JP2000233370A - Grinding method for electrodeposition grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding method for electrodeposition grinding wheel enabling precise grinding and prolonging service life of the grinding wheel. SOLUTION: Since projection amounts of SBN abrasive grains are aligned prior to grinding 42 in an initial trueing process 40, precise grinding realizing satisfactory degree of surface roughness of a material to be ground can be done using an electrodeposition grinding wheel in a grinding process 42, Moreover, when a surface roughness of the material to be ground reaches an upper limit value set in advance, retrueing for improving surface roughness of the material to be ground is applied again on a grinding face of the electrodeposition grinding wheel in retrueing processes 44, 48, thereby prolonging service life of precise grinding of the electrodeposition grinding wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for grinding an electrodeposited grindstone for grinding using an electrodeposited grindstone having superabrasive grains fixed on a base metal in a state of one abrasive layer by electroplating. Things.

[0002]

2. Description of the Related Art Electrodeposited grindstones in which superabrasive grains such as CBN abrasive grains or diamond abrasive grains are fixed on a base metal in a single abrasive layer state by electroplating are known. Such electrodeposited whetstones are usually grown so that the plating metal deposited on the base metal fills the gaps between the superabrasive grains and the plated metal firmly grips the superabrasive grains. In the electrodeposited grinding wheel constructed in this way, the super-abrasive grains are fixed in an ideal state with their tips sufficiently exposed, so that dressing is unnecessary and sharp grinding wheels are used, such as high-efficiency grinding and rough grinding. It is frequently used in

[0003]

However, in the above-mentioned electrodeposited whetstone, the amount of protrusion of the superabrasive grains is not uniform due to variations in the attitude and diameter of the superabrasive grains, and the thickness of the superabrasive grain layer is not more than 1 mm. Since it is in the state of the abrasive layer, it cannot be used in the field of precision grinding because the surface roughness of the work material cannot be obtained, and when the surface roughness of the work material exceeds the reference value, In order to limit the use of the electrodeposited grinding wheel, there is a drawback that the life is shorter than other types of grinding wheels.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of grinding an electrodeposited grinding wheel, which can perform precision grinding and extend the life of the grinding wheel. It is in.

[0005]

The inventors of the present invention have conducted various studies in order to eliminate the drawbacks of the above-mentioned electrodeposition grindstone. As a result, prior to grinding, a predetermined amount of the superabrasive grains was adjusted so as to be uniform. It is possible to apply truing to the electrodeposited whetstone with a depth of cut of not less than that the surface roughness of the work material at the precision grinding level can be sufficiently obtained. If the surface roughness of the work material exceeds a predetermined upper limit, truing of the above-mentioned minute depth of cut can be performed to reduce the surface roughness of the work material to the precision grinding level. Found that the grinding obtained in the above can be continued again. The present invention has been made based on such findings.

That is, the gist of the method of the present invention is to provide an electrodeposited grinding wheel for grinding using an electrodeposited grinding wheel in which superabrasive grains are fixed on a base metal in a single abrasive layer state by electroplating. Grinding method, (a) by performing truing at a predetermined cutting amount on the electrodeposited whetstone, an initial truing step of creating a cutting edge by aligning the protruding amount of the superabrasive grains prior to grinding processing And (b) a grinding step of grinding the work material using an electrodeposited whetstone in which the protruding amount of the superabrasive grains is aligned by the initial truing step, and (c) the grinding of the work material by performing the grinding step. When the surface roughness reaches a preset upper limit, a re-truing step of re-truing the ground surface of the electrodeposited whetstone to create a cutting edge to improve the surface roughness, and (d) ) Truing by the retruing process And a re-grinding step of grinding the workpiece again using the electrodeposited whetstone to which the grinding has been performed.

[0007]

According to the present invention, the amount of protrusion of the superabrasive grains is uniformed by the initial truing step prior to the grinding processing, so that the precision grinding processing with good surface roughness of the work material is performed in the grinding step. It can be performed using an electrodeposition whetstone. Further, when the surface roughness of the work material reaches a preset upper limit, truing for improving the surface roughness of the work material is performed by a re-truing step, so that the ground surface of the electrodeposited grinding wheel is improved. Again, the life of precision grinding of the electrodeposited whetstone is extended.

