JPS63314322A - Marine vessel with damping device - Google Patents

Abstract

PURPOSE:To reduce unbalanced moment by installing two rotary weights which is interlocked by a crankshaft facing in the ship longitudinal direction in the diesel engine mounted on a marine vessel and rotated in a hull longitudinal section at each angular velocity of once and double over rotational frequency of the crankshaft. CONSTITUTION:A diesel engine to be mounted on a marine vessel as the main engine is set up so as to cause the crankshaft 1 to be directed in the ship longitudinal direction. And, each of flywheels 7a and 7b is tightly attached to both ends in front and in the rear of the crankshaft 1 along both ends in front and in the rear of the diesel engine. And, each of longitudinal counter weights 2a and 2b is set up in these flywheels 7a and 7b so as to become opposite phase with each other. In this constitution, in and around a run, there is provided with a turning shaft in the width horizontal direction, while a rotary weight 10, rotating in a hull longitudinal section at an angular velocity of one time over rotational frequency of the crankshaft 1, is set up. In addition, in and around the top of a superstructure, there is provided with another rotary weight 11 rotating at the angular velocity of two times over the crankshaft likewise.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ship equipped with a diesel engine as a main engine.

[Conventional technology]

Generally speaking, on ships equipped with a diesel engine as the main engine in the stern engine room, the diesel engine is a reciprocating engine, so due to the inertia of its moving parts, it has a frequency of one and two times the main engine crankshaft rotation speed. An unbalanced couple is generated, which are usually called an unbalanced first moment and an unbalanced second moment, respectively.

Conventionally, a vibration-proof diesel engine as shown in FIGS. 6 to 8 has been installed in order to reduce vibrations generated in a ship due to the unbalanced moment. 6 to 8 show a conventional vibration-proof diesel engine, and FIG. 6 is a schematic diagram for explaining the mechanism of the crankshaft and combined balancer of the diesel engine. Figure 7 is a side view of the diesel engine, and Figure 8 is on the ■-■ line in Figure 7? FIG. 85 is a sectional view taken along the arrow 85. That is, as shown in FIGS. 6 to 8, a diesel engine 5 serving as the main engine is mounted with its crankshaft 1 facing in the direction of the ship's ship, and the front and rear ends of the crankshaft 1 are provided with the front and rear ends of the diesel engine 5. Flywheels 7a and 7b are fixed along the end faces, respectively.

Further, a front counterweight 2a and a rear counterweight 2b are attached to these flywheels 7a, 7b in pairs in the front and rear, respectively, so that they are in opposite phases.

The front counterweight 2a' and the rear counterweight 2b are installed so as to reduce the unbalanced first moment of the diesel engine 5 in the vertical and horizontal directions. On the other hand, above the crankshaft 1 on the front and rear end surfaces of the diesel engine 5, there are a pair of front and rear combined balancers 6a.
, 6b are arranged. The combined balancer 6a is composed of a primary balancer 3a, a secondary balancer 4a and 4b, and the combined balancer 6b is a pair of primary balancer 3a of the combined balancer 6a.
Next balancer 3b and also combined balancer 6a 2
It is composed of secondary balancers 4a and 4b and secondary balancers 4C14d each forming a pair.

As shown in FIG. 8, the combined baluns 5a and 5b each have a camshaft 9. Camshaft drive chain 8
, a camshaft drive gear (not shown), etc. Driven by a drive groove.

Further, as shown in FIG. 6, a pair of primary balancers 3a, 3
b are provided at positions in the same phase as the pair of counterweights 2a and 2b, respectively, and are driven to rotate in opposite directions in synchronization with 10 rotations of the crankshaft.

Further, the two sets of secondary balancers 4a, 4b and 4c, 4d are rotated and driven at twice the angular velocity of the crankshaft 1.

With the above-mentioned configuration, in a conventional ship equipped with a vibration-proof diesel engine, when the crankshaft 1 rotates, the front counterweight 2
A and rear counterweight 2b generate vertical and horizontal moments. These moments reduce the primary moments of unbalance in the vertical and horizontal directions of the diesel engine 5.

Furthermore, since the primary balancers 3a and 3b rotate in the opposite direction in synchronization with the rotation of the crank N1, the moment generated by these primary balancers 3a and 3b further reduces the above-mentioned complaints (l!1lr primary moment be done.

Furthermore, there are two sets of secondary balancers 4a, 4b and 4c.

4d is rotationally driven at twice the angular velocity of the crankshaft 1, so the unbalanced secondary moment in the vertical direction is also reduced.

[Problem that the invention seeks to solve]

However, in conventional vessels equipped with anti-vibration diesel engines, the balancer requires a large number of paired parts at both the front and rear of the diesel engine, and a complex drive system to drive these parts. Therefore, there are problems in that the manufacturing cost is high and the reliability of the device is reduced.

The present invention aims to solve the above-mentioned problems, and by simplifying the structure and drive system of the balancer without impairing the anti-vibration effect, it reduces manufacturing costs and improves the reliability of the equipment. The purpose of this invention is to provide a ship equipped with a vibration damping device.

