JPH0332571A - Dynamic balancer for rotor - Google Patents

Abstract

PURPOSE:To facilitate maintenance and improve reliability by providing permanent magnets on the fixed side and magneto coils in a rotary balancer main body and generating induced currents to the magneto coils by the mutual action between the magneto coils and the magnetic flux of the permanent magnets, thus utilizing this induced current as the power source. CONSTITUTION:Motors 12a, 12b and balance weights 15a, 15b driven by these motors are disposed in a balancer main body 4 fitted at an axis of rotation 2. A light source and permanent magnets 7a-7d are fitted at the supporting part of the axis of rotation, in the opposed position to the balancer main body. Light sensors for controlling the driving of the motors are further fitted in the opposed position to the light source of the main body, and magneto coils are fitted in the main body so as to enable the magnetic flux of the permanent magnets to transverse. The current induced to the magneto coils accompanied by the rotation of the axis of rotation is supplied to the motors and light sensors so as to move the balance weights, and the emission of the light source is stopped in the minimum vibrating position so as to stop the balance weights.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dynamic balancer for a rotating body for correcting unbalance during rotation of the rotating body.

[Conventional technology]

For example, it is well known that in grinding work, if the spindle to which the grinding wheel (hereinafter referred to as the grindstone) is attached is well balanced during rotation, the surface roughness of the machined surface can be improved. Therefore, grinding machines must be made rigid so that they do not vibrate not only when the main shaft rotates alone, but also when a grindstone is attached. However, since the grindstone, which is a consumable item for -1G, is not well balanced, the main shaft to which the grindstone is attached generates minute vibrations when rotating.
It is not possible to improve the surface roughness of the machined surface.

For this reason, a dynamic balancer that precisely adjusts the balance during rotation of the spindle to which the grindstone is attached was developed in Japanese Patent Laid-Open No. 59-1.
This method has been proposed in Publication No. 55642 and the like.

The above-mentioned known dynamic balancer has two balance weights movably installed inside the flange to which the grinding wheel is attached, and a stepping motor installed inside the flange that is fixed to a slip ring placed around the periphery of the flange and a non-rotating part outside the flange. The balance weights are moved in different radial directions to achieve dynamic balance.

[Problem to be solved by the invention]

The conventional dynamic balancer described above can accurately and efficiently obtain dynamic balance of the main shaft to which the grindstone is attached. However, since the power to drive the stepping motor is supplied via the slip ring and Braun, in order to maintain reliability, it is necessary to check the insulation condition between the slip rings, the wear condition of the slip ring and the brush, etc. There was a problem in that the contact parts had to be frequently maintained and inspected. Another problem is that the positions of the slip ring and the brush must be adjusted in accordance with the width of a member such as a grindstone attached to the rotating shaft.

The purpose of the present invention is to solve the problems in the above-mentioned prior art,
The object of the present invention is to provide a dynamic balancer that is reliable and easy to maintain and inspect.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a dynamic balancer for a rotating body that includes a motor and a balance weight driven by the motor inside a balancer body attached to a rotating shaft, in which the a light source and a plurality of permanent magnets installed in a position facing the balancer body; a light sensor installed in a position facing the light source of the balancer body to control the driving of the motor; The present invention is characterized in that it includes a power generation coil installed so that the magnetic flux crosses the power generation coil, and supply means for supplying the current induced in the power generation coil to the motor and the optical sensor.

Furthermore, in the above invention, the present invention is provided with a plurality of the motors, the balance weights, the light sources, and the optical sensors, each of which is provided with a support member that supports each of the balance weights. and another light source and another optical sensor for positioning the balance weight, and another supply means for supplying the current induced in the power generation coil to the other light source and the other optical sensor. It is characterized by

[Effect]

When the rotating shaft rotates, a current is induced in the power generation coil, and this induced current is supplied to the optical sensor and can also be supplied to the motor. In this state, when a light source attached to the support section is caused to emit light from the outside, the optical sensor is excited, thereby supplying current to the motor. When the motor is driven, the balance weight also moves along that path. The operator observes the magnitude of vibration of the rotating body while the balance weight is moving, and stops the light source from emitting light at the position of minimum vibration, thereby stopping the balance weight.

