JPS58102842A - Device for reducing unbalanced inertia force in reciprocating internal-combustion engine - Google Patents

Abstract

PURPOSE:To permit to cancel the unbalanced inertia force caused by the reciprocating parts of the engine by a method wherein an inertia force is generated by a balance weight driven directly by a cam integral with a carnkshaft. CONSTITUTION:A piston 2 is provided slidably in a cylinder formed in a cylinder block 1 while the piston 2 is connected to the crankshaft 4 through a connecting rod 3. The cam 6 is secured to the crankshaft 4 integrally and is receiving the resilient force of a spring 8 in a notch 1a formed in the cylinder block 1 so as to abut the balance weight 7 against the cam 6.

Description

[Detailed description of the invention]

The present invention relates to a device for reducing unbalanced inertia in a reciprocating internal combustion engine. In conventional reciprocating internal combustion engines, in order to reduce the secondary inertia force, a pair of run weights, which are driven by the crankshaft at twice the rotational speed of the crankshaft, are installed. In such a balance weight type secondary inertia force reduction device, for example, in an in-line four-cylinder reciprocating internal combustion engine, two heavy Palanne shafts are required. This increases the overall weight of the internal combustion engine, and requires gears, chains, and other complicated drive parts, which not only increases the weight but also increases costs.
Since the balance weight is driven at twice the rotational speed of the crankshaft, the speed at the bearing part of the balance 7 and 7 is fast, and each balance 7 and 7 is As the load increases, the wear of the bearings increases, resulting in large losses both in terms of output and fuel consumption. The inertia force is generated by the balance weight directly driven by the cam counter.
As a result, the unbalanced inertia force caused by the reciprocating part of the engine body is canceled out in reciprocating motion #2! A device for reducing unbalanced inertial force in an engine is provided. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an in-line four-cylinder reciprocating internal combustion engine equipped with an unbalanced inertia force reduction device. In the figure, 1 is a cylinder block, 2 is a piston that slides in the cylinder, 3 is a connecting rod, 4 is a crank 7 shaft, and 5 is a flywheel. Further, 6 is a cam fixed or integrated with the crankshaft 4, and 7 is a spring 80 in a notch 1a formed in the cylinder block 1. The spring 80 receives the elastic force and comes into contact with the cam 6 as shown in FIG. It is a balance weight. On the other hand, FIGS. 3 and 4 explain the origin of the idea of the present invention. FIG. 3 is a schematic diagram of a conventional in-line four-cylinder reciprocating internal combustion engine, and FIG. 4 is a view of this from two directions indicated by arrows. In this internal combustion engine, the total weight of the reciprocating portion of each cylinder II kWR is 1,! =4WR・ω3×r×ρx coa 2#...
......The inertial force of (1) acts. However, WR
= WJ +WRY + WRY+ WR, and WR,
, WR, , WR, , WR4 is the weight of the reciprocating portion of each cylinder. In addition, g is the gravitational acceleration, ω is the crank rotation speed, r is the stroke, ρ is the soil, L is the connecting rod length, and θ is the crank 7 shaft rotation angle (clockwise angle with the cylinder top dead center as 0). . This inertial force 1Y increases as the engine rotational speed increases, so it increases as the square of the crank rotational speed, so in an in-line four-cylinder internal combustion engine, vibrations during high-speed operation become large and the vehicle vibration becomes large and uncomfortable. At the same time, auxiliary equipment such as generators and starting motors installed in the engine, air purifiers, carburetors, etc.
It is well known that the stress applied to the intake manifold and exhaust manifold also increases, which affects the durability of these parts. In the present invention, an inertial force in the opposite direction that cancels out the inertial force that causes such problems is generated by a strainer installed on the crankshaft and an inertial superposition driven by this cam. FIG. 5 is a schematic diagram showing the internal combustion engine of the present invention, in which the cam 6 integrated with the crank 7 shaft 4 has a balance weight of 1 with respect to the rotation angle 0 of the crankshaft 4 described above.
7B = a+ (1-coIi2
θ)−・−==(2). (Lt is the maximum displacement of the balance weight, which is 10.) From this, the acceleration of the balance weight 1 is d鵞na a鵞θ韮=
4a 1 cos 2θat' -4a, (d”oo
a 2θ-, = (3). Here, if the weight of the balance weight 10 is wB, the cam to move it has a power of 4W, with the upward direction being positive! I FBI --ILI (II" cos 2#
