weight by minimizing the number of counterweights needed to maintain balance, making it possible to make the size of the crankshaft more compact. It is an excellent product that can effectively protect the surroundings and benefit the field of drivetrain technology application in the automobile industry.
It aims to provide a 60° V6 type engine crankshaft structure.

<Means for solving the problem> In order to solve the above-mentioned problem, the structure of this invention, which is based on the scope of the above-mentioned utility model registration claims, is to solve the above-mentioned problem. journals are provided, and first and second pins are provided between the first and second journals, third and fourth pins are provided between the second and third journals, and third and fourth pins are provided between the third and fourth journals. A fifth and a sixth pin are provided in between, and each journal and each pin are connected by the first to ninth arms, and when the first pin is at the highest position in the first and ninth arms, the crankshaft First and fifth counterweights are disposed at lower and upper positions relative to the center, and a third counterweight located substantially opposite to the third and fourth pins relative to the center of the crankshaft is disposed on the fifth arm. A second counterweight is disposed on the second arm, which is located substantially opposite to the first and second pins with respect to the center of the crankshaft. This is a crankshaft structure for a 60° V6 engine in which a fourth counterweight is arranged, which is located on the opposite side of the fifth and sixth pins with respect to the shaft center. Separate balance masses having a weight ratio larger than that of the counterweights are provided to the first and fifth counterweights provided on the ninth arm at the final end so as to protrude outward in the axial direction at the radial tip portions.
It took technical measures such as a 60° V6 engine crankshaft structure.

<Operation> Therefore, the pins adjacent to each other between the journals and the plurality of pins provided before and after the central fifth arm between the first journal at the front end and the fourth journal at the final end of the 60° V6 engine crankshaft. Basically, first and ninth counterweights having the same shape, the same weight, and the same section modulus are provided for each arm connected and extended so as to offset each other with respect to the ninth arm at the first and final end at the frontmost end. In addition, the second and fourth counterweights, which can be axially symmetrically offset and balanced by the second arm on the front side and the eighth arm on the rear side with respect to the fifth arm in the center, have the same shape and the same weight. , so that they are installed with the same section modulus, and
At least one arm is not provided with a counterweight symmetrically in the longitudinal direction on the front and rear sides of the central fifth arm, so that weight reduction can be achieved, and the arms without the counterweight are The first arm at the front end and the ninth arm at the final end are designed to have the smallest weight and section modulus, and to improve the total balance of the counterweight and make it more compact in the axial direction. For the first and fifth counterweights, a balance mass with a larger weight ratio than that of the counterweights is provided at the radial tip portion in a shape that protrudes toward the outside in the axial direction so as not to interfere with the connecting rod, thereby bending the crankshaft pin and each part of the journal. It is designed to reduce the moment, maintain balance while reducing the metal surface pressure of the journal, and effectively prevent the movement of the crankshaft against the center of the crankshaft and the swinging of external masses such as pulleys and flywheels. .

<Embodiment> Next, one embodiment of this invention will be described as follows based on the drawings from FIG. 4 onwards. Note that the same parts as in FIGS. 1 to 3 will be described using the same reference numerals.

As shown in Figures 4 and 14, the illustrated embodiment is 60°V6
This is an embodiment of a type engine crankshaft 1',
In the 60° V6 engine crankshaft 1', the third, fourth, sixth, and seventh arms 33, 3
4, 36, and 37 are not provided with counterweights, and as shown in Figures 5 and 13,
The first arm at the front end and the ninth arm at the final end 31, 39
The iron counterweights 61 and 69 are basically the same shape, the same weight, and the same section modulus,
Furthermore, balance masses 71, 711 made of lead or the like having a higher specific gravity than the counterweights 61, 69 are used as the former,
79, 79 are attached to the latter by an appropriate means such as screwing, press-fitting, bolting, etc. by protruding a predetermined amount axially outward so as not to interfere with a connecting rod (not shown) (each balance mass 711, 79 has the same shape,
size, weight, and protrusion).

Also, the second, fifth, and eighth arms 32, 35, 3
As for 8, since they are arranged line-symmetrically with respect to the arm 35 at intervals of 120° in the circumferential direction, counterweights 62, 65, and 68 of the same weight, same shape, and same section modulus are provided, and balance can be achieved with only these counterweights 62, 65, and 68. Let them do it.

The direction and shape of each arm and each counterweight are shown in FIGS. 5 to 1 when viewed from the front in the axial direction.
3, and the side shape is as shown in FIG. 14.

Therefore, in FIGS. 7, 8, 10, and 11, the counterweight is not provided and the arm 3
A mode in which only 3, 34, 36, and 37 are attached is shown.

