JPH06108117A - Microball blank material, polishing ball and ball forming machine - Google Patents

Abstract

PURPOSE:To provide the microball blank materials and polishing balls consisting of a cemented carbide, etc., improved in the yield of raw material powder and to provide the ball forming machine which facilitates the production thereof. CONSTITUTION:The microball blank materials are produced by pulverizing a block-shaped ingot, spheroidizing the sieved micrograins, half sintering the balls and sieving the balls. The sieved balls within a specified range are the primary blank materials. The primary blank materials are used as nuclei and are formed with adhesive layers by raw material powder added and supplied around these material sand after the grown grains obtd. by half sintering are sieved, the grains are sintered, by which the microball blank materials are obtd. The above-mentioned ingot is adequately the ingot obtd. by press molding raw material powder not added with paraffin. The adhesive layer is formed of the raw material added and supplied in the specified amt. at about 25mum thickness. A vibrating and agitatable parts feeder is utilized.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has a diameter of 0.3 to 1.8 m.
A micro ball material for manufacturing micro balls of about m
The present invention relates to a polishing ball obtained by using this material and a ball-forming machine for this minute ball, and in particular, it is intended to improve the yield of raw material powder.

[0002]

2. Description of the Related Art Conventionally, this kind of minute ball material has been used as a base ball for a pen ball, a miniature bearing, etc., for example, Japanese Patent Publication No. 42-24728 concerning a WC-Co type super hard pen ball is disclosed. Has been done. In addition, as a method for manufacturing a ball material, a raw material powder mixed with paraffin is pressure-molded into a cylindrical shape by a rotary press, and then semi-sintered to remove paraffin, and after giving a predetermined strength, a ball mill is used. A method is known in which the corners of a cylinder are removed and the ball material is made into a ball using a dedicated polishing machine for balls.

[0003]

However, in the above-mentioned manufacturing method, the material reduction from the cylindrical shape and the press,
There was a problem that the yield of the raw material powder was about 10% due to cracks and the like caused by a ball mill and a polishing machine. In addition, the recycled raw material generated by the above-mentioned manufacturing method, when the mixed pulverization is repeated many times, the powder particles become finer and the particle sizes become uniform, so that the tendency to crack during press molding becomes strong, and a small amount is added to the new raw material powder. There was also a problem that they had to be mixed and used. Further, there is a problem that the cylindrical material is cracked due to abrasion of the die and punch of the rotary press.

In view of the above, the present invention provides a fine ball material for improving the yield of raw material powder, a polishing ball obtained by using this material, and a ball forming machine for the fine ball material. Is.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and the fine ball material is made of semi-sintered fine grains as a core and adhered by the raw material powder additionally supplied to the periphery thereof. It is constituted by forming a layer and then sieving the growth grains obtained by semi-sintering, and then sintering the growth grains segmented within a certain range. In addition, when the particle diameter is further increased, the growth grains divided into a certain range are formed by repeating the formation of the adhesion layer, the semi-sintering and the sieving one or more times with the growth grains made of semi-sintering as the nucleus. Is finally sintered. In this case, the fine particles are obtained by finely crushing an ingot obtained by press-molding a raw material powder without addition of paraffin, sieving this in a certain range, then spheroidizing, and then semi-sintering. It is preferable to select. Then, it is preferable that the adhesion layer for the fine particles and the growing particles which are the nuclei is formed by the raw material powder additionally supplied in a certain amount in the parts feeder capable of electromagnetic vibration and stirring.

Further, the polishing ball is obtained by applying the above-mentioned fine ball material and polishing the surface thereof.

Further, the ball-forming machine for growing the fine ball material is composed of at least a parts feeder, a sieve, an automatic weigher and an operation panel, and the parts feeder also has a sintering furnace associated therewith. included.

[0008]

In the fine ball material of the present invention, the semi-sintered fine particles and the growth grains are used as nuclei to form an adhesion layer around the raw material powder additionally supplied, which is semi-sintered and sieved. It is made to sinter. Therefore, the conventional manufacturing method described above can be obtained in the decreasing process from large to small, while in the present invention, it can be obtained in the growing process from small to large. As a result, the yield of the raw material powder is greatly improved, cracks are less likely to occur, and the structure is stable.

Further, the polishing ball of the present invention obtained by polishing the surface of this fine ball material is capable of favorably performing the polishing process from the improvement of the quality of the material.

