JP2008155347A - Truing tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a truing tool capable of improving its useful life without losing sharpness. <P>SOLUTION: An abrasive particle layer 22 formed by binding abrasive particles 21 by electrodeposition is backed by a metal thinner than the abrasive particle layer 22 and integral with a cylindrical metal base. The abrasive particle layer 22 consists of a lower layer 24 fixed on the surface of a backing layer 40 by a plating layer 23 with the thickness of between or equal to 20% and 30% of the diameter of the abrasive particles, and an upper layer 26 fixed on the surface of the lower layer 24 and formed by separating out a plating layer 25 with the thickness of between or equal to 80% and 120% of the diameter of the abrasive particles 21 and protruding the abrasive particles 21 from the abrasive particles 21 of the lower layer 24. The abrasive particles 21 of the upper layer 26 are arranged in clearances between those of the lower layer 24. The total thickness of the two plating layers 23, 25 is 100 to 150% of the diameter of the abrasive particles 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a truing tool used as a truer when truing a superabrasive wheel using cBN, diamond or the like.

  If the grinding wheel is continuously used, eccentricity, shape collapse, clogging, etc. occur, and sufficient grinding performance cannot be obtained. In such a case, truing is performed and the grinding wheel surface is corrected. A cup-type truing tool is often used for truing an internal grinding wheel.

  Such cup-type truing tools have various structures, and an example thereof is described in Patent Document 1. Patent Document 1 describes a cup-type grinding tool that includes a cylindrical grinding portion at one end of a columnar base metal, and grinds using the tip surface of the cylindrical grinding portion, the cylindrical grinding tool The part is composed of a grindstone structure in which the abrasive grains are bonded by a metal binder, which is thinner than the grindstone structure and lined with a metal that is integral with the cylindrical base metal.

This configuration is shown in FIGS. FIG. 10 shows an example in which abrasive grains are arranged in one layer, and FIG. 11 shows an example in which abrasive grains are arranged in two layers. In any case, a cylindrical base metal 51 and a cup-shaped or cylindrical truing part 52 which is fixed to one end portion of the cylindrical base metal 51 and is open at one end are provided.
In the truing part 52 which is a cylindrical grinding part of a tool described in Patent Document 1, an abrasive grain layer 54 in which an abrasive grain 53 is bonded by a metal binder is lined by a thin metal backing layer 40 and has a thickness. Is thin, so the sharpness is good, and even if the abrasive grains on the tip surface are consumed or dropped, the lower abrasive grains appear on the tip surface, so the tool life is longer than that of conventional tools. It is supposed to be obtained.

  However, when the abrasive grains in the cylindrical grinding portion of the cup-type grinding tool described in Patent Document 1 have a single layer structure, as shown in FIG. 12, the number of abrasive grains 53 that appear on the tip surface is small. Depending on the specifications of the truing wheel and the truing conditions, the abrasive grains are consumed and dropped quickly, and the life of the truing machine is shortened. In addition, as shown in FIG. 13, in the case where the abrasive grains 53 are fixed to the first abrasive grain layer 55 and the second abrasive grain layer 56 in two layers, the tip surface is thick and the contact area is large. And the number of abrasive grains appearing on the tip surface is large, so that the truing resistance is large, and the fine-shaft grindstone or the like is bent due to the resistance, so that there is a drawback that the truing cannot be accurately performed.

  Patent Document 2 describes a cup-type truer in which abrasive grains are arranged randomly or in a streak shape. However, since this truer also has a single-layer structure, the number of diamond abrasive grains appearing on the tip surface is small as in the case where the abrasive grains of the cylindrical grinding portion of the cup-type grinding tool described in Patent Document 1 are one layer. Depending on the specification of the truing wheel and the truing conditions, there is a problem that the abrasive grains are consumed and dropped quickly, and the life as a truing machine is shortened.

Japanese Patent No. 3449379 Japanese Patent No. 3020443

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a truing tool capable of improving the life without impairing sharpness.

