JP2022136787A - Triple structure wheel for double-headed surface grinding - Google Patents

Abstract

To provide a wheel used for through-feed type double-headed surface grinding that suppresses work-piece from moving about during processing, and performs simultaneous surface grinding of both surfaces of the work-piece while through feeding the work-piece which can be ground with high efficiency and high accuracy.SOLUTION: A triple structure wheel 100 used for double-headed surface grinding that performs simultaneous through feed type surface grinding of both surfaces of work-piece has: a base metal 10 having a fitting hole 12 provided at a central part, and a ring-shaped projection 14 provided on an outer peripheral side; a ground layer 20 which contains a thermosetting resin, and is firmly attached to a top face of the projection 14 of the base metal 10; and an abrasive grain layer 30 which contains abrasive grains and a thermosetting resin, and is firmly attached to the ground layer 20. A flexural modulus of the abrasive grain layer 30 is higher than a flexural modulus of the ground layer 20 and is lower than a flexural modulus of the base metal 10.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a triple structure wheel for double-sided surface grinding.

Wheels using superabrasive grains have a longer life of the abrasive grain layer compared to general abrasive grains, and because superabrasive grains are expensive, abrasive grains containing superabrasive grains only in the surface layer that works for grinding. Many wheels have layers. One example of grinding using such a wheel is the through-feed method of double-sided surface grinding.

As a whetstone used in the through-feed method of double-sided surface grinding, Patent Document 1 discloses a grinding whetstone used in double-sided surface grinding for simultaneously surface-grinding both surfaces of a workpiece by a through-feed method, which has a cylindrical whetstone layer. A ring-shaped rough grinding area in which the flat circular grinding wheel surfaces of the disc grinding wheel are concentrically arranged successively from the outer diameter side, in the form of a disc grinding wheel formed by concentrically laminating a plurality of layers; A grinding wheel for double-sided surface grinding is disclosed which is characterized by comprising a plurality of grinding zones consisting of a fine grinding zone and a guide zone.

JP 2016-150414 A

Grinding by the through-feed method of double-sided surface grinding has conventionally had the problem that the workpiece tends to sway and flutter during machining, causing poor accuracy of the workpiece and making it difficult to improve machining efficiency. there were. It cannot be said that the whetstone of Patent Literature 1 has been sufficiently studied about the wobbling and fluttering during machining of the workpiece.

On the other hand, as whetstones using superabrasive grains, in addition to whetstones for double-sided surface grinding, disc-shaped whetstones for mirror finishing and whetstones for CMP pad polishing are known. However, while mirror finishing and CMP pad polishing are processes that remove only a small amount of work material, double-sided surface grinding requires a large amount of removal and a high load. Different characteristics are required depending on the Therefore, it has been difficult to divert a grindstone for other purposes as it is as a grindstone for flat double-sided grinding.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a workpiece that is capable of being ground with high efficiency and high precision by suppressing the workpiece from moving violently during machining. To provide a wheel for use in through-feed type double-sided surface grinding for simultaneously surface-grinding both surfaces of a workpiece while through-feeding.

As a result of earnest research to solve the above problems, the inventors of the present invention have found that the following inventions meet the above objects, and have completed the present invention.

A triple structure wheel for double-sided surface grinding according to the present invention is a triple-structured wheel for use in double-sided surface grinding for simultaneously surface-grinding both surfaces of a workpiece by a through-feed method,
platform and
a base layer containing a thermosetting resin and fixed to the upper surface of the base metal;
an abrasive grain layer containing abrasive grains and a thermosetting resin and fixed to the underlayer;
The flexural modulus of the abrasive grain layer is higher than that of the base layer and lower than that of the base metal.

In this way, the flexural modulus of the abrasive grain layer is higher than that of the base layer and lower than that of the base metal. The base layer exerts the effect of mitigating the rampage and fluttering of the wheel and the impact on the wheel. As a result, the grinding efficiency is high, and a predetermined grinding accuracy of the workpiece can be obtained in one grinding process. In particular, it is possible to achieve high-precision parallelism and flatness in one grinding process.

In the present application, the flexural modulus of the abrasive grain layer and the base layer are values measured by a three-point bending test in accordance with JISK 7171:2016, and the flexural modulus of the base metal is in accordance with JISZ 2248:2014.

In addition, it is preferable to include one or more selected from the group consisting of phenol resins, epoxy resins and imide resins as the thermosetting resin of the abrasive grain layer because the processing load during grinding can be suppressed.

In addition, it is preferable to use diamond abrasive grains and/or cubic boron nitride as abrasive grains because the tool life can be extended.

