JPH0470500B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology is applicable to small-sized, medium-sized, or large-sized automobiles.
It belongs to the technical field of reducing the weight of the crankshaft mounted on a V6 engine and eliminating its inertia couple.

This invention provides a crankshaft mounted on a six-cylinder engine with a 60° V-type arrangement installed in small, medium-sized, and large-sized automobiles. An invention relating to a crankshaft for a 60° V-type 6-cylinder 5-balance engine, in which pins for a plurality of connecting rods are integrally connected to the front and rear sides of the first to ninth arms provided between the two arms. In particular, counterweights are not provided for each of the two adjacent arms on the front and rear sides of the third, fourth, sixth, and seventh arms in the middle position, and counterweights are not provided. Regarding the counterweights, the balance of the inertial couple and the inertial force is ensured by the first and fifth counterweights, and also by the second, third, and fourth counterweights. , the first and fifth counterweights of the outermost first and ninth arms have the largest mass compared to the other counterweights, have the same cross-sectional modulus and shape, and have the same rotational direction when viewed from the axial direction. The width of the 2nd and 4th counterweights of the adjacent 2nd and 8th inner arms are made smaller so that they are balanced with the middle 3rd counterweight. was done
This invention relates to a 60° V-type 6-cylinder 5-balance engine crankshaft.

<Prior Art> As is well known, automobiles are equipped with engines. For example, small-sized, medium-sized, and large-sized passenger cars are equipped with a so-called V6 engine with six cylinders in a 60° V-type arrangement. Yes, that 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 for the main bearing,
22, 23, 24 are provided, and the first to ninth arms 31, 32, 3 are provided between them.
3, 34, 35, 36, 37, 38, 39 respectively, the first to sixth pins 41, 42, 43, 44 are arranged at 60° intervals for each connecting rod. , 45, 46 are integrally connected.

A mounting surface 6 for the flywheel 5 is integrally formed at the rear of the fourth journal 24 at the end, and one for each of the arms 31 to 39, for a total of nine first to third journals. Up to the ninth counterweights 61 to 69 are provided.

A so-called 9-balance mode having these nine counterweights 61 to 69 is schematically shown as follows.
The outline in the longitudinal direction can be as shown in FIG. 2, and the outline in the axial direction can be as shown in FIG.

As shown in FIG. 2, the mass of each counterweight 61 to 69, which is provided to cancel the inertia couple due to rotation, is as shown by the arrow in FIG. 3 when viewed from the axial direction. , expressed as a vector of inertial force, the first and ninth counterweights 61 and 69 cancel each other out in opposite directions and by equal amounts, and the second, fifth, and eighth counterweights 62, 65, and 68 are arranged in equal amounts every 120 degrees in the circumferential direction, and the same three cancel each other out,
Further, the third, sixth, fourth, and seventh counterweights 63, 66, 64, and 67 are arranged in equal amounts in line symmetry at intervals of 60 degrees in the circumferential direction with respect to the direction of the arm 35. These four counterweights offset each other, thus ensuring that overall balance is maintained.

<Problems to be Solved by the Invention> However, in the conventional crankshaft described above, the overall balance is maintained, the bearing surface pressure has sufficient margin, and there is a large margin against bending stress. Although there are some advantages, the provision of a counterweight for each arm to achieve full balance makes the overall weight extremely large, and the natural frequency of the torsional vibration of the crankshaft cannot be kept large enough. Therefore, there are disadvantages in that torsional vibration becomes large in the high rotational speed region of the engine, and furthermore, the acceleration response is unfavorable and the fuel consumption rate is deteriorated.

In contrast, for example, U.S. Patent No. 2,632,340
As shown in the specification, there is a technology for a 5-balance crankshaft for a 60° V-6 engine, but although the equipment of each counterweight is disclosed, the relationship between their weights and arrangement, i.e. However, the weight balance has not been clearly considered by those skilled in the art, and the design varies depending on the case, and as far as it has been disclosed, it has the disadvantage of lacking in versatility, and there is no technology to solve the above problems. I don't like it.

Also, it is possible to decenter the center of gravity in order to cancel the couple caused by the first and fifth counterweights that are unique to the 60° V-type engine crankshaft.
In the conventional technology, a design that allows for such eccentricity was not possible, the mass distribution could not be widened, and it was difficult to maintain balance in directions other than the pin direction.

In addition, in this crankshaft, the counterweights at both ends and the counterweight in the middle part are formed into approximately the same shape (same width in the rotational direction when viewed from the axial direction), so the 5-balance crank of a 60° V-type 6-cylinder engine When correcting the balance of the counterweight in response to the grinding motion peculiar to the shaft, there was an inconvenience in that the ability to correct the unbalance that is omnipresent in the direction of rotation around the crankshaft was low.

