JPH05329765A - Device and method for polishing by barrel - Google Patents

Abstract

PURPOSE:To prevent residence of a work on the inner wall of a tank, to reduce production of a notch owing to collision of the works with each other, and to improve a yield by providing an air device to uniformly inject air bubbles through the lower surface of the whole periphery of a microgap of the inner peripheral surface of a fixed tank. CONSTITUTION:A plurality of holes 2 are formed in the under surface of a fixed tank 1 and compressed air is fed in the holes 2 through a filter regulator 3, a solenoid valve 4, a flow rate regulating valve 5, and a check valve 6. The compressed air produces air bubbles 8 in a polishing tank and enters a barrel tank through a gap alpha between the fixed tank 1 and a rotary tank 7. The number of the holes 2 being a number enough to allow uniform injection of the air bubbles 8 through the gap alpha are formed. Thereafter, works and polishing water are charged in the barrel tank, an amount of the air bubbles 8 is regulated by the flow rate regulating valve 5. Through rotation of the rotary tank 7, barrel polishing is executed without residence of the works on the inner wall of the fixed tank 1 and the upper surface of the rotary tank 7.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a barrel polishing apparatus and method for chamfering a work such as a flat rare earth magnet which is prone to chipping.

[0002]

2. Description of the Related Art FIG. 5 shows a barrel 50, which is covered with urethane rubber 30 and is fixed with a rotary tank 7 supported by two bearings 31 and two urethane rubber 32 which is in contact with the outer circumference of the rotary tank 7 at a clearance α. It consists of tank 1. A chamber 33 is provided under the rotary tank 7 so that only polishing water, which will be described later, is drained through the gap α. At the end of polishing, a valve on the lower surface of the hole 34 is opened to drain the polishing water.

A work piece 9, a polishing stone 21,
Polishing water 35 is charged as shown in FIG. Figure 7 shows barrel 5
FIG. 2 is a view showing a mixture flow state at 0, and is an upper surface 51 of the rotary tank 7.
Further, on the inner side surface 52 of the fixed tank 1, a rotational force and a centrifugal force act and flow spirally as shown by a dotted line 41. On the upper surface of the mixture, it moves as shown by the solid line 42 by its own weight and rotational force. A curve 43 in FIG. 8 shows these movements in cross section, and the spiral movements 41 and 42 described above are combined with the curved movement 43 to flow in a combined form.

Since the volumes of the work 9 and the grinding stone 21 are different, the flow speeds are different, and further, the rotation action is taken into consideration and polishing is performed. Further, centrifugal force acts on each of the polishing stones 21 and the work 9 to perform pressure polishing.

If polishing is performed in the above-described state, a detergent (coconut oil or the like) as a cushioning material is put in to prevent chipping due to collision of the works 9 with each other, but with the work 9 shape and the barrel 50 shape. Each is very different.

[0006]

Each polishing stone 21 is shown in FIG.
The grinding stones flow while pressing each other as shown by arrows 22. Here, the polishing stone 21A at the corner portion of the fixed tank is less likely to exert a push-up force from below, is pushed from the side surface, and is pressed by the other polishing stone from above, so that it is likely to be in a semi-fixed state over the entire circumference of the barrel tank.

For this reason, the work 9 is in a semi-fixed state polishing stone 21A.
If you get into the place 59 where the thrust force from below does not work, it will easily become stagnant. Depending on the shape of the tank, the works 9 may be accumulated in order from the bottom, and the stagnant works 9 may reach the vicinity of the middle stage on the entire inner wall surface of the fixed tank 1.

Further, the work 9 is attached to the semi-fixed polishing stone 21A.
May be caught on the upper surface 60 of the rotary tank 7. The place 60 is a place where the self-weight of the polishing stone from above is applied, and the pushing force from the bottom is hard to work, and the caught work 9 repeatedly collides with the semi-fixed state polishing stone 21A and rotates itself.

In this state, when the work 9 such as a rare earth magnet which is apt to be chipped is machined, only one side is largely chipped and the remaining one side is not polished at all. The defect rate due to these stagnations increases as the inner wall surface dimension β of the fixed tank 1 in FIG. 9 increases and the rotary tank upper surface angle θ increases. At least 1-2%,
High ones reach 20-30%. Work 9 in this state
When detergent or the like is mixed in to reduce the mutual collision probability, chipping is reduced but polishing water viscosity is increased, so that stagnation is increased and the defective rate is increased by about 3%.

In the example of FIG. 10, the work stagnation phenomenon is reduced. However, since the uppermost point γ of the rotary tank is an acute angle, it wears quickly due to wear, and is 1/2 that of the normal barrel 50 of FIG.
It is not practical because it has a tank life of about 1/3. An object of the present invention is to prevent chipping defects that occur due to the reasons described above and to improve the yield.

[0011]

In order to solve the above problems, a fixed tank having a circular or polygonal cylindrical shape and a disk-shaped rotating tank which is in contact with the inner peripheral surface of the lower portion of the fixed tank with a minute gap and rotates. In a fluidized barrel polishing machine that applies centrifugal force to the workpiece, polishing stone, and polishing water that have been put into the tank to flow and polish, a workpiece such as a flat rare earth magnet, a spherical polishing stone, and a polishing stone are added during polishing. It consists of polishing water and an air device that uniformly ejects bubbles from the entire circumference of the rotating rotary tank outer peripheral surface and fixed tank inner peripheral surface. It prevents the work from staying on the upper surface of the rotary tank.

