JPH04135176A - Dressing method for poreless type grinding wheel - Google Patents

Abstract

PURPOSE:To uniformly form the distribution of abrasive grains cutting edges on a grinding wheel work face, by using the porous type stick to be ground, separately composing the stick to be ground and a free abrasive grain member, and dressing with both being combined at the dressing time. CONSTITUTION:A free abrasive grain 21 whose grain size is arranged in the grading corresponding to the necessary chip pocket depth, is fed a lot into the contact zone of a grinding wheel 11 and the stick 22 to be ground at a constant rate. This free abrasive grain 21 is brought into contact with the binder and abrasive grain 23 on the grinding wheel work face while being held on the irregularity 27 due to the pore in the surface of the stick 22 to be ground, to remove a binder, mainly, uniformly and efficiently. On the other hand, the stick to be ground also performs the similar contact, and the destruction, falling-off of the abrasive grain 23 composing the grinding wheel are caused as well, due to the contact force being large, in this case.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention relates to a method for reshaping a grindstone used as a grinding tool for grinding metals or other materials.

(Conventional technology) Grinding is used for the final processing of metals, etc.

Important machining characteristics such as the stacking rate and working speed depend on the performance of the grindstone, and the performance of this grindstone also greatly depends on the refinishing method. Refinishing is the process of changing the distribution and shape of the abrasive cutting edge on the grinding wheel work surface, which is the surface of the grinding wheel used to process the workpiece.
@It is a work of adjusting. With this work, the performance of the whetstone is 2.
Adjustments are made to efficiently achieve the workpiece dimensional accuracy, finished surface roughness, etc. required in machine design.

The refinishing work is done when the whetstone is first installed on the grinding machine and when it starts to be used, and when the whetstone becomes dull or clogged as a result of grinding with a well-adjusted whetstone and becomes unsuitable for the purpose of machining. It will be done.

A whetstone is composed of abrasive grains and a binder, and there are two types: one with pores, like a vitrified binder whetstone, and the other.
There are nonporous grindstones that do not have pores, such as those made with resinoid binders or metal bond binders. In addition, the abrasive grains used are alumina (A 120), which has been used for a long time.
3) and silicon carbide (SiC), those that use extremely hard abrasive grains such as diamond or cubic boron nitride (CBN) are called superabrasive grindstones.
According to JIS, superabrasive grindstones are considered wheels.

In this application, it is also referred to as a whetstone.

When reconditioning a non-porous type grindstone, pores called chip pockets are formed around each abrasive cutting edge on the working surface of the grinding wheel to remove chips, and the required abrasive cutting edge is It is necessary to form the distribution and shape of Conventionally, a method of refinishing a non-porous superabrasive grinding wheel by grinding a bar-shaped member called a stick using a vitrified bonding agent has been often used. In addition, metal plates are also used to attach to the sticks.

The latest method for reconditioning such non-porous superabrasive grinding wheels is described in detail in the book by Aiseki Yokoyo et al. (co-authored by Kazuhiko Yokoyo and Munehiko Yokoyo: CBN Wheel Grinding). Processing technology, industrial research publication.

(first edition published on November 1, 1988), Figure 1 shows conventional examples of cross-sections shown in this document: rp, go, and p.

This is a picture of 77. CBN is the abrasive grain that makes up the whetstone.
The following are taken up. The shape of the CBNtft crystal abrasive cutting edges as a sharp cutting tool in the fine structure of the grinding wheel working surface, the spacing between these abrasive cutting edges, and the chip pocket (a small depression adjacent to the abrasive cutting edge, l2
The presence of an appropriate size of S24) determines the performance of the grindstone. As a grindstone is used, the abrasive cutting edge may wear, break, or fall off, and chips may become clogged due to welding to the cutting edge or filling into the chip pocket, and as mentioned above, its performance may deteriorate. is deteriorating.

In (a) of the figure, this performance deterioration occurred. or.

When the CBN grinding wheel 11 is first installed on the grinding machine as described above, the solid material 13 called a stick is pressed against it (
This shows a method for refinishing by grinding a dummy work material 12 as well as performing a grinding operation.

