JPH09166182A - Low vibration v-type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the riding sensation of a motorcycle by a method wherein various forces generated during drive of an engine are offset and the generation of the various force is reduced, the generation of vibration of the engine is reduced, and further the generation of vibration of a mounted engine is reduced. SOLUTION: A low vibration V-type engine is a four-cylinder V-type engine wherein front and rear cylinders 22 and 22 are protruded in a V-shape, as seen from a line of sight along the axis 23 of the crank shaft 21, in a crank case supporting the crank shaft 21. Balancers 34 and 34 to offset a primary inertia force F1 of a reciprocation mass (m) of a piston 29 and a primary inertia couple M1 in linkage with the crank shaft 21 are provided. A crossing angle β between the two axes 26 and 27 of front and rear cylinders 22 and 22 and a phase angle αbetween the crank pins 31 of the two adjoining cylinders 22 and 22 are set so that a secondary inertia force F2 of the reciprocation mass (m) is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel low-vibration V-type engine that cancels the primary inertial force and the primary inertial couple of reciprocating mass and reduces the secondary inertial force. .

[0002]

2. Description of the Related Art Generally, a V-type engine has a crankcase that supports a crankshaft and has front and rear cylinders protruding in a V-shape when viewed from a line of sight along the axis of the crankshaft.

When the engine is driven, the air-fuel mixture supplied to the cylinder holes of each cylinder is appropriately burned, and the combustion gas is appropriately discharged, so that the piston of each cylinder causes the cylinder in each cylinder to move. The hole is reciprocally moved in the axial direction, and the crankshaft is interlocked with the hole through a connecting rod to rotate, and power is output from the crankshaft.

[0004]

By the way, when the engine is driven, a reciprocating mass of a piston or the like produces a primary inertial force, a primary inertial couple, and a secondary inertial force. It will vibrate.

In order to cancel the above vibrations, various vibration canceling means have been proposed in the past, but none of them are sufficiently satisfactory, and there is still room for improvement.

On the other hand, in motorcycles, it is desired to reduce the vibration of the mounted engine in order to improve the riding comfort.

The present invention has been made by paying attention to the above circumstances, and is a low vibration V which is designed to cancel and reduce various forces generated when the engine is driven to reduce the vibration of the engine. The challenge is to provide a type engine.

Another object is to improve the riding comfort of the motorcycle by reducing the vibration of the mounted engine.

[0009]

The low vibration V-type engine of the present invention for achieving the above object is as follows.

According to the first aspect of the present invention, the front and rear cylinders 22 and 22 are provided on the crankcase 19 supporting the crankshaft 21 so as to project in a V shape when viewed from a line of sight along the axis 23 of the crankshaft 21. A two-cylinder or four-cylinder V-type engine, which has a piston 29 linked with the crankshaft 21.
Primary inertia force F ₁ of reciprocating mass m, etc., and primary inertia couple M ₁
Balancers 34, 34 for canceling the above are provided, and on the other hand, in order to minimize the secondary inertia force F ₂ of the reciprocating mass m, the intersection angle β of the shaft center 26, 27 of the front and rear cylinders 22, 22 and the crank Both cylinders 22, which are adjacent to each other in the axial direction of the shaft 21,
The phase angle α between the piston pins 32 of 22 is set.

According to a second aspect of the invention, in addition to the first aspect of the invention, the total of the intersection angle β and the phase angle α is set to about 90 °.

The invention of claim 3 is the invention of claim 1 or 2.
In addition to the above invention, the cross angle β is set to 20 to 30 °, and the crankshaft 21 extends in the vehicle width direction.
0 is mounted on the motorcycle 1.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 is a motorcycle, and an arrow Fr in the figure indicates the front of the motorcycle 1. The left and right described below refer to the vehicle width direction toward the front.

A front fork 3 is rotatably supported on the front end of a body frame 2 of the motorcycle 1.
A front wheel 4 is rotatably supported on the lower end of the front fork 3, and a handle 5 is attached to the upper end of the front fork 3. On the other hand, the body frame 2
A rear arm 7 is pivotally supported at a rear end of the rear arm 7 so as to be vertically swingable, and a rear wheel 8 is rotatably supported at a swing end of the rear arm 7. The vehicle body of the motorcycle 1 is supported on the road surface 9 by the front wheels 4 and the rear wheels 8.