  In order to solve the above-described problems, a truing tool of the present invention includes a cylindrical truing portion fixed to one end portion of a columnar base metal and having an open end, and the tip surface of the cylindrical truing portion is used. A truing tool for performing truing, wherein the cylindrical truing portion is a metal in which an abrasive grain layer formed by bonding abrasive grains by electrodeposition is thinner than the abrasive grain layer and is integral with the cylindrical base metal The abrasive layer is composed of a lower layer in which the abrasive grains are fixed to the surface of the backing layer by a plating layer having a thickness of 20% to 30% of the grain size of the abrasive grains, The upper layer is composed of an upper layer formed by depositing a plating layer having a thickness of 80% or more and 120% or less of the grain size of the abrasive grains on the surface, and the abrasive grains projecting from and fixed to the lower abrasive grains. The grains are placed in the gaps between the underlying abrasive grains and plated Wherein the total thickness is less than 150% to 100% more than the particle size of the abrasive grains.

  With the above configuration, the number of abrasive grains is increased as compared with the one-layer structure and the number of abrasive grains is significantly increased as compared with the two-layer structure. Therefore, the thickness of the tip end face is not significantly increased, so that the service life can be improved without impairing the sharpness.

When the thickness of the lower plating layer is less than 20% of the grain size of the abrasive grains, the lower abrasive grains tend to be unable to be stably fixed. If it exceeds 30%, the fixing position of the upper abrasive grains protrudes upward in the thickness direction of the abrasive grain layer, and the thickness of the abrasive grain layer is substantially increased. This is not preferable because it increases and impairs sharpness.
Further, the thickness of the upper plating layer is preferably 80% or more and 120% or less of the grain size of the abrasive grains in terms of the holding power of the abrasive grains, and if it is less than 80%, the abrasive grain holding power of the upper abrasive grains is weak. It is not preferable because the upper layer abrasive grains easily fall off during truing. On the other hand, if it exceeds 120%, the thickness of the abrasive layer becomes thick, and the contact area of the tip surface becomes large during truing, which is not preferable.
The reason why the total thickness of the plating layer is 100% or more and 150% or less of the grain size of the abrasive grains is that this numerical range is the sum of the lower plating layer thickness and the upper plating layer thickness described above. is there.

The present invention is characterized in that the plated layer contains fine hard particles composed of any one of diamond, cBN, SiC, Si ₃ N ₄ , and Al ₂ O ₃ and having an average particle diameter of 20 μm or less. To do.
By containing the fine hard particles in the plating layer, it is possible to suppress the wear of the plated metal due to the grinding wheel chips generated during truing, so that the abrasive retention force is improved and the life of the truing tool is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the cup type truing tool which can improve a lifetime without impairing sharpness is realizable.

Below, the truing tool of this invention is demonstrated based on the embodiment.
FIG. 1 is a cross-sectional view showing the structure of a truing tool according to an embodiment of the present invention.
The truing tool 10 includes a columnar base 11 and a cup-shaped or cylindrical truing portion 12 fixed to one end of the columnar base 11 and having one end opened. In this truing tool 10, truing is performed using the tip surface 13 of the cylindrical truing portion 12. The dimensions of the truing tool 10 are such that the outer diameter of the cylindrical truing portion 12 is φ15 mm, the width of the cylindrical truing portion 12 in the longitudinal direction of the base metal is 10 mm, and the thickness of the tip surface 13 is about 0.725 mm.

FIG. 2 shows the details of the abrasive layer of the truing tool 10.
In FIG. 2, a cylindrical truing portion 12 includes an abrasive layer 22 formed by bonding abrasive grains 21 by electrodeposition, and a backing made of a metal that is thinner than the abrasive grain layer 22 and is integrated with the cylindrical base metal 11. Formed by layer 40. The abrasive grain layer 22 includes a lower layer 24 in which the abrasive grains 21 are fixed to the surface of the backing layer 40 by a plating layer 23 having a thickness of 20% to 30% of the grain size of the abrasive grains 21, and a surface of the lower layer 24. The upper layer 26 is formed by depositing a plating layer 25 having a thickness of 80% or more and 120% or less of the grain size of the abrasive grains 21 so that the abrasive grains 21 protrude from the abrasive grains 21 of the lower layer 24 and are fixed. Yes. The abrasive grains 21 of the upper layer 26 are disposed in the gaps between the abrasive grains 21 of the lower layer 24, and the total thickness of the two plating layers 23 and 25 is 100% or more and 150% or less of the grain size of the abrasive grains 21.