[Means for solving problems]

The present invention solves the above-mentioned problems, and in ships equipped with a diesel engine as the main engine with its crankshaft facing the ship's ship, the primary and In order to reduce the secondary unbalance moment, it is installed near the stern end of the ship and rotates within the longitudinal section of the ship by 1 of the crankshaft rotation speed.
a single rotating weight that rotates at twice the angular speed; a single rotating weight that is disposed near the top of the ship's superstructure and rotates within the longitudinal section of the ship at an angular speed that is twice the number of revolutions of the crankshaft; It is characterized by having a drive system for driving these.

[For production]

In the above-mentioned ship equipped with a vibration isolator of the present invention, the two rotary weights provided in the vertical section of the ship rotate at angular velocities of one and two times the crankshaft rotation speed, respectively, thereby reducing the speed of the diesel engine. Unbalanced first and second moments are reduced.

[Actual example]

Below, a ship equipped with a vibration damping device as an embodiment of the present invention will be explained with reference to the drawings. Figure 1 shows the mechanism of the crankshaft of the diesel engine installed as the main engine in the ship and the mechanism of the allocation device for the primary and secondary balancers. Fig. 2 is a schematic diagram of the allocation device and its drive mechanism, Fig. 3 is a line diagram showing the characteristics of longitudinal vibration response of the hull, and Fig. 4.5 is a diagram showing the longitudinal vibration response of the hull. FIG. 3 is a schematic diagram showing vibration modes. As shown in Figures 1 and 2, in a diesel engine installed as the main engine, the crankshaft 1 is mounted so as to face in the direction of the ship's ship, and the diesel engine 5 is mounted at the front and rear ends of the crankshaft 1. Flywheels 7a and 7b are fixed along the front and rear end surfaces, respectively. In addition, a front counterweight 2a and a rear counterweight 2b are arranged in pairs in the front and rear of these flywheels 7a and 7b, respectively, and are arranged in opposite phases. The mounting position of the rear counterweight 2b is set so as to reduce the unbalanced first moment of the diesel engine 5 in the vertical and horizontal directions.

On the other hand, near the stern end there is a rotation axis in the horizontal direction of the ship's width.
A rotary hammer 10 is provided that rotates within the longitudinal section of the hull at an angular velocity that is one times the rotational speed of the main engine crankshaft. Further, a rotating weight 11 is disposed near the top of the superstructure and has a rotating shaft in the horizontal direction of the ship's width, and rotates within the longitudinal section of the ship at an angular velocity twice the number of revolutions of the main engine crankshaft. The rotary weights 10 and 11 will be explained using the rotary weight 10 as an example in FIG. 2, and are driven by a drive mechanism 12a as shown in the figure.

Since the ship with the damping device of this embodiment is constructed as described above, when the crankshaft 1 rotates, the front counterweight 2a and the rear counterweight 2b move in the vertical and horizontal directions. A moment occurs.

These moments reduce the unbalanced first order moments of the diesel engine 5 in the vertical and horizontal directions.

In addition, two rotating weights 10 and 11 are connected to the drive mechanism 1, respectively.
2a and 12b rotate at angular velocities that are once and twice that of the crankshaft 1, respectively, and centrifugal force is generated within the longitudinal section of the hull. Here, the magnitude of this centrifugal force is
The direction is proportional to the product of the eccentric weight of rotating weights 1o and 11 and the eccentric distance from the rotating shaft, and the direction is proportional to the main engine crank in both the longitudinal direction and the vertical direction at the installation position of each rotating weight. Forces with frequencies of one and two times the rotational speed of the shaft 1 act.

At this time, if the rotation speed of the main engine crankshaft 1 is represented by R, then
The number of rotations of the rotating weight 1O511 can be written as nR (n-1 or 2), respectively.

Here, if we examine the longitudinal vibration response of the ship's hull, for example, @
As shown in Figure 3, N...frequency (cp
m), A... Vibration acceleration (ga I) taken on the vertical axis
, circle... Longitudinal acceleration (g
aI), BL-rear vibration generation area, Bn* (n=
1 or 2)...Assuming the rotation speed range of a rotating weight of 10.11, Bt is a region with a higher frequency than Bn* (n-1 or 2), and in BNR (n-1 or 2), AL is Extremely small.

That is, it can be seen that the longitudinal vibration response of the hull in the frequency range of the main engine's first moment and second moment is unlikely to generate excessive longitudinal vibration even if there is a longitudinal vibration force in the BnR range.

Next, when examining the hull vertical vibration characteristics of a ship in the range of 13nR (n-1 or 2), the hull vertical vibration mode at BIR and B2R is as shown in Figure 4.5. This can be shown as vertical vibration mode 15 and hull vertical vibration mode 16 in the range of B2R.

