JP2507893B2 - How to dress a diamond whetstone - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for dressing a diamond grindstone.

[Prior Art] Diamond grindstones are often used for grinding hard and brittle materials such as glass, superhard materials, and ceramics. In particular, ceramics cannot be cut unless they are usually diamond grindstones. Furthermore, with the advent of new ceramic-based composite materials, the applications of diamond grinding wheels are expanding.

As shown in FIG. 4, the diamond abrasive grains used for such a diamond grindstone have a sharpened sharpness due to the tip 1a of the abrasive grain 1 which becomes a cutting edge during grinding being gradually worn and flattened. Come on. As a result, the grinding resistance is increased and heat is generated, which damages the work piece or makes the grinding impossible.

Therefore, when the tip of the abrasive grain 1 is worn to some extent,
It is necessary to remove the worn flat portion (flank surface) 1b of the abrasive grain cutting edge to recover the sharpness of the grindstone. However, diamond is the hardest material in existence, so for example, diamond dresser
There is no easy way to dress like dressing a WA grindstone.

Therefore, at present, using various types of impregnators, or using a WA grindstone or a GC grindstone as a dresser, the abrasive grain joint portion 2 corresponding to one layer of abrasive grain is dug down, and the entire worn abrasive grain is dropped from the grindstone. , A method in which the abrasive grains 3 inside are exposed on the surface and thereby a new grindstone surface is created.

However, in such a method, since the amount of abrasive grains dropped is large, expensive diamond abrasive grains cannot be effectively used, and the wear of the grindstone increases. Further, along with this, the cost is increased, the shape of the grindstone is deteriorated, and the processing accuracy is lowered.

[Problems to be Solved by the Invention] A technical problem of the present invention is that when the tips of the abrasive grains in a diamond grindstone are worn and the need for dressing arises,
Without removing the entire worn abrasive grain from the grindstone, a simple means is used to regenerate the sharp crystal surface of the diamond in the flat portion (flank surface) of the worn abrasive grain cutting edge, and the worn abrasive grain itself is used as a cutting edge. The purpose is to obtain a dressing method that restores the function of.

[Means for Solving the Problem, Action] The dressing method of the present invention for solving the above-mentioned problem is a flat portion produced by the wear of the abrasive cutting edge in the diamond grindstone, and a flat tip action surface of the dresser, Oxidize the surface layer of the abrasive grains with a high pressing pressure necessary to weaken the surface layer of the abrasive grains by this pressure contact to oxidize and weaken the surface layer of the abrasive grains. It is characterized in that the sharp crystal planes inside the diamond abrasive grains are exposed by mechanically removing the portion to restore the function as a cutting edge.

In the dressing method, a dresser heated by a heating means is used, and its flat tip working surface is pressed against a flat portion caused by the wear of the abrasive grain cutting edge with a high pressing pressure, whereby the flat portion of the abrasive grain is formed. Can also be heated to oxidize and weaken the surface layer of the abrasive grains.

The method of the present invention will be described more specifically with reference to the drawings. Diamond used as an abrasive grain for grinding originally has a property of being oxidized and fragile under high temperature and high pressure. The present invention intends to utilize this property of diamond. Basically, as shown in FIG. 1, the flat portion 1b caused by the wear of the cutting edge of the abrasive grain 1 is temporarily suspended by an appropriate means. At the same time as the temperature is raised, the flat tip working surface of the dresser is pressed into a high pressure state to oxidize and weaken only the surface layer of the abrasive grain wear surface, and at the same time mechanically remove the weakened portion 1c. The sharp crystal plane 1d of the diamond is exposed to restore the function as a cutting edge.

Specifically, the flat tip working surface of the dresser is pressed against the flat portion generated by the wear of the abrasive grain cutting edge in the diamond grindstone, and the worn diamond abrasive grain surface is 0.3 to 0.6.
The temperature is raised to 700-800 ℃ for a short time of about 2 seconds, and the pressing force of the dresser against the diamond grindstone at this time is generally 8-10 N / mm ² is there. This causes the diamond abrasive grains to oxidize and weaken only the surface layer of the wear surface, so if this surface layer is mechanically removed with a WA grindstone as a dresser, the sharp crystal surface 1d inside the abrasive grains is exposed. The sharpness as a whetstone can be restored.

