JPH0372434B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for manufacturing a metal bonded grindstone.
More specifically, the present invention relates to a method for manufacturing a grindstone in which metal sheets to which abrasive grains are fixed according to certain masking pattern regulations are laminated and hot-pressed after removing a non-conductive layer in a chemical bath. Prior Art (Background of the Invention) Grinding, which has been used from the earliest times as a processing method, has many unknown points compared to other processing methods, and everything from tool (grinding wheel) selection to processing is completely dependent on intuition. This is done through experience and trial and error. As a result, significant progress has not been made in terms of machining efficiency, machining accuracy, etc. as with other machining methods. This is mainly because there are many uncertain factors in the grinding wheel, which is a tool. These uncertainties of grinding wheels compared to other tools include: (a) It is an infinitely multi-edged tool. (b) The distribution of cutting edges (abrasive grains) is random. (c) The cutting edge shape is uneven. (d) There are effective cutting edges that contribute to the cutting edge and ineffective cutting edges that do not. (The ratio of the effective cutting edge to the total cutting edge is said to be 10% or less.) The above factors (b) to (d) also change as the grinding process progresses. However, since grinding is generally used only for finishing operations where only small amounts of metal are removed under mild conditions, and because grinding wheels are extremely inexpensive compared to other tools, grinding is not suitable for this aspect of the grinding process. Delays in development have not been such a problem in the past. However, in the 1970s, with the introduction of CBN whetstones and the increased use of these superabrasive whetstones in addition to the diamond whetstones that had been used up until then, the situation changed. In other words, due to the high performance of superabrasive grains, the requirements for the grinding process itself have widened from high precision to high efficiency.Also, the abrasive grains, and by extension the grinding wheels, are extremely expensive, and unlike conventional grinding wheels, For example, I can no longer simply think that the number of whetstones decreases. In response to such changes, the following demands on grindstones, particularly superabrasive grindstones, are expected to increase. (b) Eliminate random elements in the grindstone as much as possible,
It is possible to quantitatively understand and change the performance of the grinding wheel. (b) Equalize the load on the abrasive grains and extend the life of the whetstone. (c) Eliminate ineffective cutting edges as much as possible and supply high-performance and inexpensive grindstones. Recently, in order to improve the performance of superabrasive grinding wheels, various types of grinding wheels have been proposed, such as those in which the surface of the abrasive grains is coated with metal and bonded to a resin matrix. None of them takes the elements into consideration, and the main focus is solely on the bonding of the abrasive grains to the resin matrix. However, even if such connectivity is improved, it is difficult to understand the performance of the grinding wheel in an unchanging manner unless the aforementioned uncertain factors of the grinding wheel are eliminated, and it is difficult to quantitatively change the performance of the grinding wheel. In addition, it is difficult to lower the price of superabrasive grinding wheels by reducing the proportion of ineffective cutting edges. Purpose of the Invention Therefore, the purpose of the present invention is to eliminate the randomness of the abrasive cutting edge distribution, which is considered to be the biggest factor of randomness in a grindstone, and to make it possible to manufacture a whetstone having an abrasive grain distribution that follows a certain rule. As a result, by arbitrarily changing the abrasive grain cutting edge distribution, it is possible to quantitatively understand and change the performance of the grinding wheel, and by equalizing the load applied to the abrasive grains. The purpose is to provide a high-quality, inexpensive grindstone that has a long service life and eliminates as many useless cutting edges as possible. Structure of the Invention The present invention utilizes a combination of fixing abrasive grains on the surface of a metal sheet according to a certain masking pattern regulation and laminating the metal sheet with the abrasive grains fixed in this way. The combination of the abrasive grain fixation method and the lamination method ensures an abrasive grain distribution according to a certain rule, and provides an integrally molded metal bonded grindstone having the above-mentioned characteristics and features. That is, the method for manufacturing a