Furthermore, when a plurality of balance weights are used, each of these balance weights is provided with a motor, a light source, and a light sensor, and each of the balance weights is further provided with another light source and another light sensor. First, each light source attached to the support part emits light to move each balance weight, and the other light sources and other optical sensors align the balance weights to overlapping positions. Next, each balance weight is simultaneously moved by each power source, stopped at the minimum vibration position, and each balance weight is moved in opposite directions from this position to adjust the balance.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a cross-sectional view of a dynamic suspension for a grinding machine according to an embodiment of the present invention. In the figure, 1 is the spindle head of the grinding machine, 2 is the spindle,
3 indicates a whetstone. 4 is a dynamic balancer main body fixed to the main shaft 2, 5 is a flange, and 6 is a nut. The grinding wheel 3 is fixed to the main shaft 2 by being held between the dynamic balancer body 4 and the flange 5 and tightened with a nut 6. 7a, 7b, 7
c and 7d (7b and 7d are not shown in the figure) are permanent magnets, which are attached to the wall surface of the spindle head l facing the dynamic parancer 4. 8a+, 8az, 8b+,
8bz is a light source arranged and fixed on the wall surface, and 9a and 9b are optical sensors arranged and fixed on the wall surface. The dynamic balancer 4 is configured as follows. 11 is a case fixed to the main shaft 2, 11' is a lid of the case 11, 12a, 1
2b is a motor fixed to the case 11, and 13a.

13b is a gear of the motors 12a, 12b. 14a,
14b is a large gear rotatably attached to the central cylindrical portion of the case 11, and is made of a transparent material. 15a,
15b is a balance weight attached to the large gears 14a and 14b. 17a and 17b are large gears 14a.

Masking affixed to one side of 14b, 18a18
b is an annular non-masking portion where masking 17a, 17b is not applied. In the illustrated example, the ring of the non-masking portion 18a is formed inside the ring of the non-masking portion 18b. 19a is a through hole drilled in the large gear 14a, and is formed at a position 180e opposite the non-masking portion 18b of the large gear 14b and with respect to the balance weight 15a. 19b is a through hole drilled in the large gear 14b, and the non-masking portion 18 of the large gear 14a.
1 facing the balance weight 15b and facing the balance weight 15b.
It is formed at the 80' position. 20 is a control board attached to the inner surface of the lid 11', and 21 is a regulator/amplifier mounted on the control board 20.

22 is a non-magnetic bobbin fixed to the central cylindrical portion of the case 11, and 23 is a coil made of a covered conductor wire wound around the bobbin 22. 24a and 24b are ring pieces made of magnetic material, and are fixed to the bobbin 22. Each ring piece 24a, 24b passes through the center opening of M11' and is arranged to protrude from the outer circumferential surface of the permanent magnets 7a to 7d so as to face them. The positional relationship between the permanent magnets 7a to 7d, the bobbin 22, and the ring pieces 24a and 24b is clearly shown in FIG. 2 and FIGS. 3(a) and 3(b), which will be described later. 25a
, 25b are light sources fixed to the inner wall of the case 11 on the grindstone 3 side, and 26a and 26b are optical sensors mounted on the control board 20-hi. The light tA25a and the optical sensor 26a are arranged opposite to each other via the non-masking portion 18b of the large gear 1i, and the light m25b and the optical sensor 26b are arranged opposite to each other via the non-masking portion 18a of the large gear 14a.

27 is a connection board fixed to the outer surface of M11', 28a,
.

28az, 28b+, 28h+z are tangents Vtj, t+
The optical sensors 29a and 29b mounted on the board 27 are light sources mounted on the connection board 27. Optical sensor 28a
, ~28b2 are the light sources 8 fixed to the spindle head 1, respectively.
It is arranged opposite to al~8bz, and the light jD29
a and 29b are arranged to face optical sensors 9a and 9b fixed to the spindle head 1, respectively. 30.
31 is a spacer.

Next, the magnetic fluxes of the permanent magnets 73 to 7d and the relationship between these magnetic fluxes and the coil 23 will be described. Figure 2 is a cross-sectional view of the vicinity of the permanent magnet along the line nn shown in Figure 1;
>, (b) is a cross-sectional view of the vicinity of the bobbin along the line ■-■ shown in FIG. In each figure, the same parts as those shown in FIG. 1 are given the same reference numerals. As shown in FIG. 2, the permanent magnet 7a97C is magnetized so that the center side is the north pole and the outer circumference side is the south pole, and the permanent magnets 7b and 7d are magnetized so that the center side is the south pole and the outer circumference side is the north pole. has been done. Therefore, the bobbin 22 side of the ring pieces 24a and 24b has the polarity shown in FIG. 3(a) with respect to the permanent magnets 7a to 7d.

When the main shaft 2 rotates 90 degrees from this state, each ring piece 2
The bobbin 22 side of 4a and 24b has the polarity shown in FIG. 3(b). That is, each time the main shaft 2 rotates 90 degrees, the polarity of each ring piece 24a, 24b on the bobbin 22 side is reversed.

