JP2857419B2 - Dynamic balancer of rotating body - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic balancer of a rotating body for correcting imbalance during rotation of the rotating body.

[Conventional technology]

For example, it is well known that, in a grinding operation, if the balance at the time of rotation of a spindle to which a grinding wheel (hereinafter referred to as a grinding wheel) is mounted is excellent, the surface roughness of a processed surface can be improved. Therefore, the grinding machine is provided with rigidity so that it does not vibrate when the grindstone is attached, as well as when the main spindle is rotated alone. However, since the grinding stone, which is a consumable, is generally not well-balanced, a minute vibration is generated during rotation of the spindle on which the grinding stone is mounted, and the surface roughness of the machined surface cannot be improved. For this reason, a balancer that accurately adjusts the balance at the time of rotation of the spindle to which the grindstone is attached is used.

As such a balancer, there is a means for rotating the grindstone to measure the amount of unbalance, then stopping the rotation of the grindstone and moving the balance weight. There was a problem.
Therefore, in recent years, means capable of moving the balance weight while the grindstone is rotating have been proposed. This means has a configuration in which a drive source is provided in a balancer body that rotates integrally with a grindstone, and the power is transmitted to a balance weight to move the balance weight.

[Problems to be solved by the invention]

By the way, the above-mentioned means for moving the balance weight even during the rotation of the grindstone has a complicated structure because the balancer body has a power transmission mechanism such as a drive source, a feed screw and a gear, and the rotation mechanism is There is a problem that many failures may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dynamic balancer for a rotating body which solves the above-mentioned problems of the prior art, can move the balance weight even during rotation of the rotating body, has a simple structure, and has few failures. is there.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a dynamic balancer of a rotating body having a balance weight for rotation in a balancer body attached to a rotation shaft and integrally rotating therewith, wherein a rotation ring to which the balance weight is attached, A first permanent magnet attached to the rotating ring at a predetermined angular interval, a fixed ring positioned outside the rotating ring and fixed to the balancer body, and a first permanent magnet of the fixed ring;
A plurality of electromagnets attached at positions facing the permanent magnets, current supply means for rotating the rotating ring to an arbitrary angle by selectively supplying an exciting current to these electromagnets, attached to the fixed ring, A second permanent magnet for stopping the rotation of the rotating ring by an attractive force between the first permanent magnet and stopping the rotation when the current supply by the current supply unit is stopped; It is characterized.

[Action]

In a state where the balancer body is rotating, when an exciting current is supplied to a specific electromagnet via current supply means,
The specific electromagnet is excited. As a result, an attractive force is applied to the adjacent first permanent magnet, and this first permanent magnet is generated.
Is attracted, and the rotating ring also rotates. The rotation of the rotating ring also moves the balance weight attached thereto by the same angle as the rotating angle of the rotating ring. At this time, when the current to the electromagnet is cut off by the current supply means, the first permanent magnet is attracted to the adjacent second permanent magnet. As a result, the rotation of the rotating ring is prevented, and the balance weight is also kept stopped at that position.

〔Example〕

 Hereinafter, the present invention will be described with reference to the illustrated embodiments.

FIG. 1 is a sectional view of a dynamic balancer of a rotating body according to an embodiment of the present invention, and FIG. 2 is a layout view of the permanent magnets and electromagnets shown in FIG. In each figure, 1 indicates the body of the dynamic balancer. Reference numeral 2 denotes a bolt for fixing the main body 1 to, for example, a flange (not shown) of a grindstone. Thus, when the grindstone shaft is rotated, the grindstone, the flange, and the main body 1 rotate integrally. Hereinafter, the structure of the main body 1 will be described. Reference numeral 3 denotes a case, 4 denotes a fixing ring made of an insulating member, and 5 denotes a fixing ring similarly made of an insulating member and provided in contact with the outer peripheral surface of the fixing ring 4. The fixing rings 4 and 5 are fixed to the case 3 by bolts 6 and 7, respectively. Reference numeral 8 denotes a lid, which is attached to the fixing ring 5 by bolts 9. 10a, 10b
Are ball bearings and their inner rings are spacers 11
The case 3 is fixed to the shaft portion of the case 3 while maintaining a predetermined interval by a and 11b. Reference numerals 12a and 12b denote rotating rings which are fixed to outer rings of the ball bearings 10a and 10b, respectively.
Thus, the rotating rings 12a and 12b can freely rotate with respect to the case 3.

_{15a 1 ~15a 4, 15b 1 ~15b} 4 is a permanent magnet, as shown in Figure 2, the rotary ring at intervals of 90 degrees from each other
Mounted on 12a, 12b. Reference numerals 16a and 16b denote balance weights mounted at appropriate positions on the rotating rings 12a and 12b, respectively. 17a ₁ ~17a ₄ is an electromagnet which is fixed in each bolt 18 to the fixed ring 4. Electromagnet 17a ₁ consists of four electromagnets arranged at intervals of 90 degrees as shown in Figure 2. Similarly, the electromagnets 17a ₂ , 17a ₃ , and 17a ₄ also include _four electromagnets arranged at intervals of 90 degrees. Therefore, the electromagnet group attached to the fixing ring 4 is composed of 16 electromagnets arranged at intervals of 22.5 degrees. Although not shown, other electromagnet group 17b ₁ ~17b ₄ is the same configuration as the electromagnet group 17a ₁ ~17a _4, for these, are provided displaced in the axial direction as shown in Figure 1. Reference numeral 19 denotes a permanent magnet disposed between the adjacent electromagnets, and is attached to the fixing ring 4. The polarity of the surface side of the permanent magnet 19, rotating ring 12a, the permanent magnets 15a attached to 12b ₁ ~15a _4, 15b ₁ ~15
attraction between the b ₄ is a polar, such as working, and the magnetic force of the permanent magnet 19, the electromagnet is chosen to be smaller than the magnetic force when energized.