  The truing tool of the present invention is manufactured according to the process shown in FIG. In the base metal preparation step 31, a base metal formed in a cylindrical shape from a metal material such as tool steel is prepared. At this time, the outer diameter of the portion to become the cylindrical truing portion 12 is a dimension obtained by subtracting the thickness of the abrasive layer, that is, (0.625 mm × 2 (both sides)) from the outer diameter dimension (φ15 mm) of the final product. (Φ13.75 mm). The inner diameter is set to a size that is easy to handle in the subsequent process. In the present embodiment, the thickness of one side of the base metal of the portion that becomes the cylindrical truing portion 12 is set to about 1 mm, and the inner diameter dimension is about φ11.75 mm. These dimensions are as shown in FIG. In the electrodeposition process 32, the mask is carried out except for the part where the abrasive grains are fixed to the base metal in advance, and the diamond abrasive grains are applied to the surface where the mask is not covered (the outer peripheral surface of the part that becomes the cylindrical truing portion 12). The lower abrasive layer is formed by fixing with a nickel-plated metal having a thickness of 25% of the grain size of the diamond abrasive grains deposited by the electrodeposition method.

  On top of this lower abrasive layer, the upper diamond abrasive grains are arranged so as to fill the gaps between the lower diamond abrasive grains, and the upper abrasive layer is made of nickel-plated metal having a thickness of 100% of the abrasive grain size. Form. Thereafter, the base metal inner peripheral portion is deleted in a base metal inner peripheral portion deleting step 33.

Specific examples will be shown below.
Example 1
In Example 1, the base metal having the above-described dimensions is masked except for the portion where the abrasive grains are fixed (the outer peripheral surface of the portion that becomes the cylindrical truing portion 12), and the average particle size is 500 μm as the abrasive grains. Prepare diamond abrasive grains, put base metal and abrasive grains in the electrodeposition apparatus containing plating solution, flow 0.25 A / dm ² current for 15 hours, and temporarily fix diamond abrasive grains in the lower layer with 50 μm plated metal did. Thereafter, excess diamond abrasive grains are removed, and a current of 3.0 A / dm ² is supplied again for 1.25 Hr to deposit a total of about 125 μm (25% of the grain diameter) of nickel plated metal. An abrasive layer was formed. Then, diamond abrasive grains were again sprayed on the lower layer, a current of 0.25 A / dm ² was flowed for 5 hours to deposit a 50 μm plated metal, and the upper layer diamond abrasive grains were temporarily fixed. Thereafter, excess diamond abrasive grains are removed, and a current of 3.0 A / dm ² is applied again for 4.2 hours to deposit a total of 500 μm (100% of the abrasive grain diameter) plating metal to form an upper abrasive grain. A layer was formed.

  In the base metal inner peripheral portion deleting step 33, after removing the mask applied in the previous step, the inner peripheral portion of the base metal to be the cylindrical truing portion 12 is deleted by cutting, and the base metal of this portion is removed. The backing layer 40 was formed with a thickness on one side of 0.1 mm. The thickness of the backing layer 40 is desirably such that the rigidity of the cylindrical truing portion 12 can be sufficiently obtained, and is thinner than the abrasive grain layer thickness in order to suppress the contact area in the processing of the tip surface.

Example 2
In this example 2, a truing tool is manufactured by the same manufacturing method as in example 1, but the point that fine metal particles made of diamond having an average particle diameter of 20 μm or less are contained in the plated metal is different from example 1. Different.
The product dimensions, base metal dimensions, and basic plating method are the same as in Example 1. Diamond abrasive grains having an average particle diameter of 5 μm are added to the plating solution used in the plating process for fixing 500 μm diamond. A solution obtained by mixing and suspending at a rate of 10 g per liter of plating solution was used. Details are shown below.

