KR100412558B1 - Crank shaft balancing device for V8 engine - Google Patents

Abstract

The present invention relates to a crankshaft balancing device of a V 8 engine,

Conventional crankshaft balancing device sets the mass of the first web and the eighth web installed at both ends of the crankshaft larger than the other webs in order to remove the first pitch moment by only the web installed on the crankshaft. In the part where the first web and the eighth web are installed in the door, the balance ratio is greater than 1 (the vibration rate is not applied to the bearing when the balance ratio is 1), and vibration is applied to the bearing. As the mass of the 4th and 5th webs becomes too small, the balance ratio in this part becomes low, which causes the balance ratio in the whole bearing to be poor, so that the primary vibration is transmitted to the crankshaft bearing, which adversely affects the engine. There was a problem.

Accordingly, the present invention for solving the above problems is connected to the crankshaft and the belt, and the first to fourth auxiliary webs for offsetting the primary pitch moment occurring in the crankshaft in the middle of the crankshaft bearing, The crankshaft balancing device of the V8 engine, which can improve the balance rate, cancels the vibration applied to the crankshaft bearing, reducing the vibration rate of the entire engine, and the size and weight of the web installed on the crankshaft. It is about.

Description

Crank shaft balancing device for V8 engine

The present invention relates to a crankshaft balancing device of a V8 engine, and in particular, connected to the crankshaft as a belt, in the meantime by installing the first to fourth auxiliary webs for offsetting the primary pitch moment occurring in the crankshaft. To improve the balance ratio of the crankshaft bearings to offset the vibrations applied to the bearings of the crankshaft to reduce the overall vibration rate of the engine and to reduce the size and weight of the web installed on the crankshaft. Crankshaft balancing device of the present invention.

The V 8 engine is an engine with eight cylinders and a piston.

1 shows a crankshaft balancing device of a conventional V 8 engine,

Pins 2a to 2d for coupling the conrods 3 connected to the eight pistons # 1 to # 8 are coupled to the arm 6 extending from the crankshaft 1, and the pins 2a. On the other side of the arm 6 on which ˜2d is formed, a plurality of webs 5a to 5h are provided for offsetting an unbalanced pitch moment.

On the crankshaft 1, a plurality of bearings 4 supporting the crankshaft 1 are formed.

The webs 5a to 5h have a constant weight, and in particular, the mass of the first and eighth webs 5a and 5h is larger than other webs to offset the primary pitch moments (engine lateral moments). This eliminates the unbalanced pitch moment that occurs during operation.

Here, referring to FIGS. 2 and 3, the unbalanced force and unbalanced moment for each order based on the rotational mass and the reciprocating mass are as follows.

In the formula below, M = rotational mass (crankpin mass + conrod mass x 2/3),

Mrecip = reciprocating mass (piston mass + conrod mass x 1/3), R = crankshaft rotation radius,

P = pitch between bores, θ = angle from the x-axis to the number 1 crank pin,

Note that B = left and right bank angles, and P0 = left and right bank offsets.

2 is a diagram illustrating a driving cycle of the V8 engine, in which the first to fourth fins 2a to 2d formed on the crankshaft 1 form an angle of 90 ° to each other, and the first fin 2a. It is spaced θ angle from this x axis.

The ignition sequence of the piston is ignited in the order of # 1 → # 2 → # 7 → # 8 → # 4 → # 5 → # 6 → # 3, and one cycle is 720 °.

3 shows a state in which the pistons # 1 to # 8 are installed in the cylinder block of the V8 engine, and bores in which each piston is installed are installed in the cylinder block at a predetermined interval P. FIG.

Based on the above description, the calculation of the unbalance force and unbalance moment by the conventional crankshaft balancing device is as follows.