Then, regarding the weight of each counterweight, including the arm and balance mass,
The third, fourth, sixth, and seventh (each arm only) are the smallest, and the second, fifth, and eighth are intermediate between the two.

The section modulus is grouped in the same size arrangement as the above-mentioned weight.

In the above-mentioned configuration, when the engine (not shown) is operated and the crankshaft 1' is rotated, as described above, in this invention, the crankshaft 1' maintains an accurate balance between each arm, counterweight, and balance mass. Because of this, there is no unbalanced vibration like with conventional crankshafts, and the crankshaft rotates normally.

And the third, fourth, sixth and seventh arms 3
No. 3, 34, 36, and 37 are not equipped with counterweights, which reduces the overall weight, which increases the torsional natural frequency and allows the engine to operate at high engine speeds. It is possible to increase the area.

And the 1st and 9th counterweights 61,6
Separate balance masses 71, 711, and 79 are attached to 9, so that the metal surface pressure and bending moment of the third, fourth, sixth, and seventh arms 33, 34, 36, and 37 in the high rotation range are reduced. Sufficient margin can be maintained.

Furthermore, even if the above-mentioned wobbling motion or whirling caused by external masses such as pulleys and flywheels occur in the front and rear of the center of the crankshaft 1', these are suppressed and the balance is efficiently maintained.

Further, as for the separate balance masses, unlike the above-mentioned embodiments, the design can be changed as appropriate, such as by attaching the same type of balance mass to the front end counterweight and the last end counterweight.

<Effects of the invention> As described above, according to this invention, the number of counterweights to be installed on the 60° V6 engine crankshaft can be reduced, so
It is possible to significantly reduce the weight, and as a result, the torsional natural vibration of the crankshaft is increased, which has the excellent effect of allowing the engine to be used in a high rotational speed range.

This not only improves the performance of the 60° V6 engine, but also improves fuel efficiency by reducing weight, and also improves high-speed starting performance and braking performance.

Therefore, in the crankshaft, a counterweight may not be attached to at least one arm before and after the plurality of arms provided before and after the central arm between the front end journal and the end journal. There is also the advantage that the arrangement balance in the length direction is not disrupted, the balance in the circumferential direction is not disrupted, the rotational moment balance is not disrupted as a whole, and the crankshaft function is no different from a 9-balance crankshaft.

Furthermore, by adding separate balance masses with a higher specific gravity to the front-most and last-end counterweights, the balance can be maintained without increasing the radial thickness of the counterweights. It has the effect of efficiently preventing swinging due to motion and external masses such as pulleys and flywheels.In addition, it makes the crankshaft more compact, and also reduces the metal surface pressure of the front and rear journals of the central arm. It has the excellent effect of reducing bending moment,
In addition, the shape of the balance mass protruding outward in the axial direction has the effect that the weight of the balance mass can be designed flexibly.

Further, since the structure is simple, maintenance and inspection work is easy, and serviceability is also improved.

Additionally, as the natural torsional frequency of the engine is becoming higher in the range, there is also the advantage that the vehicle body and cabin can be made quieter in the low and medium frequency ranges.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional schematic side view of a 60° V6 engine crankshaft, and Figure 2 is a crankshaft journal, pin, arm, and
FIG. 3 is a schematic side view of the arrangement of the counterweight, FIG. Schematic diagram equivalent to Figure 3,
5 to 13 are sectional views of each arm, and FIG. 14 is a partially cutaway enlarged side view of a 60° V6 engine crankshaft. 21, 22, 23, 24... Journal, 35
...Medium arm, 41, 42, 43, 44, 4
5, 46...pin, 31, 32, 33, 34, 3
5, 36, 37, 38, 39...Arm, 1'...
...Crankshaft, 61, 62, 65, 68,
69...Counterweight, 71,711,79
...Balance mass.

Claims (1)

[Scope of utility model registration request] First to fourth journals are provided from the front end toward the rear end, and first and second pins are provided between the first and second journals, and third and third pins are provided between the second and third journals. 4 pins, and 5th and 6th pins are provided between the 3rd and 4th journals, each journal and each pin are connected by 1st to 9th arms,
When the first pin is at the highest position on the first and ninth arms, first and fifth counterweights are disposed below and above the crankshaft center, and the fifth arm has the crankshaft center. A third counterweight is disposed substantially opposite to the third and fourth pins, and a third counterweight is disposed on the second arm substantially opposite to the first and second pins with respect to the center of the crankshaft. a second counterweight is disposed on the eighth arm; There is
In the 60° V6 engine crankshaft structure, separate balance masses with a larger specific gravity than the counterweights are installed in the first and fifth counterweights provided on the first arm at the forefront end and the ninth arm at the final end. A 60° V6 engine crankshaft structure characterized by a protruding shape axially outward at the tip.