In addition, since the elastic modulus of the abrasive grain layer can be easily adjusted and the grinding performance can be improved, the abrasive grain layer can further include silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and It preferably contains one or more fillers selected from the group consisting of cryolite.

From these, the thermosetting resin contained in the abrasive grain layer contains one or more selected from the group consisting of phenol resin, epoxy resin and imide resin, and the abrasive grains are diamond abrasive grains and / or cubic crystalline boron nitride, the abrasive grain layer further comprising one or more fillers selected from the group consisting of silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite. is preferred.

Further, the thermosetting resin contained in the underlayer preferably contains one or more selected from the group consisting of phenol resin, epoxy resin and imide resin.

Further, since the elastic modulus of the underlayer is easy to adjust, the underlayer is further selected from the group consisting of silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite. It is preferable to contain the above fillers.

For these reasons, the thermosetting resin contained in the underlayer contains one or more selected from the group consisting of phenol resins, epoxy resins, and imide resins, and the underlayer further contains silicon carbide, aluminum, and alumina. , nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite.

Further, it is preferable that the underlayer has a bending elastic modulus of 3 to 14 GPa, and the abrasive grain layer has a bending elastic modulus of 15 to 40 GPa.
By having such a flexural modulus, it is possible to further suppress the workpiece from wobbling and fluttering, and it is possible to perform high-quality machining.

Further, it is preferable that the underlayer has a thickness of 2 to 12 mm. If the base layer is too thin, it will be difficult to obtain the effect of alleviating the roughening and fluttering of the work material during processing. tends to get worse.

It is preferable that a plurality of slits cut into the abrasive grain layer or the underlying layer are formed radially. Such a structure having slits is preferable because it improves dischargeability of chips and reduces the processing load, thereby suppressing defects such as adhesion to the grinding surface.

According to the present invention, in the through-feed type double-sided surface grinding in which both surfaces of the workpiece are simultaneously ground while the workpiece is fed through, swaying and rattling during machining of the workpiece are suppressed, and grinding efficiency is high. A wheel is provided that can obtain a predetermined grinding accuracy of a workpiece in a single grinding operation.

1 is a plan view of a triple structure wheel 100 according to the present invention; FIG. 1 is a front view of a triple structure wheel 100 according to the present invention; FIG. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1; 4 is an enlarged view of the area indicated by arrow B in FIG. 3; FIG. FIG. 4 is a perspective view showing a state of the triple structure wheel 100 during grinding. It is the figure seen from the Z direction of FIG. It is the figure seen from the X direction of FIG. 1 is a plan view of a triple structure wheel 200 according to the present invention; FIG. 1 is a front view of a triple structure wheel 200 according to the present invention; FIG. 10 is an enlarged view of the area indicated by arrow C in FIG. 9. FIG. FIG. 5 is a diagram for explaining the width between the triple structure wheels during testing; FIG. 5 is a diagram showing the result of surface roughness of a work material when the work material is machined;

Embodiments of the present invention will be described in detail below. is not limited to the contents of In addition, when the expression "~" is used in this specification, it is used as an expression including numerical values or physical property values before and after it.

[Embodiment 1]
1 is a plan view of a triple structure wheel 100 according to the present invention, FIG. 2 is a front view, FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 4 is an enlarged view of the area indicated by arrow B in FIG. is. As shown in FIGS. 1 to 4, the triple structure wheel 100 has a base metal 10, a base layer 20 fixed to the upper surface of the base metal 10, and an abrasive grain layer 30 fixed to the base layer 20.

(Base metal 10)
The base metal 10 is disc-shaped and has a mounting hole 12 provided in the center and a ring-shaped protruding portion 14 provided on the outer peripheral side. The base metal 10 is made of a material capable of holding the base layer 20, and is made of metal such as iron or aluminum, for example. As for dimensions, the outer diameter (W ₁ ) is 250 to 950 mm, and the width (W ₂ ) of the protrusion 14 is 30 to 360 mm.

In addition, the base metal 10 has a higher flexural modulus than the base layer 20 and the abrasive grain layer 30 . The bending elastic modulus of the base metal 10 can be 60 to 210 GPa.