metal bonded grindstone according to the present invention involves forming a masking pattern on the surface of a metal sheet with a predetermined shape using a non-conductive layer to regulate the position of fixing the abrasive grains, and then attaching the metal sheet to the abrasive grains. is immersed in a metal ion-containing electrolytic bath mixed with metal ions, and by applying electricity between the metal sheet and the counter electrode, the exposed portion of the metal sheet is regulated by the masking pattern of the non-conductive layer on the surface of the metal sheet. The abrasive grains are fixed by precipitated metal, and then the obtained abrasive grain-fixed metal sheets are laminated one after another while being shifted by a certain angle after the non-conductive layer is removed in a chemical bath, and this is hot-pressed. It is characterized by this. Aspects of the Invention To explain the present invention in detail below, the method for manufacturing a metal bonded grindstone according to the present invention can be roughly divided into forming a masking pattern of a non-conductive layer on the surface of a metal sheet, and grinding in accordance with regulations for the masking pattern. It consists of the steps of electrodeposition of particles, removal of the non-conductive layer, and hot pressing. (A) Formation of masking pattern for non-conductive layer (a) Production of metal sheet Prior to forming the masking pattern for non-conductive layer, a metal sheet (copper, copper alloy, aluminum alloy) with a predetermined shape is prepared as a base material. etc. metal sheets). For example, an example of the shape of a metal sheet used in a general flat whetstone is shown in FIG. Metal sheet 1 has an outer diameter of about 130 to 450 mm,
It is donut-shaped with a difference of about 5 to 10 mm between the inner and outer circumferences,
The appropriate thickness is about 0.1 to 0.3 mm. The following description will be made based on the shape of the metal sheet shown in FIG. 1 for convenience, but it goes without saying that the shape of the metal sheet is not limited to that shown in FIG. 1. In addition, various conductive metals can be used as the material for the metal sheet, but copper 70
A brass sheet of ~90% [weight ratio] will be explained as an example. A rolled sheet is used as described below, and in this case, the hardness increases due to work hardening. Therefore, if a low hardness binder (bond base material) is required depending on the purpose of use, it is used after being annealed and softened. The second relationship between annealing conditions and hardness of 70/30 brass
As shown in the figure. On the other hand, if higher hardness is required depending on the purpose of use, a small amount of iron can be added to the brass component to obtain hardness.
In addition, the sheet thickness varies depending on the abrasive grain size used, but the typical abrasive grain size (#60 ~
#270), 30 to 100 μm is considered appropriate. If it is too thin, it will be difficult to process, handle, etc.
Moreover, if it is too thick, it is not preferable in terms of controlling the abrasive grain distribution, etc. Such a thickness can be obtained by normal rolling, but as mentioned above, post-rolling annealing is required. (b) Formation of masking pattern of non-conductive layer On the surface of the metal sheet cut into a predetermined shape as described above, a masking pattern for regulating the abrasive grain distribution position is then formed using a non-conductive layer. That is, the surface of the metal sheet is masked with a non-conductive layer pattern, leaving the abrasive grain fixing position. Various methods can be applied to form this non-conductive layer masking pattern, but considering the thinness of the lines in the non-masking area, workability, etc.
Two methods can be suitably applied: a resin coating printing method and an ultraviolet curable resin photoresist method. The resin coating printing method is a method of printing non-conductive resin on the surface of a metal sheet using various printing methods, and is an inexpensive and easy method. This method is suitable when using coarse abrasive grains (#60 to #120), but the printing thickness is 0.1
Because it is large at ~0.2mm, it is not suitable when using fine abrasive grains. In order to reduce the printing thickness, it is necessary to lower the resin viscosity, but
This is undesirable because printing sag occurs and the pattern tends to become unclear. On the other hand, the ultraviolet curable resin photoresist method is a method in which an ultraviolet curable resin is cured by irradiating ultraviolet rays through a negative film corresponding to a non-conductive masking pattern, and then fixed on the metal sheet. It is also possible to obtain a resin film of a certain thickness by applying an ultraviolet curable resin onto a metal sheet, but commercially available film resins (for example, manufactured by Asahi Kasei Co., Ltd.)
