JPH0542788U - Vibration damping device - Google Patents

Abstract

(57) [Summary] [Structure] The first weight 8 and the second weight 9 are provided in the main space chamber 4.
And the first and second compression springs 10A, 1 for arranging movably in a predetermined direction so as to have a gap a therebetween and for suppressing the movement of each of the first and second weights.
0B are respectively arranged, the main space chamber 4 is filled with the viscous fluid 12, and the natural frequency of the first weight 8 is equal to or twice the frequency equal to the engine speed generated by the diesel engine. The frequency of the second weight 9 is set so that the natural frequency of the second weight 9 becomes twice as high as the engine speed generated by the diesel engine or becomes equal to the engine speed. It is a vibration damping device. [Effect] Due to the dynamic vibration absorption effect caused by the movement of both weights, the vibration generated in the diesel engine can be effectively damped, and the vibration damping device itself is driven like the flywheel of the conventional diesel engine. There is no need to consume wasted energy.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vibration damping device that damps the vibration of a vibration generating object.

[0002]

[Prior Art]

 Generally, in a diesel engine, a moment is generated by a primary (frequency equal to engine speed) and secondary (frequency twice engine speed) inertial force, which causes the entire engine to vibrate. , That force is transmitted to the surroundings through the engine installation part and vibrates the peripheral equipment.

In particular, in the case of a diesel generator, the diesel engine and the generator are installed on a common base, and the common base is installed on a vibration-proof rubber in order to reduce the transmission of vibration to the ground. However, in this case, since the natural frequency of the whole is lowered, the frequency of the vibration force of the engine and the natural frequency may be close to each other and the vibration may be increased.

[0004] Conventionally, in order to damp such vibrations, flywheels having counterweights attached to front and rear ends of a crankshaft of a diesel engine are mounted, and moments due to primary and secondary inertial forces are mounted. There is a device for attenuating the vibration caused by (e.g., Japanese Patent Publication No. 94-8221).

[0005]

[Problems to be solved by the device]

 However, according to the configuration using the flywheel as described above, there is a problem that rotating the flywheel consumes power and is uneconomical.

Therefore, an object of the present invention is to provide a vibration damping device that can solve the above problems.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a vibration damping device of the present invention is a vibration damping device that is attached to a vibration generating object to damp the vibration, and has a first weight and a second weight in a space chamber. , The first and second biasing members for respectively restraining the movement of the first and second weights are arranged so as to be movable in a predetermined direction so as to have a gap therebetween, and the above space is provided. The chamber is filled with a viscous fluid, and the natural frequency of the first weight is set to be equal to or twice the frequency generated by the vibration generating object, and The natural frequency is set to be equal to or equal to the double frequency generated by the vibration generating object.

[0008]

[Action]

 According to the above configuration, when vibration is generated in the vibration-generating object, the first and second weights arranged in the space move in the vibration direction, and move in the respective biasing members and the gaps between them. The viscous fluid suppresses the movement of each weight, and the natural frequency of each weight is equal to or twice the frequency of the generated weight. The vibration generated and generated in the vibration generating object is effectively attenuated.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a vibration damping device which is attached to a vibration generating object, for example, the top portion 2a of the diesel engine 2 to damp the vibration generated in the diesel engine 2.

The vibration damping device 1 is attached to the top portion 2 a of the diesel engine 2 via the leg portion 3, and has a main cylindrical body 5 having a cylindrical main space chamber 4, and the main cylindrical body 5 The sub-cylindrical bodies 7A and 7B, which are attached to the upper and lower wall portions 5a and 5b and have columnar sub-space chambers 6A and 6B smaller than the main space chamber 4, and the vertical shaft end portions 8a and 8b thereof are respectively the vertical wall portions 5a , 5b, and a cylindrical first weight 8 which is arranged so as to be vertically movable through insertion holes 5c and 5d formed in the first and second weights, and a gap a is formed between the first weight 8 and the first weight 8. An annular second weight 9 movably arranged in the vertical direction in the surrounding main space chamber 4 and the first weights arranged in each of the sub space chambers 6A and 6B. Flange portions 8c and 8d formed on the vertical shaft end portions 8a and 8b for guiding 8 Upper and lower first compression springs (biasing members) 10A, 10B, second compression springs (biasing members) 11A, 11B for pressing the upper and lower surfaces of the second weight 9, and the main space The viscous fluid 12 is filled inside the chamber 4.