-----(4) is required. In equation (4), when the balance weight 7 is driven, the force 1 acting on it is the force Fc of the cam 6 pushing the balance weight 1 in the Y direction, and the force IFsp of the spring 8 pushing it in the -Y direction. The difference is FB = F
o-F,p (5). Also, the sum of the forces applied to the engine body is the reaction force of the fixed end of the spring 8 pushing the 71J double block 1 in the Y direction at point A shown in FIG. − It is the difference between the force IFa acting in the Y direction, and (5)
From the formula, it becomes. Therefore, in order to completely cancel out the inertial force IPY in equation (1) above with Fm, it is necessary to set FY+pBt=Q. That is, it is necessary to set WRX r x p = wBxal -- (7). Here, if VB = WR, a11
=:r/. In a normal internal combustion engine, ρ is 4, so. a + = '4. In addition, if the weight WR of the reciprocating part of the cylinder is not doubled, B = 2WR, and lj is 4, then all will be in the middle. Fig. 7 and Fig. 8 show other embodiments. In the example, the reaction force applied to the cam 1 is added to the crankshaft as a variable torque, increasing the engine rotational force variation.In particular, depending on the magnitude of the load on the spring 8, a large starting force is required when starting the engine. A starting motor with a large capacity is required.For this reason, in this embodiment, the balance weight is divided into two pieces of 1.1', and these are arranged symmetrically with respect to the center of the crankshaft, and the spring is also divided into two pieces of 1.8'. We also have two 6.6' cams available.
These are arranged 90' apart from each other in terms of crank angle. Therefore, the downward displacement p of the lower balance weight 2'. 7'B, = a - a, cos(#+4) = a
-a, cos 2 e ---・-・-
・-(8). By doing this, the inertia force entering the engine due to the balance weight 7' can be calculated from equation (6) as follows in the vertical direction in the figure: = −""al ω" cos (2# + r
), and for the Y direction, the resultant force y due to the two balance ways)7.7'
, is, If WB' is set to 1/ of wB of the previous embodiment, the effect of reducing the unbalanced inertial force will be the same as above. Next, the relationship between the above embodiment and the rotational force fluctuation will be described. The spring loads r and p of the spring 8 are necessary to make the balance weight 1 follow the cam 6, and (5
) What is Pc derived from the formula? . = y, p+ yB≧0
・・・・・・・・・It must be aυ. Now, the force 'IPB acting on the balance weight 7 at the maximum operating speed of 03 is Fnmax: FBm, XX cots
2θ ・・・・・・・・・-aa, FBmaX ”÷ × a, 匈鵞 wax
... ... ... becomes 0. On the other hand, in this example, the spring 8 load F, p is as follows: P, p = FB max x (: "1%) -=-0
4) Set the dimensional load of the spring 8 so that the following load can be obtained. By doing this! 7. Substitute equation (2) with (
4) Entering into the equation, F8p=FIImax×(t1cO112θ> ・−,
-, as, and when formula 02 and formula (c) are put into formula 0θ, 1°=Fi1max ×5/B
-θ)≧0, and the parallel weight 7 can follow the cam 6 up to the ignition rotation speed ωWLX. The fluctuating torque M that enters the crankshaft 4 of the above embodiment using such a spring 8 is as shown in Fig. tiA6, M=-pxe...--Jfe. Here, ・represents the eccentricity of the load with respect to the center of the crank 7, 7, and 4. s 6 = d7B/(1θ, (21
From the formula, a = 2a, m 2θ ・・・・・・・・・07)
becomes. Also, from the 00 formula 'Q' 1Fap ''B
From the equation (4) and (I!9), 'O
” F'!l ma! ×(!-t.m2θ) + flat al
(al' OOg 2#......becomes.Here, by substituting the above on and aa expressions into the rIl1 expression, '''-'j FBmax ''+''2''
# p”BmaX-tortoise, wz becomes 40. ω=0
M in M. =. Then, Mca+=o=FBmax
-a, x (5 sin 2 θ 1”' 4 B>...old... [8] On the other hand, a similar design was carried out for this example!, and the variable torque y' that enters the crankshaft 4# was calculated. Then, the variable torque y due to the upper balance weight 1 and spring 8 in FIG. 7, and the lower balance weight 1
The composite value of the variable torque M due to the edict and the spring 8', that is, %' = M, + M! ...River...(21). Ml is M, = -F, as in the # real NIi example. X
・Since it is an irises and FB' = ","x al ω"rnax -Yu (22), -i@, *-1-4θ- = (233). On the other hand, M, = 7° , ×・, ... River... (24) FC,
== IP, p, + IFB, ・----(2
5), if the spring characteristics for P and I are set similarly to equation (14), then
-7) ......Kuni), which leads to (8
) By substituting the formula, '8Pl = )"'mmax ×
(B” C082θ)・・・・・・・・・Kan aym. @, = −45= +2a1 aut 20
・” ・” ...(28). Saita, (9)
According to the formula, FBt = -4W'B/ ・al (d″e
Since o1i2θ, −) is expressed as 1), @I)
, (Substituting into formula 91, -