As stick members, rod-shaped members (P, E, and G sticks) are considered in which alumina-based white alundum (hereinafter abbreviated as WA) abrasive grains are hardened with polyethylene glycol. By pressing this against the CBN grinding wheel and performing a grinding operation, the WA abrasive grains of the stick 13 that have been scraped off by the CBN grinding wheel 11 infiltrate into the contact area between the grinding wheel 11 and the dummy workpiece 12, thereby forming chip pockets and grinding. Remove any buildup.

As a similar method, a method of simply pressing a rod-shaped grindstone (WA stick) 15 made of a vitrified bond using WA abrasive grains as a stick member shown in FIG. There is.

In addition, (c) in Figure 1 is another typical example, while grinding a flat metal 'J & 17 with a whetstone, fine abrasive grains (free abrasive grains) 16 are in contact am between the CBN whetstone and the metal plate. This is a method of sending in the materials and revising them. When feeding the loose abrasive grains, the abrasive grains are adhered with grease or the like to prevent them from scattering.

(The invention seeks to solve [1 There are two possible effects of reshaping a nonporous grindstone.

One is to appropriately remove the binder of the nonporous type grindstone from the abrasive powder and free abrasive particles that have fallen off or cracked from the stick within the contact area between the grindstone and the stick or metal plate. The other is by grinding sticks or metal plates with a nonporous grindstone.

Properly wears the abrasive cutting edge on the non-porous grindstone working surface.

Breaking, falling off, and adjusting the distribution and shape of the cutting edge.

In addition, it is necessary to remove clogging and the like. These operations meet the processing objectives. A sharp grindstone working surface is formed. Therefore, on the reconditioned grindstone working surface, the cutting force distribution and chip pocket size must be uniform and uniform, and the shape of the cutting edge must also be appropriate. This point can be said to be a requirement for performing highly accurate grinding. For revising work,
It is required that such a grindstone working surface can be formed easily and efficiently.

In the conventional method shown in FIGS. 11(a) and 11(b), the particle size distribution of the abrasive powder that falls off or cracks from the stick 13 or 15 is close to the maximum particle size of the abrasive grains constituting the stick. The abrasive powder has a wide distribution, ranging from extremely fine powder, and the amount of abrasive powder is small.For this reason, it is difficult to form chip pockets of the required depth accurately, and the reshaping speed is slow. Refinishing may be done unevenly depending on the location of the surface. Furthermore, Figure 1!1 (
In method a), a CBN grinding wheel 11 and a dummy work material 12 are used.
However, since the surface of the dummy workpiece is smooth, the abrasive powder is discharged from the contact area between the grinding wheel 11 and the workpiece 12. Also, some of the metal may adhere to the grindstone as a blockage. For these reasons, there are drawbacks such as insufficient refinishing depending on the location of the grindstone working surface and slow refinishing speed.

In addition, in the method shown in FIG. 3(c), the free abrasive grains and the metal plate are used for refinishing, but as mentioned above, the metal plate 17 is smooth, and the supplied free abrasive grains 16 touch the grindstone 11 and the metal plate. 17, and a part of the metal is easily discharged from the contact area with the grinding wheel 1.
It may also adhere to 1 as a blockage. Furthermore, in the conventional method, the particle size of the stick and free abrasive grains to be used is not determined, and there is also the drawback that it is difficult to form the required chip pocket size accurately.

In addition, these traditional methods do not allow eyelids during facelift.

Another drawback was that the abrasive grain cutting edges could break or fall off, making it difficult to form a grindstone working surface with a dense distribution of cutting edges.

(Means for Solving Problem 1111) The present invention provides a microscopic grindstone that is made up of a hard micromember that can remove the binder of a nonporous grindstone as a stick work material, a micromember that can hold the hard micromember, and pores. An object with a structure 9, for example, a WA stick is used. Then, add free abrasive grains whose particle size is matched to the required depth of the chip pocket.

A separate means for supplying a large amount of free abrasive grains corresponding to the required depth of the chip pocket is supplied in a large amount to the contact area between the grinding wheel and the stick workpiece to be reconditioned, and there is no porous A new refinishing method that uniformly and efficiently forms chip pockets of the required depth on the working surface of the molded whetstone, and also adjusts the distribution and shape of the cutting edge by adjusting the contact state between the hard micro parts and the whetstone. I will provide a.