By using Dry Film Resist (Dry Film Resist), a fine resin film with a uniform thickness can be easily obtained and a clear pattern can be obtained. Dry Film Resist above
has a laminated structure of carrier film/photoresist/cover film, and the types shown in the table below are commercially available.

[Table] The relationship between pattern resolution and ultraviolet exposure amount is as shown in FIG. 3, and resolution on the order of 100%, which cannot be obtained with the coating method, is obtained. After exposing the masking pattern, the unexposed resist and carrier film are dissolved and removed with a solvent such as 1,1,1-trichloroethane. A masking pattern of a non-conductive layer is formed on the surface of a metal sheet using the method described above, an example of which is shown in FIGS. 4 and 5. In FIGS. 4 and 5, 2 is a non-conductive layer, and 3 is an unmasked part of the metal sheet 1 exposed between the non-conductive layers 2 according to the masking pattern of the non-conductive layer. In this example, the non-masking portions 3 are masked radially. The interval between each non-masking part is suitably around 10 mm, but it can be set to an appropriate value according to the size of the grindstone and control of the abrasive grain distribution, which will be described later. Abrasive grains are electrodeposited on the non-masking portion 3 of the metal sheet 1. Examples of masking patterns for other non-conductive layers are shown in FIGS. 6 and 7. In FIG. 6, the non-masking portion 3a extends in a spiral shape, while in FIG. 7, in addition to the radial non-masking portion 3 shown in FIG. Masking is performed so that a non-masking portion 3b is formed. The masking pattern of the non-conductive layer is not limited to the one shown in the figure, but can be formed into any shape. (B) Electrodeposition of abrasive grains On the metal sheet on which the desired masking pattern has been formed as described above, abrasive grains are then applied to the non-masking parts (exposed parts of the metal sheet) exposed from the gaps between the non-conductive layers. Electrodeposited. Electrodeposition is performed by a normal electrodeposition method. First, the negative electrode of the plating device is connected to the metal sheet 1 on which the masking pattern of the non-conductive layer 2 is formed as described above, and this is placed in a metal ion-containing electrolytic bath (plating bath) in which abrasive grains are dispersed. Immerse horizontally. Then, since the abrasive grains are heavier than the electrolyte, they settle, and the metal sheet 1 is covered with coated grains. Here, when electricity is applied between a suitable counter electrode immersed in an electrolytic bath and the metal sheet 1, the abrasive grains 4 existing on the non-masking part (exposed part) 3 of the metal sheet 1 are transferred to the non-masking part 3. Precipitated metal layer 5 (plated layer)
is fixed as shown in FIG. Thereafter, when the metal sheet 1 is pulled up from the electrolytic bath, the metal sheet 1 with the abrasive grains 4 fixed only in the non-masking portion 3 is obtained as shown in FIG. In order to achieve accurate control of the abrasive grain distribution, a non-conductive layer coating is also formed on the entire surface of the metal sheet 1 opposite to the surface on which the non-conductive layer 2 is formed, and the abrasive layer is applied to this surface. Electrodeposition of particles may be completely eliminated. However, since the abrasive grains are heavier than the electrolytic solution, most of the abrasive grains present below will settle when the metal sheet is left standing in the electrolytic bath, so the above-mentioned treatment is usually not necessary. Further, it is desirable that the thickness of the line in the non-masking portion 3 be as thin as possible from the viewpoint of controlling the abrasive grain distribution. The same applies to the electrodeposition plating conditions, and it is sufficient to temporarily fix the abrasive grains 4 at a predetermined position on the metal sheet 1 so that they do not move during lamination, which will be described later. As the plating bath, various conventional plating baths such as nickel plating, chrome plating, copper plating, and alloy plating can be used, and the plating bath is not limited to a specific plating bath or plating liquid composition. This is because the electrodeposition plating in the method of the present invention mainly has the technical significance of fixing abrasive grains, so the deposited metal is not limited to a specific metal. However, since it is necessary to prevent the metal sheet from being attacked by the plating liquid, it is necessary to select a suitable plating liquid depending on the type of metal of the metal sheet to be used. Plating is divided into a preliminary plating process to fill the gap between the non-conductive layers in the non-masking area, and a main plating process to fix the abrasive grains. Preliminary plating only fills in the grooves in the non-masked areas, so it is difficult to meet rough plating conditions, such as plating current density.