Furthermore, for example, although the technology disclosed in Utility Model Application Publication No. 53-78308 discloses the magnitude relationship of the counterweight weights of each arrangement, the technology does not apply to a 5-main bearing engine crank of an in-line 4-cylinder arrangement. It is a shaft, and there are various problems in balancing it when directly applied to a V-type 6-cylinder engine.

The purpose of the present invention is to solve the problem of excessive weight caused by the counterweight of the crankshaft of an automobile engine based on the above-mentioned prior art and its balance.
The problem of applying a 60° V6 engine to a crankshaft is a technical issue to be solved,
Utilizing bearing surface pressure and flexibility in bending,
While taking full advantage of this, the overall weight of the crankshaft is reduced as much as possible by minimizing the number of counterweights that can maintain balance, and efficient balance correction is possible, making it suitable for use in drive technology applications in the automobile industry. The purpose of the present invention is to provide an excellent 60° V-type 6-cylinder 5-balance engine crankshaft.

<Means for Solving the Problems> In order to solve the above problems, the structure of the present invention, which is based on the scope of the preceding claims, is as follows:
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 are provided between the third and fourth journals, fifth and sixth pins are provided between the third and fourth journals, each journal and each pin are connected by the first to ninth arms, and the first
When the first pin is at the highest position on the ninth arm, first and fifth counterweights are arranged, which are positioned lower and upper with respect to the center of the crankshaft. A third counterweight is disposed on the second arm and is located on the opposite side of the first and second pins with respect to the center of the crankshaft. , a second counterweight is disposed, and a fourth counterweight is fixedly attached to the eighth arm, the fourth counterweight being located approximately on the opposite side of the fifth and sixth pins with respect to the center of the crankshaft. In a V-type 6-cylinder 5-balance engine crankshaft structure, each of the pins is arranged at 60° intervals from each other, and the counterweight is arranged from the outside to the inside of the middle fifth arm. The two adjacent arms, the 3rd, 4th, 6th, and 7th arms, are not equipped with counterweights, and the counterweights fixed to the 1st and 9th arms are mutually balanced. and the 2nd, 3rd, and 4th arms fixed to the 2nd, 5th, and 8th arms.
The mass of the counterweights is such that the first and ninth counterweights of the outermost first and ninth arms are more balanced than the other counterweights. and the width of the counterweight in the rotational direction as seen from the axial direction is made wider than the width of the other counterweights in the rotational direction, and the second The fourth counterweight is then provided with a 60° V6 five-balance engine crankshaft, which is reduced in weight.

<Function> Therefore, the first arm installed before and after the middle fifth arm between the first and fourth journals of the crankshaft of a 60° V-type 6-cylinder 5-balance engine. , 2nd, 3rd, 4th, 6th, and 7th pins and the 1st to 9th pins connected and extended adjacently between the 1st, 2nd, 3rd, and 4th journals.
Regarding two arms, the first and fifth arms have the same mass, the same shape, and the same section modulus, which are as large as possible to eliminate the inertia couple, and are mutually balanced. A counterweight is provided for the 3rd, 4th, 6th, and 7th arms located inside the counterweight, and no counterweight is provided for the 2nd and 8th arms located in the middle. In this case, the 5th counterweight is balanced with the 2nd and 4th counterweights, and these counterweights balance the 5th counterweight.
A balanced configuration, and the intermediate first, second,
Regarding the 1st, 2nd, 3rd, 4th, and 5th counterweights provided for the 5th, 8th, and 9th arms, the mass of each counterweight from the outside to the inside is equal to the mass of the 1st and 5th counterweights on the outside. The eccentricity of the center of gravity of the counterweight is reduced when the balance is corrected by making the weight gradually smaller than that of the weight, and by making the first and fifth counterweights wider in the direction of rotation when viewed from the axial direction. (In a 5-balance crankshaft, the counterweights at both ends are maximized to reduce the couple of V-type engines,
In this case, the center of gravity of the counterweights at both ends needs to be symmetrical with respect to the center counterweight for overall balance, but since the counterweights at both ends are the largest, manufacturing errors are large. Also, when the center of gravity of the counterweight at both ends shifts in the crank rotation direction, the width of the counterweight at both ends is wide, so if you steal meat from both ends of the counterweight, it will inevitably shift far from the center of gravity. Since meat is stolen in certain parts, it is possible to correct the center of gravity position with a small weight, without worsening the weight balance.
Eccentricity (correction) of the center of gravity becomes possible. ), it is possible to efficiently correct the balance, and the first and fifth counterweights can be balanced in directions other than the pin direction due to the spread of mass distribution.