Further, the natural frequency of the first weight 8 is made to be the same as the engine speed of the diesel engine 2 (or twice the engine speed), and the second weight 9 The natural frequency is set to be twice the engine speed of the diesel engine 2 (or the same as the engine speed).

Therefore, when the diesel engine 2 is rotating, the vibrations due to the moments of the reciprocating motion part and the rotary motion part are transmitted to the vibration damping device 1, and the first and second weights 8 are , 9 move in the vertical direction, and with the movement, the viscous fluid 12 passes through the gap a between the weights 8 and 9, and due to the action of each compression spring 10A, 10B, 11A, 11B. The movement of the weights 8 and 9 is suppressed, and in the diesel engine 2 to which the vibration damping device 1 is attached, the vibration equal to the engine speed and the vibration twice the vibration speed are effectively damped.

This is because when an oscillating system having a natural frequency equal to or close to this is added to an object vibrating at a certain natural frequency, a phenomenon occurs in which the natural frequencies of the two repel each other. This is because the so-called dynamic vibration absorption effect is used, in which the amplitude of the object decreases as the natural frequency of changes and the added vibration system vibrates.

By the way, in the above embodiment, the first weight 8 is described as a column shape and the second weight 9 is described as a ring shape. However, as shown in FIG. 3 and FIG. The vertical weights 18a, 19a may be formed on the outer peripheral surface of the second weight 19 and the inner peripheral surface of the second weight 19, and as shown in FIG. A groove portion 19a may be formed on the surface, and as shown in FIGS. 6 and 7, a horizontal groove portion 28a is formed on the outer peripheral surface of the first weight 28 and the inner peripheral surface of the second weight 29. , 29a may be formed respectively.

Further, in the above embodiment, the shape of each weight was described as a cylinder and an annular shape, but it is needless to say that the shape is not limited to such a shape, and for example, a rectangular parallelepiped and a center of the rectangular parallelepiped. Alternatively, a rectangular parallelepiped hole may be formed.

Further, although the compression springs are arranged above and below each weight in the above-mentioned embodiment, for example, the compression springs may be arranged only on the lower side. Further, although the weights of the vibration damping device in the above-described embodiment have been described as the vertical type that moves in the vertical direction, of course, the weights may be configured in a horizontal type that moves in the horizontal direction. In this case, compression springs are arranged on the left and right of each weight. The installation direction of the vibration damping device is made to substantially coincide with the direction of vibration generated by the moving direction of the weight.

Further, in the above description, the compression spring has been described as the biasing member that restricts the movement of each weight, but the same effect can be obtained even if a tension spring is used, for example.

[0018]

[Effect of the device]

 As described above, according to the configuration of the present invention, the first and second weights are arranged in the space filled with the viscous fluid so that they can move freely with each other, and the movement of these weights is suppressed. A biasing member is arranged, and the natural frequency of the first weight is set to be equal to or twice the frequency generated by the vibration generating object, and the second weight is also used. Since the natural frequency of is set to be equal to or equal to the double vibration frequency generated by the vibration-generating object, the vibration generated by the vibration-generating object is effectively Since it is not necessary to drive the vibration damping device itself as in the flywheel of a conventional diesel engine, wasteful energy is not consumed.

[Brief description of drawings]

FIG. 1 is a sectional view of a vibration damping device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of a first weight according to another embodiment.

FIG. 4 is a plan view of a second weight according to another embodiment.

FIG. 5 is a plan view of a second weight according to another embodiment.

FIG. 6 is a side view of a first weight in another example.

FIG. 7 is a sectional view of a second weight in another example.

[Explanation of symbols]

 1 Vibration Damper 2 Diesel Engine 4 Main Space Chamber 5 Main Cylindrical Body 6 Sub Space Chamber 7 Sub Cylindrical Body 8 First Weight 9 Second Weight 10A, 10B First Compression Spring 11A, 11B Second Compression Spring 12 Viscous fluid

Claims (1)

[Scope of utility model registration request] 1. A vibration damping device attached to a vibration generating object to damp vibrations thereof, comprising: a first weight and a second weight in a space chamber in a predetermined direction so as to have a gap therebetween. The first and second urging members are arranged so as to be movable and suppress the respective movements of the first and second weights, respectively, and are filled with a viscous fluid in the space chamber and The natural frequency of one weight is set equal to or double the frequency generated by the vibration generating object, and the natural frequency of the second weight is generated by the vibration generating object. A vibration damping device characterized in that the frequency is doubled or equal to the frequency.