An engine 10 which is an internal combustion engine is mounted on the motorcycle 1 and the engine 10 is supported by a vehicle body frame 2. A fuel tank 12 that supplies fuel to the engine 10 is supported on the vehicle body frame 2. Further, an oil tank 13 for supplying lubricating oil to the engine 10 is provided. A power transmission device 14 is connected to the engine 10 and is connected to the engine 10.
The output shaft and the rear wheel 8 are interlocked by a chain-type winding power transmission means 15. Reference numeral 16 is a cowling.

The power generated by the drive of the engine 10 can be transmitted to the rear wheel 8 via the power transmission device 14 and the winding power transmission means 15.
The motorcycle 1 is capable of traveling on a road surface 9.

1 to 4, the engine 10 has a crankcase 19 made of aluminum alloy casting. The crankshaft 21 is housed in the crank chamber 20 in the crankcase 19, and the crankcase 21 is rotatable about its axis 23.
9 is supported. The axis 23 of the crankshaft 21 extends in the left-right direction, that is, the vehicle width direction.

A plurality of (four) cylinders 22 made of cast aluminum alloy are provided on the crankcase 19 so as to project therefrom.
The cylinders 22 are arranged side by side on the left and right, and from the left side to the right side, the first cylinder 22 (A), the second cylinder 22 (B), the third cylinder 22 (C), and the fourth cylinder 2 are sequentially arranged.
2 (D).

The first and third cylinders 22 (A) are viewed from the side of the line of sight along the axis 23 of the crankshaft 21.
(C) is the second and fourth cylinders 22 (B) and (D) on the front side.
Are inclined rearward relative to each other about the cylinder 22 of the crankshaft 21. That is, the first and the third
The cylinders 22 (A) and (C) are front cylinders 22, and the second and fourth cylinders 22 (B) and (D) are rear cylinders 22. These are provided in the crankcase 19 so as to project in a V shape. There is.

The first and third cylinders 22 (A) (C)
Of the cylinder hole 25 of the cylinder hole 25, and the center of the cylinder hole 25 of the second and fourth cylinders 22 (B) and (D) 27.
And, when viewed from the side, intersect at the axis 23 of the crankshaft 21, and the intersection angle β is an acute angle (20 to 30 °) and forms a narrow angle, that is, the engine 10 is a 4-cylinder narrow-angle V type. It is said to be an engine.

A piston 29 is fitted in each of the cylinder holes 25 so as to be slidable in the axial direction of its axis 26, 27. A connecting rod 30 for interlockingly connecting the piston 29 and the crank shaft 21 is provided, and a large end portion of the connecting rod 30 has a crank pin 31 of the crank shaft 21.
Is connected to the piston 2.
9 is connected via a piston pin 32.

A pair of front and rear balancers 34, 34 which are interlockingly connected to the crankshaft 21 by gears are provided, and these balancers 34, 34 rotate at a constant speed in the opposite direction to the crankshaft 21.

When the engine 10 is driven, the air-fuel mixture supplied to each cylinder hole 25 is appropriately burned and the combustion gas is appropriately discharged, whereby the pistons 29 of the respective cylinders 22 are moved to the respective cylinders 22.
The inner cylinder hole 25 is reciprocally moved in the axial direction, and the crankshaft 21 is interlocked with the cylinder hole 25 via a connecting rod 30 to rotate, and power is output from the crankshaft 21.

In a side view of FIG. 1, an imaginary line that intersects with the shaft center 23 of the crankshaft 21 and passes through the centers of both shaft centers 26 and 27 of the cylinder holes 25 of the front and rear cylinders 22 is shown in side view. When a reference crank angle θ is set from the center line 35 of the side view toward the front in the rotational direction of the crankshaft 21 (arrow in FIG. 1), the first to fourth cylinders are set from the reference crank angle θ. The angles of reaching the crank pins 31 of 22 (A) to (D) are rotation angles ψ _{1 to} ψ ₄ . Further, the phase angle between the crank pins 31 of the first cylinder 22 (A) and the second cylinder 22 (B) adjacent to each other in the axial direction of the crankshaft 21 is the rotation angle ψ ₂ -the rotation angle ψ _1.
Is obtained, and this is the phase angle α.