(Base layer 20)
The underlying layer 20 is fixed to the upper surface of the projecting portion 14 of the base metal 10 and has a thickness (H ₂ ) of 2 mm to 12 mm. If the base layer 20 is too thin, it will be difficult to obtain the effect of alleviating the roughening and fluttering of the work material during processing. If the base layer 20 is too thick, the amount of deformation of the base layer 20 increases, and the parallelism and flatness of the workpiece tend to deteriorate. Therefore, the thickness (H ₂ ) of the underlying layer 20 is preferably 2 mm or more, and may be 6 mm or more or 8 mm or more. Also, the thickness (H ₂ ) of the underlying layer 20 is preferably 12 mm or less, more preferably 11 mm or less, and even more preferably 10 mm or less.
Moreover, the thickness (H ₂ ) of the underlayer 20 is preferably greater than the thickness (H ₁ ) of the abrasive grain layer 30 .

The base layer 20 has a bending elastic modulus lower than that of the base metal 10 and the abrasive grain layer 30, and is 3 to 14 GPa. If the flexural modulus of the underlying layer 20 is too low, grinding precision such as parallelism and flatness may deteriorate, and variations may increase. Further, if the flexural elasticity of the base layer 20 is too high, it will be difficult to obtain the effect of alleviating the roughness and variation of the work material during processing. Therefore, the flexural modulus of the underlying layer 20 is preferably 14 GPa or less, more preferably 12 GPa or less, and even more preferably 10 GPa or less. Moreover, 3 GPa or more is preferable, and 5 GPa or more is more preferable.

The base layer 20 is a layer containing a thermosetting resin 24 and a filler 26, and the thermosetting resin 24 is 10 to 65% by mass and the filler 26 is 35 to 90% by mass. A desired flexural modulus can be obtained by adjusting the types and ratios of the thermosetting resin 24 and the filler 26 . The bending elastic modulus tends to increase as the proportion of the filler 26 increases, and the bending elastic modulus tends to decrease as the proportion of the thermosetting resin 24 increases. For example, the thermosetting resin 24 in the base layer 20 is 45 to 65% by mass and the filler 26 is 35 to 55% by mass. If it is increased, it is easier to adjust the bending elastic modulus to be lower than that of the abrasive grain layer 30 .

Thermosetting resin 24 includes one or more selected from the group consisting of phenolic resins, epoxy resins and imide resins. Filler 26 is one or more selected from the group consisting of silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite.

(Abrasive grain layer 30)
The abrasive grain layer 30 has a ring shape and is fixed to the base layer 20, and the upper surface in the axial direction constitutes the grinding surface.

The thickness (H ₁ ) of the abrasive grain layer 30 is 1 mm to 10 mm. If the thickness is less than 1 mm, it becomes difficult to manufacture the abrasive grain layer 30 . Further, if the abrasive grain layer 30 is too thick, there may be a problem that the underlayer's effect of alleviating the roughening and fluttering of the work material is reduced. Therefore, the abrasive grain layer 30 is preferably 1 mm or more, and may be 2 mm or more or 3 mm or more. Also, the abrasive grain layer 30 may be 7 mm or less, or 5 mm or less.

The abrasive grain layer 30 has a bending elastic modulus higher than that of the base layer 20 and lower than that of the base metal 10, and is 15 to 40 GPa. If the flexural modulus of the abrasive grain layer 30 is too low, grinding accuracy such as parallelism and flatness deteriorates, and there is a problem of increased variation. Further, if the flexural modulus of the abrasive grain layer 30 is too high, the abrasive grain layer is difficult to deform and difficult to conform to the workpiece. tends to decrease. Therefore, the bending elastic modulus of the abrasive grain layer 30 is preferably 15 GPa or more, more preferably 18 GPa or more. Moreover, the upper limit is preferably 40 GPa or less, more preferably 30 GPa or less, and even more preferably 25 GPa or less.

The abrasive grain layer 30 is a layer containing abrasive grains 32, a thermosetting resin 34, and a filler 36. The abrasive grains 32 are 2 to 95% by mass, and the thermosetting resin 34 is 3 to 80% by mass. Filler 36 is 1 to 90% by mass. By using the thermosetting resin 34 as a binder for the abrasive grains 32 and the filler 36, it is possible to achieve high impact resistance and resistance to breakage. In addition, by including the filler 36, it is possible to adjust to a desired flexural modulus while achieving a desired degree of concentration and the like.

The flexural modulus of the abrasive grain layer 30 can be adjusted by adjusting the types and ratios of the abrasive grains 32 , the thermosetting resin 34 and the filler 36 , similarly to the base layer 20 . The bending elastic modulus tends to increase as the ratio of the abrasive grains 32 and the filler 36 increases, and the bending elastic modulus tends to decrease as the ratio of the thermosetting resin 34 increases. For example, the thermosetting resin 34 in the abrasive grain layer 30 is 5 to 25% by mass, and the total amount of the abrasive grains 32 and fillers 36 is 75 to 95% by mass (the abrasive grains 32 are 35 to 55% by mass, the filler 36 is 20 to 60% by mass), if the total proportion of the abrasive grains 32 and fillers 36 is greater than the proportion of the thermosetting resin 34, the flexural modulus can be easily adjusted to be higher than that of the base layer 20.