[0012]

EXAMPLE FIG. 1 shows a first example. Several holes 2 are provided on the lower surface of the fixed tank 1, and the filter regulator 3,
Compressed air is sent through the solenoid valve 4, the flow rate adjusting valve 5, and the check valve 6. The compressed air becomes bubbles 8 in the polishing tank, and the fixed tank 1
And enters into the barrel tank through the gap α of the rotary tank 7. The number of the holes 2 is set so that the bubbles 8 uniformly come out from the gap α.
Add spherical polishing stone, work such as rare earth magnet, polishing water,
The amount of the bubbles 8 is adjusted by the flow rate adjusting valve 5, and the rotary tank 7 is rotated for polishing.

FIG. 2 shows a second embodiment. Drill several holes 2 on the lower surface of the fixed tank 1. A wear-resistant magnet pump or the like 11 is coupled to each hole 2. As many holes 12 as holes 2 are provided in the fixed tank 1 near the outermost periphery of the rotary tank 7,
The pump 11 for flowing polishing water through the flow rate adjusting valve 13
Combine with.

A component 15 covered with urethane rubber 14 is joined to the upper surface of the rotary tank 7 with screws or the like. Parts 15 and rotating tank 7
Is the same as the clearance α between the rotary tank 7 and the fixed tank 1,
The structure is such that only polishing water is introduced.

This polishing water is introduced into the pump 11 through the hole 16 formed in the rotary tank and the hole 2. Polishing water flow is pump 1
1, flow rate adjusting valve 13, hole 12, clearance α between rotary tank 7 and fixed tank 1, flow motion 17, clearance α between component 15 and rotary tank 7, hole 1
6 and hole 2 in that order.

The number of holes 2 is set so that the polishing water is uniformly discharged from the gap α. The number of holes 16 is determined by the pump capacity. A spherical polishing stone, a work such as a rare earth magnet, and polishing water are charged, the flow rate adjusting valve 13 is adjusted, and the rotary tank 7 is rotated to perform polishing.

As shown in FIG. 3, the rotary tank 7 and the fixed tank 1 are
The bubbles 8 jetting out from the gap push up the semi-fixed state polishing stone 21 at the corner portion of the fixed tank from below, and prevent the polishing stone from staying there. As a result, there is no work stagnation on the inner wall of the fixed tank 1 or catching work on the upper surface of the rotary tank 7.
It is possible to prevent a defect in which only one side is largely chipped. FIG. 4 shows a graph obtained by averaging the number of chips and the amount of chamfering generated in one workpiece by averaging them after barrel-polishing after mixing detergent with the conventional method and the method according to the present invention. As shown in the figure, the chamfering amount is not much different from the conventional method. However, the total amount of chips is decreasing. These chips are caused by the collision of the workpieces with each other in the barrel tank. The reason why these chips are reduced compared to the conventional method is that the spouted bubbles 8 stir the detergent more and more bubbles for collision prevention are generated than before. , Because the work was protected. As described above, the stagnation of the work on the inner wall of the tank is prevented, the chipping due to the collision of the works is reduced, and the yield is improved. Further, since the uppermost angle of the rotary tank 7 is not an acute angle as shown in FIG. 10, the life of the tank is not different from that of the conventional method. The water flow by the pump 11 of FIG.
Produces the same effect as.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of the effect of the present invention.

FIG. 4 is a table showing effects of the present invention.

FIG. 5 is a sectional view of a conventional barrel device.

FIG. 6 is a view showing a mixed state of a polishing stone, a work, and polishing water.

FIG. 7 is a diagram showing a motion state of a fluidized barrel.

FIG. 8 is a diagram showing a motion state of a fluidized barrel.

FIG. 9 is a diagram illustrating a conventional defect.

FIG. 10 is a sectional view of one embodiment from the shape of the tank.

[Explanation of symbols]

 1 Fixed tank 7 Rotating tank 8 Bubbles 9 Work 21 Spherical grinding stone α Gap between the outer surface of the rotating tank and the inner surface of the fixed tank

Claims (2)

[Claims] 1. A stationary tank having a circular or polygonal cylindrical shape, and a disk-shaped rotating tank which is in contact with the inner peripheral surface of the lower portion of the fixing tank with a minute gap, and rotates. In a fluid-type barrel polishing device that imparts centrifugal force to water to flow and polish, a work such as a flat-shaped rare earth magnet, a spherical polishing stone, polishing water to be introduced at the time of polishing, and a rotating tank outer peripheral surface, It consists of an air device that uniformly ejects bubbles from the entire circumference of the minute gap on the inner surface of the fixed tank, and prevents air bubbles from uniformly ejecting from the lower surface of the inner surface of the fixed tank to prevent work stagnation on the inner wall of the fixed tank and the upper surface of the rotating tank. A polishing device with a barrel characterized by being capable of. 2. A work such as a flat rare earth magnet,
A spherical polishing stone, polishing water to be added during polishing, a groove with an interval for extracting only polishing water from the upper surface of the rotating rotary tank, and a minute outer surface of the rotating tank that rotates this polishing water, and a minute inner surface of the fixed tank. The polishing by a barrel according to claim 1, which comprises a pump that applies pressure from the entire circumference of the gap and feeds it, and prevents the work stagnation on the inner wall of the fixed tank and the upper surface of the rotary tank by the polishing water that is sprayed uniformly from the lower surface of the inner circumference of the fixed tank. Method. [0001]