【stomach! Hesitate'&? (
al" x ssn 4g , , , . Furthermore, by substituting equations (231 and (29) into equation (21), we get I-] M 4 F' Bwax X ILIth4θ-11!
! liL'X a+ω1×-40...GO). Now, VB' = Bow/WB, so F≦=14.
becomes F-, IA'= FBmJLx °alsin 4θ-4%
xar” ω” sin 4# ・・・・・・Gl)
becomes. If ω=0 here, then M-1. = FB maz' IL+
・・・・・・・・・(32) Type 01 and M of type (31)
', and also M in Kan style. 8° and M = 0 in formula C31), -4・FB wax xyl,
The w 2θ component is reduced, and the required starting force when starting the engine is reduced. In addition, balance weight 7゜7' and notch 1
Lubricating oil is supplied between a and a. As explained above, according to the present invention, the crank 7
By driving the balance weight with a cam fixed to the engine, an inertia force of the engine rotational multiple method is generated, thereby canceling out the unbalanced inertia force generated by the reciprocating part of the engine. #) Compared to the conventional balance shaft method I, the structure is simpler, and it can be easily added to existing engines. Further, by installing the pair of intermediate stages for canceling the inertial force, it is possible to cancel the rotational fluctuation force and improve the starting characteristics.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of the bulge showing the device for reducing unbalanced inertial force of the present invention, FIG. 2 is a sectional view taken along line A--M in FIG. 1,
Fig. 3 is a schematic diagram of a reciprocating internal combustion engine for explaining the present invention, Fig. 4 is a schematic diagram similarly seen from the side, Fig. 5 is a schematic diagram of the internal combustion engine of the present invention, and Fig. 6 is a schematic diagram of the internal combustion engine of the present invention. A sectional view of the same portion as FIG. 2, and FIGS. 7 and 8 are side sectional views and front sectional views of main parts of other embodiments. 4...Crank 7 Yajito, 6.6'...Cam 7
, 7#... Balance weight, s, s'... Spring. Figure 1 Figure 2 Figure 7 Figure 8

Claims (1)

[Claims] It has a cam fixed to the crank 7 shaft and a balance weight that is in elastic contact with the cam by a spring,
A device for reducing unbalanced inertial force in a reciprocating internal combustion engine, which reduces the inertial force caused by one of the reciprocating parts of the engine body by the inertial force generated by reciprocating the rotation weight of a crankshaft.