KR20120021876A

KR20120021876A - Crankshaft for 2 cylinders engine

Info

Publication number: KR20120021876A
Application number: KR1020100080744A
Authority: KR
Inventors: 이창호
Original assignee: 현대자동차주식회사
Priority date: 2010-08-20
Filing date: 2010-08-20
Publication date: 2012-03-09

Abstract

The present invention is different from the inertia force of the first crank arm (1) and the second crank arm (2) connected by the crank pin (5), and the third crank arm (3) connected by another crank pin (5) By making the crankshaft different from the inertia force of the fourth crank arm 4, the moment of the third journal 13 having the fourth crank arm 4 and the driving gear 20 together is minimized. It is possible to implement the optimization of the balance such that the total moment of the crankshaft becomes zero around the second journal 11.

Description

Crankshaft for 2 Cylinders Engine

The present invention relates to a crankshaft for a two-cylinder engine, and more particularly to a crankshaft for a two-cylinder engine with optimized balance.

In general, a two-cylinder engine vehicle can realize a lighter weight and fuel savings than a three- and four-cylinder engine, and has a low price.

To generate power, whether it is a two-cylinder engine or a three- or four-cylinder engine, the crankshaft converts the linear motion generated by the piston of each cylinder into a rotary motion and applies a force to the piston reaching the bottom dead center for continuous linear motion. Crankshaft must be applied.

Crankshafts that rotate at high speeds use flywheels for balance, but flywheels larger in the rear end are applied to the two-cylinder crankshaft due to the characteristics of a two-cylinder engine with a 360-degree explosion phase, which has a greater angular velocity fluctuation than the three- and four-cylinder engines. Inevitably, this crankshaft structure tilts the center of gravity of the engine towards the flywheel.

Therefore, a balance shaft type crankshaft is applied to the two-cylinder engine in consideration of the balance.

In view of the above, the present invention has an object to provide a crankshaft for a gear drive balance shaft type two-cylinder engine by optimizing the overall balance by varying the inertia force of each of the four crank arms.

The present invention for achieving the above object is a first crank arm and a crank pin connected to the first crank arm is connected to, the third crank arm and a crank pin connected to the second crank arm by a second journal In a crankshaft for a two-cylinder engine, in which a third journal is connected to a fourth crank arm connected with a drive gear,

The inertial forces of the first crank arm and the second crank arm are asymmetric with each other, and the inertial forces of the third crank arm and the fourth crank arm are asymmetric with each other.

It is characterized in that the total of the total moment around the second journal is zero (0).

The inertia force size of the first crank arm and the inertia force size of the third crank arm are equal to each other, the inertia force size of the second crank arm is smaller than the inertia force size of the fourth crank arm, and the same first The inertia force size of the crank arm and the third crank arm is greater than the inertia force size of the second crank arm and the inertia force size of the fourth crank arm.

The present invention uses the difference in the inertia force of the crank arm consisting of a total of four, there is an effect that can optimize the overall balance with almost no shape change or structural change.

1 is a configuration diagram of a crankshaft for a two-cylinder engine according to the present invention, Figure 2 is a schematic diagram of a crankshaft for a two-cylinder engine according to the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the exemplary embodiments of the present invention may be embodied in various different forms, one of ordinary skill in the art to which the present invention pertains may be described herein. It is not limited to the Example to make.

1 shows a block diagram of a crankshaft for a two-cylinder engine according to the present invention.

As shown, the crankshaft for a two-cylinder engine has a structure in which the first crank arm 1, the second crank arm 2, and the third crank arm 3 and the fourth crank arm 4 are arranged coaxially. Is made of.

The first crank arm 1 and the second crank arm 2 are connected to each other by a crank pin 5, and the third crank arm 3 and the fourth crank arm 4 are also crank pins 7. Are connected to each other.

The first crank arm 1 is connected to the first journal 9, the second crank arm 2 and the third crank arm 3 are connected to each other by a second journal 11, the fourth crank The arm 4 is connected to the third journal 13.

The driving gear 20 is formed together at the portion where the fourth crank arm 4 and the third journal 13 are connected.