FIGS. 4(a) and 4(b) are cross-sectional views showing the state of magnetic flux in the coil portion. The ring pieces 24a and 24b are the third
When in the position shown in FIG. 4(a), the magnetic flux crosses the coil 23 from the direction of the grinding wheel 3 to the direction of the spindle head 1, as shown in FIG. 4(a), and the ring pieces 24a, 24b are 4(a) as shown in FIG. 3(1)).
) The coil 23 is crossed in the opposite direction to the case shown in ). That is, each time the main shaft 2 rotates 90 degrees, the direction of the magnetic flux that crosses the coil 23 is reversed. Therefore, due to the rotation of the main shaft 2, an alternating current induced current is generated in the coil 23.

Here, the circuit configuration of this embodiment will be explained.

FIG. 5 is an electrical circuit diagram of the dynamic balancer of this embodiment. In the figure, the same parts as those shown in FIG. 1 are given the same reference numerals. To facilitate understanding of the connection lines in the figure, power lines are shown as solid lines and signal lines are shown as broken lines. 31 is a holding circuit that holds the signals of each of the optical sensors 28a and 28b2 for a period of one revolution of the main shaft, and 32a and 32b are motors 12a, respectively.
, 12b. Holding circuit 31
, motor drive circuit 32a.

32b is configured on the control board 20; the motor drive circuit 32a connects the motor 12a to the rectifier 21 and rotates it in the normal direction according to the signal from the optical sensor 28a1;
The motor 12a is reversed by the signal from a2. or,
The motor drive circuit 32b is an optical sensor 28b.

The motor 12b is rotated forward by the signal from the optical sensor 2.
The motor 12b is reversed by the signal from 8b2.

Next, the unbalance correction operation of this embodiment is shown in FIG.
), (b) and FIGS. 7(a) and (b). First, in order to measure vibrations due to unbalance, a vibration pickup (not shown) is attached to an appropriate position on the spindle head 1.

A vibration meter (not shown), which has a function of processing the electric signal taken out from the vibration pickup and displaying the vibration amplitude of the component corresponding to the rotational speed of the main shaft 2, is installed at a position easily visible to the operator.

Also, light sources 8al, 8az, 8b+, 8b2
An operation panel (not shown) is provided at the operator's hand, which is equipped with four switches connected to the light sensors 9a and 9b to turn them on, and two light sources connected to the optical sensors 9a and 9b and turned on by receiving light from them.

When the main shaft 2 rotates in this state, an induced current is generated in the coil 23 as described above, and this induced current is rectified by the rectifier 21 and supplied to each part as shown in FIG.
5a and 25b are lit immediately. Here, the operator performs an operation to bring the balance weighers 5a and 15b into an overlapping state. Although these two are shown in an overlapping state in FIG. 1, normally, immediately before unbalance correction is started, they are not in this overlapping state but are in an arbitrary position.

First, the worker operates the switch on the operation panel to turn on the power supply 8a.
Turn on +. The optical sensor 28a receives this light and outputs a signal to the holding circuit 31. In this case, since the main shaft 2 is rotating, the power source 8a and the optical sensor 28a only momentarily face each other, and until the next time they face each other, no light is received by the optical sensor 28a. The signal from the optical sensor 28a is transmitted to the holding circuit 31 during one rotation of the main shaft 2.
is retained. The motor drive circuit 32a is switched by the signal from the optical sensor 28a1, the motor 12 rotates, and the large gear 14a rotates normally. During this time, the light from the power source 25a passes through the non-massive tongue portion 18b of the large gear 14b and reaches the large gear 14a, but is blocked by the masking portion 17a. The large gear 14a continues to rotate, and its through hole 19
When a reaches a position facing the electric wire 1jK25a as shown in FIG. The light is received at 9a. This lights up one light source on the operation panel, and the operator sees this and releases the switch. Therefore, the light source 8a+ is turned off,
There is no signal from the optical sensor 28a, the motor drive circuit 32a is cut off, and the motor 12a is stopped.

At this time, the balance weight 15a is in the position shown in FIG. Next, the operator operates the switch to turn on the light source 8b.
, when the balance weight 15b is turned on, the balance weight 15b reaches the position shown in FIG. 1 through the same operation as described above, and stops when the switch is opened. That is, both balance weights 15a,
L5b is in an overlapping state.

Next, the operator rotates both balance weights 15a and 15b 3606 times while keeping them overlapped to find a position where the vibration amplitude is minimum. Therefore, the operator operates two switches to turn on the lights 11Et8a+ and 8b+, simultaneously rotates the large gears 14a and 14b, and observes the vibration meter. FIG. 6(a) is a graph showing the amplitude of vibration at this time. This graph shows that the amplitude is at its minimum value when the movement angle of the balance weights 15a, 15b is θ°. The worker moves the movement angle θ°
The two switches are simultaneously opened at the balance weight 15a.

