JPH025550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grinding tool used in electrolytic grinding.

Various types of tools are used, such as wire, rod, band, and plate shapes, and the base materials for these tools include various metals and alloys, as well as cloth belts, vitrified materials, resinoids, rubber, and other mechanical grinding wheels. Materials that have been given conductivity through conductive treatment such as chemical plating are used.

Conventionally, electrolytic grinding tools in which various types of abrasive grains are bonded to the surface of the tool base material using non-conductive resin or fixed using plating methods are well known, but when the former method is used, adhesive Since the agent is non-conductive, it interferes with the conduction of electricity during electrolytic grinding, so a thick adhesive layer cannot be provided, which causes the abrasive grains to fall off and wear out. In such cases, the abrasive grains are usually mixed into the plating solution and fixed in the plating metal at the same time as the plating overlay, but this method does not allow a large amount of abrasive grains to be uniformly interposed and fixed. Furthermore, it is not possible to align and fix abrasive grains along a certain polishing surface. There is also a known method of imparting conductivity by providing a coating layer of a mixture of resin and abrasive grains on the base material and heating it to carbonize the resin part, but carbonization by processing heat alone does not provide good conductivity. Instead, deformation cracks and the like occur due to heating, making it unsatisfactory as an electrolytic grinding tool.

The present invention was proposed in view of these points, and uses a tool base material formed into a desired shape, and mixes hard particles and metal particles with an adhesive that exerts a grinding function on the surface or recesses of this base material. Provide an adhesive layer.

The adhesive for bonding the ultra-hard particles is usually a synthetic resin or an organic adhesive, and fine metal particles are mixed and dispersed therein to impart electrical conductivity. As mixed metal fine particles, metals obtained by chemical or mechanical pulverization are usually in the form of granules, foils, etc., so the better they are mixed with adhesive resin, etc., the more each particle will be wrapped in resin, etc. However, this can be prevented by mixing uneven metal fine particles having a large number of whiskers or protrusions on the surface, which the inventor has already proposed. can be produced chemically or electrochemically, or by electrolytic deposition of an aqueous solution containing metal ions or electrolytic deposition of molten salt, or by heating a chemical plating solution to precipitate metal particles from the contained metal ions. Thermal decomposition method, reduction method of metal oxide by heating in a reducing atmosphere, chemical reduction method of metal salt solution, etc. can be used, and by increasing the liquid temperature during this reduction precipitation, many protrusions are formed on the particle surface. When the particles are generated by means of decomposing them from the gas phase to generate metal particles, the uneven particles can be generated by controlling the generation conditions such as heating temperature and atmospheric pressure. The metals obtained include Ni,
There are Cu, Fe, etc., and if such uneven particles are mixed with an adhesive resin, etc., the metal particles will be bonded even if the entire surface is covered with the adhesive resin because the surface has an uneven surface with many protrusions. By pressurizing and adhering the metal particles, the protrusions between the metal particles are adhered in close contact with each other, imparting conductivity, and good conductive adhesion can be achieved.

Then, if ultra-hard particles such as diamond grains or CBN grains are mixed into the adhesive that has been given conductivity in this way and applied to the tool base material, the entire applied layer will have uniform conductivity. Even if the coating layer is formed thickly, a conductive layer can be formed, and the ultrahard particles are firmly adhesively fixed in this adhesive layer. In addition, the fixation of these ultra-hard particles is achieved by interposing the metal particles mixed in the adhesive in such a way that their surface irregularities fit into each other with the adhesive interposed between them, and the particles and resin are well wetted. binds with strong affinity,
As a result, the ultrahard particles are fixed extremely firmly by adding the reinforcing effect of the metal particles to the adhesive force of the adhesive. Moreover, since this adhesive layer adheres to the tool base material with the desired shape, the shape can be easily formed with high precision, and since it is reinforced and held by the base material, there is no damage, wear and tear deformation, and it is mechanically strong. form a layer.

Since the grinding tool configured as described above does not apply heat, it can be formed with extremely high precision, has good and uniform electrical conductivity, and can perform stable electrolytic grinding. Due to the mechanical grinding action of the bonded ultra-hard particles and the interaction effect with the electrolytic action, extremely highly efficient and long-life grinding can be achieved. Furthermore, since the ultra-hard particles are firmly fixed by the adhesive, the machining process, which is completed by turning off the electricity, can be performed stably and with high efficiency without falling off. Moreover, since diamond grains or CBN grains are particularly used as the ultra-hard particles, even if the workpiece is a super-hard material such as WC material, electrolytic grinding and mechanical finish grinding can be easily performed.