Further, the ball forming machine for the fine ball material functions so as to ensure the additional supply of the raw material powder during the growth process of the fine grains or the growing grains.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fine ball material, a polishing ball and a ball forming machine of the present invention will be described below with reference to the drawings.

FIG. 1 is a flow chart showing the manufacturing process of the microball material of the present invention. The primary material is finely ground, sieved within a certain range, spheroidized, and then semi-sintered microparticles. It is a grain. Specifically, for example, in the case of a cemented carbide ball, the fine particles have a size of 0.25 mm to 0.45 after the ingot formed by pressure molding the raw material powder is crushed.
It is sieved to a size of about mm and spheroidized and sintered in the latter half. In this case, the ingot presses the raw material powder without paraffin at a pressure of 1.5 t / cm ² ,
It is molded into a block shape of 0 mm × 100 mm × 20 mm. Then, the crushing of the ingot is performed using a steel rod in a stainless steel pan, for example. It is also applicable to paraffin-containing ingots or semi-sintered ingots without paraffin,
When used as a core, since it tends to be acicular, an ingot obtained by pressure-molding a raw material powder without paraffin is preferable.

The fine particles thus screened are shown in FIG.
And, by putting it in the parts feeder 10 of the ball-forming machine shown in FIG. 4 and applying an electromagnetic vibration amplitude of 1.2 and a vibration frequency of 3600 vpm for 2 hours, the corners of the fine particles are removed and made spherical. The spheroidized fine particles are then put into a carbon board and semi-sintered by raising the temperature to 1050 ° C. by a sintering furnace (not shown) arranged in association with the parts feeder 10. The semi-sintered fine particles are sieved with, for example, a sieve having an opening of 0.633, the fine particles 1 of 0.633 or less are used as the primary material, and the fine particles of 0.633 or more are used as a waste material. .

The fine particles as the primary material semi-sintered in this manner serve as nuclei, and an adhesion layer is formed around them. This adhesion layer is formed by the additional supply of the raw material powder, which is weighed in a predetermined amount by the automatic weighing device 11. That is, the raw material powder from the automatic weighing device 11 is supplied to the dropping port 12
From the sieve 13 into the parts feeder 10. Specifically, 2.5 kg of nuclear particles are put in the parts feeder 10 and electromagnetic vibration (amplitude 1.2, frequency 3600 vpm) is applied to the raw material powder from the automatic weighing machine 1. 25 times at 4 minute intervals (35 g /
In this 4 minute period, the fine particles and the raw material powder as the nuclei are stirred by the stirring blade 15 five times (twice per rotation) so that the raw material powder is sufficiently spread around the fine particles. This means that the raw material powder is solidified on the outer periphery of the hard core by the application of electromagnetic vibration, and at the same time, it is made spherical. Further, after the raw material powder has been charged, the fine particles having an adhesion layer formed on the periphery thereof are taken out, placed in a carbon boat, and heated to 1050 ° C. in a sintering furnace (not shown) to be semi-sintered. The adhesion layer solidified by this is
It becomes harder and growth grains are formed. The semi-sintered grown grains are sieved with sieves having openings of 0.633 and 0.693.
The grown grains thus screened become the fine ball material 3 for φ0.4 mm when sintered in a sintering furnace (not shown). In this case, the reason why the value is larger than the corresponding ball diameter is that the polishing allowance is added. The thickness of the adhesion layer is about 25 μm as a guide. Table 1 shows a summary of these processes.

[0015]

[Table 1] Furthermore, when it is desired to obtain a fine ball material having a diameter of more than 0.4 mm, as shown in FIG. 2, the fine ball material is manufactured by using the grown grains obtained in FIG. 1 as a nucleus. For example,
If the growing grains in Table 1 are applied, the growing grains serving as nuclei are sieved with sieves having openings of 0.633 and 0.693, and the steps of forming an adhesion layer by supplying the raw material powder and semi-sintering are performed once. Alternatively, by repeating the process a plurality of times, the grown grains become larger. Note that one or a plurality of steps means steps surrounded by a frame in FIG. Then, specifically, grown grains are obtained in the process shown in Table 2 and sintered to form a fine ball material.

[0016]

[Table 2] Note that the semi-sintered growth grains are sintered in the process of commercialization, and those that are suitable for shape selection are sintered, and after sintering, shape selection and size selection are performed to complete the microball material. The microball material produced in this manner can be applied not only to the material of the superhard ball but also to cermet, ceramics, etc. A ball having a diameter of 1.8 mm is used as a target, and polishing of fine balls is performed by a usual method.