20a _{1 to} 20a ₄ , 20e, 20b _{1 to} 20b ₄ are fixed rings 5 respectively
Reference numeral 21 denotes a brush arranged and fixed on the outer peripheral surface of the brush, and 21 denotes a brush which is in sliding contact with each slip ring. Each brush 21 is fixed to a non-rotating part (not shown), for example, a spindle head of a grinding machine. The slip ring 20a ₁ is connected to four electromagnets 17a ₁ via fixing rings 5 and 4. For everyday use, slip ring
20a ₂ through 20a ₄ is connected to the electromagnet 17a ₂ ~17a ₄ respectively, are connected to the electromagnet 17b ₁ to 17 ₄ which slips ring 20b ₁ ~20b ₄ are not shown, respectively. Also, slip ring 2
0E are slips ring for common ground to the electromagnets _{17a 1 ~17a 4, 17b 1 ~17b} 4.

Next, the operation of this embodiment will be described. First, the rotating body is rotated while the balancer main body 1 is dynamically attached to the rotating body, and vibration is measured. From this measurement, it is determined how much the balance weights 16a and 16b should be moved in the circumferential direction from the current position (this position is known). During the rotation, no current is supplied to each electromagnet, and each permanent magnet 15a ₁ of the rotating rings 12a, 12b
15a ₄ , 15b _{1 to} 15b ₄ are located at positions facing the permanent magnets 19 of the fixed ring 4, whereby the rotating rings 12a, 12b are prevented from rotating by the mutual attraction.

Next, while referring to FIG.
The operation in the case where is rotated 22.5 degrees counterclockwise will be described. First, to supply an exciting current to the electromagnet 17a _3, 17a ₄ through the slips rings 20a _3, 20a _4. This allows
Force the electromagnet 17a _3, 17a ₄ occurs, this force is selected to be the polarity direction acting suction force wears the permanent magnet 15a ₁ to 15A _4. It was but connexion, the permanent magnets 15a ₁ to 15A ₄ is moved to an intermediate position thereof electromagnets 17a _3, 17a ₄ are attracted to the electromagnets 17a _3, 17a _4. That is, the rotating ring 12a rotates 22.5 degrees counterclockwise, and the balance weight 16a also moves 22.5 degrees counterclockwise. When interrupting the current of the electromagnets in this state, the permanent magnets 15a ₁ to 15A ₄ are attracted to the permanent magnet 19 opposing the rotation of the rotating ring 12a is prevented,
The balance weight 16a is kept stopped at that position.

From this position, in order to move the balance weight 16a further counterclockwise, may be energized electromagnet 17a _4, 17a _1, also in order to move in a clockwise direction, the electromagnet 17a _3, 17a
You only need to excite ₂ . The movement of the balance weight 16b is performed in exactly the same manner as the movement of the balance weight 16a.

As described above, in the present embodiment, the permanent magnet and the balance weight are attached to the rotating ring, the electromagnet is provided on the fixed ring facing the permanent magnet, and the rotating ring is rotated by an arbitrary angle by selectively exciting the electromagnet. Since the balance weight is moved, the balance weight can be moved even while the rotating body is rotating, and the configuration can be simplified. Further, the number of movable parts is small, so that occurrence of failure can be reduced. Further, since the permanent magnet is attached to the fixed ring, the balance weight can be maintained in a stopped state in cooperation with the permanent magnet of the rotating ring.

In the description of the above-described embodiment, an example in which four permanent magnets are provided on the rotating ring and sixteen electromagnets are provided on the fixed ring has been described. However, these numbers can be arbitrarily determined. It is clear that finer balance weight can be adjusted. In addition, the permanent magnet provided on the fixing ring can be incorporated in each electromagnet, and in that case, the movement of the balance weight only needs to excite one adjacent electromagnet.

〔The invention's effect〕

As described above, according to the present invention, a plurality of first permanent magnets and a balance weight are provided on a rotating ring, and a plurality of electromagnets are arranged at positions of the fixed ring facing the first permanent magnets. Since the second permanent magnet is provided, the balance weight can be moved even during the rotation of the rotating body with a simple configuration. Together, the balance weights can be kept stationary.

[Brief description of the drawings]

FIG. 1 is a sectional view of a dynamic balancer according to an embodiment of the present invention,
FIG. 2 is an arrangement diagram of the permanent magnet and the electromagnet shown in FIG. 1 ... body, 3 ... case, 4,5 ... fixing ring, 10a, 1
0b …… Ball bearing, 12a, 12b …… Rotating ring, 15a
_{1 ~15a 4, 15b 1 ~15b 4} , 19 ...... permanent magnet, 16a, 16b ...... balance weights, 17a ₁ ~17a ₄ ...... electromagnets, 20a ₁ ~20b _4, 2
0E ... slip ring, 21 ... brush.

Claims (1)

(57) [Claims] 1. A dynamic balancer of a rotating body provided with a rotatable balance weight in a balancer body attached to a rotating shaft and rotating integrally therewith, wherein a rotating ring having the balance weight attached thereto, and a predetermined weight attached to the rotating ring. A first permanent magnet attached at an angular interval of, a fixed ring located outside the rotating ring and fixed to the balancer body, and attached to a position of the fixed ring facing each of the first permanent magnets. A plurality of electromagnets, a current supply means for selectively rotating the rotating ring at an arbitrary angle by supplying an excitation current to the electromagnets, and a current supply means attached to the fixed ring and supplying current by the current supply means. A second permanent magnet is provided which, when rejected, prevents the rotation of the rotating ring by the attraction force between the first permanent magnet and the second permanent magnet to hold the stopped state. Dynamic balancer rotating body, wherein a.