JPS6148628A - V-type internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce a remaining unbalanced inertial force including a high-order remaining unbalanced inertial force to the minimum value by adjusting the over- balance factor of a crank shaft and the crank pin relative angle. CONSTITUTION:In a V-type internal-combustion engine having a capiper angle of less than 60 deg. between one cylinder train and the other cylinder train, a remaining unbalanced inertial force can be reduced to the minimum value by adjusting DELTAdelta and DELTAbeta to limit the over-balance factor and the crank pin relative angle beta expressed in equations beta=2alpha+180 deg.+DELTAbeta, delta=0.5+DELTAdelta, (DELTAbeta>0, DELTAdelta>0), where DELTAdelta is the deviation of the over-balance factor of a crank shaft when only the primary unbalanced inertial force is 0, DELTAbeta is the deviation of the crank pin relative angle, and alpha is a caliper angle.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement of a V-type internal combustion engine, and particularly to one in which high-order residual unbalanced inertia force is reduced to a minimum value.

(Prior Art) A so-called phase crank (Japanese Unexamined Patent Publication No. 113646/1982) has been developed in which the crank pin of a V-type internal combustion engine is provided with a predetermined deflection angle to reduce the primary residual unbalanced inertia force to O.

In this prior art, as shown in Fig. 6, the primary residual unbalanced inertia becomes 0 when the overbalance ratio δ of the crankshaft and the relative angle β of the crank pin are set as β=2α+180°δ−0,5. There is a problem in that the higher-order residual unbalanced inertial force does not necessarily reach the minimum value.

(Objective of the Invention) The present invention is a V-type internal combustion engine that includes high-order residual unbalanced inertia force and can bring the residual unbalanced inertia force close to a minimum value. The purpose is to provide a leap.

(Structure of the Invention) The present invention provides a crankshaft adjustment for when only the primary unbalanced inertia force is O in a V-type internal combustion engine in which the included angle between one cylinder row and the other cylinder row is less than 60 degrees. - When the deviation of the bar balance ratio is △δ, the deviation of the crankshaft relative angle is Δβ, and the included angle is α, then β-2α+1806+Δβ δ-0,5+△δ (△β〉0, Δδ〉0) A V-type internal combustion engine characterized in that the overbalance ratio δ and the crankbin relative angle β, which are expressed as be.

(Example) In FIG. 1 showing a case where the present invention is applied, 2 is a front cylinder, and 4 is a rear cylinder. r indicates the crank arm length, and L indicates the connecting rod length.

The overbalance rate δ is expressed as β-and when the mass of the reciprocating system such as the piston and piston pin is defined as the mass 7n of the rotating system such as the m1 counter palancer 6 and the unranked bin 8. Note that the mass of the rotating system n is the center of the crankshaft o2
The masses of the counter-parancer 6 and the multi-rank bin 8, which are placed in opposing positions and whose centrifugal forces act in directions that cancel each other out, are canceled out.

The deviation of the overbalance rate when the residual unimpinged inertial force, including higher-order ones, is the minimum value compared to the case where the − of the first-order unimpinged inertial force is 0. If the overbalance rate is Δδ, then the overbalance rate δ is δ−0,5+Δδ (1).

Similarly, the relative angle β between the front cylinder 2 and the rear cylinder 4 is the deviation pitch Δβ, and the cylinder angle fa is β=2α+1
80°10Δβ...(2).

In Fig. 1, the resultant unimpinged inertial force F when the crank rotation angle is θ is given by B'x, the unimpinged inertial force component in the X-axis direction, and Fy, the unimpeded inertial force component in the y-axis direction. 77Σdoor...Displayed as (3). At this time, Fx
, Fy is the mass of the reciprocating system m1 The crank arm length is r1 The crankshaft axis angle is ω, then Fx = ("'+ Fr2) aoSa-b"mrJ
(c6's o'+cos f-θ))-(4)E'
7= (Frl −Fr2) S′1na−δwr
It is expressed as ω2 (sin θ - 8fLn (β -) - (5). Fr1 and Fr2 in equations (4) and (5) are the connecting rod length and L1 cylinder offset amount is ε... ...(6) ?r2=mrct+2(cos (0+4-β)+(λ
c, oe2(θjuyo-β)-1-sin(θjutoβ)・
(λ5in(θ10μmβ)-H)"-ξ5j-n(θ10-β)/(1-(λ51n(qJ+ξ)2)")...
...(7) However, λ=-1ξ=LL L.