<Example> Next, an example of the present invention will be described with reference to FIG.
The explanation will be 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 FIG. 4, in this invention, the third, fourth, sixth, seventh arms 33, 34,
36, 37, and the first and fifth counterweights 61, 6 for the first and ninth arms 31, 39.
9 with the same shape, the same weight, and the same section modulus so that only the two are balanced, and furthermore, the 5th and 1st
As shown in FIG. 3, the counterweight 69 is formed into a substantially fan shape with a wide width (L) in the rotational direction when viewed from the axial direction (for convenience of illustration, only the width L in the rotational direction of the fifth counterweight 69 is shown), and 2nd, 5th, 8th arm 3
2, 35, and 38 are provided so that they are balanced only by the second, third, and fourth counterweights 62, 68, and 65, and the counterweights 62,
The mass of the counterweight 68 is smaller than the maximum mass of the counterweights 61 and 69.

The arrangement direction and shape of each arm and counterweight are as shown in FIGS. 5 to 13 when viewed from the front in the axial direction.

And in Figures 7, 8, 10, and 11,
An embodiment is shown in which only the third, fourth, sixth, and seventh arms 33, 34, 36, and 37, which are not provided with a counterweight, are mounted so that they are balanced by the arms 33 and 34, and by the arms 36 and 37. has been done.

Therefore, for each counterweight, 60°V
In order to eliminate the inertia couple peculiar to a type 6-cylinder engine, the first and fifth counterweights 61 and 69, which are most effective for this purpose, have the largest mass, and
As described above, the counterweight is formed to have a wider width L in the rotational direction than other counterweights when viewed from the axial direction, and then,
The second and fourth counterweights 62 and 68 are the next largest, and the third, fourth, sixth and seventh arms 33, 34, 36,
37 hardly contributes effectively to removing the inertial couple, so the thickness of the arms 31 and 3
9 is the thickest, 32, 38 is the next thickest, 33,
The thicknesses of 34, 36, and 37 are the thinnest.

Note that the third counterweight 65 is used in conjunction with the second and fourth counterweights 62 and 68 in order to balance the entire crankshaft and reduce the main bearing surface pressure.
It is designed to have a mass and thickness that balances the

Lid, first and ninth outer arms 31
It is effective to increase the thickness of the counterweight and 39 and to form it wider L than other counterweights in the direction of rotation.
In addition, there is a limit to the increase in radial length, and as shown in the <effects> section above, the eccentricity of the center of gravity is facilitated and efficient balance correction is possible, and the mutual mass of the counterweights cancels out the inertial couple. This is because by widening the distribution, balance in areas other than the pin direction can be achieved.

In the above configuration, when the engine (not shown) is operated and the crankshaft 1 rotates, as described above, in this invention, the crankshaft 1 rotates each arm and the like as in the conventional crankshaft.
Since the overall balance of the counterweight is maintained accurately, no unbalanced vibration occurs and the counterweight is rotated normally.

Since no counterweights are attached to the third, fourth, sixth, and seventh arms 33, 34, 36, and 37, the natural frequency of torsional vibration becomes higher, and the engine The rotation can be increased up to the high rotation range.

Even in the high rotation range, the design allows sufficient margin for main bearing surface pressure and bending stress to be maintained.

Furthermore, the first, ninth, second, and eighth counterweights 61, 69, 62, and 68 from the outside to the inside of the intermediate arm 35 are distributed so that their masses decrease from large to small. 60°V
The inertia couple peculiar to type 6-cylinder engines has been removed,
Stable rotation in the high rotation range is achieved.

And the first and fifth counterweights 6
1,69 is formed to have a wider width in the rotational direction L than other counterweights when viewed from the axial direction, making it easier to decenter the center of gravity of the counterweight,
(In other words, in a 5-balance crankshaft, the counterweights at both ends are maximized in order to reduce the couple of forces in the V-type engine, but in this case, the center of gravity of the counterweights at both ends changes the overall balance with respect to the center counterweight. Therefore, they must be in symmetrical positions, but since the counterweights at both ends are the largest, manufacturing errors tend to be large, and when the center of gravity of the counterweights at both ends shifts in the direction of crank rotation, Since the width of the counterweight is wide, if you steal meat from both ends of the counterweight, you will inevitably steal meat from the part far from the center of gravity, so it is possible to correct the position of the center of gravity with a small weight. Therefore, it is possible to eccentrically (correct) the center of gravity without deteriorating the weight balance.), and the balance can be corrected efficiently.

Also, the first and fifth counterweights 61,6
By expanding the mass distribution of the 9 comrades, the balance in areas other than the pin direction is improved.

It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments, and various embodiments can be adopted.

<Effects of the Invention> As described above, according to the present invention, the number of counterweights attached to the crankshaft of a 60° V-type 6-cylinder 5-balance engine can be reduced to 5, and therefore the overall weight can be significantly reduced. As a result, the natural frequency of the torsional vibration of the crankshaft becomes higher, which has the excellent effect of allowing the engine to be used in a high rotational speed range.