Abrasive grains 32 are diamond and/or cubic boron nitride. Abrasive grains 32 are dispersed in a thermosetting resin 34 in the abrasive grain layer 30 . The grain size of the abrasive grains 32 is #60-1000. The concentration of the abrasive grain layer 32 is 25-125. By setting it as such a grain size and concentration degree, it can be made into the grindstone suitable for double-sided surface grinding.

Thermosetting resin 34 includes one or more selected from the group consisting of phenolic resins, epoxy resins and imide resins. Also, the thermosetting resin 34 may be the same as or different from the thermosetting resin 24 .

Filler 36 is one or more selected from the group consisting of silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite.

It should be noted that the abrasive grain layer 30 contains abrasive grains 32 and a thermosetting resin 34 and has a higher flexural modulus than the base layer 20 and a higher flexural modulus than the base metal 10 . may be configured without For example, the filler content in the abrasive grain layer 30 may be 0 to 90 mass %.

The triple-structured wheel 100 is obtained, for example, by integrally forming the base layer 20 on the base metal 10 and the abrasive grain layer 30 on the base layer 20 by hot pressing and directly attaching them. Also, if the thickness of the adhesive is thin (about 50 to 200 μm), the base metal 10 and the base layer 20 and the base layer 20 and the abrasive grain layer 30 may be bonded with the adhesive. If the thickness of the adhesive is sufficiently thin, the same properties as direct attachment can be exhibited.

(Grinding method using triple structure wheel)
The triple-structured wheel 100 is used as a pair, and is used by being attached to the rotating shaft of a double-disc surface grinder. 5 to 7 are diagrams showing the state of grinding with the triple structure wheel 100 attached to a vertical double-disc surface grinder. 5 is a perspective view showing the state of the triple structure wheel 100 during grinding, FIG. 6 is a view seen from the Z direction in FIG. 5, and FIG. 7 is a view seen from the X direction in FIG.

As shown in FIGS. 5 to 7, a pair of triple structure wheels 100, 100 are mounted on a pair of vertical rotation shafts (not shown) of a vertical double-disc surface grinder so that the grinding surfaces 40, 40 face each other. The work 50 is ground by passing the work 50 (workpiece) between the rotating triple structure wheels 100, 100. A plurality of workpieces 50 are held on the outer peripheral side of a disc-shaped carrier 52 at predetermined intervals in the circumferential direction. supplied to A workpiece 50 supplied between the triple-structured wheels 100, 100 is ground by approaching the grinding surfaces 40, 40 of the wheels with its front and back sides. At this time, the triple-structured wheels 100, 100 are arranged with an inclination angle θ, and the width of the grinding surfaces 40, 40 is widened at the inlet 42 of the workpiece 50 and narrowed at the outlet 44 of the workpiece 50. .

[Embodiment 2]
8 to 10 are schematic diagrams showing another embodiment of the triple structure wheel according to the present invention. 8 is a plan view of a triple structure wheel 200 according to the present invention, FIG. 9 is a front view, and FIG. 10 is an enlarged view of the area indicated by arrow C in FIG.

The triple-structured wheel 200 has a base metal 10, a base layer 20 fixed to the upper surface of the protruding portion 14 of the base metal 10, and an abrasive layer 30a fixed to the base layer. The base metal 10 and the base layer 20 are the same as the triple structure wheel 100 .

The abrasive grain layer 30a is a layer containing abrasive grains 32, a thermosetting resin 34, and a filler 36, and has a plurality of slits 38 radially formed therein. The types and proportions of the abrasive grains 32 , the thermosetting resin 34 and the filler 36 , and the bending elastic modulus and thickness of the abrasive grain layer 30 a are the same as those of the abrasive grain layer 30 .
Although the shape of the slit 38 is U-shaped, it is not limited thereto, and may be any shape such as a V-shape or a U-shape. Also, although the abrasive grain layer 30a has eight slits 38, the number of slits is arbitrary. Although it can be appropriately designed according to the size of the wheel and the like, it is preferable to have 3 to 48 (eg, 3 to 16) in consideration of grinding efficiency and the like.