[0008]

In another embodiment of the present invention, preferably, the cut amount in the re-truing step is set in advance so that the surface roughness of the work material falls sufficiently below a predetermined upper limit. It is set to a very small value, for example, 10 μm or less, preferably about 3 to 4 μm. In this way, the truing with a small cutting amount (micro truing) adjusts the shape of the ground surface so that the surface roughness of the work material is improved, and regenerates the cutting edge of the superabrasive. Is necessary and sufficient, so that the number of regrinds can be increased as much as possible.

Preferably, in the re-grinding step, when a power consumption value for rotationally driving the electrodeposited grinding wheel exceeds a predetermined value, the re-grinding by the electrodeposited grinding wheel is terminated. is there. In this way, even if the grinding surface shape is adjusted by re-truing and the cutting edge of the superabrasive is regenerated, the protruding amount of the superabrasive becomes a predetermined value, for example, 30 μm or less, and the electrodeposited whetstone is removed. Re-grinding is terminated when the power consumption for rotating drive increases,
Grinding burn and the like are suitably prevented.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an electrodeposition grindstone 10 used in one application example of the present invention. This electrodeposited whetstone 10
A metal-made base metal 12 having a disc shape, and a grinding surface 16 on the outer peripheral surface of which a CBN abrasive grain 14 having a particle size of, for example, about 80 is fixed by electrodeposition with a thickness of one particle layer. It has.

FIG. 2 shows a manufacturing process of the electrodeposition grindstone 10. First, in the masking step 20, the other surface, that is, the non-electrodeposited surface, of the surface of the base metal 12 except the surface functioning as a ground surface is masked using a masking material such as a masking coating agent or a masking adhesive. . Next, in a first nickel plating step 22,
In the plating solution in which the CBN abrasive grains 14 are dispersed, a first nickel plating layer 24 is formed on an unmasked portion of the surface of the base metal 12. FIG.
(A) of this figure shows this state. Next, the cleaning step 26
In FIG. 3, the CBN abrasive grains 14 on the base metal 12 which are not fixed by the first nickel plating layer 24,
(A) is removed by washing. Then, in a second nickel plating step 28, a second nickel plating layer 30 is formed so as to overlap the first nickel plating layer 24, and the first nickel plating layer 24 is formed.
And the total thickness of the second nickel plating layer 30 is a value enough to fix the CBN abrasive grains 14, for example, the CBN abrasive grains 14
Is approximately 1/2 of the particle size of FIG. 3B shows this state. Then, in the masking removing step 32, the masking is removed.

The electrodeposited whetstone 10 as manufactured as described above has a large projection amount of the CBN abrasive grains 14 as shown in FIG. 3 (b) or FIG. 5 (a).
Since the abrasive grains 14 are firmly fixed in an ideal state with their tips sufficiently exposed, they are frequently used for high-efficiency grinding, rough grinding, and the like as sharp grinding wheels without dressing.
However, the amount of protrusion of the CBN abrasive grains 14 is not uniform due to variations in the posture and diameter of the CBN abrasive grains 14, and the thickness of the abrasive grain layer composed of the CBN abrasive grains 14 is in one abrasive grain layer state. Conventionally, it cannot be used in the field of precision grinding in which the surface roughness of the work material is required, and when the surface roughness of the work material exceeds the reference value, the
Has a drawback that its service life is shorter than other types of grinding wheels.

FIG. 4 shows a high peripheral speed of 200 m / s and a high grinding efficiency of 300 mm ³ / mm · s, and the electrodeposition grinding wheel 10 can be used for precision grinding and the life of the grinding wheel is prolonged. It is a figure explaining a grinding method. In FIG. 4, in the initial truing step 40, the amount of protrusion of the CBN abrasive grains 14 is made substantially constant prior to the grinding process by truing the electrodeposited grindstone 10 at a predetermined cutting amount using, for example, a diamond rotary dresser. Aligned. The amount of cut in the initial truing step 40 is, for example, 2 μm of the surface roughness Ry of the workpiece in the grinding step 42.
m or less. FIG. 5A shows a state before the initial truing step 40 is performed.
(b) shows a state after the initial truing step 40 has been performed.