The piston 2 for each cylinder 22 is also provided.
9, reciprocating mass by connecting rod 30, piston pin 32 is m
(Not shown).

The radius of the locus of rotation of the crank pin 31 around the axis 23 of the cylinder 22 is the crank radius γ. The lengths of the connecting rods 30 of the cylinders 22 are the same as each other, which is the connecting rod length l. Further, the connecting rod length 1 / crank radius γ = λ. The crankpin 31 is supposed to rotate at the crankpin rotational angular velocity ω, and the unit of the crankpin rotational angular velocity ω is rad / s.

In the front view of FIG. 4, the center line 37 of the front view passing vertically through the centers of the second and third cylinders 22 (B) and (C).
To the first cylinder 22 (A) is l ₂ , the dimension to the second cylinder 22 (B) is l ₁ , and the third cylinder 22 is
The dimension reaching (C) is l ₃ , and the dimension reaching the fourth cylinder 22 (D) is l ₄ .

Using the above-mentioned symbols, the primary inertial force F ₁ generated by the reciprocating mass m is calculated by the following "equation 1" which is a general formula. Here, the primary inertial force F ₁ is an inertial force around the shaft center 23 of the crankshaft 21, and is generated in proportion to the rotation speed of the crankshaft 21. In addition, the units of the intersection angle β, the rotation angles ψ _{1 to} ψ ₄ , and the phase angle α in each mathematical expression below are radians.

[0031]

[Equation 1]

The primary inertia couple M ₁ generated by the reciprocating mass m is calculated by the following "equation 2" which is a general formula. Here, the primary inertia couple M ₁ is the total of the moments about the center line 37 in the front view of the crankshaft 21 in the front view, and is generated in proportion to the rotation speed of the crankshaft 21.

[0033]

(Equation 2)

Secondary inertia force F generated by the reciprocating mass m
₂ is calculated by the following "equation 3" which is a general formula. Here, the secondary inertial force F ₂ is a vibration generated in the axial direction of the cylinder 22, and this vibration has a cycle twice the rotation speed of the crankshaft 21.

[0035]

(Equation 3)

In the engine 10, what is called a "360 ° crank" is ψ ₁ = ψ ₃ , ψ ₂ = ψ ₄ ,
ψ ₂ = ψ ₁ + α.

At this time, the primary inertial force F ₁ is the above-mentioned "Equation 1".
Therefore, the following “Equation 4” is obtained.

[0038]

(Equation 4)

Maximum absolute value | F ₁ | m of the above “Equation 4”
The ax is the following “Equation 5”.

[0040]

(Equation 5)

Further, the primary inertia couple M ₁ is given by the following “Equation 6” from the above “Equation 2”.

[0042]

(Equation 6)

Maximum absolute value | M ₁ | m of the above-mentioned “Equation 6”
The ax is the following “Equation 7”.

[0044]

(Equation 7)

Further, the secondary inertial force F ₂ becomes the following “Equation 8” from the above “Equation 3”.

[0046]

(Equation 8)

The maximum absolute value | F ₂ | m of the above [Equation 8]
The ax is the following “Equation 9”.

[0048]

(Equation 9)

In the engine 10, what is called a "180 ° crank" is ψ ₁ = ψ ₃ + π, ψ ₂ = ψ
₄ + π, ψ ₂ = ψ ₁ + α.

At this time, the primary inertial force F ₁ is the above-mentioned "Equation 1".
Becomes 0.

Further, the primary inertia couple M ₁ becomes the following “Equation 10” according to the above “Equation 2”.

[0052]

(Equation 10)

Maximum absolute value | M ₁ |
max is the following “Equation 11”.

[0054]

[Equation 11]

Further, the secondary inertial force F ₂ becomes the following “Equation 12” according to the above “Equation 3”.