In Example 2, a base metal having the same dimensions as in Example 1 is masked except for the part where the abrasive grains are fixed (the outer peripheral surface of the part that becomes the cylindrical truing portion 12), and the average grain is used as the abrasive grains. Prepare diamond abrasive grains with a diameter of 500 μm, and put a base metal and diamond abrasive in an electrodeposition apparatus containing a plating solution in which diamond abrasive grains with an average particle diameter of 5 μm are mixed and suspended at a rate of 10 g per liter of plating solution. The grains were put, a current of 0.25 A / dm ² was passed for 15 hours, and the diamond diamond grains in the lower layer were temporarily fixed by a 50 μm plating layer.

Thereafter, excess diamond abrasive grains are removed, and again in an electrodeposition apparatus containing a plating solution in which diamond abrasive grains having an average particle diameter of 5 μm are mixed and suspended at a rate of 10 g per liter of plating solution. A current of 0 A / dm ² was passed through 1.25 Hr to deposit a nickel-plated metal having a thickness of 25% of the total grain size of about 125 μm) to form a lower abrasive layer.

Then, again, diamond abrasive grains are dispersed on the lower abrasive layer in a plating solution in which diamond abrasive grains having an average particle diameter of 5 μm are mixed and suspended at a rate of 10 g per liter of the plating solution. A dm ² current was applied for 5 hours to deposit a 50 μm plating layer, and the upper diamond abrasive grains were temporarily fixed. Thereafter, excess diamond abrasive grains are removed, and a current of 3.0 A / dm ² is applied again in a plating solution in which diamond abrasive grains having an average particle diameter of 5 μm are mixed and suspended at a rate of 10 g per liter of the plating solution. By flowing 4.2 Hr, a total of 500 μm (100% of the abrasive grain diameter) of the plated metal was deposited to form an upper abrasive layer.

  In the base metal inner peripheral portion deleting step 33, after removing the mask applied in the previous step, the inner peripheral portion of the base metal to be the cylindrical truing portion 12 is deleted by cutting, and the base metal of this portion is removed. The backing layer 40 was formed with a thickness on one side of 0.1 mm.

In order to confirm the effect of the present invention, the truing tool (invention product) of Examples 1 and 2 described above and the tool having the structure described in Patent Document 1 (one-layer and two-layer abrasive layer structure product) are used. The truing test was carried out.
The dimensions of the tool subjected to the truing test and the grain size of the diamond abrasive grains were the same. However, since the thickness of the abrasive layer varies depending on the abrasive layer structure, the thickness of the tip surface of the cylindrical truing portion and the inner diameter of the cylindrical truing portion differ depending on each truing tool.
Table 1 shows the dimensions of each truing tool used in the test.

  In Table 1, the comparative product 1 has the one-layer structure described in Patent Document 1, and the comparative product 2 has the two-layer structure described in Patent Document 1. Moreover, the dimension from A to F in Table 1 is each dimension shown in FIG.4 (b).

Truing performance confirmation test 1
In order to confirm the resistance during truing, the power consumption during truing of the four types of truing tools shown in Table 1 was compared under the following truing conditions. Although this truing tool is often used for internal grinding, the power consumption is small and accurate measurement is difficult with internal grinding, so a test was conducted with a surface grinder.

The test conditions are as follows.
・ Use wheel CBN 140 O 125 VN1KP
(Wheel dimensions: 205 x 20 x 76.2)
-Truing conditions Machine: Surface grinding machine Truing method: Traverse rotary method Wheel peripheral speed (V): 45m / s
Truer peripheral speed (Vd): 7.0 m / s
Truer rotation direction: Down cut Truing lead: 0.10 mm / r. o. w
True cutting depth: ^R 2μm / pass × 100pass
Grinding oil: Synthetic type SEC-700 (dilution ratio 50 times)

  The test results are shown in Table 2.