In the grinding step 42, a workpiece (not shown) is ground by using the electrodeposited grindstone 10 in which the amount of protrusion of the CBN abrasive grains 14 is made substantially constant in the initial truing step 40. Since the protruding amounts of the CBN abrasive grains 14 are made substantially constant, precision grinding is performed, for example, in which the surface roughness Ry (= maximum value Rmax) of the work material is 3.0 μm or less.

When the surface roughness Ry of a plurality of workpieces reaches a preset upper limit value, for example, 3.0 μm by performing precision grinding on a plurality of workpieces in the above-described grinding step 42, In one retruing step 44, retruing is performed again on the ground surface 16 of the electrodeposition grindstone 10 in order to improve the surface roughness Ry of the work material again. The truing in the re-truing step 44 is a so-called micro truing with a minute cut amount of about 3 to 4 μm. This first retruing step 44
Is set to the upper limit value of the preset grinding process, for example, 3 μm.
Is set in advance to a value sufficiently lower than, for example, 2 μm.

In the subsequent first re-grinding step 46, the work material is formed using the electrodeposited whetstone 10 trued by the first re-truing step 44, as in the grinding step 42.
It is precision ground again. In addition, when the surface roughness Ry of the work material reaches a preset upper limit value, for example, 3.0 μm by performing the precision grinding process on the plurality of work materials in the first re-grinding step 46, In the second re-truing step 48, as in the first re-truing step 44, in order to improve the surface roughness Ry of the work material again, a minute cut of about 3 to 4 μm is made in the ground surface 16 of the electrodeposition grindstone 10. A quantity of so-called microtruing is applied.
FIG. 5C shows this state.

In the second re-grinding step 50, a plurality of the electrodeposited whetstones 10 having been subjected to the truing by the second re-truing step 48 are used, similarly to the grinding step 42 or the first re-grinding step 46. Is precisely ground again. In the second re-grinding process 50, the power consumption value KW / mm for rotating and driving the electrodeposition grindstone 10 is described.
Exceeds a preset value, the regrinding by the electrodeposition grindstone 10 is terminated. In such a case, usually, the protrusion amount B of the CBN abrasive grains 14 is 30 μm.
m or less.

Incidentally, an electrodeposited whetstone (CB80PA5: 380 × 15 × 80 ×
U9), truing was performed in the initial truing step 40 under the following truing conditions so that the surface roughness Ry of the work material was 2 μm, and the surface roughness R of the work material was obtained.
FIGS. 6 to 9 show the results of re-truing to 3 μm when y becomes 3 μm and high-speed precision grinding under the following grinding conditions.

[0020]

[Trueing conditions]

 Truer: SD40Q75M (110φ × U1) Lead: 0.1mm / r.o.w. Cutting depth: 4μmφ / pass

[0021]

[Grinding conditions]

Electroplated whetstone: CB80PA5: 380 × 15 × 80 × U9 Work material: SCM435 (HRC48) (60φ × 5
t) Grinding method: wet cylindrical plunge grinding Circumferential speed of electrodeposited grindstone: 200 m / s Workpiece speed: 2 m / s (V / v = 100) Grinding efficiency: 300 mm ³ / mm · s Spark out: 20 rev. Grinding oil: Soluble type (× 50), (Use high pressure pump)

FIG. 6 and FIG. 7 show that after the initial truing, if the surface roughness Ry of the work material becomes 3 μm, re-truing is performed three times so that the surface roughness Ry becomes 2 μm, so that grinding per wheel unit length is performed. Cumulative cross-sectional area is 67mm ²
2 shows a change in the surface roughness Ry and a change in the power consumption value (KW / mm) when the surface is processed to a value of / mm. FIG.
As is clear from FIG. 7, the re-truing allows the finished surface roughness Ry of the work material to be controlled. In addition, every time the retruing is performed, the increase in the surface roughness Ry becomes gentle, and the dressing interval is lengthened. Further, the power consumption value increases each time re-truing is performed.