[0056]

(Equation 12)

The maximum absolute value | F ₂ | of the above [Equation 12]
max is the following "Equation 13".

[0058]

(Equation 13)

In both the "360 ° crank" and "180 ° crank" engines 10, the primary inertia force F ₁ and the primary inertia couple M ₁ are the balancers 34, 34.
It is supposed to be canceled by. In this case, as described above, the primary inertial force F ₁ and the primary inertial couple M ₁ are generated in proportion to the rotation speed of the crankshaft 21.
Therefore, the primary inertial force F ₁ and the primary inertial couple M ₁ are effectively canceled by the balancers 34, 34 that rotate in reverse at a constant speed with the crankshaft 21.

The cylinders 22 are balanced by 50%. This 50% balance means crank pin 31
The balance weight of m / 2 is added to the crankshaft 21 at the axis center of. At this time, the vector distribution of the inertial force is a perfect circle when viewed along the axis of the crankshaft 21. That is, the magnitude of the inertial force is the same for each crank angle.

On the other hand, since the secondary inertial force F ₂ has a cycle twice the rotation speed of the crankshaft 21 as described above, it is difficult to eliminate it by the balancers 34, 34, but the crossing angle β and , By setting the phase angle α to a certain value, the above cancellation can be effectively performed.

More specifically, the intersection angle β is 20 to 30 ° in crank angle, and the phase angle α is 70 to 70 in crank angle.
60 °, and the sum of the intersection angle β and the phase angle α is about 9
It is set to 0 °.

The grounds for determining the values of the intersection angle β and the phase angle α as described above will be described with reference to FIGS.
6 will be described.

In each of the following examples, the above-mentioned "expression 4" to "expression 13" are used, and all are λ = 4, and the solid lines in the graphs of FIGS. ₁ , the one-dot chain line is the primary inertial couple M ₁ , and the two-dot chain line is the secondary inertial force F _2.
Is shown. Further, # 1 corresponds to the first cylinder 22 (A), and # 2 corresponds to the second cylinder 22 (B).

[0065]

EXAMPLE FIG. 5 shows Example 1, which is a “360 ° crank” and an intersection angle β = 20 °.

From these results, it can be seen that the phase angle α≈70 ° is optimal for minimizing the secondary inertial force F ₂ . Further, in this case, the intersection angle β + the phase angle α≈20 ° + 70
° = 90 °.

FIG. 6 shows the second embodiment, where the "360 ° crank" and the intersection angle β = 25 °.

From this result, it is understood that the phase angle α≈65 ° is optimal for minimizing the secondary inertial force F ₂ . Further, in this case, the intersection angle β + the phase angle α≈25 ° + 65
° = 90 °.

FIG. 7 shows the third embodiment, where the "360 ° crank" and the intersection angle β = 30 °.

From this result, it is understood that the phase angle α≈60 ° is optimal for minimizing the secondary inertial force F ₂ . Further, in this case, the intersection angle β + the phase angle α≈30 ° + 60
° = 90 °.

FIG. 8 shows the fourth embodiment in which the "180 ° crank" and the intersection angle β = 20 °.

From this result, it is understood that the phase angle α≈70 ° is optimum for minimizing the secondary inertial force F ₂ . Further, in this case, the intersection angle β + the phase angle α≈20 ° + 70
° = 90 °.

FIG. 9 shows the fifth embodiment, where the "180 ° crank" and the intersection angle β = 25 °.

From this result, it is understood that the phase angle α≈65 ° is optimal for minimizing the secondary inertial force F ₂ . Further, in this case, the intersection angle β + the phase angle α≈25 ° + 65
° = 90 °.

FIG. 10 shows the sixth embodiment, where the "180 ° crank" and the intersection angle β = 30 °.

From these results, it is understood that the phase angle α≈60 ° is optimal for minimizing the secondary inertial force F ₂ . Further, in this case, the intersection angle β + the phase angle α≈30 ° + 60
° = 90 °.