Note that a metal coating may be formed on the diamond grains or CBN grains by an appropriate method such as vapor deposition or soaking before mixing with the adhesive. Since particles and metal particles are used together, the amount of metal particles mixed in the adhesive can be reduced. In addition, in the above embodiments, in order to increase the adhesive strength with the base metal, the surface of the base metal is roughened by creating scratches or irregularities using an appropriate method such as mechanical or electrochemical. Strength can be increased.

Next, the diamond grains or CBN mentioned above
After bonding the ultra-hard particles to the base material with an adhesive in a conductive state, the top surface of the bond is further plated with metal to form a metal film, thereby eliminating holes between the ultra-hard particles, the particle surface layer, etc. It is well filled with metal conductors and can further increase conductivity and adhesive strength. During this plating process, as the adhesive layer has conductivity, it is possible to perform not only chemical plating but also electroplating. The metal film on the surface can serve as a nucleus to grow the plating metal, which has the effect of increasing the adhesive strength between the adhesive layer and the plating metal layer thereon.

The drawing shows an example of a grinding process using the electrolytic grinding tool described above, in which reference numeral 1 denotes a support head, at the tip of which a wire-shaped tool 2 is supported with a predetermined tension. The head 1 is supported by a bearing 4 on a sliding wall 3 so as to be movable up and down, and is connected by a pin 8 to a crank 6 rotating around a rotating shaft 5 through a connecting rod 7, giving it reciprocating motion up and down. Reference numerals 9 and 10 are rotary motors provided at the tip of the head, which give rotational motion to the wire 2. 11 is a workpiece, and 12 is a current-carrying terminal for passing an electrolytic current between the workpiece and the wire tool.

In electrolytic grinding, an electrolytic solution is supplied between the workpiece 11 and the wire tool 2 from a nozzle (not shown), and electricity is applied through the electrolytic solution. wire tool 2
is rotated by motors 9 and 10, and vertically reciprocated by a crank 6. Machining is performed using electrolytic action based on electrolysis of an electrolytic solution and mechanical grinding action caused by friction of ultra-hard particles due to the rotation and vertical movement of the wire tool 2, allowing processing such as high-speed cutting and polishing. will be carried out.

Furthermore, mechanical finishing by turning off the current from the terminal 12 can be easily accomplished because the ultrahard particles are adhesively fixed to the tool 2.

For example, on a 0.3mmφ piano wire, #400 diamond particles are vapor-deposited with Ni to give it conductivity, and this is mixed with an epoxy adhesive to bond it, and then on this adhesive layer.
When machining WC material with a tool that has a Cu plating film of approximately 3μ thick formed with a Cu chemical plating solution (55°C), electrolytic grinding can be performed at an electrolytic current of 10 A, a tool rotation speed of 8000 RPM, and a vertical movement of 10 Hz. However, when an adhesive containing 50% by volume of 30 μΦ Ni uneven particles was used as the adhesive in the above case, the amount of mechanical grinding was reduced when processing was performed under the same conditions as above. Although there was almost no change in the electrical resistance, the machining current increased and electrolytic grinding became smoother.

As explained above, in the present invention, a tool base material having a desired shape is provided, and a coating layer containing an adhesive, hard particles, and metal particles is provided on the surface of the tool base material. Grinding tools can be manufactured extremely easily, and tools with arbitrarily complex shapes can be easily obtained with improved shape accuracy. In addition, the grinding performance of the obtained grinding tool is ensured by the fact that the coating layer that has the grinding function is firmly reinforced and held by the base material, so it will not be damaged or worn out by external forces such as pressure or impact, and it will not change due to strong pressure. It can be used for grinding and improves grinding performance. In the coating layer of the mixture, hard particles and metal particles are uniformly distributed through an adhesive, and there is no directionality and exhibits homogeneous and stable electrical conductivity and grindability.

[Brief explanation of drawings]

The drawing is a configuration diagram of an apparatus according to an embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. A mixture of ultra-hard particles such as diamond grains or CBN grains and uneven metal fine particles having a large number of whiskers or protrusions on the surface is mixed with an adhesive to form a desired shape such as a wire, rod, band, or plate. By applying it to the surface or recesses of the shaped tool base material, a coating layer of the desired thickness is provided,
An electrolytic grinding tool characterized in that metal plating is formed on the coating layer as necessary. 2. Diamond particles or
The electrolytic grinding tool according to claim 1, characterized in that the ultra-hard CBN grains are made of particles whose surfaces have been subjected to conductive treatment.