FIG. 8 shows the projection of the CBN abrasive grains after each truing when continuous machining is performed until the grinding allowance cross-sectional area per wheel unit length becomes from 3.2 mm ² / mm to 6.4 mm ² / mm. The relationship between the amount (μm), the power consumption value (KW / mm) and the truing rate (%) is shown. As the number of truing increases and the protrusion amount B of the CBN abrasive decreases, the power consumption value increases. Further, the rate of increase increases with an increase in the number of truings. Further, the truing rate is opposite to the power consumption, and decreases with a decrease in the protrusion amount B of the CBN abrasive grains. FIG. 9 shows the workpiece residual stress (MPa) when grinding is performed until the grinding allowance cross-sectional area per wheel unit length becomes 0.64 mm ² / mm after each truing. On the work material surface, 2
The compression stress is in the range of 00 to 400 MPa, and almost no tensile stress is found inside. However, as the number of retruing increases and the amount of protrusion B of the CBN abrasive grains decreases, the compressive stress on the surface of the work material decreases. FIG. 8 above
As is clear from FIG. 9, by performing the re-truing, all the residual stresses of the work material become the compressive stress until the protrusion amount B of the CBN abrasive grains becomes 30 μm, and high-quality precision grinding can be performed.

As described above, according to the present embodiment, in the initial truing step 40, the S
Since the protrusion amount B of the BN abrasive grains 14 is uniform, the grinding process 4
In 2, precision grinding with good surface roughness of the work material can be performed using the electrodeposition grindstone 10. When the surface roughness of the work material reaches a predetermined upper limit, the re-truing steps 44 and 48 perform the re-truing for improving the surface roughness of the work material by the electrodeposition. Since the grinding is performed again on the grinding surface 16 of the grindstone 10, the life of the precision grinding of the electrodeposited grindstone 10 is extended.

Further, according to the present embodiment, the cutting amounts of the retruing steps 44 and 48 are set in advance so that the surface roughness Ry of the work material falls sufficiently below a predetermined upper limit. Very small value, for example, 10 μm or less, preferably 3 to 4
μm, the ground surface shape is adjusted so that the surface roughness Ry of the work material is improved (small) by truing (micro truing) with a minute cutting amount, and the CBN abrasive grains 14 are formed. Since the cutting depth is set to be a necessary and sufficient amount for regenerating the cutting edge, the number of regrinds can be increased as much as possible.

According to the present embodiment, the re-grinding step 4
6, 50, when the power consumption value (KW / mm) for rotationally driving the electrodeposition grindstone 10 exceeds a preset value, re-grinding by the electrodeposition grindstone 10 is terminated. Even if the grinding surface shape is adjusted by re-truing and the cutting edge of the CBN abrasive grains 14 is regenerated,
The protrusion amount B of the CBN abrasive grains 14 is a predetermined value, for example, 30 μm.
m or less, and when the power consumption for rotationally driving the electrodeposition grindstone 10 becomes high, the re-grinding is terminated.

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, the electrodeposition grindstone 10 of the above-described embodiment is used.
Has a grinding surface 16 on which CBN abrasive grains 14 are electrodeposited, but diamond abrasive grains may be electrodeposited on the grinding surface 16.

The electrodeposited grinding wheel 10 of the above-described embodiment is formed in a disk shape with a cylindrical grinding surface 16 as shown in FIG. It may be configured in a complicated shape such as

In the above-described grinding method shown in FIG. 4, two re-truings are performed in the first re-truing step 44 and the second re-truing step 48. Good, or three or more retruings may be performed.

In the first re-truing step 44 and the second re-truing step 48 in FIG. 4, a rotary dresser is used for re-truing. However, there is no problem in the holding force of the CBN abrasive grains 14. Other types of dressers, such as blade type, may be used.

The above description is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an electrodeposition grindstone used in a grinding method according to one embodiment of the present invention.

FIG. 2 is a process chart illustrating an example of a process for manufacturing the electrodeposited whetstone of FIG.

3A and 3B are diagrams illustrating a process of manufacturing the electrodeposited whetstone of FIG. 2, wherein FIG. 3A shows a fixed state of CBN abrasive grains after a first nickel plating step, and FIG. This shows a state in which the CBN abrasive grains are fixed later.