4 indicates the distance between the rotating weight 10 and the stern side node of the vertical vibration mode 15, and tnR in FIG. 5 indicates the height from the main hull neutral axis 18 to the rotating electrolytic erosion 11. Show that. Here, if the centrifugal forces generated by the rotating weights 10 and 11 are respectively FIR and F2R, the generated moments MIR and M2R can be expressed by the following equation (1).

Mn* = FnRX inn (n=1.2)・
In other words, the moment given by equation (1) is generated by the rotating weights 10 and 11, so by appropriately setting the weight, eccentric distance, and phase, the main engine unbalance primary moment and secondary moment can be reduced. It can be reduced.

By the way, if the length of the diesel engine 5 in the longitudinal direction is mu, the relationship between inn (n=1.2) and mu is often expressed as equation (2) shown in the general case law.

tnR>mu (n=1.2) ・+2
1 Therefore, the centrifugal force FI of the rotating weight 10 in this example
R can be made smaller than the centrifugal force of the conventional primary balancers 3a and 3b. Similarly, the centrifugal force F2R of the rotating weight 11 can be made smaller than the centrifugal force of the conventional secondary balancers 4a, 4b, and 4C14d. Therefore, the eccentric weight of the rotary electrolytic corrosion 10 and 11 can be reduced to less than % of the total eccentric weight of 3a, 3b, 4as4b, and 4C14d, respectively. 2 more
Since there are only two rotating weights, the drive mechanism can also be simplified.

In addition, in Figure 5, the hull vertical vibration mode 1 from the stern end
When the distance between the nodes on the stern side of 6 is expressed as t, equation (3) shown in the general case law often holds true.

Lz*) l...(3) Therefore, the eccentric weight of the rotating weight 11 in this example is 2
The weight can be reduced compared to the eccentric weight of a rotary weight installed near the stern end as a secondary balancer.

In this way, in the ship equipped with the vibration damping device of this embodiment, the vibration damping device 1 reduces the primary and secondary vibrational forces of the diesel engine 5.
3 is a single rotating weight 1 located near the stern end of the hull.
0 and a single rotating weight 11 located near the top of the superstructure.
and its drive shaft 12, so as in the past, there are primary balancers 3a, 3b, secondary balancers 4a, 4b, 4c, 4 on the front and rear end surfaces of the diesel engine 5, respectively.
d is no longer necessary, the mechanism can be made lighter, and the drive system can also be simplified.

Therefore, the manufacturing cost of the allocation device can be reduced, and the reliability of the device can be greatly improved.

〔Effect of the invention〕

As detailed above, in the ship equipped with the vibration damping device of the present invention,
By arranging two rotating weights near the stern end that rotate within the longitudinal section of the hull at angular velocities that are one and two times the main engine crankshaft speed, the primary unbalance generated by the diesel engine can be reduced. Since it is possible to reduce moments and secondary moments, the allocating device and its drive system are lighter and simpler, reducing the manufacturing cost of allocating devices for ships equipped with diesel engines, and greatly improving the reliability of the equipment. There are five effects that can be enhanced.

[Brief explanation of drawings]

Figures 1 to 5 show a ship equipped with a vibration damping device as an embodiment of the present invention. A schematic diagram for explaining the vibration damping device of the primary balancer and the secondary balancer disposed near the top of the superstructure; FIG. 2 is a schematic diagram of the allocation device and its drive mechanism;
The figure is a diagram showing the characteristics of longitudinal vibration response of the hull, Section 4.5.
The figure is a schematic diagram showing the vertical vibration mode of the hull. 6th
Figures 8 to 8 show a conventional anti-vibration diesel engine, Figure 6 is a schematic diagram to explain the mechanism of the diesel engine's crankshaft and combined balancer, and Figure 7 is a side view of the diesel engine. , Figure 8 is the ■− of Figure 7.
3 is a cross-sectional view taken along the line. 1... Crankshaft, 2a... Front counterweight, 2b... Rear counterweight, 3a, 3b...
Weight group as conventional primary balancer, 4a, 4b, 4c
, 4d ... Weight group as a conventional secondary balancer, 5
...Diesel engine, 6a, 6b...Conventional combined balancer, 7a, 7b...Flywheel, 8
...Camshaft, drive chain, 9...Camshaft, 10.
... Rotating weight as a primary balancer, 11... Rotating weight as a primary balancer, 12 a... Drive shaft of the primary balancer, 12 b... Drive shaft of the secondary balancer, 13
a... Vibration damping device as a primary balancer, 13 b.
... Vibration damping device as a secondary balancer, 14... Hull,
15.16...Hull vertical vibration mode, 17...Superstructure, 18...Main hull neutral axis.

Claims (1)

[Claims] In a ship equipped with a diesel engine, the crankshaft is oriented toward the ship's ship's length.In a ship equipped with a diesel engine, there are two parts that rotate within the longitudinal section of the hull in conjunction with the crankshaft at angular velocities of 1 and 2 times the number of revolutions of the crankshaft, respectively. A ship equipped with a vibration damping device characterized by being equipped with a rotating weight.