15b is stopped at this position. At this time, as shown in FIG. 6(b), the balance weights 15a and 15b are rotated at an angle of 180° with respect to the unbalanced UB that is causing the vibration.
It is located at

Here, the centrifugal force of the unbalanced UB during rotation is Fu, and the centrifugal force of the balance weights 5a and 15b is F-, respectively.
In the state shown in FIG. 6(b), the centrifugal force due to the balance weights 53 and 15b is the centrifugal force F-, F
It becomes the sum of b. The value of this sum is usually larger than the centrifugal force Fu. Therefore, if the state shown in FIG. 6(1) remains as it is, an imbalance will still exist. Therefore, the operator operates the balance weights 15a and 15b so that each centrifugal force becomes F, =Fi +Fb.

Therefore, the operator must operate a switch to connect, for example, an optical fiber.
Turn on 8a+ and 8bz, balance weight 15a,
Observe the vibration meter while moving the parts 15b in opposite directions to find the position where the vibration is minimum.

The amplitude of vibration in this case is shown in the graph of FIG. 7(a), and the minimum amplitude is for both balance weights 5a and 1.
This is when the angle between 5b and 5b is close to 30'. The operator blinks the light sources 3a and 8bz as appropriate.
Both balance weights 15a, 151) are stopped at the above angular positions. The state at this time is shown in FIG. 7(b). That is, centrifugal force F.

and the centrifugal force F at the bottom of the centrifugal force F, ,F. are in a balanced state.

In this way, in this example, a permanent magnet is provided on the stationary side and a coil is provided on the rotating side, so that power is generated within the balancer body, so there is no need to use slip rings or brushes, and therefore maintenance is required. This is easy and can improve reliability.

In addition, in the description of the above embodiment, an example using two balance weights was explained, but three balance weights are used.
More than one can be used, or one can be used if it is configured to move in both the radial and circumferential directions.

[Effects of the Invention] As described above, in the present invention, a permanent magnet is placed on the fixed side,
In addition, a generator coil is installed inside the rotating balancer body, and the interaction between the magnetic flux of the permanent magnet and the generator coil generates an induced current in the lightning generator coil, which is used as a power source, so slip rings and brushes can be used. There is no need to use it (
, maintenance can be facilitated and reliability can be improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a dynamic balancer for a grinding machine according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-■ shown in Fig. 1, and Figs. 3(a) and (b). is a rear view of the bobbin shown in Fig. 1, Figs. 4(a) and 4(b) are cross-sectional views of the bobbin shown in Fig. 1, and Fig. 5 is a circuit diagram of the electric circuit of the dynamic balancer shown in Fig. 1. , Figures 6(a) and (b) are vibration amplitude waveform diagrams and corresponding vector diagrams, and Figure 7(a).
, (b) is a waveform diagram of vibration amplitude and a vector diagram corresponding thereto. 1...Spindle head, 2...Spindle, 3...
... Grinding wheel, 4 ... Dynamic parenser body, 7a ~
7d...Permanent magnet, 12a, 12b...
・Motor, 14a, 14b...Large gear, 15a
, 15b...Balance weight, 22...
...Bobbin, 23...Coil, 24a, 24b
・・・・・・Ring piece. Figure 2 ■ 10 Figure 3 (a) (b) Figure (0) (b) Figure 5 Figure 6 (a) (b) Figure 7 (0) (b) Procedural amendment (voluntary) Heisei November 2, 1 year

Claims (2)

[Claims] (1) In a dynamic balancer for a rotating body, which includes a motor and a balance weight driven by the motor inside the balancer body attached to the rotating shaft, the balancer body is attached at a position facing the balancer body on the support part of the rotating shaft. a light source and a plurality of permanent magnets; an optical sensor attached to the balancer body at a position facing the light source to control driving of the motor; and an optical sensor attached to the balancer body so that the magnetic flux of the permanent magnets crosses the balancer body. A dynamic balancer for a rotating body, comprising a power generation coil and supply means for supplying the current induced in the power generation coil to the motor and the optical sensor. (2) In the dynamic balancer for a rotating body according to claim (1), a plurality of the motors, the balance weights, the light sources, and the optical sensors are provided in correspondence with each other, and each of the motors, the balance weights, the light sources, and the optical sensors are provided for each of the balance weights. Another light source and another optical sensor are provided on both sides of the support member that supports the balance weight, and another light source and another optical sensor are provided to position the balance weight. A dynamic balancer for a rotating body, characterized in that it is provided with a supply means.