As a means for heating the worn diamond abrasive grain surface for a short period of time to a high temperature and high pressure state, for example, a method of pressing a dresser against the working surface of a rotary grindstone and generating a high temperature and high pressure state by friction between the two, , The dresser pressed against the grindstone is provided with an auxiliary heating means for heating the tip of the diamond abrasive grains, and the dresser is pressed against the grindstone to accelerate the oxidation and weakening of the abrasive grain surface layer by heating. Can be used.

[Embodiment] Next, an example of an apparatus for carrying out the dressing method of the present invention will be described.

FIG. 2 shows an example of a dressing device for carrying out the method of the present invention. A dresser 12 for pressing against a rotating diamond grindstone 10 is held by a supporting member 13 in a machine frame 11 of the dressing device. The whetstone 10 is supported in a retractable manner in the direction of the whetstone 10, and a cam 15 rotated by a handle 14 moves the dresser 12 forward and backward. The cam 15 is provided with a dresser cut portion 15a and a high speed retreat portion 15b which are gently inclined on the cam surface, and a retreat spring 16 is provided between the support member 13 and the machine frame 11.

The dressing device presses the flat tip working surface 12a of the dresser 12 against the working surface of the rotary grindstone 10 having worn abrasive grains, and the high temperature and high pressure generated when rubbing are used for dressing. The dresser 12 is preferably hard, brittle, and poor in thermal conductivity, and for example, silicon nitride can be effectively used. The dresser notch 15a of the cam 15 has an optimum pressure force for the grindstone 10 (normal grinding resistance).
The handle 14 is used to make the cut manually, but it is also possible to provide an automatic cut mechanism. Further, the high-speed retreat portion 16 is the oxidation of the surface layer of the abrasive grains,
It is used to detach the dresser 12 from the grindstone 10 after a high pressure load (mechanical removal of the weakened portion) for a short time after the weakening starts.

FIG. 3 exemplifies a dressing device provided with heating means for heating the tip portion of the dresser. In this device, as the heating means, a high frequency induction for heating the tip portion 32a of the dresser 32 is used. A coil 33 is attached. Instead of the high frequency induction coil 33, another high temperature heat source body or the like may be used.

When this heating means is used, a mechanism as shown in FIG. 2 may be used as a mechanism for pressing the dresser against the grindstone 10.

[Effects of the Invention] According to the method of the present invention described in detail above, when the tips of the abrasive grains in the diamond grindstone are worn and the need for dressing arises, the entire worn abrasive grains are not removed from the grindstone, By a simple means, a sharp crystal plane of diamond can be regenerated on the flat portion of the worn abrasive grain cutting edge, and the worn abrasive grain itself can recover the function as a cutting edge.

[Brief description of drawings]

FIG. 1 is an explanatory view related to the method of the present invention, FIG. 2 is a front view showing a partial section of a device for dressing by the method of the present invention, FIG. It is explanatory drawing about the conventional dressing method. 1 ... abrasive grain, 1b ... flat part, 1c ... weakened part, 1d ... crystal surface, 10 ... diamond grindstone, 12 ... dresser, 12a ... tip working surface.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Waida, 1-2 Namiki, Tsukuba-shi, Ibaraki Institute of Mechanical Engineering, Institute of Industrial Technology (72) Inventor, Madeley Reza, 1-2-chome, Namiki, Tsukuba, Ibaraki Inside the Technical Research Institute (56) References: Actual Development Sho 58-191956 (JP, U)

Claims (2)

(57) [Claims] 1. A flat tip portion of a diamond grindstone caused by wear of an abrasive grain cutting edge is pressed against a flat tip working surface of a dresser with a high pressing pressure required to oxidize and weaken the surface layer of the abrasive grain. , The pressure contact causes the flat portion of the abrasive grains to be heated to oxidize and weaken the surface layer of the abrasive grains, and mechanically removes the weakened portions to expose the sharp crystal surface inside the diamond abrasive grains, A diamond whetstone dressing method characterized by recovering the function as a cutting edge. 2. A flat tip portion of a diamond grindstone caused by wear of abrasive grain cutting edges, a flat tip working surface of a dresser heated by a heating means, and a surface layer of abrasive grains are oxidized.
Pressing with a high pressing pressure necessary for weakening, thereby raising the flat part of the abrasive grain to oxidize and weaken the surface layer of the abrasive grain, mechanically remove the weakened part, and diamond A method for dressing a diamond grindstone, which comprises exposing a sharp crystal surface inside an abrasive grain to restore the function as a cutting edge.