表２は、ツルーイング電力の比較を示す。

Table 2 shows a comparison of truing power.

As shown in Table 2, there was no clear difference between the inventive products 1 and 2, and both were confirmed to have the same power consumption (truing resistance) as the comparative product 1 and showed good sharpness. This is because there is no significant difference between the cutting edge thicknesses of the inventive products 1 and 2 and the cutting edge thickness of the comparative product 1, and thus it is determined that there was no difference in resistance during truing.
Comparative product 2 has a thick cylindrical truing part with a thick tip and a large number of abrasive grains appearing on the tip, resulting in a large contact area with the wheel during truing and high truing resistance. It is judged.

Truing performance confirmation test 2
Next, in order to confirm the life and truing performance of each truing tool, the truing tool used in the truing performance confirmation test 1 was used, and the truing of the vitrified bond cBN wheel was performed, and the internal grinding of the automobile parts was performed using the wheel. Carried out.

The test conditions are as follows.
-Wheel used: CB200O160V
-Truing conditions Machine: Internal grinding machine Wheel peripheral speed (V): 37 m / s
Truer peripheral speed (Vd): 2.83 m / s
Truer rotation direction: Down cut Truing lead: 0.036mm / rotation True cutting depth: ^R 5μm x 1pass
-Work material Material: SUJ-2 (HRC60)
Workpiece dimensions: outer diameter 16 x thickness 30.5 x inner diameter 10.6
Trade fee: φ0.4

  The test results are shown in Table 3.

  As shown in Table 3, it is considered that the comparative product 1 is not extremely short in the truing interval as compared with other truing tools, and the truing working surface of the wheel is adjusted to a stable abrasive surface state. The cylindrical truing part has a thickness structure in which the abrasive grains are arranged in one layer, so that the truing resistance is low and the cBN abrasive grains on the truing working surface are not flattened, and a good abrasive surface is obtained. Since the number of abrasive grains appearing on the tip surface of the tool is small, the wear resistance is inferior and the life is short.

  Moreover, in the comparative product 2, the cylindrical truing portion has a thickness structure in which abrasive grains are arranged in two layers, so that it has high wear resistance and a relatively long life, but it appears on the tip surface. Since the number of abrasive grains to be processed is too large and the cutting edge thickness of the tip surface is thick, the truing resistance is high and the cBN abrasive grains on the truing working surface tend to be flattened. Therefore, the truing interval is shortened.

  Compared with the comparative products 1 and 2, the inventive products 1 and 2 have a longer truing interval, and their effectiveness was confirmed in terms of life and point. The abrasive layer structure of the comparative products 1 and 2 is a structure in which the lower abrasive layer and the lower abrasive grain protrude above the lower abrasive layer and the upper abrasive grains are arranged in the gap between the lower abrasive grains. Therefore, the number of abrasive grains appearing on the front end surface is larger than that of the comparative product 1, while it is not excessively large as compared with the comparative product 2, and is an appropriate number of abrasive grains. Furthermore, since the tip edge thickness is not much different from that of the comparative product 1, the truing resistance is low, the cBN abrasive grains on the truing working surface are not flattened, a good abrasive surface is obtained, and the truing interval is long. It was done.

  In addition, it has been confirmed that the wear resistance is high and the life is long. Especially, the invention product 2 contains diamond abrasive grains having an average grain diameter of 5 μm in the plating metal fixing the abrasive grains. Accordingly, the wear resistance of the plated metal is high and the holding power of the abrasive grains is high, so that the life is long.

Next, the optimum range of the plating layer thickness will be described with reference to FIG.
FIG. 5A shows a case where the thickness of the lower layer 24 is less than 20% of the particle diameter of the abrasive grains 21, and the thickness of the lower layer 24 is insufficient and the abrasive grains 21 are not stably fixed. Variation such as a decrease in the number of abrasive grains 21 adhering to the surface tends to occur.