A condition of 1A/dm2 or ^higher is sufficient. The plating processing time varies depending on the thickness of the non-conductive layer and the gap distance between the non-masking areas, but about 10 to 20 minutes is sufficient. This plating is performed under weak plating conditions in order to keep the amount of plating to a minimum. For example, the plating current density is 0.1 to 0.5 A/dm ² and the plating time is about 10 to 20 minutes. After plating, the non-conductive layer is removed using a chemical bath or the like. (C) Hot pressure forming The metal sheets to which the abrasive grains have been fixed (electrodeposited by plating) as described above are then laminated in the required number (for example, 100 to 500 sheets) in a mold, and
Hot pressure sintering. The molding conditions vary depending on the size of the whetstone being manufactured (warp, thickness, etc.), but it is usually 400 to 600 kg.
Under a pressure of f/ ^cm2 , the temperature is raised to about 70% of the melting point of the metal sheet material (approximately 650°C for brass) in a cyclic atmosphere.
Hold for 30-120 minutes. The metal sheets are integrated by hot pressurized contact between the sheets, and a metal bonded grindstone material in which abrasive grains are present between the metal sheets is obtained. Thereafter, a core made of aluminum or the like is bonded to the hollow hole. In addition, if the metal sheet is too thin and the abrasive grain distribution interval in the axial direction is too narrow, or if the binder (metal) supply is insufficient, the abrasive-fixed metal sheet and unfixed metal sheet or metal powder for filling may be separated. They may be stacked alternately. The abrasive-fixed metal sheets (or even unfixed metal sheets or metal powder for filling) are preferably laminated according to a certain rule. The purpose of this lamination rule is to control the abrasive grain distribution, which will be described later.The lamination rule (in the axial direction and circumferential direction of the grinding wheel) is performed by rotating each layer by a certain angle around the axis of the stacked abrasive grain-fixed metal sheets. directional abrasive grain distribution control). The abrasive grains in the metal bonded whetstone are given a one-dimensional (in the whetstone rotation direction) or two-dimensional (in the whetstone rotation direction and radial direction) distribution by the masking pattern of the non-conductive layer, and are further layered by the metal sheet lamination method. The distribution of the grinding wheel in the direction (axial direction for flat grinding wheels) is determined. The appearance of the laminate L is shown in FIG. 9, and it is the outer surface M of the laminate L that will later become the surface to be ground by the whetstone.
In order to improve the surface roughness of the ground surface, as shown in FIGS. 10A and B, when the grindstone surface is viewed along the rotation direction of the grindstone (arrow direction in FIG. 9),
It is necessary that the abrasive grains 4 overlap. In the method of the present invention, the method of laminating metal sheets determines the abrasive grain distribution in the whetstone axis direction, which influences the degree of overlapping of the abrasive grains 4, so sufficient consideration is required. Control of abrasive grain distribution: Since it has been common knowledge that grinding wheels have a random cutting edge distribution, there is no theory regarding the appropriate cutting edge distribution. However, there are several papers regarding the distribution of abrasive grains that contribute to grinding, that is, effective abrasive grains, on the surface of a grinding wheel. According to Kazuo Nakayama, "Relationship between Grinding and Cutting," Machinery Research Vol. 23, No. 5 (1971), p. 174, the percentage of abrasive grains that actually contribute to grinding to the total abrasive grains present on the surface of the grinding wheel. This means that the remaining 98% are ineffective cutting edges. Also, what is considered to be the most noteworthy point is that the abrasive grain spacing and the continuous cutting edge spacing on the same circumference in the rotating direction of the whetstone are approximately 100 mm. The present invention effectively controls the abrasive grain distribution of such a grinding wheel, thereby making it possible to eliminate as many ineffective cutting edges as possible and improve grinding performance. As described above, the abrasive grain distribution can be controlled one-dimensionally, two-dimensionally, and three-dimensionally. First, as a one-dimensional control, there is a distribution in the rotating direction (circumferential direction) of the grindstone, and this is performed by forming the masking pattern of the non-conductive layer described above. For example, in the case of a masking pattern as shown in FIG. 4, the abrasive grains are arranged on the non-masking part 