(1) Unbalance force by rotating mass

(2) Unbalance moment due to rotating mass (based on the center of cylinders 4 and 5)

(3) unbalance due to reciprocating mass (1 ^st )

The inertial force generated in the short-term cylinder by the piston reciprocating motion

The 1 ^st (primary) component value of the cylinder axial unbalance is

= 0

(4) Unbalance force due to reciprocating mass (2 ^nd )

2 ^nd component value of the cylinder axial force is unbalanced

= 0

(5) Unbalanced moment due to reciprocating mass (1 ^st )

(6) Unbalanced moment due to reciprocating mass (2 ^nd )

= 0

(7) Unbalance force and moment throughout the engine

= Complaint by the rotating mass ryeongryeok (1 ^st) + by a rotating mass unbalance couple of forces (1 ^st) + unbalanced force (1 ^st) by the reciprocating mass + unbalanced couple of forces due to the reciprocating mass (1 ^st) + unbalanced due to the reciprocating mass Force (2 ^nd ) + Unbalanced force due to reciprocating mass (2 ^nd ) + .........

It can be seen that.

As described above, in the conventional crankshaft balancing device, the mass of the first web and the eighth web installed at both ends of the crankshaft is larger than the other webs in order to remove the primary pitch moment by only the web installed on the crankshaft. Because of this, there is a problem that the vibration ratio is applied to the bearing because the balance ratio exceeds 1 (the vibration rate is not applied to the bearing when the balance ratio is 1) at the portions where the first web and the eighth web are installed. In addition, as the mass of the fourth and fifth webs becomes too small, the balance ratio in this part becomes low, and for this reason, the balance ratio in the whole bearing becomes poor, and primary vibration is transmitted to the bearing of the crankshaft. There is a problem that adversely affects the engine.

Accordingly, the present invention for solving the above problems is connected to the crankshaft and the belt, and the first to fourth auxiliary webs for offsetting the primary pitch moment occurring in the crankshaft in the middle of the crankshaft bearing, The crankshaft balancing device of the V8 engine, which can improve the balance rate, cancels the vibration applied to the crankshaft bearing, reducing the vibration rate of the entire engine, and the size and weight of the web installed on the crankshaft. It is intended to provide.

The present invention for achieving the above object,

In the pin for coupling the eight piston connected to the arm is coupled to the arm extending from the crankshaft, the other side of the pin-shaped arm is formed with a web of constant weight for canceling the unbalanced force,

A first pulley is formed on one side of the crankshaft, and a balance shaft having a second pulley for connecting as the belt and the first pulley is formed below the crankshaft,

It is characterized in that the first to fourth auxiliary webs for offsetting the primary pitch moment generated in the crank shaft in the middle of the balance shaft is provided.

The first subweb is in the same direction as the first and second webs, the second subweb is in the same direction as the third and fourth webs, and the third subweb is in the same direction as the fifth and sixth webs. The fourth auxiliary web is installed in the same direction as the seventh and eighth webs, and each of the auxiliary webs has the same mass.

1 is a view showing a conventional crankshaft balancing device.

2 is a diagram showing an operation cycle of a conventional crankshaft.

Figure 3 is a view showing a cylinder block equipped with a conventional crankshaft.

4 shows a crankshaft balancing device of the present invention.

※ Explanation of code for main part of drawing

1: crankshaft, 2a-2d: pin,

# 1 ~ # 8: pistons, 5a ~ 5h: web,

10: first pulley, 11: second pulley,

12: belt, 20: balance shaft,

21: secondary bearing, 30a ~ 30d: secondary web,

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present invention will be described.

In the description of the present invention, the same components as in the prior art are denoted by the same reference numerals to avoid duplicate explanation.

The biggest feature of the present invention is to form a balance shaft 20 for offsetting the primary pitch moment under the crankshaft (1).

A first pulley 10 is formed on one side of the crankshaft 1 to connect the balance shaft 20, and a second pulley 11 to be connected as the belt 12 with the first pulley 10. It is formed in the balance shaft 20.

Preferably, the rotation ratio of the first pulley 10 and the second pulley 11 is 1: 1.

Auxiliary bearings 21 are respectively provided at both ends and the center of the balance shaft 20, and the first to the first pitch moments for canceling the first pitch moment generated in the crankshaft 1 between the auxiliary bearings 21. Fourth auxiliary webs 30a to 30d were installed.

The auxiliary webs 30a to 30d are made to be the same as the installation directions of the webs 5a to 5h installed on the crankshaft 1, respectively.