Furthermore, the balance can be corrected to reduce the grinding motion peculiar to a 60° V-6 engine crankshaft without increasing the overall length or height of the engine.

As a result, the inertia couple of the crankshaft is primarily removed, resulting in the effect that stable operation in a high rotation range is possible.

Further, the damper mass can also be made lighter as the crankshaft is made lighter, which has the advantage of reducing material costs and manufacturing costs.

In this way, not only the engine performance is improved, but also the fuel consumption is improved due to the weight reduction, and the transient acceleration performance and braking performance are also improved.

Therefore, by providing a counterweight with the largest mass than the other counterweights in the first and ninth arms so that they are balanced, the inertia couple can be removed most effectively. The excellent effect of being able to do this is achieved.

Furthermore, the fact that counterweights are not provided in each of the 3rd, 4th, 6th, and 7th arms on both sides of the middle 5th arm is the reason why the 1st and 9th arms mentioned above are not equipped with counterweights. Coupled with the provision of a counterweight with the largest mass, there is an effect that can contribute secondarily and synergistically to the removal of the inertial couple.

Then, by balancing the counterweight of the middle fifth arm and the counterweights of the second and eighth arms, the counterweight of the second and eighth arms is Next to the counterweights of the 9th and 9th arms, it can be made lighter and has the excellent effect of thirdly acting on removing the inertia couple.

Therefore, by forming the first and fifth counterweights to be wider in the rotational direction when viewed from the axial direction, it is possible to eccentrically center the center of gravity of the counterweights (i.e., a five-balance crankshaft). In order to reduce the couple force of a V-type engine, the counterweights at both ends are maximized, but in this case, the center of gravity of the counterweights at both ends must be symmetrical with respect to the center counterweight for overall balance. Although it is necessary,
Since the counterweights at both ends are the largest, manufacturing errors tend to be large, and when the center of gravity of the counterweights at both ends shifts in the direction of crank rotation, the width of the counterweights at both ends is wide. If you steal meat from both ends, you will inevitably steal meat from a part far from the center of gravity, so it is possible to correct the position of the center of gravity with a small amount of weight, so the center of gravity can be adjusted without worsening the weight balance. Eccentricity (correction) becomes possible. ) Not only does it have the excellent effect of efficiently correcting the balance, but it also has the excellent effect of widening the mass distribution between the counterweights to cancel out the inertial couple, and improving the balance in directions other than the pin direction. It is played.

[Brief explanation of the drawing]

Figure 1 is a schematic partial cross-sectional side view of the crankshaft of a 60° V6 five-balance engine, Figure 2 is a schematic side view of the arrangement of crankshaft journals, pins, arms, and counterweights based on the prior art. The figure is a schematic diagram of the balance of the axial and circumferential arrangement of the arm and counterweight, Figure 4 and the following are explanatory diagrams of one embodiment of the present invention, Figure 4 is a schematic diagram equivalent to Figure 3, and Figure 5 Figure 13 is the first
It is a sectional view from - to - in the figure. 21, 22, 23, 24... Journal, 35...
Middle arm, 41, 42, 43, 44, 45, 4
6...Pin, 31, 32, 33, 34, 35, 3
6, 37, 38, 39... Arm, 1... Crankshaft, 61, 62, 65, 68, 69... Counterweight, L... Width in the rotational direction of the counterweight.

Claims (1)

[Claims] 1 First to fourth journals are provided from the front end toward the rear end, and a first and second pin is provided between the first and second journal, and a third pin is provided between the second and third journal. A fourth pin is provided between the third and fourth journals, and fifth and sixth pins are provided, and each journal and each pin are connected by first to ninth 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, and a fourth counterweight is fixed to the eighth arm, the fourth counterweight being substantially opposite to the fifth and sixth pins with respect to the center of the crankshaft. 60°V
In a 6-cylinder 5-balance engine crankshaft, the above pins are arranged at 60° intervals from each other, and the counterweight arrangement from the outside to the inside is arranged before and after the middle 5th arm. The third, fourth, sixth, and seventh two adjacent arms are not provided with a counterweight, and the counterweights fixed to the first and ninth arms are mutually balanced, Also, the 2nd, 3rd, and 4th arms fixed on the 2nd, 5th, and 8th arms
The mass of each counterweight is such that the first and ninth counterweights of the outermost arms are the most balanced than the other counterweights. and the width of the counterweight in the rotational direction as seen from the axial direction is made wider than the width of the other counterweights in the rotational direction, and the second A 60° V-type 6-cylinder 5-balance engine crankshaft characterized by a fourth counterweight that is next smaller in weight.