FIG. 2 shows a CBN grinding wheel 11 showing a typical embodiment of the present invention.
On the other hand, porous stick work material (WA stick)
22, the grindstone 11 is reconditioned while adding free abrasive grain members 21 that are soft and fixed with grinding fluid, wax, or the like. The shape 23 of the abrasive cutting edge that generates chips is shown in Figure (b), which shows a microscopic illustration of the refinishing process, and Figure (c), which shows a cross-sectional view of the working surface of the grindstone after the refinishing. -1 is appropriate, and the important requirements are that the distribution on the grinding wheel working surface is uniform, and that the depth of the concavity that is the chip pocket 24 and the distribution on the grinding wheel working surface are uniform.

The stick work material 22 shown in FIG.
It has a fine structure composed of a hard micro member 25 capable of removing the binder and abrasive grains of the hard micro member 26, a micro member 26 capable of holding the hard micro member, and pores 27. An example of a hard micro member is Al 203. SiC, Zr2.03.
Examples include CBN, diamond, glass, etc., which are harder than the bonding agent of the whetstone being refinished. Also,
The free abrasive grains 21 shown in FIG. 2(b) can be supplied with uniform particle size by using a sieve or the like.

The loose abrasive grains may be the same as or different from the hard ill/J1 member constituting the stick work material, depending on the reshaping work to be applied. Furthermore, by fixing these together and uniformly and feeding them at a constant speed, it is possible to supply them at a constant rate.

(Function) By the method according to the present invention, the free abrasive grains 21 whose two grain sizes are aligned to the grain size corresponding to the required chimp socket depth are brought into the contact area between the grinding wheel 11 and the stick work material 22 at a constant rate. Supplied in large quantities. The loose abrasive grains come into contact with the binder and the abrasive grains 23 on the working surface of the grindstone while being held by the unevenness 27 formed by the pores on the surface of the stick workpiece, and mainly remove the binder uniformly and efficiently. On the other hand, the stick workpiece also makes similar contact, and in this case, the contact force is large.

Breaking of the abrasive grains 23 constituting the whetstone and R-fall also occur, and chip pockets 24 with a depth larger than the grain size of the free abrasive grains are formed on the work surface of the whetstone.

The abrasive cutting edge 23-1 on the grindstone working surface is formed into an appropriate shape. In order to make the abrasive cutting edge distribution denser, the conditions for cutting the stick workpiece material (table speed, depth of cut, etc.) should be moderated, and the 2M separation abrasive grains should be mainly used to form chip pockets.

C Example 1] It was carried out using the method shown in FIG. 2(a) under the following conditions.

Whetstone: CB N 12QN 100B Wheel Stain Ink Work material: WA stick (grain size 600
) Free abrasive material: WA abrasive grains (particle size 600) are aggregated with a grinding fluid, and the depth of the chip pocket is about 1.0 to 1.3 times the average particle diameter of the free abrasive grains, which is the conventional WA abrasive material. It was possible to form the face more uniformly and more quickly than with the touch-up using only a stick.

In addition, it was possible to form a grindstone working surface with a dense distribution of cutting edges, which was difficult with conventional methods.

[Example 2] This is an example in which a WA stick cut material having a width wider than the grindstone was used. An example of its configuration is shown in FIG. 3, and the width of the grinding wheel is usually about 100 mm rather than 11 meters.

Use a stick material that is wider than this. When this wide stick work material 22-1 is used for reshaping and grinding is performed while adding free abrasive grains, it is easier to create a groove with the same width as the grinding wheel in the stick work material than with a metal plate. , protruding walls on both ends of the stick workpiece to prevent scattering of loose abrasive grains are formed. For this reason, the loose abrasive grains sent to the stick-cut Murakami are less likely to fall out in the width direction of the grinding wheel.

It was possible to effectively work through the contact between the grinding wheel and the stick work material. This improves the efficiency of retouching.

[Embodiment 3] Fig. 4 shows a grinding wheel 11 using a nine disc-shaped stick work material 41 and free abrasive grains instead of a flat stick work material.
It shows you how to revise your eyes. In Examples 1 and 2, since a flat plate-shaped stick work material is used, the relative speed of contact with the CBN grinding wheel cannot be increased. Since it is possible to rotate at high speed, the relative speed of contact with the CBN grindstone can be increased, improving the reshaping efficiency.

[Embodiment 4] FIG. 5 shows an embodiment of a composite stick member having a structure that uniformly and easily supplies free abrasive grains to the contact area between the grindstone and the stick workpiece according to the present invention.