FIG. 3 and FIG. 4 show a ball forming machine for producing a fine ball material, which is an automatic weighing machine 11.
On the other hand, it is of a double type in which two sets of parts feeder 10 and sieve 13 are connected. From the raw material powder dropping port 12 of the automatic weighing device 11, the raw material powder is supplied to the sieve 13 via the gutter 14. in this case,
The gutter 14 is provided with an air vibrator 16 for ensuring the supply, and a switching gutter 17 is provided for the raw material powder dropping port 12 so as to start with a time lag.

The parts feeder 10 is provided with electromagnetic vibration and stirring action.
It is performed by lowering the stirring blade 15 provided at the upper part. And in this parts feeder 10,
A sintering furnace (not shown) is associated therewith.

Further, the operation of the parts feeder 10, the automatic weighing device 11 and the like is performed by the operation panel 18. The operation panel 18 is operated by at least the number of times of stirring of the parts feeder 10, the stirring time and the stop, the automatic weighing machine 1
The number of supply times and the supply time from 1 are set.

In this embodiment, the raw material powder is supplied to the sieve 13 through the gutter 14, but it may be supplied from the automatic weigher 11 directly to the sieve 13.
In addition, in the present embodiment, the double type is applied to connect the sieve 13 and the parts feeder 10 to the automatic weighing device 11, but the present invention is not limited to this, and the single type or triple type or more may be used.

[0021]

As described above, the present invention uses, as cores, fine grains obtained by semi-sintering a fine ball material or growth grains obtained based on the fine grains, to form an adhesion layer around the core and semi-burn. It is obtained by sintering the material after binding and sieving. Therefore, since the fine ball material is obtained by the growth process, the yield of the raw material powder is about 98%, which is a significant improvement over the conventional method of about 10%.

Further, since the amount of recycled raw materials is remarkably small, foreign substances are less likely to be mixed in, and the quality control of the material is facilitated.

[Brief description of drawings]

FIG. 1 is a flowchart of a manufacturing process showing an embodiment of a microball material of the present invention.

FIG. 2 is a flow chart of a manufacturing process showing an example of growing grains.

FIG. 3 is a conceptual front view showing an embodiment of the ball-forming machine of the present invention.

FIG. 4 is a plan view of the same.

[Explanation of symbols]

 10 parts feeder 11 automatic weighing machine 12 raw material powder dropping port 13 sieve 14 gutter 15 stirring blade 16 air vibrator 17 switching gutter 18 operation panel

Claims (8)

[Claims] 1. A semi-sintered fine particle is used as a core, and an adhesion layer is formed around the fine particle, which is additionally supplied, and then the semi-sintered growth grain is sieved,
A fine ball material characterized in that the growth particles divided into a certain range are sintered. 2. The semi-sintered growth grains according to claim 1 are used as nuclei, and the periphery thereof is subjected to formation of an adhesion layer by additional supply of raw material powder, semi-sintering and sieving one or more times. A fine ball material that is repeatedly sintered so that the growth particles divided into a certain range are finally sintered. 3. The fine particles according to claim 1 are obtained by finely crushing an ingot obtained by press-molding a raw material powder containing no paraffin, sieving this in a certain range, and then spheroidizing. The fine ball material according to claim 1 or 2, which is selected from those sintered in the latter half. 4. The adhesion layer according to claim 1 is formed by a raw material powder additionally supplied in a fixed amount in a parts feeder capable of electromagnetic vibration and stirring. Micro ball material. 5. A polishing ball obtained by sintering the fine ball material according to claim 1 and claim 2 and polishing the surface thereof. 6. A parts feeder 10 in which fine particles or grown particles are electromagnetically vibrated and agitated, and a predetermined amount of a raw material for the semi-sintered fine particles or grown particles serving as a nucleus in the part feeder 10. Sieve 1 for additional powder supply
3, an automatic weighing device 11 for supplying the automatically weighed raw material powder from the dropping port 12 to the sieve 13 directly or indirectly through the gutter 14, the number of times of stirring of the parts feeder 10, stirring time and stop time, automatic weighing A ball machine comprising a control panel 18 in which the number of times of supply from the vessel 11 and the supply time are set at least. 7. The ball machine according to claim 6, wherein a plurality of sets of sieves 13 and a parts feeder 10 are connected to the automatic weighing device 11 according to claim 6. 8. The ball-casting machine according to claim 6 or 7, wherein a sintering furnace is associated with the parts feeder 10 described in claim 6.