The slit 38 is formed by cutting to a predetermined depth in the axial direction. The depth (d) of the slit 38 is 1 to 10 mm and can be arbitrarily adjusted, but from the viewpoint of improving the discharge of chips and reducing the processing load, it is preferable to make it equal to or greater than the thickness of the abrasive grain layer 30a. . The slits 38 may be cut into the base layer 20 to a predetermined depth in the axial direction, but are preferably less than the total thickness of the abrasive grain layer 30a and the base layer 20 . The width (L) of the slit 38 is 1-3 mm.

The triple-structured wheels 100 and 200 for double-sided surface grinding described above are examples of the triple-structured wheel according to the present invention, and the triple-structured wheel according to the present invention is the triple-structured wheel 100 described above. , 200.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless the gist thereof is changed.

[Example]
A grinding test was conducted using a triple structure wheel having the structure shown in FIGS. The structures of the abrasive grain layer, underlayer and base metal are as follows.
Abrasive grain layer: cubic boron nitride abrasive grains (#120), concentration 75, abrasive grains 46% by mass, phenolic resin 14% by mass, filler 40% by mass, bending elastic modulus 18GPa
・ Underlying layer: 53% by mass of phenolic resin, 47% by mass of filler, bending elastic modulus of 8GPa
・Base metal: made of aluminum, bending elastic modulus 70 GPa

As shown in Fig. 11, the width between the triple structure wheels was adjusted at the entrance side and the exit side of the carrier. Roughness was compared.

[Comparative example]
The amount of cut material removed and the surface roughness when the work material was machined were compared in the same manner as in the example except that no underlayer was provided.

Table 2 shows the results of the amount of cut material removed when the work material was machined. Further, FIG. 12 shows the results of the surface roughness of the work material when the work material was machined. The surface roughness was evaluated using a stylus-type surface roughness tester according to JISB 0633:2001.

As shown in Table 2 and FIG. 12, the wheel provided with the base layer had an increased machining allowance of the work material and improved surface roughness. In other words, it was confirmed that the base layer alleviates fluttering when grinding the work material and increases the machining allowance. Moreover, as the thickness of the base layer increases, the machining allowance of the work material increases. This is because as the volume of the underlayer increases, the effect of alleviating fluttering of the work material becomes more pronounced. Also, when the thickness of the underlayer was less than 2 mm, only the abrasive grain layer was equivalent to the removal amount. Therefore, it was confirmed that the thickness of the underlayer is preferably 2 mm or more.

INDUSTRIAL APPLICABILITY The triple-structured wheel according to the present invention can be widely used in industrial fields in which machining is performed by double-sided surface grinding.

REFERENCE SIGNS LIST 10 Base metal 12 Mounting hole 14 Protrusion 20 Base layer 24, 34 Thermosetting resin 26, 36 Filler 30, 30a Abrasive layer 32 Abrasive grain 38 Slit 40 Grinding surface 42 Entrance 44 Exit 50 Work 52 Carrier 100, 200 Triple structure wheel

Claims (6)

A triple structure wheel for use in double-sided surface grinding for simultaneously surface-grinding both surfaces of a workpiece by a through-feed method,
platform and
a base layer containing a thermosetting resin and fixed to the upper surface of the base metal;
an abrasive grain layer containing abrasive grains and a thermosetting resin and fixed to the underlayer;
A triple structure wheel for double-sided surface grinding, wherein the flexural modulus of the abrasive grain layer is higher than that of the base layer and lower than that of the base metal. The thermosetting resin contained in the abrasive layer contains one or more selected from the group consisting of phenol resins, epoxy resins and imide resins,
The abrasive grains are diamond abrasive grains and / or cubic boron nitride,
2. The abrasive layer of claim 1, further comprising one or more fillers selected from the group consisting of silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite. Triple structure wheel. The thermosetting resin contained in the underlayer contains one or more selected from the group consisting of phenol resins, epoxy resins and imide resins,
3. The underlayer according to claim 1 or 2, further comprising one or more fillers selected from the group consisting of silicon carbide, aluminum, alumina, nickel, copper, chromium oxide, graphite, molybdenum disulfide and cryolite. 3-layer structure wheel. The flexural modulus of the underlayer is 3 to 14 GPa,
The triple structure wheel according to any one of claims 1 to 3, wherein the abrasive grain layer has a flexural modulus of 15 to 40 GPa. The triple structure wheel according to any one of claims 1 to 4, wherein the underlayer has a thickness of 2 to 12 mm. 6. The triple structure wheel according to any one of claims 1 to 5, wherein a plurality of slits cut into said abrasive grain layer or to said abrasive grain layer are formed radially.

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