With this @r=86M111%L7124ffl, e
When the characteristics of the deviations Δβ and Δδ with respect to the included angle α are determined by calculating the maximum value of the resultant inertial force F to be the minimum, the graph shown in FIG. 2 is obtained. Therefore, if the residual unimpingement inertia force Fi is calculated by selecting the optimal △β, Δδ for a given angle a, then the residual unimpingement inertia force Fi becomes 0 within the range of 606 α. Impact inertia 't100
%, it can be seen that the residual unimpingement inertia force F is reduced by selecting the optimal values of Δβ and Δδ.

Then a = 45°, r = 3 f) n, L = 12
4ff.

When ε=0, the overbalance rate δ obtained by calculation by changing the relative angle β of the crankshaft and the coefficient = F/mr
The relationship of ω2 is shown in FIG. It can be seen from FIG. 8 and FIG. 2 that when the angle α is 45°, the coefficient K becomes the minimum when δ=0.58 and β=280°.

(Effect of the invention) As explained above, according to the unexploded 8AK, the deviation of the overbalance rate δ of the crankshaft is △δ, and the deviation of the crankshaft relative angle β is As the sound Δβ, Δδ and Δβ are selected so that the maximum value of the high-order residual unimpulsive inertial force F is minimized, so that the residual unimpulsive inertial force F can be reduced. Moreover, it is not necessary to change the structure of the ■-type engine, and the deviations △δ, Δ
Since the residual unimpingement inertia force F is reduced only by selecting β, it is extremely easy to implement.

(Another embodiment) (1) As shown in Fig. 4, the front cylinder 2 and the rear cylinder 4
If it is offset outward by an offset xε, as shown in Figure 5, the minimum value of the maximum value of the residual unbalanced inertia crab p is further reduced compared to the case of Figure 1 with the offset amount ε-〇. be able to.

(2) The present invention is not limited to an even-numbered ■-type engine in which the number of cylinders in the -1 cylinder row and the other cylinder row are equal, but if the reciprocating system mass and rotating system mass of both cylinder rows are equal to each other, for example, the front cylinder row It can also be applied to an odd-numbered V-type engine with two cylinders and one cylinder in the rear cylinder row.

[Brief explanation of the drawing]

Fig. 1 is a structural schematic diagram of a V-type two-cylinder engine to which the present invention is applied, and Fig. 2 is a diagram showing the cylinder angle of the engine shown in Fig. 1 - residual unimpeded inertia force, deviation of overbalance ratio, and relative crankshaft angle. Figure 8 is a graph showing the characteristics of the deviation component of
The figure is a structural diagram showing another embodiment of the present invention, and FIG.
6 is a graph showing the offset amount-minimum value of the maximum value of the residual unimpingement inertia force F, the oat (-)5 lance ratio, and the relative angle characteristics of the crank bin in the case shown in FIG. 6. FIG. 6 is a schematic structural diagram showing the conventional example. 2...front cylinder, 4...rear cylinder, 6...
・・Counter Noku Ransa, 8・・Crankbin

Claims (1)

[Claims] The included angle between one cylinder row and the other cylinder row is 60
In a V-type internal combustion engine with a diameter of less than Adjust △δ and Δβ to overbalance rate δ and crank pin relative angle β, which are displayed as β=2α+180°+△β δ=0.5+△δ (△β>0, Δδ>0) A V-type internal combustion engine characterized in that the residual unbalanced inertia force is set so as to approach a minimum value.