2 illustrates a first crank arm 1, a second crank arm 2, and a first journal 9 on the left side of the second journal 11 based on the third crank arm 3 and the fourth crank arm ( 4) and a balance diagram of the crankshaft for the two-cylinder engine according to the present embodiment, in which the drive gear 20 and the third journal 13 are provided on the right side.

At this time, the first crank arm (1), the second crank arm (2), the third crank arm (3) and the fourth crank arm (4) to which the crank pins 5 and 7 are coupled based on the center of the crankshaft. The first crank arm (1), the second crank arm (2) and the third crank arm (2) are referred to as first? The parts opposite to 3) and the fourth crank arm 4 are called first-2-3-4 counterweights, respectively.

Since the inertia force (F) is the product of the mass (M) multiplied by the distance (r, the distance from the crankshaft shaft center), as shown in the inertial force of the first to two to four arms are F1, F2, F3 respectively , F4, and the inertial forces of the first to second counter weights are represented by Fc1, Fc2, Fc3, and Fc4, respectively.

In the present embodiment, the inertia force F4 of the fourth arm has a larger value than the inertia forces F1, F2, and F3 of the first to second to third arms, and the fourth crank arm 4 has a drive gear ( 20) is formed together.

In addition, Fc1, Fc2, Fc3, and Fc4, which are inertia forces of the first to second to fourth counterweights, respectively, have a relationship of Fc2 <Fc4 <Fc1 because Fc1 = Fc3, Fc2 <Fc4.

Thus, the inertia force size (F1 + Fc1) of the first crank arm (1) and the inertia force size (F2 + Fc2) of the second crank arm (2) connected to each other by the crank pin (5) are formed asymmetrically, and The inertia force size (F3 + Fc1 (= Fc3)) of the third crank arm 3 and the inertia force size (F4 + Fc4) of the fourth crank arm 4, which are connected to each other by the other crank pins 7, are formed asymmetrically. It is done.

As described above, the asymmetrical relationship between the first crank arm 1, the second crank arm 2, the third crank arm 3, and the fourth crank arm 4 of the first, second, third, and fourth counterweights This is caused by different inertia forces (Fc1, Fc2, Fc3, Fc4).

Therefore, as described above, the first crank arm 1 and the third crank arm 3 have the same inertia force size (F1 + Fc1 = F3 + Fc3), and the second crank arm 2 The inertia force size F2 + Fc2 has a smaller value than the inertia force size F4 + Fc4 of the fourth crank arm 4, and the first crank arm 1 and the third crank arm 3 are the same as each other. Inertia force size (F1 + Fc1 = F3 + Fc3)) is greater than the inertia force size (F2 + Fc2) of the second crank arm (2) and the inertia force size (F4 + Fc4) of the fourth crank arm (4) It is formed.

In the present embodiment, the inertia forces of the first crank arm 1 and the second crank arm 2 connected to the crank pin 5 are different from each other, and the third crank arm 5 is connected to another crank pin 5. The moment of the third journal 13 having the fourth crank arm 4 and the driving gear 20 together by making the crank shaft by varying the inertia force sizes of the third crank arm 4 and the fourth crank arm 4 Moment) can be minimized, and it is possible to realize the optimization of the balance such that the total moment of the crankshaft becomes zero around the second journal 11.

1: first crank arm 2: second crank arm
3: third crank arm 4: fourth crank arm
5,7 Crankpin 9: First Journal
11: Second Journal 13: Third Journal
20: drive gear

Claims

The second crank arm is connected to the first crank arm and the crank pin connected to the first journal, and the driving gear is connected to the fourth crank arm connected to the third crank arm and the crank pin connected to the second crank arm. In the crankshaft for the two-cylinder engine to which the third journal is connected,
Crankshafts for two-cylinder engines, characterized in that the inertial forces of the first crank arm and the second crank arm are asymmetric with each other, and the inertial forces of the third crank arm and the fourth crank arm are asymmetric with each other. .

The crankshaft for a two-cylinder engine as set forth in claim 1, wherein the total moment total is zero around the second journal.

The inertia force size of the first crank arm and the inertia force size of the third crank arm are equal to each other, and the inertia force size of the second crank arm is smaller than the inertia force size of the fourth crank arm. The crankshaft for the two-cylinder engine, characterized in that the inertia force of the first crank arm and the third crank arm are greater than the inertia force of the second crank arm and the inertia force of the fourth crank arm.