  FIG. 5B shows a case where the thickness of the lower layer 24 exceeds 30% of the grain size of the abrasive grain 21, and the position of the abrasive grain 21 fixed to the upper layer 26 is the abrasive grain fixed to the lower layer 24. Since the protrusion to the abrasive grains 21 fixed to the lower layer 24 becomes considerably higher than the position 21, the thickness of the abrasive grain layer itself is increased. For this reason, the contact area of the tip surface is increased and the sharpness is liable to be impaired.

  FIG. 5C shows a case where the thickness of the upper layer 26 is less than 80% of the particle size of the abrasive grains 21, and the protrusion of the abrasive grains 21 fixed to the upper layer 26 from the plating layer becomes large, and the abrasive grains Since the holding force of 21 decreases, the abrasive grains easily fall off during truing.

  FIG. 5 (d) shows a case where the thickness of the upper layer 26 exceeds 120% of the grain size of the abrasive grains 21, and since the thickness of the abrasive grain layer is increased, the contact area of the tip surface is increased during truing. The sharpness is apt to be damaged.

Hereinafter, data demonstrating that the thickness of the plating layer in the present invention is in the optimum range will be described.
Table 4 shows the results of investigating the state of abrasive grain adhesion when the plating thickness of the lower layer 24 was changed.

  In Table 4, it represents with the index | exponent which set to 100 the time of the ratio of the plating thickness of the lower layer 24 with respect to the particle size of an abrasive grain being 25%. A graph of this is shown in FIG. When the plating thickness with respect to the grain size of the abrasive grains is 20% or more, the abrasive grains are stably and uniformly attached. On the other hand, when the plating thickness is less than 20%, the number of attached abrasive grains rapidly decreases. The state is uneven.

  Table 5 shows the results of examining the sharpness (power consumption) using the truing tool produced by the method of Example 1 using the base metal having the structure shown in FIG. 4 while changing the plating thickness of the lower layer 24. The test conditions are the same as those of the above truing performance test 1. A graph of this is shown in FIG.

  As the plating thickness of the lower layer 24 increases, as a result, the thickness of the abrasive layer 22 including the upper layer 26 increases and the sharpness tends to decrease. When the ratio of the plating thickness of the lower layer 24 to the grain size of the abrasive grains is 30% or less, no significant reduction in sharpness is observed, but when the ratio exceeds this, it increases remarkably.

In addition, as described above, the sharpness is not determined only by the thickness of the entire abrasive layer 22 but is determined by the plating thickness of the lower layer 24 for the following reasons. That is, by increasing the thickness of the lower layer 24, the position of the abrasive layer adhesion of the upper layer 26 is simply increased, so that not only the thickness of the abrasive layer 22 is increased, but also the plating thickness of the lower layer 24 is increased. Thus, the abrasive grain density of the lower layer 24 is increased, whereby the abrasive grains fixed to the upper layer 26 are not stably disposed in the gaps between the abrasive grains of the lower layer 24, and the abrasive grains are fixed on the abrasive grains of the lower layer 24. There will be grains. Therefore, the presence of the abrasive grains fixed on the abrasive grains of the lower layer 24 further increases the thickness of the abrasive grain layer 22.
In the present invention, the quality of the sharpness is determined by such a mechanism. Judging from the test results, the ratio of the plating thickness of the lower layer 24 to the grain size of the abrasive grains is 30% or less as described above. The presence of the abrasive grains of the upper layer 26 fixed on the abrasive grains of the lower layer 24 without being fixed to the gaps of the abrasive grains of the lower layer 24 can be prevented. Therefore, setting the upper limit of the ratio of the plating thickness of the lower layer 24 to the grain size of the abrasive grains to be 30% is significant for the above reason.

  From the above two test results, by setting the plating thickness of the lower layer 24 to 20% or more and 30% or less of the grain size of the abrasive grains, the fixing of the abrasive grains can be ensured and the sharpness is kept good. be able to.

  Next, Table 6 shows the results of investigating the lifetime when the plating thickness of the upper layer 26 is changed.