3 at regular intervals in the rotational direction, and even if the metal sheets are laminated randomly, By setting the spacing between the non-masking parts 3, the abrasive grain distribution can be controlled one-dimensionally. In the case of the masking pattern shown in FIG. 6, the distribution in the other radial direction is also taken into consideration in addition to the distribution in the rotational direction, so that the masking pattern has a two-dimensional element. In the case of the masking pattern shown in FIG. 7, the abrasive grain distribution is distributed in both the rotational direction and the radial direction, making it possible to control the two-dimensional abrasive grain distribution. In addition to the distribution in the rotational direction and the distribution in the radial direction, the thickness of the metal sheet is also an element of the two-dimensional abrasive grain distribution. That is, depending on the thickness of the metal sheet (total thickness of the abrasive-fixed metal sheet and the filling metal sheet), the abrasive grains are distributed at regular intervals in the axial direction on the outer peripheral surface of the grindstone. The abrasive grain distribution can be controlled two-dimensionally by combining the above-mentioned abrasive grain distribution in the radial direction, the abrasive grain distribution in the rotational direction, and the thickness of the metal sheet, and the abrasive grain distribution can be controlled three-dimensionally by the combination of all the above-mentioned elements. Distribution can be controlled. Elements of the three-dimensional distribution include, in addition to the thickness of the metal sheet, the rotation angle when laminating the abrasive-fixed metal sheet layers. That is, the abrasive grain distribution in the lamination direction (axial direction) can also be controlled by rotating and laminating the abrasive grain-fixed metal sheets little by little during lamination. Therefore, the abrasive grain distribution in the radial direction on the abrasive grain-fixed metal sheet surface,
The abrasive grain distribution in the direction of rotation as well as the abrasive grain distribution in the stacking direction enables three-dimensional control of the abrasive grain distribution. As previously pointed out, FIG. 11 schematically shows an example of the abrasive grain distribution (abrasive grain distribution in the rotating direction and axial direction of the whetstone) on the important grinding surface (outer peripheral surface) of the whetstone. The direction of the arrow is the direction of rotation of the grindstone. According to research conducted by the present inventors, it has been found that it is convenient for grinding performance that the abrasive grain spacing in the rotational direction of the grindstone (f dimension) is 25 mm or less, and the abrasive grain spacing in the axial direction (e dimension) is 1 mm or less. As described above, the f dimension can be controlled by the abrasive grain distribution in the rotational direction, and the e dimension can be controlled by the abrasive grain distribution in the lamination direction (rotation angle of each abrasive fixed metal sheet during lamination). The method of the present invention is applicable not only to superabrasives such as diamond and cubic boron nitride, but also to general abrasives (alumina-based and carborundum-based abrasives).
However, the method of the present invention cannot deal with the randomness of the cutting edge shape. However, compared to general abrasive grains, superabrasive grains have a high proportion of abrasive grains with abrasive grain shapes that follow the atomic structure, such as octahedral crystals, and are less random in this respect. In addition, it is thought that temporal changes in the surface condition of abrasive grains can be almost ignored in superabrasive grindstones because the hardness of the abrasive grains is high and the wear of the abrasive grains is extremely low. Therefore, the method of the present invention
When applied to superabrasive grains, even greater sound meaning beyond the effects of the present invention is found, so it can be most suitably applied to superabrasive grains. Examples Hereinafter, a specific example of the manufacturing method of the present invention will be shown to assist in understanding the present invention, but it goes without saying that the present invention is not limited to the following examples in any way. Rolled sheet of brass (70% copper by weight) (approximately 0.1 mm)
into a donut shape (inner diameter 150 mm,
The inner and outer circumference difference was 5 mm). A phenolic resin was applied to the surface of the obtained metal sheet to form the pattern shown in FIG. 4. Connect the negative electrode of the plating device to the metal sheet after forming the masking pattern of the obtained non-conductive layer,
This was dispersed with #80 diamond abrasive grains.
