JPS6350514Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a generator-driving engine that operates to generate electricity by directly connecting a crankshaft to a generator, and particularly relates to improving the vibration characteristics of a vibration system including the generator.

[Conventional technology]

Normally, in a single engine, a balance weight is attached to the crankshaft to balance the inertia force due to the mass of the rotating parts and part of the inertia force due to the reciprocating parts to maintain balance, and a flywheel with a magnet is used to smooth rotation. Measures such as these are being taken. By the way, there is a so-called engine generator set (see Utility Model Application Publication No. 132508/1983) in which the engine and generator are placed adjacent to a common frame and the flank shaft is directly connected to the rotor shaft to generate electricity. be.

[Problems to be solved by the invention] However, in the engine-generator set described above, the main cause of vibration force generation is the unbalance of the engine's balance weight, connecting rod, and piston. The weight of the balance weight is set to appropriately distribute vibrations generated in three directions of the engine: front and rear, left and right, and up and down. However, when the engine and generator are coupled, the entire center of gravity moves to a position closer to the generator than the balance weight. As a result, the position where the excitation force is generated differs from the position of the overall center of gravity, and an inertia couple around this center of gravity is generated, causing problems such as increased wear of the brushes that contact the slip ring on the roke shaft side of the generator. arise. Therefore, in the past, when the vibration in a certain direction exceeds the permissible limit when the engine and generator are set, the shape, hardness, and location of the vibration isolating rubber,
Vibration is reduced by changing the layout or rigidity of the frame, but there are limits to measures taken only on the side receiving such vibrations, and it may not be possible to obtain sufficient and appropriate effects. .

[Means to solve the problem]

The present invention was developed in view of these circumstances, and focused on the fact that the crankshaft is directly connected to the generator side and has a direct influence on it, and is equipped with a balance weight to prevent vibrations. Change the weight ratio of the two balance weights on the flywheel magnet side and the generator side by reducing the weight of the balance weight on the flywheel magnet side.
The vibration force generation position is moved closer to the center of gravity of the entire engine and generator, in order to appropriately and effectively reduce vibrations.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In FIG. At the same time, a generator 5 is similarly placed via a stand 4. A crankshaft 6 in the engine body 3 is connected to a piston side (not shown) via a connecting rod 7, and has balance weights 8, 9 on both left and right sides of the connecting rod 7,
It also has a flywheel magnet 10, a recoil starter device 11, etc. at one end. A rotor shaft including a rotor coil 12 of the generator 5 is directly connected to the output side of the other end of the crankshaft 6 . . The generator 5 has a stator coil 14 on the fixed side facing the rotor coil 12, and a brush 16 contacts a slip ring 15 that is insulated and fitted into the rotor shaft 13 to supply exciting current to the rotor coil 12. When the engine is running, the crankshaft 6 rotates the rotor coil 12 which is excited together with the rotor shaft 13, and the stator coil 14 cuts the magnetic flux of the rotor coil 12, thereby inducing an alternating current voltage and generating electricity. be. In such a configuration, according to the present invention, the weight ratio of the two balance weights 8 and 9 of the crankshaft 6 can be changed, and as a result, the balance of the engine as a single unit becomes unbalanced.
The position of generation of the excitation force can be changed in a direction closer to the position of the entire center of gravity including the engine body 3 and the generator 5. In other words, regarding the acceleration of vibration, in Fig. 2, the vertical vibration of the head is represented by curve a, and the vibration of the brush part is represented by curve b.
As shown by curve c, the vertical vibration of the engine base and the vibration of the brush portion become smaller as the weight of the magnet-side balance weight 8 is reduced. Regarding the amplitude, as shown in Fig. 3 by curve d for the left and right sides of the head, and by curve e for the top and bottom of the head, the former becomes smaller due to the weight reduction of the balance weight 8 on the magnet side and the balance weight 9 on the generator side. , in the latter case it changes to become larger. For this reason, the directionality of vibration changes significantly due to changes in the weight ratio of the two balance weights 8 and 9 of the crankshaft 6, and the direction of vibration changes significantly in the entire state including the engine body 3 and generator 5. The vibrations in the three directions can be brought close to appropriate values, and in particular, the vibration of the brush 16 portion of the generator 5 is significantly reduced by reducing the weight of the balance weight 8 on the magnet side, as is clear from curve b in Fig. 2. do. It goes without saying that it is even more effective to use conventional countermeasures such as anti-vibration rubber, and in the case of a single cylinder like the example, it is not limited to only an alternator. .

[Effect of the idea]

According to the present invention, in a generator that generates electricity by directly connecting the rotor shaft of a generator to the output side of the crankshaft opposite to the flywheel magnet, the flywheel magnet side of the crankshaft and the generator side Change the weight ratio of the two balance weights by reducing the weight of the balance weight on the flywheel magnet side, and change the position where the excitation force is generated.
Since the center of gravity of the entire engine and generator is located close to each other, the inertia couple around the center of gravity is reduced, effectively reducing vibrations in designated areas and preventing wear on the brushes of the generator. .

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of an embodiment of an engine according to the present invention, and FIGS. 2 and 3 are graphs showing changes in vibration with respect to the weight ratio of a crankshaft balance weight, respectively. 3... Engine body, 5... Generator, 6... Crankshaft, 8... Balance weight on the flywheel magnet side, 9... Balance weight on the generator side, 10... Flywheel magnet, 1
3...Rotor shaft.

Claims (1)

[Scope of utility model registration request] In a device that generates electricity by directly connecting the rotor shaft of a generator to the output side of the crankshaft opposite to the flywheel magnet, the weight of the two balance weights on the flywheel magnet side and the generator side of the crankshaft is An engine for driving a generator, which is characterized by changing the ratio by reducing the weight of the balance weight on the flywheel magnet side, and moving the position where the excitation force is generated closer to the center of gravity of the entire engine and generator.