  The truing tool used for the test was prepared by the method of Example 1 using a base metal having the structure shown in FIG. 4, and the test conditions were the same as those of the truing performance confirmation test 2 described above. A graph of this is shown in FIG. When the plating thickness of the upper layer 26 is less than 80% of the grain size of the abrasive grains, the lifetime is clearly reduced. This is because, since the plating thickness of the upper layer 26 is small, the holding force of the abrasive grains of the upper layer 26 is not sufficient, and the abrasive grains fall off early due to truing resistance and bond wear due to grinding stone chips during truing.

  Table 7 shows the result of investigating the sharpness (power consumption) when the plating thickness of the upper layer 26 is changed.

  The truing tool used for the test was prepared by the method of Example 1 using a base metal having the structure shown in FIG. 4, and the test conditions were the same as those of the truing test 1 described above. A graph of this is shown in FIG. According to the test results, the power consumption tends to increase as the plating thickness of the upper layer 26 increases. Moreover, when the plating thickness of the upper layer 26 exceeds 120%, the increase in power consumption becomes significant. This sharpening is because the contact area of the abrasive grain layer 22 including the lower layer 24 is increased by increasing the plating thickness of the upper layer 26, and this is a resistance during truing.

Moreover, in general truing, by setting the plating thickness to a thickness that can cover the abrasive grains, it is possible to ensure the abrasive grain holding force. Increasing the plating thickness beyond that will cause adverse effects such as an increase in truing resistance.
From the above two test results, by setting the plating thickness of the upper layer 26 to 80% or more and 120% or less of the grain size of the abrasive grains, the life can be improved and the sharpness can be kept good.

  The present invention can be used as a truing tool capable of improving the life without impairing sharpness.

It is sectional drawing which shows the structure of the truing tool which concerns on embodiment of this invention. It is a figure which shows the detail of the abrasive grain layer of a truing tool. It is a figure which shows the process of manufacturing a truing tool. It is a figure which shows the dimension and specification of a truing tool. It is a figure for demonstrating the thickness of a plating layer. It is a figure which shows the result of having investigated the abrasive grain adhesion state when changing the plating thickness of a lower layer. It is a figure which shows the result of having investigated the sharpness (power consumption) when changing the plating thickness of a lower layer. It is a figure which shows the result of having investigated the lifetime (truing frequency | count) when changing the plating thickness of an upper layer. It is a figure which shows the result of having investigated sharpness (power consumption) when changing the plating thickness of an upper layer. It is a figure which shows the structure of the conventional truing tool. It is a figure which shows the structure of the conventional truing tool. It is a figure which shows the detail of the abrasive grain layer of the conventional truing tool. It is a figure which shows the detail of the abrasive grain layer of the conventional truing tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Truing tool 11 Column base metal 12 Cylindrical truing part 13 Tip surface 21 Abrasive grain 22 Abrasive grain layer 23 Plating layer 24 Lower layer 25 Plating layer 26 Upper layer 31 Base metal preparation process 32 Electrodeposition process 33 Base metal inner peripheral part deletion process 40 backing layer

Claims (2)

  A truing tool that is fixed to one end of a cylindrical base metal and has a cylindrical truing portion that is open at one end, and that performs truing using the tip surface of the cylindrical truing portion, wherein the cylindrical truing portion is An abrasive layer formed by bonding abrasive grains by electrodeposition is configured to be thinner than the abrasive layer and lined with a metal that is integral with the cylindrical base metal. A lower layer in which grains are fixed to the surface of the backing layer by a plating layer having a thickness of 20% to 30% of the grain size of the abrasive grains, and 80% to 120% of the grain size of the abrasive grains on the surface of the lower layer A plating layer having a thickness is deposited, and the abrasive grains protrude from the lower abrasive grains and are fixed, and the upper abrasive grains are arranged in the gaps between the lower abrasive grains, The thickness is 100% or more and 150% or less of the grain size of the abrasive grains. Ruingu tool. _2. The truing tool according to claim 1, wherein the plated layer contains minute hard particles having an average particle diameter of 20 μm or less, which are made of any one of diamond, cBN, SiC, Si ₃ N ₄ , and Al ₂ O ₃ .

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