That is, the first auxiliary web 30a is in the same direction as the first and second webs 5a and 5b, and the second auxiliary web 30b is in the same direction as the third and fourth webs 5c and 5d. The third auxiliary web 30c is provided in the same direction as the fifth and sixth webs 5e and 5f, and the fourth auxiliary web 30d is provided in the same direction as the seventh and eighth webs 5g and 5h. .

In addition, the mass of the auxiliary web 30 installed on the balance shaft 20 is preferably set to a mass such that the balance ratio is calculated by calculating a balance ratio that affects the bearing load of the crank shaft 1. Do.

Here, looking at the mass setting process of the auxiliary web 30 as follows.

In the following formula, P1: distance between the first and fourth auxiliary webs in the center of the balance axis 20, P2: distance between the second and third auxiliary webs in the center of the balance axis 20, M ₁ r ₁ ω ² : Rotational mass of the first and fourth auxiliary webs, M ₂ r ₂ ω ² : rotational masses of the second and third auxiliary webs.

The unbalanced moment appearing on the crankshaft 1 is

Appears as

The balancing moment by the auxiliary web 30 installed on the balance shaft 20 is

Appears.

Therefore, in order for the balancing ratio to be 100% Should be

Therefore, if the unbalanced moment of the crack shaft 1 and the balancing moment of the balance shaft 20 are substituted into the above equation,

to be.

Therefore, M ₁ r ₁ P ₁ = 3 (2M + M _recip ) RP / 2, and M ₂ r ₂ P ₂ = (2M + M _recip ) RP / 2. Just set the mass.

As described in the above description, if the mass of the auxiliary web 30 installed on the balance shaft 20 is set to a mass capable of offsetting the balancing rate occurring in the crank shaft 1, the crank shaft 1 at the time of engine driving. It is possible to almost completely offset the primary pitch moment applied to the bearing (4) of the, thereby allowing the mass of each web (5a ~ 5h) installed on the crankshaft (1) can be set smaller than before It is possible to compensate for the disadvantage that the balance ratio at a specific portion is increased or decreased, and the reaction force at the bearing 4 can be minimized, thereby reducing the occurrence of vibration at the bearing 4.

As described above, the present invention is connected to the crankshaft as a belt, and the balance ratio of the crankshaft bearing is adjusted by providing first to fourth auxiliary webs for offsetting the primary pitch moment generated in the crankshaft. It provides a crankshaft balancing device for the V8 engine that can be improved to offset the vibration applied to the bearings of the crankshaft to reduce the vibration rate of the entire engine and to reduce the size and weight of the web installed on the crankshaft. You can expect the effect.

Claims (3)

Pins 2a to 2d for coupling the conrods 3 connected to the eight pistons # 1 to # 8 are coupled to the arms 6 extending from the crankshaft 1, and the pins 2a to 2d. In the web (5a-5h) of a certain weight body for canceling the unbalanced force is formed on the other side of the arm (6) is formed, Forming a first pulley 10 on one side of the crankshaft (1), the balance shaft 20 formed with a second pulley 11 for connecting the first pulley 10 and the belt 12 is the It is formed on the lower side of the crankshaft (1), and the first to fourth auxiliary webs (30a ~ 30d) for offsetting the primary pitch moment generated in the crankshaft (1) in the middle of the balance shaft (20) , The first auxiliary web 30a is in the same direction as the first and second webs 5a and 5b, and the second auxiliary web 30b is in the same direction as the third and fourth webs 5c and 5d. The third auxiliary web 30c is installed in the same direction as the fifth and sixth webs 5e and 5f, and the fourth auxiliary web 30d is installed in the same direction as the seventh and eighth webs 5g and 5h, respectively. The crankshaft balancing device of the V 8 engine, characterized in that the secondary web 30 of the same mass. delete The method of claim 1, The crank of the V 8 engine is characterized in that the mass of the auxiliary web 30 is set to a mass which calculates a balance ratio that affects the load of the bearings 4 of the crankshaft 1 so that this balance ratio becomes 1. Axial Balancing Device.