FIG. 4 is a process diagram illustrating a grinding method using the electrodeposition grindstone of FIG. 1;

5A and 5B are diagrams illustrating a state of a ground surface of an electrodeposited grindstone in the grinding method of FIG. 4, wherein FIG. 5A shows a state before an initial truing step, and FIG. 5B shows a state after a first retruing step. (C) shows the state after the second re-truing step.

FIG. 6 is a view showing a grinding test result using the electrodeposited whetstone of FIG. 1, and shows a surface roughness R of a work material after initial truing.
When re-truing is performed three times so that y becomes 3 μm when it becomes 3 μm, the surface roughness Ry of the surface roughness Ry when processed until the grinding allowance cross-sectional area per wheel unit length becomes 67 mm ² / mm cumulatively. The change is shown.

FIG. 7 is a view showing a grinding test result using the electrodeposition whetstone of FIG. 1, and shows a surface roughness R of a work material after initial truing.
When re-truing is performed three times so that y becomes 3 μm when it becomes 3 μm, the power consumption value (KW) when processing is performed until the cumulative grinding allowance cross-sectional area per wheel unit length becomes 67 mm ² / mm. / Mm).

FIG. 8 is a view showing a grinding test result using the electrodeposited grinding wheel of FIG. 1 until the grinding allowance cross-sectional area per wheel unit length becomes from 3.2 mm ² / mm to 6.4 mm ² / mm. The graph shows the relationship between the power consumption value (KW / mm) and the truing rate (%) with respect to the protrusion amount (μm) of the CBN abrasive grains after each truing when performing continuous processing.

9 is a view showing a grinding test result using the electrodeposited whetstone of FIG. 1, in the case where grinding is performed until the grinding allowance cross-sectional area per wheel unit length becomes 0.64 mm ² / mm after each truing. It shows the residual stress (MPa) of the work material.

[Explanation of symbols]

 10: Electroplated whetstone 12: Base metal 14: CBN abrasive (super abrasive) 16: Ground surface 40: Initial truing process 42: Grinding process 44: First re-truing process (Re-truing process) 46: First re-grinding Process (re-grinding process) 48: Second re-truing process (re-truing process) 50: Second re-grinding process (re-grinding process)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tatsuya Ito 3-136 Noritake Shinmachi, Nishi-ku, Nagoya City, Aichi Prefecture Inside Noritake Company Limited (72) Inventor Shinjiro Sakuragi 3-1-1 Noritake Shinmachi, Nishi-ku, Nagoya City, Aichi Prefecture No. 36 Noritake Co., Ltd. F-term (reference) 3C047 AA05 AA08 AA13 3C063 AA02 AB03 BB02 BB24 CC13 CC30 FF20

Claims (3)

[Claims] 1. A method for grinding an electrodeposited grindstone for grinding using an electrodeposited grindstone in which superabrasive grains are fixed on a base metal in a state of one abrasive grain layer by electroplating, By performing truing on the grindstone at a predetermined cutting amount, an initial truing step of creating a cutting edge by aligning the protruding amount of the superabrasive grains prior to grinding, and projecting the superabrasive grains by the initial truing step A grinding step of grinding the work material using an electrodeposited grinding wheel, wherein the surface roughness of the work material reaches a preset upper limit value by performing the grinding step; A re-truing step of again applying truing to the ground surface of the electrodeposited grindstone to improve cutting performance to create a cutting edge, and using the electrodeposited grindstone subjected to truing by the re-truing step, the work material is removed. Regrind to grind again And the extent,
A method for grinding an electrodeposited whetstone, comprising: 2. The electrodeposition method according to claim 1, wherein the depth of cut in the re-truing step is a value set in advance so that the surface roughness of the work material falls sufficiently below a preset upper limit value. Grinding stone grinding method. 3. The re-grinding step is to terminate the re-grinding with the electrodeposited grindstone when a power consumption value for rotationally driving the electrodeposited grindstone exceeds a preset value. Or the grinding method of the electrodeposition whetstone of 2.