According to each of the above embodiments, in order to minimize the secondary inertial force F ₂ , the phase angle α is 70 to 6 as described above.
0 ° is preferable, and the sum of the intersection angle β and the phase angle α is preferably about 90 °.

Although the above is based on the illustrated example, the engine 10 may have two cylinders. Also, the intersection angle β is 0 to 90
May be °.

[0079]

The effects of the present invention are as follows.

According to the first aspect of the present invention, the crankcase supporting the crankshaft has two cylinders or four cylinders in which the front and rear cylinders are projected in a V shape when viewed from the line of sight along the axis of the crankshaft. V-type engine of the present invention, in which the primary inertia force of reciprocating mass of a piston or the like is interlocked with the crankshaft,
A balancer for canceling out the primary inertia couple is provided, and on the other hand, in order to minimize the secondary inertial force of the reciprocating mass, the angle of intersection between the axial centers of the front and rear cylinders and the two adjacent in the axial direction of the crankshaft are minimized. The phase angle between the crank pins of the cylinder is set.

Therefore, the primary inertial force and the primary inertial couple are reliably canceled by the balancer, and the secondary inertial force is reduced. The balancer in this case is rotating at the same speed as the crankshaft and in the reverse direction, and generally, noise and drive are higher than those of the inline 4-cylinder rotating as the balancer of the secondary inertia force at twice the crankshaft. It is advantageous in terms of loss.

Therefore, vibrations when the engine is driven are reduced, the life of the engine is improved, and noise is reduced.

According to the second aspect of the present invention, the total of the intersection angle and the phase angle is about 90 °.

Therefore, by setting the optimum intersection angle and phase angle calculated based on the general formula, particularly, the secondary inertial force is effectively reduced.

Therefore, the vibration when the engine is driven can be more effectively reduced.

According to the invention of claim 3, the intersection angle is 20 to 3
The engine is mounted on the motorcycle such that the crankshaft is 0 ° and the crankshaft extends in the vehicle width direction.

Therefore, the vibration of the vehicle body due to the vibration of the mounted engine is reduced, and the riding comfort of the motorcycle is improved.

Further, in the case of a motorcycle, the extra space is particularly narrow, but since the engine is a V type with an extremely narrow angle and is compact, there is also an advantage that the engine can be easily mounted on the vehicle body.

[Brief description of the drawings]

FIG. 1 is a side view of an engine.

FIG. 2 is a side view of the motorcycle.

FIG. 3 is a perspective view of an engine.

FIG. 4 is a front view of the engine.

FIG. 5 is a graph showing Example 1.

FIG. 6 is a graph showing Example 2;

FIG. 7 is a graph showing Example 3;

FIG. 8 is a graph showing Example 4.

FIG. 9 is a graph showing Example 5.

FIG. 10 is a graph showing Example 6;

[Explanation of symbols]

10 engine 19 crankcase 21 crankshaft 22 cylinder 23 shaft center 25 cylinder hole 26, 27 shaft center 29 piston 30 connecting rod 31 crankpin 32 piston pin 34 balancer 35 side view centerline 37 front view centerline α phase angle β crossing angle m Reciprocating mass F ₁ 1st inertial force F ₂ 2nd inertial force M ₁ 1st inertial couple

Claims (3)

[Claims] 1. A two-cylinder or four-cylinder V cylinder in which a front and rear cylinders are provided in a V shape in a crankcase supporting the crankshaft as seen from a line of sight along the axis of the crankshaft.
Type engine, in which a balancer for canceling the primary inertial force of the reciprocating mass of the piston and the primary inertial couple in cooperation with the crankshaft is provided, while the secondary inertial force of the reciprocating mass is minimized. Thus, the low-vibration V-type engine in which the intersecting angle between both axial centers of the front and rear cylinders and the phase angle between the crank pins of both cylinders adjacent to each other in the axial direction of the crankshaft is set. 2. The low vibration V-type engine according to claim 1, wherein the total of the intersection angle and the phase angle is approximately 90 °. 3. The low-vibration V-type engine according to claim 1, wherein the engine is mounted on a motorcycle with an intersection angle of 20 to 30 ° and a crankshaft extending in the vehicle width direction.