Immersed horizontally in Ni plating solution, current density 1A/
dm ² for about 15 minutes, and a current density of 0.5A/
Plating treatment was performed for 10 minutes under ^dm2 conditions. The non-conductive layer was removed with butyl ether. The obtained abrasive grain-fixed metal sheets are alternately stacked together with abrasive grain-free metal sheets in a mold,
A pressure of 400 Kgf/cm ² was applied and the temperature was maintained at about 650°C.
The holding time was about 1 hour, during which time the pressure was removed several times to remove gas. The abrasive material layer produced using this method was joined and finished with the aluminum main body (core) using the usual method to form a whetstone. The grinding speed of the grindstone manufactured in this way is
1600m/min, work speed 10m/min, depth of cut 10,
When surface grinding was performed under the condition of 30μm, good grinding performance was shown. Effects of the Invention As described above, the method for manufacturing a metal bonded grindstone according to the present invention includes the creation of a masking pattern of a non-conductive layer that regulates the position of fixing abrasive grains on the surface of a metal sheet, and the production of a masking pattern according to the masking pattern regulation. This method basically consists of fixing abrasive grains by electrodeposition and hot pressing of laminated metal sheets with fixed abrasive grains laminated according to a certain rule. The abrasive grain cutting edge distribution of a grinding wheel, which has been considered common knowledge, can be controlled arbitrarily, and a grindstone having an arbitrary two-dimensional distribution within its grinding surface can be manufactured. Therefore, by equalizing the load applied to the abrasive grains, it is possible to extend the life of the whetstone, and it is also possible to reduce and eliminate ineffective abrasive cutting edges, which were a factor in the high cost of superabrasive grain wheels. It is possible to reduce the price of the whetstone. Furthermore, it becomes possible to quantitatively understand and change the performance of the grinding wheel, which has not been possible until now.

[Brief explanation of drawings]

Figure 1 is a plan view showing an example of the shape of a metal sheet used in a flat whetstone, Figure 2 is a graph showing the relationship between annealing conditions and hardness for 70/30 brass, and Figure 3 is an ultraviolet curable film resin. A graph showing the relationship between the pattern resolution of (Dry Film Resist) and the amount of ultraviolet light exposure, Figure 4 is a partial plan view showing an example of the masking pattern of the non-conductive layer formed on the surface of the metal sheet, and Figure 5 is the Figure 4 is an enlarged perspective view of section X, Figures 6 and 7 are partial plan views showing other examples of masking patterns, Figure 8 is a schematic explanatory diagram showing the state of adhesion of abrasive grains to the metal sheet, The figure is a perspective view of the abrasive-fixed metal sheet laminate, Figure 10A is a plan view of the outer peripheral surface of the laminate shown in Figure 9, and Figure 10B is the first
FIG. 11 is a schematic diagram showing an example of the abrasive grain distribution on the grinding surface of the grindstone. 1 is a metal sheet, 2 is a non-conductive layer, 3, 3
a and 3b are non-masking parts, 4 is an abrasive grain, and 5 is a metal layer.

Claims (1)

[Claims] 1. A masking pattern is formed on the surface of a metal sheet of a predetermined shape to regulate the fixed position of the abrasive grains using a non-conductive layer, and then the metal sheet is immersed in a metal ion-containing electrolytic bath mixed with abrasive grains. By applying current between the metal sheet and the counter electrode, the abrasive grains are fixed by the precipitated metal to the exposed portion of the metal sheet that is regulated by the masking pattern of the non-conductive layer on the surface of the metal sheet, and then the obtained A method for manufacturing a metal bonded grindstone, which comprises removing the non-conductive layer from the abrasive-fixed metal sheets in a chemical bath, stacking them one after another while shifting them at a fixed angle, and then hot-pressing the sheets.