A free abrasive member 21 in which free abrasive grains are fixed with a soft liquid resin or the like, and a stick cut material 22 are integrally fixed with an outer frame 51 made of plastic or the like to form a composite stick member. As a hard micro member of the stick work material, Al2O3, siC+ Z r 203
1 CB L A material harder than the bonding agent of the grinding wheel, such as diamond or glass, can be used alone or in combination. As a free abrasive grain.

A member similar to the hard micro member of the WA stick is finely ground and sieved to obtain particles with uniform particle sizes. !
! The particle size of the free abrasive grains depends on the condition of the grinding wheel working surface that is the target of formation. use Generally, the required chip pocket depth is 10
The average grain size of the *difficult-abrasive grains used is approximately 70% or less of the required depth of the chip pocket.

In the figure (a), one stick work material 22 and one free abrasive grain member 21 are laminated together. Same figure (b)
This shows an embodiment in which one abrasive grain member 2 is sandwiched between two stick workpieces 22. Same figure (
C) shows an embodiment in which a large number of abrasive grain members 21 are sandwiched between a large number of stick workpieces 22. FIG. 2D shows an embodiment in which a free abrasive member 21 is sandwiched between stick cut materials 52 having hole shapes. Figure (e) shows an embodiment in which a free abrasive grain member 21 is sandwiched between stick workpieces 53 having one or more groove shapes, making it possible to supply abrasive grains at a constant rate, making it possible to perform 9 operations. This has the effect of simplifying the method.

[Effects] The effects of the refinishing method according to the present invention have been described in each example, but to summarize, the effects of the reshaping method according to the present invention are as follows:

1) The abrasive grain cutting edge distribution on the grindstone working surface can be formed uniformly. Furthermore, the distribution and shape of the abrasive cutting edge can be adjusted.

2) Evenly distribute the required chip pocket depth, which varies depending on various grinding conditions, on the grinding wheel work surface.

It can be formed with high efficiency.

3) Can be applied to grinding wheels made of various binders.

[Brief explanation of the drawing]

- Figure 1 is a diagram illustrating the conventional method of reshaping. 11-m-Poreless grindstone 12-m-Work material (dummy) 13--P, E, G stick 14-m-Table 15--W A stick 16--W A abrasive grain + grease or wax 17--
-Metal Plate FIG. 2 is a diagram illustrating a grindstone reconditioning method using a stick work material and free abrasive grains according to the present invention. (a) is an overall configuration diagram, and (b) is a perspective view. 21--Free abrasive grain member 22--Stick work material 132!1 23---CB N abrasive grain 23-1-m-Abrasive cutting edge 24--1-Chip bocket 25--W A Abrasive grain 2
6----Binding agent 27--Pores Figures 1 and 3 are diagrams showing other embodiments of the method of the present invention, in which a refinishing method using a stick workpiece having a scattering prevention wall is shown. Explaining. 22-1-m - Stick work material with wall to prevent scattering of loose abrasive grains (a) Example of using P, E, G sticks - Figure 4 shows the refinishing method using the disc-shaped stick work material according to the method of the present invention. This is to explain. 41-m-Disc-shaped stick cut material・115 FIG. 115 is a diagram illustrating two embodiments of a composite stick member according to the present invention. 51-m-Outer frame (plastic etc.) 52--Single hole stick work material 53--Groove stick work material (b) Example of using WA stick (c) Free abrasive method Figure 2 (a) Example of refinishing (b) Refinishing mechanism (details of part A) (c) Grinding wheel working surface after refinishing Fig. 4 Disc-shaped stick workpiece Fig. 3 Fig. 5 ζ1 (a) Single layer overlapping method 2 layers Overlap method (c) Multilayer overlay method (d) Square hole stick method (e) Groove stick method

Claims (1)

[Scope of Claims] 1) A method for reconditioning a non-porous grindstone used as a grinding tool, using a porous stick work material, the stick work material and a free abrasive member. A method of revising the eyes by configuring and combining them separately. 2) The method according to claim 1, in which a stick work material wider than the width of the grinding wheel is used to form a wall to prevent scattering of loose abrasive grains. 3) A refinishing method according to claim 1, in which free abrasive grains having an average particle size not exceeding the required chip pocket depth are used to form a required chip pocket depth in the grindstone. 4) The method according to claim 1, in which a composite stick member is used, in which a stick work material and a free abrasive member are combined into one or more layers.